Shark cartilage is purported to contain angiogenesis inhibitors, which prevent the formation of new blood vessels that tumors need to grow. A modest anti-angiogenic effect has been seen in test tubes, but not in humans at this point. Shark cartilage is supplied in powder and capsule forms. It is taken orally and sometimes as an enema.
The news program 60 Minutes gave shark cartilage a huge boost in the 90's. The program reported a Cuban study of 29 patients with"terminal" cancer who were placed on shark cartilage. Most patients "felt better" several weeks after starting the shark cartilage. "Feeling better" is not a reliable endpoint in a scientific study. The National Cancer Institute (NCI) performed a review of the study and felt the data was "incomplete and unimpressive." 60 Minutes subsequently refused to broadcast the findings of the NCI.
A small study on shark cartilage was reported at the American Society for Clinical Oncology in 1997. Patients with advanced cancer were given sharkcartilage for 12 weeks. Of the 58 patients treated, there was not one complete response or partial response to shark cartilage. Only 2 patients had significant improvement in quality of life. There are currently some ongoing studies of shark cartilage at a number of institutions, but no positive trials have been published in the scientific literature.
Shark cartilage is relatively expensive. If it is taken as described by William Lane, the 16 week program cost is approximately $3000. There are discount suppliers, but beware of utilizing some sources. Some producers do not supply pure shark cartilage and there may be additives and fillers.
There are some cautions for the cancer patient regarding shark cartilage: