“Sharks can't get cancer.”

The persistent notion that sharks are immune to cancer is a widespread misconception with a specific origin. This myth gained significant traction following the publication of the 1992 book "Sharks Don't Get Cancer" by I. William Lane and Linda Comac. The book, despite its title, primarily suggested that shark cartilage possessed cancer-fighting properties, leading to the erroneous belief that sharks themselves were immune to the disease. This idea was further amplified by media attention, including segments on the television program "60 Minutes" in 1993, which unfortunately solidified the myth in public consciousness.

However, scientific evidence clearly busts this myth. Sharks, like virtually all other animals, can and do develop cancer. Researchers have documented numerous cases of both benign and malignant tumors in various shark species, with the earliest recorded malignancy in a shark dating back to 1908. For instance, a great white shark was found with a significant tumor, and a bronze whaler shark also displayed a cancerous mass. In fact, scientists have even observed the long-term progression of a cancerous lesion on a wild bull shark over a period of seven years, demonstrating that these formidable ocean predators are not exempt from the disease.

The reason this myth became so commonly believed largely stems from a desperate hope for a cancer cure. The idea that a powerful creature like a shark might hold the key to defeating this devastating disease was incredibly appealing. While some laboratory studies have explored compounds in shark cartilage for their potential to inhibit blood vessel growth in tumors, there is no scientific evidence to support the claim that ingesting shark cartilage can treat or prevent cancer in humans. The misleading title of the book, combined with the understandable desire for a breakthrough, contributed to the widespread and enduring nature of this biological inaccuracy.