WEDNESDAY, May 25, 2005 (HealthDay News) -- America's interest in shark cartilage as a cancer therapy began in 1993 after a TV report on Cuban research that claimed patients with advanced cancer went into remission after treatment with the compound.
But a new study finds that the risks associated with shark cartilage outweigh any possible benefits it might have in treating advanced breast or colorectal cancer.
A study to be published in the July 1 issue of Cancer found no difference in overall survival or quality of life between patients who took shark cartilage and those who took a placebo. In fact, toxicity related to taking shark cartilage caused a significant number of patients to drop out of the study after just one month.
Mayo Clinic oncologist Dr. Charles L. Loprinzi and his colleagues in the North Center Cancer Treatment Group concluded that "shark cartilage did not demonstrate any efficacy in patients with advanced breast or colorectal cancers."
Some previous studies suggested that some forms of shark cartilage had a modest ability to slow the growth of new blood vessels in laboratory cell cultures and in animals.
However, those results were never published in a peer-reviewed medical journal, the researchers said, and the U.S. National Cancer Institute later concluded that the results of the Cuban study were "incomplete and unimpressive."
The U.S. National Cancer Institute has more about shark cartilage.