June 2, 2007

Adding shark cartilage extract to standard chemotherapy and radiation therapy for patients with advanced non-small cell lung cancer does not extend patients' lives, according to a large phase III clinical trial.

Shark cartilage products have been marketed as alternative medicine "cures" that work by blocking the formation of blood vessels that feed tumors. This clinical trial evaluated the shark cartilage extract Æ-941 (Neovastat) in 384 patients at 53 sites in the United States and Canada. The National Cancer Institute (NCI) and Aeterna Zentaris (the Canadian biopharmaceutical company that manufactures Æ-941) sponsored the study.

Non-small cell lung cancer is the most common type of lung cancer. The patients in this study had stage III cancer, meaning that the cancer could not be surgically removed. Most patients with this type of cancer are initially treated with combined chemotherapy and radiation therapy.

In this study, 188 patients received the standard treatment plus the shark cartilage extract (as a liquid, which they drank twice a day), and 191 patients received the standard treatment plus a placebo (a liquid with no shark cartilage extract). After nearly four years of follow-up, patients that received the shark cartilage lived an average of 14 months, compared with nearly 16 months for the patients who did not receive the shark cartilage, a difference that was not significant.

What This Means for Patients

"These results definitively demonstrate that this shark cartilage extract is not effective against lung cancer when combined with chemoradiotherapy," said Charles Lu, MD, Associate Professor in the Department of Thoracic and Head and Neck Medical Oncology at The University of Texas M. D. Anderson Cancer Center in Houston and the study's lead author. "These negative results are disappointing, but this study shows the benefit of conducting scientifically rigorous studies on potential cancer treatments, including those that some may consider to be alternative therapies."