The following Healthcast report by Channel 4 Action News medical editor Marilyn Brooks first aired Dec. 18, 2003, on Action News at 5 p.m.

---

Researchers know cancer cells create their own blood supply as they grow and spread through the body. A clinical trial sponsored by the National Cancer Institute is looking at a therapy derived from sharks that may prevent it from happening.

Patsy Jones was diagnosed with advanced lung cancer three years ago. She decided to participate in a Phase 3 clinical trial of liquid shark cartilage extract -- a new therapy that researchers hope will keep her tumors at bay.

All patients in the trial received chemotherapy and radiation treatments. Half of them also drink the shark cartilage extract, while the other half drink a placebo. Twice a day, they drink a fishy-smelling slush.

Jones: "I'm very devoted to it. I take it first thing in the morning, and then I take it between 7 and 8 at night."

In humans, cartilage is the tissue that separates and cushions our bony joints. It has no blood vessels, so researchers believe it contains an agent that prevents blood vessel growth and may help a process called anti-angiogenesis.

Dr. Charles Lu: "Effective anti-angiogenic agents could prevent tumors from developing their own blood supplies and growing, preventing them from metastasizing."

Why use shark cartilage?

Lu: "In sharks, they have a large cartilagenous skeleton, so they happen to be a very rich supply of cartilage."

Jones: "I hope that it will extend my life. I realize it's not going to cure me, but it does extend your life, from all that I've read about it."

Lu: "The ultimate hope would be, we could treat someone with chemotherapy and radiation to shrink their tumor as much as possible, but then to go on to give them a drug which could keep the tumor at bay for a long period of time."

There are no definitive results available for this particular trial, but if you want to know more about it, or what researchers are doing with shark cartilage, call the cancer information service at 800-4-CANCER.