Cancer is already scary. Cancer that can be passed from one person to another, like a virus, is exponentially more frightening. But a cancer that can be passed from one species to a completely different one is just unimaginably horrific. And it’s now proven that such a cancer exists.
A research team from Columbia University Medical Centre has discovered a type of cancer that is not only contagious, but can spread from one animal species to another.
And the scientists believe this is a widespread occurrence.
Although we previously discovered cancers that spread between animals of the same species, we didn’t know of any that jumped species.
Ultimately, this hikes up the list of cancers identified to be contagious. Two types of transmissible cancers are known to spread in Tasmanian devils and another type spreads in dogs. Recent studies have found an additional five more types infecting four species of mollusks and their close relatives.
The newly discovered contagious cancer is spreading between different species of bivalves. Mussels gathered near Canada were found to be affected by the same leukemia-like cancer as the one afflicting cockles and golden carpet shell clams from the coast of Spain. Research leader Stephen Goff and his team have found incriminating evidence that the same cancer is responsible for infecting different species living in these underwater colonies.
“The tumour cells didn’t have the same DNA as their host. Instead, every mussel was being killed by the same line of cancerous cells, which were jumping from one individual to the next like a virus,” as Washington Post reporter Sarah Kaplan outlines.
Genetic analysis of the tumors show that they did not originate from the existing host and that they came from outside sources.
Researchers believe that the sick bivalves may be releasing cancerous cells when they die. It wouldn’t take long before another bivalve picks up the cells passively, becoming a new host itself. And since mussels, cockles, and clams are passive filter feeders, their immune systems are underdeveloped and ill-equipped to fend off the infection.
Although interspecies transmission is a nightmare, it does not jump too between species that are too far apart. It needs species that are closely related, making us, human, safe.