TWENTY-FOURTH ANNUAL EASTERN FISH HEALTH WORKSHOP Royal Pavilion Resort, Atlantic Beach, NC MARCH 9-11, 1999 Elasmobranch Neoplasms John C. Harshbarger1 and Gary K. Ostrander2 1Registry of Tumors in Lower Animals, Department of Pathology, George Washington University Medical Center, Washington, DC 20037;2Zanvyl Krieger School of Arts and Sciences, Johns Hopkins University, Baltimore, MD 21218 Shark cartilage extract and shark embryo extracts are widely available for treatment of cancer, arthritis and aging based on claims that sharks do not get cancer. In fact, 35 cases of elasmobranch neoplasms are in the Registry of Tumors in Lower Animals and/or have been reported in the literature. These cases represent 19 species in 4 orders. Tumors originate from 15 cell types representing all organ systems except respiratory. Types of tumors include squamous carcinoma, fibroma, fibrosarcoma, myxofibrosarcoma, melanoma, hepatocellular adenoma, renal adenocarcinoma, olfactory neuroepithelioma, choroid plexus papilloma and lymphoma. Ironically, they include three chondromas contradictory to the popular misconception that shark cartilage contains an anti-carcinogenic substance. Cartilaginous fish more primitive than elasmobranchs also get neoplasms. This includes a metastatic melanoma in a lamprey and epizootic hepatocellular carcinoma in hagfish. In the other phylogenetic direction, neoplasms are well known in primitive Osteichthyes including lungfish, paddlefish, sturgeon, gar and bowfin. For example, paddlefish from the Detroit River have epizootic hepatocellular carcinoma. Not only is it untrue that sharks do not get cancer, a just reported clinical study concluded that shark cartilage was inactive in patients with advanced cancer and had no salutary effect on quality of life (Miller et al. J. Clin. Oncol. 16: 3649-3655, 1998). In conclusion, sharks are being destroyed needlessly to exploit desperate people based on bogus information. The Registry of Tumors in Lower Animals is supported by NCI Contract No. NO1-CP-77021. Return to 24th Annual Eastern Fish Health Workshop Return to Leetown Science Center Home Page