Lung cancer patients taking shark cartilage fared no better than patients not taking the extract, scientists report in the June 16 Journal of the National Cancer Institute.
Shark cartilage is frequently recommended as a cancer treatment by complementary or alternative medicine practitioners, and surveys suggest that between six and 25 percent of cancer patients do take it. Yet there is little research in cells or animals to back up the substance’s supposed anticancer effects, says Jeffrey White of the Division of Cancer Treatment and Diagnosis at the National Cancer Institute in Bethesda, Md., who was not involved in the study.
Patients enrolled in the study had non–small cell lung cancer, the most common type. Half of the 397 participants took the shark cartilage extract, also known as AE-941 or Neovastat, and half got a placebo. All of the study participants also received chemotherapy and radiation.
The extract had no effect on the progression of the patients’ cancer, their tumors didn’t respond differently to treatment and they didn’t live any longer than patients not receiving extract.
The result was disappointing, because the cartilage extract had already been rigorously examined in the lab and had shown promising results as a tumor shrinker. Studies of sick mice suggested the extract slowed the spread of lung carcinomas, and a trial study of 48 people with lung cancer found that patients receiving higher doses of the extract lived a bit longer. But in this larger study, the extract “did not have the activity that was hoped for,” says White, who wrote an editorial that accompanied the paper.
It’s difficult to say whether this means there aren’t compounds in cartilage that may one day be useful anticancer therapeutics, says medical oncologist Charles Lu of the University of Texas M. D. Anderson Cancer Center in Houston, who led the new work. Only research can answer that. For now, Lu says, when a patient asks a doctor about cartilage as a cancer treatment, at least the physician can point to one rigorous study.
“It’s important to get this data out there,” Lu says. “People should know that it didn’t work.”