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Questionable Cancer Practices In Mexico

Other common name(s): many possible names

Scientific/medical name(s): none


Some practitioners of alternative medicine who treat cancer using unproven and unapproved therapies -- especially those who market their treatment as a "cure" -- have moved just across the Mexican border, where they are still able to attract US patients. Although there are certainly many legitimate cancer treatment centers in Mexico, many of these "border clinics" offer treatments that are unproven or simply don't work. Some also have offices in San Diego or other U.S. towns near the Mexican border. These offices are used as contact points to find U.S. patients, who are then referred to the actual clinics in Mexico. Specific information can be difficult to obtain because of secrecy requirements: in some cases the clinics are operating illegally in Mexico and are subject to closure by Mexican authorities if they are caught.


One estimate is that there are about 35 to 50 alternative medicine clinics and hospitals in Mexican border towns, especially Tijuana. Investigative news reporters offer some accounts of what the clinics do, but getting good information on their actual practices can be difficult. Before entering some of these clinics, patients are reportedly required to sign agreements stating that they will not to talk to the press. Oftentimes, reporters, investigators, and other outside observers are not allowed in.

Despite these secrecy requirements, some family members have come forward to place complaints that their loved ones got worse or died shortly upon returning home, often after being told they were cured. Families have also told tragic stories of loved ones whose cancer was detected early enough to be treated effectively, but who instead sought care in these border clinics. By the time many of these people learned their cancer had progressed during alternative treatment, it was too late for conventional treatment that could have cured them.

How is it promoted for use?

Some clinics offer a "cure," while others have toned down their advertising and no longer claim to cure cancer. However, most patients who ask are told they "can be helped" or that there is a "good chance" their cancer can be cured. Treatment in these clinics is often advertised as an alternative to traditional medical care, a "natural" or "non-toxic" alternative to cancer treatment.

Treatment may be promoted based on some of the beliefs listed below about how cancer begins and progresses:

  • The belief that a "buildup of toxins" from foods, food additives, and environmental pollution is the main cause of chronic diseases. While it is true that there is a link between diet and disease, available scientific evidence does not point to food "toxins" or additives as the cause of disease. The idea that sugar feeds cancer cells is often cited as a reason to avoid certain foods. But even the healthiest foods contain some form of sugar or carbohydrate. The body converts these sugars into glucose as a fuel to supply energy to all of its cells, which cannot function without it. For example, whole fruits and vegetables contain sugars, but have actually been proven to help reduce cancer risk.
  • The belief that removing toxins from the body (a process called detoxification) and dietary changes can reverse cancer after it has developed and spread. Available scientific evidence does not support claims that removing certain foods or other substances from the diet or environment will change the outcome of cancer once it has been found. While dietary changes may be helpful to a cancer patient, there is no proof that they will cure cancer. Other measures used for detoxification, such as colon cleansing, can be harmful.
  • The belief that tumors can and do thrive without oxygen and are killed by substances that increase the oxygen supply to the tumor. The idea that cancer cells thrive in low oxygen levels is based on the lower-than-normal rates of respiration in tumors. However, modern researchers attribute the reduced respiration rate and lower oxygen levels in tumors to the poor blood supply and lack of blood vessels in tissue surrounding rapidly growing tumors. Currently, there is no available scientific evidence supporting the use of products that claim to kill tumors by raising levels of oxygen in the blood (also called hyperoxygenation or oxymedicine), such as hydrogen peroxide and ozone (see Oxygen Therapy).

The belief that food additives, such as artificial colors and preservatives, cause cancer and that "natural" substances are not harmful. There is no evidence that food additives are a major threat when used properly and in normal amounts. It is known that some types of industrial pollution and hazardous substances in the workplace have been linked with a higher number of some tumors. However, even if these substances could be removed from the body of a person with cancer (and, in most cases, this is not possible), doing so would not influence growth of a cancer that has already formed.

What does it involve?

Border clinics offer a variety of treatments. They often advertise "individualized therapy," which combines different kinds of alternative and complementary treatments. Metabolic therapy is one of the main treatments offered in these clinics (see Metabolic Therapy). Metabolic therapy is not well defined and includes many different kinds of treatment. Although some of the individual methods used in metabolic therapy can be found in the United States, border clinics commonly offer a number of those different treatments used in metabolic therapy in each facility. Because the focus in metabolic therapy is more on the body's function or condition than on the specific treatments, an endless variety of activities that are supposed to help the body's function can be included. These treatments are claimed to be for the 3 purposes described below: detoxification, immune system support, and fighting the cancer.

Detoxification ("detox") refers to removing so-called toxic agents from the body. It can use many methods:

To reduce the risk of fluid and mineral imbalances, small amounts of juices or other foods may be given. Enemas or colonics may be given as often as every 2 hours to remove "toxic buildup" in the bowel. The claim that colon cleansing improves the body's ability to digest food shows a basic error in understanding human anatomy and physiology, since almost all of the nutrients are actually absorbed in the small intestine. The digested material then enters the large intestine (colon), which absorbs only water and a few minerals. The belief that detox will help the large intestine absorb nutrients is false.

Immune system support is another part of metabolic therapy and may include vitamins, special diets, and nutrition treatments, as well as herbs and other practices, that are supposed to help the body fight the cancer. Large amounts of nutritional supplements are included in most metabolic therapies. Supplements are claimed to balance the diet, detoxify the body, help restore the patient's normal metabolic patterns, strengthen the immune system, and destroy tumors. Various "tumor-specific" substances are promoted and sold with the claim that they are effective, natural, and non-toxic.

A number of different supplements may be offered:

Some of these treatments have not been studied by scientists. Others have been tested and appear to have no helpful effect. Some are known to cause harm.

Anti-tumor treatments are supposed to attack the cancer. Various substances and devices are promoted and sold with the claim that they are effective, natural, and non-toxic to normal cells. Although there are many types of treatment available in Mexico, the treatments listed below are some of the most common:

  • electronic "zappers" -- electromagnetic devices that are supposed to kill cancer cells (see Electromagnetic Therapy)
  • light therapy, including UV blood irradiation (see Light Therapy)
  • bee venom therapy (see Apitherapy)
  • cancer salves (see Cancer Salves)
  • enzyme therapy (see Enzyme Therapy)
  • shark cartilage (see Shark Cartilage)
  • induced hypoglycemic (insulin) therapy (see Insulin Potentiation Therapy)
  • homeopathy (see Homeopathy)
  • oxygen therapy, such as ozone or hydrogen peroxide (see Oxygen Therapy)
  • antineoplaston therapy (see Antineoplaston Therapy)
  • anti-cancer vaccines (other than those that been researched by conventional immunologists and oncologists and found to be helpful in carefully controlled clinical trials)
  • hydrotherapy (see Hydrotherapy)
  • whole body hyperthermia (see Hyperthermia)
  • laetrile, which is often given with massive doses of vitamins, and dimethylsulfoxide (see Laetrile, DMSO)
  • glandular (organ) extracts, or live cells or blood from animals, promoted to boost the affected organ system (for example, liver extract for liver cancer, lung extract for lung cancer, and other injections of animal organ extracts; see Cell Therapy for more information)
  • urea, based on the idea that urine has cleansing powers (see Urotherapy)
  • cesium chloride, claimed to inhibit cancer growth by making the pH of cancer cells "basic" instead of acidic (see Cesium Chloride)
  • hydrazine sulfate, said to destroy tumors (see Hydrazine Sulfate)
  • germanium sesquioxide (see Germanium)
  • low-dose chemotherapy (using doses not researched or recommended by mainstream oncologists) sometimes in combination with other types of treatments

Few of the dozens of products promoted as anti-tumor agents by metabolic therapists have been approved for use or even recognized as experimental drugs by the U.S. Food and Drug Administration. Several products, such as Laetrile and germanium sesquioxide, have been tested and found to be toxic and/or ineffective. Hyper-oxygenators have no demonstrated benefits, and both hydrogen peroxide (given by mouth and into the vein), and ozone (given rectally) can be harmful. Several clinics use low-dose (also called micro-dose) chemotherapy in combination with other treatments.. Available scientific evidence does not support the claim that micro-dose chemotherapy is effective.

What is the history behind it?

According to an article in Time magazine, no one is exactly sure when U.S. citizens began going to alternative medicine clinics in Mexico. Since the early 1960s, U.S. regulatory agencies have become increasingly stringent in their requirements for treatments' proof of effectiveness. Ralph Moss, in his brief history of the Tijuana clinics, notes that the clinics were set up mainly by U.S. citizens in response to stronger regulation of non-standard treatments, many of which were unproven.

According to Mr. Moss, the number of clinics in Tijuana increased in the 1970s because of interest in laetrile. The popularity of these clinics began to decline after the mid-1980s and many have since closed. This decline was caused partly by the North American Free Trade Agreement (NAFTA), which was passed in the 1990s. Among other things, NAFTA allows the United States, Canada, and Mexico to work together to take action against cross-border health fraud. The three countries banded together in 1994 to form the Mexico-United States-Canada Health Fraud Work Group, or MUCH.

There have been a number of investigations and convictions of fraudulent providers over the past decade. According to an investigative report in the San Diego Times-Union, Mexican regulators shut down or restricted about a dozen clinics in 2001 after finding that many of the clinics were unlicensed and that some were offering very dangerous treatments. One clinic founder pleaded guilty to fraud and money laundering in 2002, after he set up a company that offered "magnetic field" therapy. In an article on the Monterrey (Mexico) Wellness Center, Dr. Stephen Barrett noted that the clinic operator advertised a high cure rate for cancer and other serious diseases at his clinic in Monterrey, Mexico. The clinic operator discouraged people from getting standard medical care, and he and other company officers solicited investments in their "new technology." The company reportedly had received $675,000 in payments before it closed. Its owner, who had represented himself as a world-renowned scientist, was sentenced to more than seven years in federal prison. According to the U.S. attorney prosecuting the case, all of the clinic's patients died.

In 2003, the U.S. Federal Trade Commission (FTC) stopped a Canadian company that was marketing treatments with its "zoetron" machine to U.S. consumers. According to an FTC press release, the patients wired $15,000 to Canada, then traveled to Tijuana for treatment with "Cell Specific Cancer Therapy," which was claimed to be a pulsed magnetic field. The company's owners were charged with making false claims about their device. The FTC states that the zoetron machine turned out to be a ring of weak magnets that did nothing for the cancer. Mexican authorities, working with the United States and Canada, shut down the clinic where the "treatment" was offered.

In 2004, United States and Mexican authorities worked together to shut down yet another Tijuana clinic. The owners, who were based in Bonita (in San Diego County), were charged with fraud. In a separate case, the clinic where Coretta Scott King was treated in 2006 was shut down by Mexican authorities. Mrs. King died shortly after being treated there, and Mexican investigators subsequently learned that the clinic providing her treatment was not authorized to do surgery, laboratory tests, or diagnostic procedures, according to an article in the San Diego Union Tribune. This clinic was headed by an American man. According to the Atlanta Journal-Constitution, he had been charged with practicing medicine without a license in 1970 in California and had pleaded guilty to charges of smuggling illegal medicines into the United States in 1996. As reported by Dr. Stephen Barrett, the clinic operator had previously obtained a naturopathic license using a forged degree, misrepresented hydrogen peroxide as a treatment for cancer and arthritis, and pleaded guilty to tax evasion as well as the smuggling charge. In this and other cases, clinic operators who have been convicted of crimes in the United States have still been able to open and run clinics in Mexico.

Despite regulatory agencies' attempts to stop illegal or fraudulent activities, many clinics close and then reopen under other names in new locations. According to Mexican official Dr. Alfredo Gruel Culebro, "Even if they are shut down, they can request a new permit altogether and start operating practically next door."

What is the evidence?

It is impossible to fully and precisely evaluate all of the treatments described in this section in a single discussion. For the most part, the methods promoted in Mexican border clinics are not consistent with scientific understanding of how cancer and its treatment work. On the other hand, there are many medical practitioners in Mexico who use methods based in responsible science. Some practitioners combine scientifically proven methods with other therapies that show no evidence of helping. But because the hundreds of regimens used in clinics change often, any full evaluation would be outdated almost immediately. For information on each treatment, see the description and evidence regarding that particular treatment.

Although these clinics often claim great success in advertisements and books, they have not published convincing evidence in medical journals to support those claims. Attempts by researchers to study results from those clinics have been constrained by incomplete records and limited follow-up with patients, which usually does not allow any comparison with results of mainstream oncology treatment.

Are there any possible problems or complications?

These substances may have not been thoroughly tested to find out how they interact with medicines, foods, or dietary supplements. Even though some reports of interactions and harmful effects may be published, full studies of interactions and effects are not often available. Because of these limitations, any information on ill effects and interactions below should be considered incomplete.

Patients traveling to the Tijuana area for treatment appear to be subjecting themselves to costly and potentially hazardous regimens, especially if they postpone standard medical care. They usually do not know exactly what they are getting, and they do not know whether the treatment is helpful until the time and money have been spent. During the treatment, for example, patients are generally told that they are improving. When symptoms worsen, it may be described as a "healing crisis" or "the toxins coming out."

Most of these therapies have not been tested using the safeguards put in place by U.S. regulatory agencies and the scientific community to ensure treatments are effective and safe. Available scientific evidence does not support claims that they work. Often, only lay literature such as patient testimonials and books written by those selling the treatments, is provided when promoters are asked for proof that their treatments work.

There are reports of cancer patients leaving these clinics very happy with their care, believing themselves cured. But most clinics offer no proof of their cure rates and rarely follow up with patients over the long term to see whether their conditions were actually improved by treatment. There are many reports of people who have had severe or life-threatening side effects from the treatments. And there are far more who have died needlessly after coming to mainstream oncologists too late to get timely, effective treatment

Finally, patients at these border clinics can expect to pay $2,500 to $7,000 a week or more for treatment plus travel expenses. They are often required to pay all or most of the fee before entering the program. Some clinics have additional costs for extra treatments, and companions may be charged up to $300 a week to share a room with the patient. The recommended stay is often several weeks. Outpatient programs often cost $1,000 to $2,000 a week. Insurance programs almost never cover these treatments, although some of the clinics with US offices have tried to file for insurance reimbursement. Some of these offices have been prosecuted for filing false or fraudulent insurance claims. Most programs also recommend follow-up therapy at home for additional fees, and some patients may be urged to return to the clinic for more treatment. Those who look to these border clinics for alternative treatments often bankrupt themselves in search of a cure.

For more specific information on complications and risks of these kinds of treatments, see the sections on the individual therapies being offered.

The American Cancer Society urges individuals with cancer to seek treatment from qualified cancer care professionals who can offer cancer treatments that have been proven to be safe and effective or that are currently being studied in carefully monitored clinical trials. If you believe you have experienced fraud at the hands of any Mexican border clinic, you can contact the U.S. Food and Drug Administration at 1-888-463-6332, or make a report online at www.fda.gov/medwatch.

Relying on this type of treatment and avoiding or delaying conventional medical care for cancer may have serious health consequences.

Additional resources

More information from your American Cancer Society

The following information on complementary and alternative therapies may also be helpful to you. These materials may be found on our Web site (www.cancer.org) or ordered from our toll-free number (1-800-ACS-2345).

Dietary Supplements: What Is Safe?

The ACS Operational Statement on Complementary and Alternative Methods of Cancer Management

Complementary and Alternative Methods and Cancer

Placebo Effect

Learning About New Ways to Treat Cancer

Learning About New Ways to Prevent Cancer


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Note: This information may not cover all possible claims, uses, actions, precautions, side effects or interactions. It is not intended as medical advice, and should not be relied upon as a substitute for consultation with your doctor, who is familiar with your medical situation.

Last Medical Review: 11/01/2008
Last Revised: 11/01/2008