In a recent manuscript, Goff and collaborators (Metzger et al. 2016) reported data arguing for the spread of contagious cancer cells among different species of shellfish. Although horizontal transmission of cancer cells has been observed in a few cases in higher organisms, it appears to be rather frequent among molluscs. Recent evidence supports the concept of inter-species horizontal infectious transmission of cancer cells both in molluscs but also in mammals, including humans.
September 2016: Journal of Cell Communication and Signaling