Identification of an Outbreak of Bivalve Transmissible Neoplasia in Soft-Shell Clams () in the Puget Sound Using Hemolymph and eDNA Surveys.

Bivalve transmissible neoplasia (BTN) is one of three known types of naturally transmissible cancer-cancers in which the whole cancer cells move from individual to individual, spreading through natural populations. BTN is a lethal leukemia-like cancer that has been observed throughout soft-shell clam () populations on the east coast of North America, with two distinct sublineages circulating at low enzootic levels in New England, USA, and Prince Edward Island, Canada. Major cancer outbreaks likely due to BTN (MarBTN) were reported in 1980s and the 2000s and the disease has been observed since the 1970s, but it has not been observed in populations of this clam species on the US west coast.