Transmissible Cancer Found in Lake Champlain Catfish

Researchers identified the first known transmissible cancer in fish, affecting a population of brown bullhead catfish (Ameiurus nebulosus) in Lake Champlain, a body of water spanning Vermont and Quebec. This discovery, detailed in a study published in the journal Nature, marks a significant finding in cancer research, as transmissible cancers are exceedingly rare, with only a handful of known instances across all species, primarily in Tasmanian devils and certain bivalves.

The cancer, a type of leukemia, appears to spread between individual fish through direct contact or the transfer of cancerous cells. Scientists observed that the tumors were not caused by a virus or environmental carcinogen but rather by the cancer cells themselves acting as an infectious agent. This phenomenon is similar to clonal transmissible cancers found in other species, where the cancer cells are essentially an allograft that the host's immune system fails to reject.

Studying this transmissible cancer in catfish provides a unique opportunity to understand the mechanisms of metastasis and immune evasion. The researchers aim to investigate how the cancer cells survive and proliferate within different hosts and how they manage to avoid detection by the immune system. This could offer novel insights into cancer progression and potential therapeutic targets applicable to human cancers.

The affected catfish population resides in the Missisquoi Bay area of Lake Champlain. The research team, led by scientists from the University of Vermont and the University of New Mexico, has been monitoring the lake for over a decade. Their findings highlight the ecological and biological significance of this specific aquatic environment and raise questions about the broader implications of such transmissible diseases in wildlife populations.