Questionable Cancer Therapies

Stephen Barrett, M.D.

The American Cancer Society (ACS) has defined questionable methods as lifestyle practices, clinical tests, or therapeutic modalities that are promoted for general use for the prevention, diagnosis, or treatment of cancer and which are, on the basis of careful review by scientists and/or clinicians, deemed to have no real evidence of value [1]. Under the rules of science (and federal law), proponents who make health claims bear the burden of proof. It is their responsibility to conduct suitable studies and report them in sufficient detail to permit evaluation and confirmation by others. The ACS evaluates cancer methods by asking three questions:

FDA Historian Wallace F. Janssen has noted that in every decade since 1940, a questionable cancer remedy has attracted a large following and become a national issue [2]. It was Koch Antitoxins in the 1940s, Hoxsey treatment in the 1950s, Krebiozen in the 1960s [3], laetrile in the 1970s, and immuno-augmentative therapy in the 1980s. Today's questionable methods include corrosive agents, plant products, special diets and "dietary supplements," drugs, correction of "imbalances," biologic methods, devices, miscellaneous concoctions, psychological approaches, and worthless diagnostic tests. Many promoters combine methods to make themselves more marketable. A 1987 ACS investigation found that 452 (9%) of 5,047 cancer patients identified through a telephone survey had used questionable treatments. Of these, 49% had used "mind therapies" (mental imagery, hypnosis, or psychic therapy) and 38% had used diets [4]. The dangers of using questionable treatments include delay in getting appropriate treatment, decreased quality of life, direct physical harm, interference with proven treatment, waste of valuable time, financial harm, and psychological damage [5].

Quackwatch has heard from many people who have been defrauded of large sums of money pursuing nonexistent cancer "cures." Most of these cases involved offshore clinics to whom money was wired in advance. The Federal Bureau of Investigation (FBI) has jurisdiction over cases involving wire fraud. Americans who believe they have been victims of wire fraud should report what happened to the FBI.

Typical Misrepresentations

Proponents of questionable methods typically claim that marketplace demand and testimonials from satisfied customers are proof that their remedies work. However, proponents almost never keep score or reveal what percentage of their cases end in failure. Cancer cures attributed to questionable methods usually fall into one or more of five categories:

  1. The patient never had cancer.
  2. A cancer was cured or put into remission by proven therapy, but questionable therapy was also used and erroneously credited for the beneficial result
  3. The cancer is progressing but is erroneously represented as slowed or cured.
  4. The patient has died as a result of the cancer (or is lost to follow-up) but is represented as cured.
  5. The patient had a spontaneous remission (very rare) or slow-growing cancer that is publicized as a cure.

Promoters of questionable methods often misrepresent their methods as "alternatives." Genuine alternatives are comparable methods that have met the criteria for safety and effectiveness. Experimental alternatives are unproven but have a plausible rationale and are undergoing responsible investigation. Questionable "alternatives" are unproven and lack a scientifically plausible rationale. When referring to the latter, we use quotation marks because they are not true alternatives. Some promoters of "alternative" methods are physicians or other highly educated scientists who have strayed from scientific thought. The factors that motivate them can include delusional thinking, misinterpretation of personal experience, financial considerations, and pleasure derived from notoriety and/or patient adulation.

Misinformation about questionable cancer therapies is spread through books, articles, audiotapes, videotapes, talk shows, news reports, lectures, health expositions, "alternative" practitioners, information and referral services, and word of mouth. Promoters typically explain their approach in commonsense terms and appear to offer patients an active role in their care: (a) cancer is a symptom, not a disease; (b) symptoms are caused by diet, stress, or environment; (c) proper fitness, nutrition, and mental attitude allow biologic and mental defense against cancer; and (d) conventional therapy weakens the body's reserves, treats the symptoms rather than the disease [6]. Questionable therapies are portrayed as natural and nontoxic, while standard (responsible) therapies are portrayed as highly dangerous. The figure below comes from a misleading comic book designed to undermine public trust in conventional methods.

During the past few years, the news media have publicized "alternative" methods in ways that are causing great public confusion. Most of these reports have contained no critical evaluation and have featured the views of proponents and their satisfied clients. Many have exaggerated the significance of the National Institutes of Health (NIH)'s Office of Alternative Medicine (OAM)—now called the Center for Research in Alternative and Complementary Medicine—whose creation was spearheaded by promoters of questionable cancer therapies who wanted more attention paid to their methods. Most of the its advisory panel members have been promoters of "alternative" therapies. In 1994, the OAM's first director resigned, charging that political interference had hampered his ability to carry out OAM's mission in a scientific manner [7]. The OAM has funded several dozen studies related to "alternative" methods, including a few related to cancer treatment. However, it remains to be seen whether such research will yield useful results. Even if it does, the benefit is unlikely to outweigh the publicity bonanza given to questionable methods. Some of today's "alternative" methods are described below in alphabetical order. Longer reports on many of the methods can be accessed by following the hyperlinks.

Antineoplastons

Stanislaw R. Burzynski, M.D., has given the name "antineoplastons" to substances he claims can "normalize" cancer cells that are constantly being produced within the body. He has published many papers stating that antineoplastons extracted from urine or synthesized in his laboratory have proven effective against cancer in laboratory experiments. He also claims to have helped many people with cancer get well. A 1992 analysis concluded that none of Burzynski's "antineoplastons" has been proven to normalize tumor cells [8].

In 1988, Burzynski got a tremendous boost when talk-show hostess Sally Jesse Raphael featured four "miracles," patients of Burzynski, who she said were cancer-free. The patients stated that Burzynski had cured them when conventional methods had failed. In 1992, "Inside Edition" reported that two of the four patients had died and a third was having a recurrence of her cancer. (The fourth patient had bladder cancer, which has a good prognosis.) The widow of one of Raphael's guests stated that her husband and five others from the same city had sought treatment after learning about Burzynski from a television broadcast—and that all had died of their disease. In 1995, a federal grand jury indicted Burzynski for mail fraud and marketing an unapproved drug. The indictment charged that he had billed insurance companies using procedure codes for chemotherapy, even though his treatment was not chemotherapy. He was tried in 1997 but not convicted.

In 1998, the Texas Attorney General secured a consent agreement stating that Burzynski: (a) cannot distribute unapproved drugs in Texas; (b) can distribute "antineoplastons" only to patients enrolled in FDA approved clinical trials, unless the FDA approves his drugs for sale; (c) cannot advertise "antineoplastons" for the treatment of cancer; and (d) on his website and in promotional material and ads must place a disclaimer that the safety and effectiveness of "antineoplastons" have not been established. The agreement also called for Burzynski to pay $50,000 to reimburse the Attorney General's office and the Texas Health Department for the cost of their investigation [9]. The Cancer Letter subsequently noted that although Burzynski has set up many "clinical trials," they do not conform to usual standards [10].

CanCell

CanCell—originally called Entelev and recently renamed Cantron and Protocel—is a liquid claimed to cure cancer by "lowering the voltage of the cell structure by about 20%," causing cancer cells to "digest" and be replaced with normal cells. Accompanying directions have warned that bottles of CanCell should not be allowed to touch each other or be placed near any electrical appliance or outlet. CanCell has also been promoted for the treatment of AIDS, amyotrophic lateral sclerosis, multiple sclerosis, Alzheimer's disease, "extreme cases of emphysema and diabetes," and several other diseases. In 1989, the FDA reported that CanCell contained inositol, nitric acid, sodium sulfite, potassium hydroxide, sulfuric acid, and catechol. Subsequently, its promoters claimed to be modifying the formulation to make it more effective [11]. They have also claimed that CanCell can't be analyzed because it varies with atmospheric vibrations and keeps changing its energy [12]. Laboratory tests conducted between 1978 and 1991 by the NCI found no evidence that CanCell was effective against cancer. The FDA has obtained an injunction forbidding its distribution to patients.

Cell Specific Cancer Therapy (also called Zoetron Therapy)

According to information on the promoter's web site during 1997, Cell Specific Cancer Therapy (CSCT) was applied with a device that was four inches thick, shaped like a donut, and exposed the patient to a magnetic field that was much weaker than that of magnetic resonance imaging. It was offered a clinic in the Dominican Republic that later was moved to Mexisco. The advertised fee was $20,000, payable in advance, but the fee was sometimes reduced or waived for people unable to pay. CSCT was claimed not to cure cancer but to "destroy active cancerous cells in a body and to do so without causing any damage to healthy cells." Its stated objective was to destroy enough cancerous cells that the body's immune system is "once again able to take over and do its normal job." The device was claimed to "detect cancerous cells with a sensitivity much greater than that of either conventional magnetic resonance imaging (MRI) or CAT scans" and to destroy cancer cells without harming adjacent normal cells." The promoter claimed that cancerous cells have an "atypical metabolic mechanism that made them "susceptible to polarizing electromagnetic fields." There is no scientific evidence that magnetic energy can selectively destroy cancer cells. Coordinated action by agencies in the United States, Canada, and Mexico resulted in closure of the clinic in 2003. Similar treatment was offered at the Davidson Cancer Clinic in Mexico, whose proprietor was imprisoned for fraud.

Clark's "Cure for All Cancers"

Hulda Clark, Ph.D., N.D., an unlicensed naturopath claimd that (a) all cancers and many other diseases are caused by "parasites, toxins, and pollutants"; (b) cancers can be detected with a blood test for ortho-phospho-tyrosine and a device that identifies diseased organs and toxic substances; (c) cancers can be cured by killing the parasites and ridding the body of environmental chemicals; (d) black walnut hulls, wormwood, and common cloves can rid the body of over 100 types of parasites; and (e) the amino acids ornithine and arginine improve this recipe. Her book Cure for All Cancers, contains 103 case histories of her supposed cancer cures. However, judging from her descriptions (a) most did not have cancer, and (b) of those that did, most had received standard medical treatment or their tumors were in early stages. In 2009, Clark died of complications of multiple myeloma, a form of lymphoma in which plasma cells become overabundant in the bone marrow. Information posted by supporters suggests that life was shortened because she treated herself rather than seeking timely and appropriate medical care.

Devices

Many types of devices are used with unfounded claims that they are effective against cancer. These include devices that pass low-voltage electrical current through tumors or the body, "electroacupuncture" devices purported to measure the electrical resistance of "acupuncture points," electrical devices claimed to "charge" blood samples taken from patients and later reinjected, negative ion generators claimed to have an effect against tumors, radionics devices claimed to diagnose and cure cancer by analyzing and emitting radio waves at the correct frequencies, magnets claimed capable of curing cancers by "improving circulation" or by intracellular effects, and projectors of colored light claimed to exert healing effects [13].

Essiac

Essiac is an herbal remedy that was prescribed and promoted for about 50 years by Rene M. Caisse, a Canadian nurse who died in 1978. Shortly before her death, she turned over the formula and manufacturing rights to the Resperin Corporation, a Canadian company that has provided it to patients under a special agreement with Canadian health officials. Several reports state that the formula contains burdock, Indian rhubarb, sorrel, and slippery elm, but there may be additional ingredients. Essiac tea claimed to be Caisse's original formulation is also marketed in the United States. Several animal tests using samples of Essiac have shown no antitumor activity. Nor did a review of data on 86 patients performed by the Canadian federal health department during the early 1980s [14].

Fresh Cell Therapy

Fresh cell therapy, also called live cell therapy or cellular therapy, involves injections of fresh embryonic animal cells taken from the organ or tissue that corresponds to the unhealthy organ or tissue in the patient. Proponents claim that the recipient's body automatically transports the injected cells to the target organ where they repair and rejuvenate the ailing cells. The American Cancer Society states that fresh cell therapy has no proven benefit and has caused serious side effects (infections and immunologic reactions to the injected protein) and death [15]. In 1984, The FDA issued an Import Alert asking the U.S. Customs and Postal Services to block the importation of all "cell therapy" powders and extracts intended for injection.

Gerson Method

Proponents of the Gerson diet claim that cancer can be cured only if toxins are eliminated from the body. They recommend "detoxification" with frequent coffee enemas and a low-sodium diet that includes more than a gallon a day of juices made from fruits, vegetables, and raw calf's liver. This method was developed by Max Gerson, a German-born physician who emigrated to the United States in 1936 and practiced in New York City until his death in 1959. Gerson therapy is still available at Hospital Meridien in Tijuana, Mexico and, since February 1997, at the Gerson Healing Center in Sedona, Arizona.

Gerson therapy is still actively promoted by his daughter, Charlotte Gerson, through lectures, talk show appearances, and publications of the Gerson Institute in Bonita, California. Gerson protocols have included liver extract injections, ozone enemas, "live cell therapy," thyroid tablets, royal jelly capsules, linseed oil, castor oil enemas, clay packs, laetrile, and vaccines made from influenza virus and killed Staphylococcus aureus bacteria.

In 1947, the NCI reviewed ten cases selected by Dr. Gerson and found his report unconvincing. That same year, a committee appointed by the New York County Medical Society reviewed records of 86 patients, examined ten patients, and found no evidence that the Gerson method had value in treating cancer. An NCI analysis of Dr. Gerson's book A Cancer Therapy: Results of Fifty Cases concluded in 1959 that most of the cases failed to meet the criteria (such as histologic verification of cancer) for proper evaluation of a cancer case [16]. A recent review of the Gerson treatment rationale concluded: (a) the "poisons" Gerson claimed to be present in processed foods have never been identified, (b) frequent coffee enemas have never been shown to mobilize and remove poisons from the liver and intestines of cancer patients, (c) there is no evidence that any such poisons are related to the onset of cancer, (d) there is no evidence that a "healing" inflammatory reaction exists that can seek out and kill cancer cells [17].

Between 1980 and 1986 at least 13 patients treated with Gerson therapy were admitted to San Diego area hospitals with Campylobacter fetus sepsis attributable to the liver injections [18]. None of the patients was cancer-free, and one died of his malignancy within a week. Five were comatose due to low serum sodium levels, presumably as a result of the "no sodium" Gerson dietary regimen. As a result, Gerson personnel modified their techniques for handling raw liver products and biologicals. However, the Gerson approach still has considerable potential for harm. Deaths also have been attributed to the coffee enemas administered at the Tijuana clinic.

Charlotte Gerson claims that treatment at the clinic has produced high cure rates for many cancers. In 1986, however, investigators learned that patients were not monitored after they left the facility [19]. Although clinic personnel later said they would follow their patients systematically, there is no published evidence that they have done so. Three naturpaths who visited the Gerson Clinic in 1983 were able to track 18 patients over a 5-year period (or until death) through annual letters or phone calls. At the 5-year mark, only one was still alive (but not cancer-free); the rest had succumbed to their cancer [20].

Greek Cancer Cure

The principal proponent of the Greek Cancer Cure was microbiologist Dr. Hariton-Tzannis Alivizatos, of Athens, Greece, who died in 1991. He claimed to have a blood test that could determine the type, location, and severity of any cancer. He also asserted that his "serum" enabled the patient's immune system to destroy cancer cells, and helped the body rejuvenate parts destroyed by cancer. Knowledgeable observers believe that the principal ingredient of the so-called Greek Cancer Cure was niacin. The American Cancer Society and the NCI asked Alivizatos several times for detailed information on his methods, but he never replied [21].

Hoxsey Treatment

Naturopath Harry Hoxsey promoted an herbal treatment consisting of an externally used paste or powder and a tonic taken orally. The external preparations contained corrosive agents such as arsenic sulfide. The internal medicine, said to be adjusted on a case-by-case basis, contained potassium iodide and such things as red clover, licorice, burdock root, Stillingia root, Berberis root, pokeroot, cascara, prickly ash bark, and buckthorn bark. Hoxsey said that the formulas were developed in 1840 by his great grandfather and passed to him by his father while the latter was dying of cancer.

Hoxsey's treatment was offered at clinics in the United States from 1924 until repeated clashes with the FDA led him to close his main clinic in Dallas in the late 1950s. In 1963, Hoxsey's former chief nurse Mildred Nelson began offering it at a clinic in Tijuana, Mexico [22]. Hoxsey himself contracted prostate cancer in 1967 and underwent surgery after treating himself unsuccessfully with his tonic. Most of the herbs in the tonic have been tested for antitumor activity in cancer, with negligible results for a few and no results for the others. Some of these herbs, most notably pokeroot, have toxic side effects. The NCI evaluated case reports submitted by Hoxsey and concluded that no assessment was possible because the records did not contain adequate information [23]. Hoxsey died in 1974. Nelson died in January 1999.

Hydrazine Sulfate

In the mid-1970s, hydrazine sulfate was proposed for treating the progressive weight loss and debilitation characteristic of advanced cancer. Based on animal data and preliminary human studies, it has also been claimed to cause tumor regression and subjective improvement in patients. However, three recent trials sponsored by the National Cancer Institute demonstrated no benefit attributable to hydrazine sulfate [24-26]. The trials involved 243 patients with newly diagnosed non-small cell lung cancer, 266 patients with advanced non-small cell lung cancer, and 127 patients with advanced colorectal cancer. The largest of the three found that nerve damage occurred more often and that quality of life was significantly worse in the hydrazine sulfate group. After these studies were published, proponents claimed that they were flawed because patients were permitted to ingest tranquilizers, barbiturates, or alcohol, which allegedly would nullify the effect of hydrazine sulfate. The National Cancer Institute rejected these concerns, and an investigation by United States General Accounting Office found no difference in survival times between the patients who had taken these drugs and those who had not [27]. In December 2000, the Annals of Internal Medicine published a case report of a 55-year-old man with cancer of the sinus near his left cheekbone. Instead of undergoing recommended medical treatment, he obtained hydrazine sulfate through a Web site and, for four months, followed the regimen published on the kathykeeton.com Web site. Two weeks later, he was hospitalized with signs of kidney and liver failure. Despite intensive hospital care, he died within a week [28,29].

"Hyperoxygenation" Therapies

"Hyperoxygenation" therapy—also called "bio-oxidative therapy" and "oxidative therapy"—is based on the erroneous concept that cancer is caused by oxygen deficiency and can be cured by exposing cancer cells to more oxygen than they can tolerate. The most touted agents are hydrogen peroxide, germanium sesquioxide, and ozone. Although these compounds have been the subject of legitimate research, there is little or no evidence that they are effective for the treatment of any serious disease, and each has demonstrated potential for harm [30]. Germanium products have caused irreversible kidney damage and death [31]. The FDA has banned their importation and seized products from several U.S. manufacturers.

Immuno-augmentative Therapy

Immuno-augmentative therapy (IAT) was developed by Lawrence Burton, Ph.D., a zoologist who claimed he could stimulate the immune system's natural ability to detect and destroy cancer cells. He claimed to accomplish this by injecting protein extracts isolated with processes he had patented. However: (a) the immune system does not detect and destroy cancer cells as Burton postulated, and (b) the substances he claimed to use cannot be produced by the procedures described in his patent applications and have not been demonstrated to exist in the human body [32].

NCI scientists who analyzed IAT treatment materials given to several patients concluded that the materials were dilute solutions of ordinary blood proteins, primarily albumin. None were electrophoretically pure, and none contained Burton's postulated components. Burton did not publish detailed clinical reports, divulge to the scientific community the details of his methods, publish meaningful statistics, conduct a controlled trial, or provide independent investigators with specimens of his treatment materials for analysis. During the mid-1980s, several of his patients developed serious infections following IAT [33].

In 1980, CBS-TV's "60 Minutes" gave Burton a tremendous publicity boost when a prominent physician stated that one of his patients appeared to have recovered miraculously with Burton's treatment. Although the patient died of his cancer twelve days after the program was shown, "60 Minutes" refused to inform viewers of this fact. In 1986, the Congressional Office of Technology Assessment assembled a group of technical experts and representatives of Burton to design a clinical trial to evaluate IAT. However, communication between Burton and U.S. government authorities broke down after he insisted that a "pre-test" be conducted at his clinic [34]. Burton died in 1993, but the clinic is still operating.

Iscador

Iscador is an extract of mistletoe first proposed for the treatment of cancer in 1920 by Rudolph Steiner (1861-1925), who espoused many occult beliefs. Steiner founded the Society for Cancer Research to promote mistletoe extracts and occult-based practices he called anthroposophical medicine. A 1962 report by the society claimed that the time of picking the plants was important because they react to the influences of the sun, moon, and planets. Various mistletoe juice preparations have been studied with the hope of finding an effective anticancer agent. However, in 1984, the expert working group of the Swiss Society for Oncology concluded that there was no evidence that Iscador was effective against human cancers [35]. To date, more than 30 clinical studies have investigated imistletoe as a cancer treatment. The National Cancer Institute has concluded: "Reports of improved survival and/or quality of life have been common, but nearly all of the studies had major weaknesses that raise doubts about the reliability of the findings." [36]

Kelley/Gonzalez Metabolic Therapy

In the 1960s, William Donald Kelley, D.D.S. (1925-2005), developed a program for cancer patients that involved dietary measures, vitamin and enzyme supplements, and computerized "metabolic typing." Kelley classified people as "sympathetic dominant," "parasympathetic dominant," or metabolically "balanced" and made dietary recommendations for each type. He claimed that his "Protein Metabolism Evaluation Index" could diagnose cancer before it was clinically apparent and that his "Kelley Malignancy Index could detect "the presence or absence of cancer, the growth rate of the tumor, the location of the tumor mass, prognosis of the treatment, age of the tumor and the regulation of medication for treatment."

In 1970, Kelley was enjoined from practicing medicine without a license after witnesses testified that he had diagnosed lung cancer on the basis of blood from a patient's finger and prescribed dietary supplements, enzymes, and a diet as treatment. In 1976, following unsuccessful court appeals, his dental license was suspended for five years [37]. However, he continued to promote his methods until the mid-1980s through his Dallas-based International Health Institute. Under the institute's umbrella, licensed professionals and "certified metabolic technicians" throughout the United States would administer a 3,200-item questionnaire and send the answers to Dallas. The resultant computer printout provided a lengthy report on "metabolic status" plus detailed instructions covering foods, supplements (typically 100 to 200 pills per day), "detoxification" techniques, and lifestyle changes.

Treatment said to be similar is still provided today by Nicholas Gonzalez, M.D., of New York City, who claims to have analyzed Kelley's records and drafted a book about his findings. The manuscript was never published, but experts who evaluated its chapter on 50 cases found no evidence of benefit. Gonzalez says that he offers "10 basic diets with 90 variations" and typically prescribes coffee enemas and "up to 150 pills a day in 10 to 12 divided doses."

In 1994, after investigating six of Gonzalez's cases, New York State licensing authorities had concluded: (a) his "alternative protocol" did not entitle him to an alternative standard of care; (b) he had failed to correctly interpret signs and symptoms of disease progression, (c) he had treated the patients incompetently, and (d) his record-keeping was inadequate. He placed on probation for three years with a stipulation that he undergo retraining and his work be supervised by the Office of Professional Conduct. [Download documentation]

In 1997, a jury in New York City awarded $2.5 million in actual damages and $150,000 in punitive damages to a former Gonzalez patient. The woman testified that she had been diagnosed with an early stage of uterine cancer in 1991 and underwent a hysterectomy. Instead of following through with medically recommended radiation and chemotherapy, she consulted Gonzalez who discouraged her from following her cancer specialist's advice. Based on his interpretation of a hair test, Gonzalez prescribed up to 150 dietary supplement pills a day plus frequent coffee enemas. Later he claimed that the cancer was cured even though it was progressing. It eventually damaged her spine and left her blind. An appeals court upheld the $2.5 million verdict but dismissed the punitive damage award. In April 2000, a jury awarded $282,000 in damages to the husband of a 40-year-old college professor who had died of Hodgkin's disease in 1995. According to an article in The New York Daily News, the jury found him negligent because he failed to arrange "appropriate testing" to track the cancer, relying instead on an unproven method of hair analysis [38].

Laetrile

Laetrile, which achieved great notoriety during the 1970s and early 1980s, is the trade name for a synthetic relative of amygdalin, a chemical in the kernels of apricot pits, apple seeds, bitter almonds, and some other stone fruits and nuts. Many laetrile promoters have called it "vitamin B17" and falsely claimed that cancer is a vitamin deficiency disease that laetrile can cure. Claims for laetrile's efficacy have varied considerably [39]. First it was claimed to prevent and cure cancer. Then it was claimed not to cure, but to "control" cancer while giving patients an increased feeling of well being. More recently, laetrile has been claimed to be effective, not by itself, but as one component of "metabolic therapy" (described below).

Laetrile was first used to treat cancer patients in California in the 1950s. According to proponents, it kills tumor cells selectively while leaving normal cells alone. Although laetrile has been promoted as safe and effective, clinical evidence indicates that it is neither [40]. When subjected to enzymatic breakdown in the body, it forms glucose, benzaldehyde, and hydrogen cyanide [41]. Some cancer patients treated with laetrile have suffered nausea, vomiting, headache and dizziness, and a few have died from cyanide poisoning. Laetrile has been tested in at least 20 animal tumor models and found to have no benefit either alone or together with other substances. Several case reviews have found no benefit for the treatment of cancer in humans.

In response to political pressure, a clinical trial was begun in 1982 by the Mayo Clinic and three other U.S. cancer centers under NCI sponsorship. Laetrile and "metabolic therapy" were administered as recommended by their promoters. The patients had advanced cancer for which no proven treatment was known. Of 178 patients, not one was cured or stabilized, and none had any lessening of any cancer-related symptoms. The median survival rate was about five months from the start of therapy. In those still alive after seven months, tumor size had increased. Several patients experienced symptoms of cyanide toxicity or had blood levels of cyanide approaching the lethal range [42].

In 1975, a class action suit was filed to stop the FDA from interfering with the sale and distribution of laetrile. Early in the case, a federal district court judge in Oklahoma issued orders allowing cancer patients to import a six-month supply of laetrile for personal use if they could obtain a physician's affidavit that they were "terminal." In 1979, the U.S. Supreme Court ruled that it is not possible to be certain who is terminal and that even if it were possible, both terminally ill patients and the general public deserve protection from fraudulent cures. In 1987, after further appeals were denied, the district judge (a strong proponent of laetrile) finally yielded to the higher courts and terminated the affidavit system [39]. Few sources of laetrile are now available within the United States, but it still is utilized at several Mexican clinics.

Livingston-Wheeler Regimen

Virginia C. Livingston, M.D., who died in 1990, postulated that cancer is caused by a bacterium she called Progenitor cryptocides, which invades the body when "immunity is stressed or weakened." She claimed to combat this by strengthening the body's immune system with vaccines (including one made from the patient's urine); "detoxification" with enemas; digestive enzymes; a vegetarian diet that avoided chicken, eggs, and sugar; vitamin and mineral supplements; visualization; and stress reduction. She claimed to have a very high recovery rate but published no clinical data to support this. Scientists who attempted to isolate the organism she postulated found that it was a common skin bacterium. Researchers at the University of Pennsylvania Cancer Center compared 78 of its patients with similar patients treated at the Livingston-Wheeler Clinic. All had advanced cancers for which no proven treatment was known. As expected, the study found no difference in average survival time of the two groups. However, Livingston-Wheeler patients reported more appetite difficulties and pain [43]. The treatment Livingston originated is now offered at the Livingston Foundation Medical Center in San Diego.

Macrobiotics

Macrobiotics is a quasireligious philosophical system that advocates a semivegetarian diet. ("Macrobiotic" means "way of long life.") Macrobiotic diets have been promoted for maintaining general health and for preventing and "relieving" cancer and other diseases. The optimal diet is said to balance "yin" and "yang" foods. It is composed of whole grains (50 to 60% of each meal), vegetables (25 to 30% of each meal), whole beans or soybean-based products (5 to 10% of daily food), nuts and seeds (small amounts as snacks), miso soup, herbal teas, and small amounts of white meat or seafood once or twice weekly. Some macrobiotic diets contain adequate amounts of nutrients, but others do not.

Macrobiotic practitioners may base their recommendations on "pulse diagnosis" and other unscientific procedures related to Chinese medicine [44]. Pulse diagnosis supposedly involves six pulses at each wrist that correspond to twelve internal spheres of bodily function. Other diagnostic methods include "ancestral diagnosis," "astrological diagnosis," "aura and vibrational diagnosis," "environmental diagnosis" (including consideration of celestial influences" and tidal motions), and "spiritual diagnosis" (an evaluation of "atmospheric vibrational conditions" to identify spiritual influences, including "visions of the future").

Today's leading proponent is Michio Kushi, founder and president of the Kushi Institute in Brookline, Massachusetts. According to Institute publications, the macrobiotic way of life should include chewing food at least 50 times per mouthful (or until it becomes liquid), not wearing synthetic or woolen clothing next to the skin, avoiding long hot baths or showers, having large green plants in your house to enrich the oxygen content of the air, and singing a happy song every day. Kushi claims that cancer is largely due to improper diet, thinking, and way of life, and can be influenced by changing these factors. He recommends yin foods for cancers due to excess yang, and yang foods for tumors that are predominantly yin. His books contain case histories of people whose cancers have supposedly disappeared after they adopted macrobiotic eating. However, the only reports of efficacy are testimonials by patients, many of whom received responsible therapy [45]. The diet itself can cause cancer patients to undergo serious weight loss [46]. In July 2001, Kushi's wife and colleague Aveline died of cervical cancer. According to an Associated Press obituary, she underwent standard radiation treatment when the cancer was discovered. When the cancer spread to her bones and she was told that no standard treatment was available, relied on acupuncture and "Eastern" methods [47].

Metabolic Therapy

Proponents of "metabolic therapy" claim to diagnose abnormalities at the cellular level and correct them by normalizing the patient's metabolism. They regard cancer, arthritis, multiple sclerosis, and other "degenerative" diseases as the result of metabolic imbalance caused by a buildup of "toxic substances" in the body. They claim that scientific practitioners merely treat the symptoms of the disease while they treat the cause by removing "toxins" and strengthening the immune system so the body can heal itself. The "toxins" are neither defined nor objectively measurable. "Metabolic" treatment regimens vary from practitioner to practitioner and may include a "natural food" diet, coffee enemas, vitamins, minerals, glandulars, enzymes, laetrile, and various other nostrums that are not legally marketable in the United States. No scientific study has ever shown that "metabolic therapy" or any of its components is effective against cancer or any other serious disease.

The most visible proponent of "metabolic therapy" was Harold Manner, Ph.D., a biology professor who announced in 1977 that he had cured cancer in mice with injections of laetrile, enzymes, and vitamin A. (Actually, he digested the tumors by injecting them with digestive enzymes, which cannot cure cancers that have metastasized.) During the early 1980s, Manner left his teaching position and became affiliated with a clinic in Tijuana, Mexico. Although he claimed a 74% success rate in treating cancers, there is no evidence that he kept track of patients after they left his clinic [48]. He died in 1988, but the clinic is still operating.

Pau D'arco

Pau d'arco tea, sold through health food stores and by mail, is also called taheebo, lapacho, lapacho morado, ipe roxo, or ipes. The tea is claimed to be an ancient Inca Indian remedy prepared from the inner bark of various species of Tabebuia, an evergreen tree native to the West Indies and Central and South America. However, stories about its origins contain geographic and botanical errors. Proponents claim that pau d'arco tea is effective against cancer and many other ailments. Tabebuia woods contains lapachol, which has been demonstrated to have antitumor activity in a few animal tumor models. However, no published study has shown a significant effect on cancer in humans. Studies during the early 1970s found that lapachol is not as readily absorbed by humans as by rats, and that plasma levels high enough to influence tumors would be accompanied by anticoagulant effects. Even low doses can cause nausea and vomiting and can interfere with blood clotting [49]. Some researchers believe that lapachol should be studied further using vitamin K to inhibit its anticoagulant activity .

Psychic Surgery

Psychic surgery is claimed to remove tumors without leaving a skin wound. Actually, its practitioners use sleight-of-hand to create the illusion that surgery is being performed. A false finger or thumb may be used to store a red dye that appears as "blood" when the skin is "cut." Animal parts or cotton wads soaked in the dye are palmed and then exhibited as "diseased organs" supposedly removed from the patient's body. (However, one Philippine "healer" has been reported to use human blood, which raises the possibility that HIV or hepatitis B could be transmitted.) The American Cancer Society has concluded that "all demonstrations to date of psychic surgery have been done by various forms of trickery." [50] Most "psychic surgeons" practice in the Philippines or Brazil, but some have made tours within the United States. A few have been prosecuted for theft and/or practicing medicine without a license [51].

Psychologic Methods

Various psychologic methods are being promoted to cancer patients as cures or adjuncts to other treatment. The techniques include imagery, visualization, meditation, progressive muscle relaxation, and various forms of psychotherapy. These techniques may reduce stress, alleviate depression, help control pain, and enhance patients' feelings of mastery and control. Individual and group support can have a positive impact on quality of life and overall attitude. A positive attitude may increase a patient's chance of surviving cancer by increasing compliance with proven treatment. However, it has not been demonstrated that emotions directly influence the course of the disease.

Bernie Siegel, M.D., author of Love, Medicine & Miracles and Peace, Love & Healing, claims that "happy people generally don't get sick" and that "one's attitude toward oneself is the single most important factor in healing or staying well." Siegel also states that "a vigorous immune system can overcome cancer if it is not interfered with, and emotional growth toward greater self-acceptance and fulfillment helps keep the immune system strong." However, he has published no scientific study supporting these claims. A 10-year study co-authored by Siegel found that 34 breast cancer patients participating in his program did not live longer after diagnosis than comparable nonparticipants. The program consisted of weekly peer support and family therapy, individual counseling, and the use of positive imagery [52]. In November 1998, Siegel sent a series of email messages to Dr. Barrett in which he said that the study bearing his name had been done by a student and was improperly designed.

O. Carl Simonton, M.D., claimed that cancers can be affected by relaxation and visualization techniques. He claimed that this approach can lessen fears and tension, strengthen the patient's will to live, increase optimism, and alter the course of a malignancy by strengthening the immune system. However, he never published the results of any well-designed study testing his ideas. Simonton theorized that the brain can stimulate endocrine glands to inspire the immune system to attack cancer cells. He and his wife Stephanie (a psychotherapist) taught cancer patients to imagine their cancer being destroyed by their white blood cells. However, there is no evidence that white cells actually attack cancer cells in this manner or that "immune suppression" is a factor in the development of common cancers.

Simonton's book Getting Well Again included reports on patients who got better after using his methods. However, an analysis of five of the reports that might seem most impressive to laypersons noted that two of the patients had undergone standard treatment, one had a slow-growing tumor, and one probably did not have cancer. The fifth patient's tumor was treatable by standard means [53].

Some people suggest that Simonton's program may have positive effects by helping people to relax and to feel that they are "doing something" positive. Although this approach is physically harmless, it can waste people's time and money and encourage some to abandon effective care. It can also cause people to feel ashamed or guilty that some inner inadequacy caused them to develop cancer and is interfering with their recovery. Patients seeking a support program should select one that is based on scientific principles and has competent professional supervision.

Revici Cancer Control

Revici Cancer Control (also called lipid therapy and "biologically guided chemotherapy") is based on the notion that cancer is caused by an imbalance between constructive ("anabolic") and destructive ("catabolic") body processes. Its main proponent, Emanuel Revici, M.D., prescribed lipid alcohols, zinc, iron, and caffeine, which he classified as anabolic, and fatty acids, sulfur, selenium, and magnesium, which he classified as catabolic. His formulations were based on his interpretation of the specific gravity, pH (acidity), and surface tension of single samples of the patient's urine. Scientists who have offered to evaluate Revici's methods were unable to reach an agreement with him on procedures to ensure a valid test [54]. However, his method of urinary interpretation is obviously not valid. The specific gravity of urine reflects the concentration of dissolved substances and depends largely on the amount of fluid a person consumes. The acidity depends mainly on diet, but varies considerably throughout the day. Thus, even when these values are useful for a metabolic determination, information from a single urine sample would be meaningless. The surface tension of urine has no medically recognized diagnostic value. In 1993, following a lengthy struggle with New York State licensing authorities, Revici's medical license was permanently revoked. He died in January 1998 at the age of 101.

714X

714X is a chemical solution produced in Quebec by Gaston Naessens, who also operates the International Academy of Somatidian Orthobiology. He claims that 714X can "fluidify the lymph" and "direct nitrogen into the cancerous cells in order to stop their toxic secretions which block the organism's defense system." 714X has been analyzed by the Canadian Health Protection Branch and found to contain a mixture of camphor, ammonium chloride and nitrate, sodium chloride, ethyl alcohol, and water. The Health Protection Branch has received no scientific data to support claims that 714X can cure cancer or AIDS. Its Expert Advisory Committee has deplored its use for these purposes and warned that there could be adverse side effects [55]. In 1956, in connection with alleged cancer remedy called GN-24, Naessens was convicted of illegal medical practice and ordered by a French court to pay the maximum applicable fine. He was prosecuted again in 1964 after another alleged cancer remedy he administered in Corsica was proven not to work [56].

Shark Cartilage

Powdered shark cartilage is purported to contain a protein that inhibits the growth of new blood vessels needed for the spread of cancer. Although a modest anti-angiogenic effect has been observed in laboratory experiments, it has not been demonstrated that feeding shark cartilage to humans significantly inhibits angiogenesis in patients with cancer. Even if direct applications were effective, oral administration would not work because the protein would be digested rather than absorbed intact into the body. (If the proteins could enter the body, they would cause an immune response that would make the individual allergic to them and could trigger disastrous allergic responses with further exposure to the protein.)

Nevertheless, in the spring of 1993, "60 Minutes" aired a program promoting the claims of biochemist/entrepreneur I. William Lane, Ph.D., author of the book Sharks Don't Get Cancer. The program highlighted a Cuban study of 29 "terminal" cancer patients who received shark-cartilage preparations. Narrator Mike Wallace filmed several of the patients doing exercise and reported that most of them felt better several weeks after the treatment had begun. The fact that "feeling better" does not indicate whether a cancer treatment is effective was not mentioned. Nor was the fact that sharks do get cancer, even of their cartilage. NCI officials subsequently reviewed the Cuban data and concluded that they were "incomplete and unimpressive." [57]

In May 1997, at the American Society of Clinical Oncology's annual meeting, researchers reported a study that found shark cartilage ineffective against advanced cancer in adults with a life expectancy of at least 12 weeks. The study followed 58 people who were prescribed oral doses of shark cartilage as their only form of anti-cancer treatment. After 12 weeks, none achieved a complete or partial response to the shark cartilage treatment. Only ten showed no progression of their cancer, and only two had a quantifiable improvement in quality of life. (The fact that ten cancers did not progress is not evidence that the shark cartilage was responsible for this. The progression of cancer is not always rapid.) The researchers concluded: "Shark cartilage was inactive in patients with advanced stages of cancer, specifically in breast, colon, lung, and prostate cancer." The study was sponsored by Cancer Treatment Research Foundation, Cartilage Technologies (a manufacturer), and Cancer Treatment Centers of America. A few months later, Cartilage Technologies announced that it would support no additional research on shark cartilage as a cancer remedy [58].

Government agencies have taken action against at least three companies marketing shark cartilage. In September 1997, the FDA warned Lane Labs-USA, of Allendale, New Jersey, to stop claiming that its shark cartilage product BeneFin can help fight cancer, arthritis, and psoriasis [59]. In December 1999, the U.S. Department of Justice filed a lawsuit intended to stop the company from continuing its illegal marketing [60]. In 1998, the Federal Trade Commission obtained two consent agreements barring unsubstantiated claims for shark-cartilage products. Nutriveda, Inc., of Brooklyn, New York, had claimed that its product Cardilet was effective against cancer, rheumatism, arthritis, diabetes, fibroids, bursitis, circulatory problems, and cysts. Body Systems Technology, of Castleberry, Florida, had advertised that its product was effective against cancer. In June 2000, the FTC announced that Dr. Lane and Lane Labs-USA had signed consent agreements to stop illegal claims for Benefin and to pay $550,000 in penalties and $450 toward the cost of an approved clinical trial involving shark cartilage [61] The trial found no benefit [62].

Vitamin C

The claim that vitamin C is useful in the treatment of cancer is largely attributable to Linus Pauling, Ph.D. During the mid-1970s, Pauling began claiming that high doses of vitamin C are effective in preventing and curing cancer. In 1976 and 1978, he and a Scottish surgeon, Ewan Cameron, reported that a group of 100 terminal cancer patients treated with 10,000 mg of vitamin C daily had survived three to four times longer than historically matched patients who did not receive vitamin C supplements [63,64]. However, Dr. William DeWys, chief of clinical investigations at the NCI, found that the patient groups were not comparable. The vitamin C patients were Cameron's, while the other patients were managed by other physicians. Cameron's patients were started on vitamin C when he labeled them "untreatable" by other methods, and their subsequent survival was compared to the survival of the "control" patients after they were labeled untreatable by their doctors. DeWys found that Cameron's patients were labeled untreatable much earlier in the course of their disease-which meant that they entered the hospital before they were as sick as the other doctors' patients and would naturally be expected to live longer [65]. Nevertheless, to test whether Pauling might be correct, the Mayo Clinic conducted three double-blind studies involving a total of 367 patients with advanced cancer. All three studies found that patients given 10 g of vitamin C daily did no better than those given a placebo [66-68]. Despite many years of taking huge daily amounts of vitamin C, both Pauling and his wife Ava died of cancer—she in 1981 and he in 1994.

Conspiracy Theories

Quacks typically charge that the medical profession, drug companies, the food industry, government agencies, and/or other "vested interests" are conspiring against "natural" cancer cures. No such conspiracy has ever been exposed. Yet many patients—especially those whom standard medicine cannot cure—embrace the notion that a small but dedicated band of rebels is defying the medical establishment by making natural cures available. And desperate patients may find it more comfortable to believe that cures are being suppressed than to feel that their situation is hopeless.

The conspiracy charge has two common scenarios. In one, opposition is based on fear of competition. In the other, a cure discovered within the establishment is suppressed. Neither of these situations makes sense [69,70]

For Additional Information

References

  1. American Cancer Society. Questionable methods of cancer treatment. Atlanta: American Cancer Society, 1993.
  2. Janssen WF: Cancer quackery: Past and present. FDA Consumer 11(6):27-32, 1977.
  3. Holland JF. The Krebiozen story: Is cancer quackery dead? JAMA 200:213-218, 1967.
  4. Lerner IJ, Kennedy BJ. The prevalance of questionable methods of cancer treatment in the United States. CA—A Cancer Journal for Clinicians 42:181-191, 1992.
  5. Jarvis WT. How quackery harms. In Barrett S, Cassileth BR, editors. Dubious Cancer Treatment. Tampa, FL: American Cancer Society, Florida Division, 1991. [Online summary]
  6. Brigden ML: Unorthodox therapy and your cancer patient. Postgraduate Medicine 81:271-280, 1987.
  7. Marshall E. The politics of alternative medicine. Science 265:2000-2002, 1994.
  8. Green S. "Antineoplastons": An unproved cancer therapy. JAMA 267:2924-2928, 1992.
  9. Texas Attorney General's Office. Morales halts use of unapproved cancer treatment. News release, Feb 10, 1998.
  10. The antineoplaston anomaly: How a drug was used for decades in thousands of patients, with no safety, efficacy data. Cancer Letter, Sept 25, 1998.
  11. Gelb L. Unproven cancer treatments: Help or hoax? FDA Consumer 26(2):10-15, 1992.
  12. Trull L. The Cancell Controversy. Norfolk, VA: Hampton Roads, 1993.
  13. American Cancer Society. Questionable methods of cancer management: Electronic devices. CA—A Cancer Journal for Clinicians 44:115-127, 1994.
  14. Gelband H and others. Essiac. In Gelband H and others. Unconventional cancer treatments. Washington, DC: U.S. Government Printing Office, 1990, pp 71-75.
  15. Unproven methods of cancer management: Fresh cell therapy. CA—A Cancer Journal for Clinicians 41:126-128, 1991.
  16. American Cancer Society. Unproven methods of cancer management: Gerson method. CA—A Cancer Journal for Clinicians 40:252-256, 1990.
  17. Green S. A critique of the rationale for cancer treatment with coffee enemas and diet. JAMA 268:3224-3227, 1992.
  18. Ginsberg MM and others. Campylobacter sepsis associated with "nutritional therapy"—California. MMWR 30:294-295, 1981.
  19. Lowell J. The Gerson Clinic. Nutrition Forum 3:9-12, 1986.
  20. Austin S, Dale EB, DeKadt S. Long-term follow-up of cancer patients using Contreras, Hoxsey and Gerson therapies. Journal of Naturopathic Medicine 5(1):74-76, 1994.
  21. American Cancer Society. Unproven methods of cancer management: Greek Cancer Cure. CA—A Cancer Journal for Clinicians 40:368-371, 1990.
  22. Lowell J. Hoxsey treatment still available. Nutrition Forum 4:89-91, 1987.
  23. Gelband H and others. Hoxsey Treatment. In Gelband H and others. Unconventional Cancer Treatments. Washington, D.C.: U.S. Government Printing Office, 1990, pp 80-81.
  24. Loprinzi CL and others. Placebo-controlled trial of hydrazine sulfate in patients with newly diagnosed non-small cell lung cancer. Journal of Clinical Oncology 12:1126-1129, 1994.
  25. Kosty MP and others. Cisplatin, vinblastine, and hydrazine sulfate in advanced, non-small cell lung cancer. Journal of Clinical Oncology 12:1113-1120, 1994. [Full Text]
  26. Loprinzi CL and others. Randomized placebo-controlled evaluation of hydrazine sulfate in patients with advanced colorectal cancer. Journal of Clinical Oncology 12:1121-1125, 1994.
  27. Nadel MV. Report to the Chairman and Ranking Minority Member, Human Resources and Intergovernmental Relations Subcommittee, House Committee on Government Reform and Oversight. Cancer Drug Research—Contrary to Allegations, Hydrazine Sulfate Studies Were Not Flawed. Document No. HEHS-95-141. Washington, D.C.: U.S. General Accounting Office, September 1995. [PDF format]
  28. MI and others. Fatal hepatorenal failure associated with hydrazine sulfate. Annals of Internal Medicine 133:877-880, 2000. [PDF]
  29. Black M, Hussain H. Hydrazine, cancer, the internet, isoniazid, and the liver. Annals of Internal Medicine133:911-913, 2000. [PDF]
  30. American Cancer Society. Questionable methods of cancer management: Hydrogen peroxide and other "hyperoxygenation" therapies. CA—A Cancer Journal for Clinicians 43:47-55, 1993.
  31. Obara Kand others. Germanium poisoning: Glinical symptoms and renal damage caused by long-term intake of germanium. Japanese Journal of Medicine 30:67-72, 1992.
  32. Green S. Immunoaugmentative therapy. An unproven cancer treatment. JAMA 270:1719-1723, 1993.
  33. Curt GA, Katterhagen G, Mahaney F. Immunoaugmentative therapy: A primer on the perils of unproved treatments. JAMA 255:505-507, 1986.
  34. Gelband H and others. Immuno-Augmentative Therapy. In Gelband H and others. Unconventional Cancer Treatments. Washington, D.C.: U.S. Government Printing Office, 1990, pp 129-147.
  35. Working group on unproven methods in oncology. Iscador. File No. 10E. Bern: Swiss Cancer League, 1984.
  36. Mistletoe extracts (PDQ): Overview. NCA Web site, accessed 8/22/04.
  37. Dentist directed McQueen therapy. ADA News, Nov 17, 1980.
  38. Arena S. Doctor liable in death of patient. New York Daily News, April 20, 2000.
  39. Wilson B: The rise and fall of laetrile. Nutrition Forum 5:33-40, 1988.
  40. American Cancer Society. Unproven methods of cancer management: Laetrile. CA—A Cancer Journal for Clinicians 41:187-192, 1991.
  41. Herbert V. Pseudovitamins. In Shils ME, Young VR, editors. Modern Nutrition in Health and Disease, 7th ed. Philadelphia: Lea & Febiger, 1988, pp 471-477.
  42. Moertel C and others. A clinical trial of amygdalin (Laetrile) in the treatment of human cancer. New England Journal of Medicine 306:201-206, 1982
  43. Cassileth BR and others. Survival and quality of life among patients receiving unproven as compared with conventional cancer therapy. New England Journal of Medicine 324:1180-1185, 1991.
  44. Raso J. A Kushi seminar for professionals. Nutrition Forum 7:17-21, 1990.
  45. American Cancer Society: Unproven methods of cancer management: Macrobiotic diets for the treatment of cancer. CA—A Cancer Journal for Clinicians 39:248-251, 1989.
  46. Dwyer J. The macrobiotic diet: No cancer cure. Nutrition Forum 7:9-11, 1990.
  47. Associated Press. Aveline Kushi, 78, Leading proponent of macrobiotic diet. Newsday, July 6, 2001.
  48. South J. The Manner Clinic. Nutrition Forum 5:61-67, 1988.
  49. Tyler VE. Pau d'arco. Nutrition Forum 2:8, 1985.
  50. American Cancer Society. Unproven methods of cancer management: 'psychic surgery.' CA—A Cancer Journal for Clinicians 40:184-188, 1990.
  51. True, GN II. The facts about faith healing. Health Frontiers, accessed Sept 3, 2000.
  52. Gellert G, Maxwell RM, Siegel BS. Survival of breast cancer patients receiving adjunctive psychosocial support therapy: A 10-year follow-up study. Journal of Clinical Oncology 11:66-69, 1993.
  53. Friedlander ER. Mental imagery. In Barrett S, Cassileth BR. Dubious cancer treatment. Tampa, Florida: American Cancer Society, Florida Division, 1991, pp 73-78.
  54. American Cancer Society. Unproven methods of cancer management: Revici method. CA—A Cancer Journal for Clinicians 39:119-122, 1989.
  55. Canadian Health Protection Branch. 714X: An unproven product. Issues, Jan 24, 1990.
  56. American Cancer Society. Naessens Serum, or Anablast. Position paper, 1967.
  57. Mathews J. Media feeds frenzy over shark cartilage as cancer treatment. Journal of the National Cancer Institute 85:1190-1191, 1993.
  58. Miller DR and others. Phase I/II trial of the safety and efficacy of shark cartilage in the treatment of advanced cancer. Journal of Clinical Oncology 16(11): 3649-3655, 1998.
  59. Ellsworth DI. Letter to Andrew Lane, President of Lane Laboratories. Sept 24, 1997.
  60. FDA takes action against firm marketing unapproved drug. Talk Paper T99-56., Dec 10, 1999.
  61. Operation Cure.all" nets shark cartilage promoters: two companies charged with making false and unsubstantiated claims for their shark cartilage and skin cream as cancer treatments. FTC news release, June 29, 2000.
  62. Loprinzi CL and others. Evaluation of shark cartilage in patients with advanced cancer. Cancer 104(1), July 1, 2005.
  63. Cameron E, Pauling L. Supplemental ascorbate in the supportive treatment of cancer: prolongation of survival times in terminal human cancer. Proceeding of the National Academy of Sciences 73:3685-3689, 1976.
  64. Cameron E, Pauling L. Supplemental ascorbate in the supportive treatment of cancer: reevaluation of prolongation of survival times in terminal human cancer. Proceeding of the National Academy of Sciences 75:4538-4542, 1978.
  65. DeWys WD. How to evaluate a new treatment for cancer. Your Patient and Cancer 2(5):31-36, 1982.
  66. Creagan ET and others. Failure of high-dose vitamin C (ascorbic acid) therapy to benefit patients with advanced cancer. A controlled trial. New England Journal of Medicine 301:687-690, 1979.
  67. Moertel CG and others. High-dose vitamin C versus placebo in the treatment of patients with advanced cancer who have had no prior chemotherapy. A randomized double-blind comparison. New England Journal of Medicine 312:137-141, 1985.
  68. Tschetter L and others. A community-based study of vitamin C (ascorbic acid) in patients with advanced cancer. Proceedings of the American Society of Clinical Oncology 2:92, 1983.
  69. Novella S, Barrett S. Is there a conspiracy to suppress cancer cures? Quackwatch, June 22, 2000.
  70. Higgins M. Is there really a conspiracy to suppress cancer cures? Cancer Treatment Watch, Oct 24, 2007.

Portions of this article were originally published with Victor Herbert, M.D. as coauthor in Cancer Medicine, 4th Edition, published by Williams & Wilkins (1996). At that time, Dr. Herbert was Professor of Medicine, The Mount Sinai School of Medicine and Chief, Hematology and Nutrition Research Laboratory, the Bronx Veterans Affairs Medical Center.

This article was revised on July 27, 2010.

Links to Recommended Vendors