Can a virus cause cancer in humans?
In a word, yes. In fact, at this point multiple viruses have been identified as playing a role in the progression of many different cancers. The very first of these cancer-causing viruses was discovered by Peyton Rous in 1911, making the field of tumor virology over one century old. While this initial discovery was a virus that causes tumors in chickens, many important human cancers have since been discovered to have a viral component. The first human tumor virus to be discovered was Epstein-Barr virus (EBV) in association with Burkitt’s lymphoma in 1965. Since then many more viruses have been found to be tumorigenic in humans and more may still be awaiting to be discovered.
How is it that these many different viruses are involved in so many different types of cancers? What about these viruses makes them tumorigenic?