Actress Farrah Fawcett and the late Coretta Scott King are among the thousands of people who have turned to alternative approaches to cancer treatment when conventional medicine has failed.
It's often a last-ditch attempt to find a cure, one that brings the patient into a murky world of offshore clinics and unproven courses of treatment that are scorned by the medical establishment.
"I would [tell a patient considering alternative treatment] that they are signing their own death certificate," said Barrie Cassileth, chief of the Integrative Medicine Department at the Memorial Sloan-Kettering Cancer Center. Cassileth has not treated Fawcett. "I would say they are wasting time they could otherwise spend happier and with their families."
Fawcett, who was first diagnosed with anal cancer in September 2006, went into remission for several months after receiving traditional cancer treatments in California. In May 2007, however, Fawcett's cancer returned.
Anal cancer, according to Anil K. Rustgi, the chief of gastroenterology at the University of Pennsylvania, is fairly uncommon in the United States and is often associated with the human papillomavirus virus, or HPV.
According to People.com, Fawcett, 60, was "disheartened" by both the reoccurrence of the cancer and the treatment she was receiving in the United States, so she traveled to Germany's University Clinic in Frankfurt in search of an alternative course of treatment.
Calls to Fawcett's publicist regarding what specific treatment the star will be receiving were not returned.
Fawcett joins a number of other high-profile patients who have sought often unproven techniques in countries outside the United States to beat cancer.
King, the widow of Martin Luther King, traveled to a cancer clinic called Hospital Santa Monica, in Tijuana, Mexico, in search of a cure for ovarian cancer. King died just a few days later.
Actor Steve McQueen also went to Mexico in 1980 hoping to find a cure for his mesothelioma, a cancer caused by exposure to asbestos.
From high doses of vitamins administered intravenously to varying levels of chemotherapy and radiation, alternative cancer treatments run the gamut in technique, according to medical professionals.
German facilities, said Frank Cousineau, the president of the Cancer Control Society who has spent years visiting alternative treatment facilities worldwide, often use hypothermia techniques and employ extracts from mistletoe against cancers.
But further details about the techniques are hard to come by — the clinics approached by ABCNEWS.com declined to comment or simply did not return calls — which makes supporters of the treatments harder to come by.
"[Alternative treatment] is a marking term that means anything anybody wants it to mean," said Stephen Barrett, a retired psychiatrist who runs a site called quackwatch.com, which publishes information about alternative clinics. "It indicates it has not been proven, but people use it for different wants, and the implication by promoters is simply that it's a legitimate alternative."
Barrett, who has made it his job to warn cancer patients about the risks of alternative treatments, says he has spoken to people who have visited clinics in other countries and have suffered tremendously from unsanitary IVs and infections.
"I've asked people who are pretty involved in [the clinics] what the names of the doctors are or for medical records and 95 percent say 'no,'" said Barrett. "Once in a great while I've had someone offer records, but they were never traceable."
But Cousineau maintains that getting new cancer treatments approved is expensive and time-consuming for these clinics, which is why they choose to keep them under wraps — not because they don't work.
"I think the [clinics'] reputation is undeserved," said Cousineau, who is not a licensed physician. "The process to get a therapy of any kind approved in the U.S. takes a long time and is extremely costly. Just because they aren't approved doesn't mean they aren't working."
In addition to these alternative cancer clinics, patients may also seek what's known as "complimentary" treatments.
According to the American Cancer Society, everything from acupuncture to mediation to message therapy has been proven to help patients deal with anxiety and pain, both chief symptoms for cancer patients.
While accepting unproven and untested medicine may seem unwise to some, others who may feel like they've run out of options in the United States could see it as a last-ditch effort for a cure.
"I think it's human nature," said Len Lichentheld, deputy chief medical officer for the American Cancer Society. "Human nature is such that we always want to believe there is something else and so people become vulnerable to claims that somebody has something that is going to work."
"There are people who claim they've been helped, but you look at the data and you can't substantiate many of the claims, but still many will spend the money to send their relatives for a 'last try,'" said Lichentheld.
Patricia Chavez, whose mother visited one of the clinics in Mexico, told ABCNEWS.com that the treatment alone started at $9,000, but additional consultations and herbal medicines were added expenses. Doctors estimated that many alternative treatments cost in the tens of thousands of dollars.
"There are no viable 'alternatives' to mainstream cancer care," said Cassileth, who after 25 years as a cancer specialist said that she never saw someone cured by these methods. "There are dozens — probably hundreds — of spas and clinics that claim to treat advanced cancer successfully. None of them work."