Is cancer a pathogen

Answer 1

Cancer itself is not a pathogen, i.e. it is not an infectious agent communicated from one living being to another. It is a condition, the condition of unregulated cell growth.

Cancer is, of course, not a single disease and there are hundreds of diseases which are deemed to be a type of cancer. Of those many forms of cancer, there are some which are known to be linked to particular pathogens, i.e. some kind of infection agent, such as a virus (e.g. Human papillomavirus or HPV linked to Cervical cancer), bacteria (e.g. Streptococcus bovis (S. bovis) colorectal cancer) or even mold (e.g. Aspergillus flavus and A. parasiticus are known to cause liver cancer) , is known to be the "cause" of the cancer. It is highly uncertain, but (see link below) it has been estimated that around 20% of cancers are connected to, if not caused by, a pathogen.