Zosia Chustecka

June 06, 2007

June 6, 2007 (Chicago) — Shark cartilage, marketed as an "alternative medicine" for use in cancer, was shown to have no effect in a large phase 3 study sponsored by the National Cancer Institute (NCI). The supplement was added to treatment with chemoradiation in patients with non–small-cell lung cancer (NSCLC) and was shown to have no effect on survival when compared with placebo.

The study was reported here at the American Society of Clinical Oncology (ASCO) 43rd Annual Meeting by Charles Lu, MD, from the University of Texas MD Anderson Cancer Center, in Houston. "These results definitely demonstrate that this shark-cartilage extract is not effective," he said, and "they do not support the routine use of these products as anticancer therapies."

Shark cartilage has been a controversial product and has been very popular among cancer patients, but this study shows that "it provides no benefit at all," commented Bruce Cheson, MD, from the Lombardi Comprehensive Cancer Center and Georgetown University Hospital, in Washington, DC. "We have needed studies like this, rigorous and carefully controlled trials to provide us with scientific evidence about the supplements our patients are taking," he commented while moderating an ASCO press briefing at which the study was highlighted.

This study arose from a US congressional mandate to the NCI in the late 1990s, when the growing popularity of shark-cartilage extract for use in cancer was seen as a public health issue, Dr. Lu explained to Medscape. It was designed as a definitive trial to show whether or not the product works, he added. The theory behind its use in cancer rests on the fact that cartilage is an avascular tissue, and so it may contain inhibitors of angiogenesis that could be useful in stopping tumor growth, he explained. There is also the intriguing fact that the incidence of cancer is very rare in sharks.

The product used in this trial was AE-941 (Neovastat), which was donated by the manufacturer, Aeterna Zenartis. This product is unusual in that it was never sold over the counter, unlike other shark-cartilage supplements. It was being developed by Aeterna Zenartis as a pharmaceutical for use in cancer, but the company announced recently that this project has been dropped. The company has several other pharmaceuticals in its pipeline for use in cancer, which it featured at a marketing booth in the exhibition hall, and early results on 2 products were featured in other presentations during the meeting.

The study was conducted in 384 patients with stage 3 NSCLC at 53 sites in the United States and Canada. Depending on the site, patients received either carboplatin and paclitaxel or cisplatin and vinorelbine, given both as induction chemotherapy and then concomitantly with radiation. In addition, patients were randomized to receive either placebo or liquid shark-cartilage extract, 120 mL orally twice daily.

After a median follow-up of 3.7 years, there was no significant difference in the overall survival between the 2 groups (15.6 months for placebo vs 14.4 months for shark cartilage; P = .73).

"Clearly, these results demonstrate that AE-941 is not an effective therapeutic agent for lung cancer," Dr. Lu concluded. "So, too, these findings have to cast major skepticism on shark-cartilage products that are being sold for profit and have no data to support their efficacy as cancer-fighting agents.

"We have absolutely no data showing improvements in survival, tumor shrinkage, and/or clinical benefits to patients," he added. "Now when patients ask their oncologists about shark cartilage, physicians can point to this large NCI-sponsored phase 3 trial and tell their patients that, at this point, the only studies that have been done with cartilage-derived products have been negative."

American Society of Clinical Oncology 43rd Annual Meeting: Abstract 7527. Presented June 2, 2007.


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