“Sharks can't get cancer.”

Many people believe that sharks are immune to cancer, a widespread misconception that gained significant traction due to a popular book published in the 1990s titled 'Sharks Don't Get Cancer'. This book, along with subsequent marketing efforts, heavily promoted the idea that shark cartilage could serve as a miracle cure or preventative measure for human cancer, leading to a boom in the shark cartilage supplement industry. The notion that these ancient predators were somehow impervious to a disease so common in other species proved to be a compelling, albeit incorrect, narrative.

However, scientific evidence overwhelmingly busts this myth. Researchers have documented various types of cancerous tumors in over 40 species of sharks and their relatives, including skates and rays. These findings come from numerous studies and observations of both wild and captive sharks. Scientists have discovered everything from benign growths to aggressive malignant tumors affecting different organs and tissues within these cartilaginous fish, directly contradicting the long-held belief.

The persistent belief in this myth can largely be attributed to the hope for a novel cancer treatment and the powerful influence of anecdotal claims over scientific data. The idea of a creature immune to cancer was incredibly appealing, especially to those seeking alternative therapies. Unfortunately, this misconception not only misinformed the public but also contributed to the overfishing of shark populations for an unproven and ineffective treatment, diverting resources and attention away from evidence-based cancer research.