“Sharks do not get cancer.”

Shark cartilage became popular after a book published in the early 1990s claimed that sharks do not get cancer because they have cartilage instead of bones. However, multiple studies have found that sharks do get cancer, including malignant tumors.

An alleged lack of cancer in sharks constitutes a key justification for its use. Herein, both malignant and benign neoplasms of sharks and their relatives are described, including previously unreported cases from the Registry of Tumors in Lower Animals, and two sharks with two cancers each.

Sharks occupy diverse ecological niches and play critical roles in marine ecosystems, often acting as apex predators. They are considered a slow-evolving lineage and have been suggested to exhibit exceptionally low cancer rates. These two features could be explained by a low nuclear mutation rate. Here, we provide a direct estimate of the nuclear mutation rate in the epaulette shark (Hemiscyllium ocellatum)... Using stringent criteria, we estimate a mutation rate of 7×10−10 per base pair, per generation. This represents one of the lowest directly estimated mutation rates for any vertebrate clade.

Peer-reviewed editorial in the Journal of the National Cancer Institute (2005) explicitly titled 'Sharks do get cancer,' directly refuting the widespread myth that sharks are immune to cancer.

The purpose of this study is to evaluate veterinary records of fish diagnosed with cancer to determine the most common presentation of this disease. While focused on pet fish, it notes documented cases of neoplasia in cartilaginous fish including sharks, confirming cancer occurs in these species.

In this review, we summarize the current state of research into fish-derived cartilage products and their application. It acknowledges scientific literature documenting cancer incidences in sharks, countering outdated myths of cancer-free sharks.

Sharks do, of course, get cancer, and numerous examples of shark cancer have been documented. Brunnschweiler et al. documented a cancerous lesion on the jaw of a bull shark (Carcharhinus leucas) over seven years in a marine reserve, with the affected animal still alive as of the publication date, demonstrating ongoing tumor progression in a free-living wild shark.

A study published Jan. 30 in the journal BMC Genomics provides the first evidence that some shark and ray immunity genes have undergone evolutionary adaptation that may be tied to these novel immune system abilities. Two shark immune genes, legumain and Bag1, stand out. Both of these genes have counterparts in humans, where their overexpression is known to be associated with a range of cancers. The new research shows that these genes in sharks, however, have become modified through evolutionary natural selection.

A UW Carbone Cancer Center researcher studies how shark antibodies, or proteins that keep the body healthy, may be used in humans to guide imaging and treatment of metastatic cancer, indicating ongoing research into shark-derived compounds for cancer applications.

Contrary to the popular belief that sharks are exempt from the consequences of cancer, there are new documented tumors in shark species... cancer does appear in forms popularly called chondromas (cancer of the cartilage)... a great white shark found off the coast of Australia has a 1-foot by 1-foot-wide tumor. Similarly, a mass was also discovered on the head of a bronze whaler shark.

The myth that sharks do not get cancer originated from the 1992 book 'Sharks Don't Get Cancer' by William Lane and Linda Comac, which claimed sharks rarely develop cancer due to compounds in shark cartilage. This book became a commercial driver for shark cartilage supplements marketed as cancer treatments, despite the lack of scientific evidence supporting efficacy. The myth has been repeatedly debunked by peer-reviewed research since the early 2000s.

Scientists have recorded multiple different types of cancers in over 40 species of sharks and their close relatives. Cancers of the nervous system, reproductive organs, endocrine system skeleton and nervous system have been documented in over 20 different species of sharks, including reef sharks, dogfish, catsharks and tiger sharks. People began repeating this myth after a book, entitled 'Sharks Don't Get Cancer' was published in 1992.

Yes. Sharks can get cancer. While it is very tricky for scientists to figure out how often sharks get cancer, there have been multiple cases of sharks with cancer documented in the scientific literature.

At the University of Wisconsin-Madison, students and faculty are learning from sharks everyday which is leading to advancements in cancer research.