We think of cancer as caused by mutations. Mutations are necessary, but not sufficient, to cause cancer. New research indicates that it’s the body’s response to mutant cells that determines whether cancer will develop. James S. Welsh, MD, a radiation oncologist and researcher, has written a book on the immunology of cancer, Sharks Get Cancer, Mole Rats Don’t: How Animals Could Hold the Key to Unlocking Cancer Immunity in Humans. In it, he pieces together clues from animals, pregnancy, Ebola virus, infections, organ transplantation, parasites, and human cancer patients, weaving a web of insights that point to a better understanding of cancer biology and treatment.
Sharks do get cancer
The first book claiming that sharks don’t get cancer came out in 1992. It persuaded so many people to take shark cartilage that the world market exceeded $30 million and shark populations decreased by as much as 80%. Sharks do get cancer, as you can see in this picture.
Ironically, sharks can even get cancer of the cartilage! And of course shark cartilage supplements don’t prevent cancer in humans. Welsh explains how that myth got started. It was magical thinking based on extrapolation from a legitimate scientific study on angiogenesis where tumor growth in lab animals was suppressed by placing rabbit cartilage next to the tumors.