Abstract of the chapter

Oncogenic virus and evolution

Catarina Reis Vieira

Cancer is one of the deadliest diseases with a high incidence rate in the world, given that it can manifest itself in a number of different ways and gain resistance to the majority of treatments currently available. Despite being well know to the general public, the mechanisms involved in the origin of a cancer are still object of study and debate in the scientific community. One of the proposed hypothesis is that cancer might have arisen as a side-effect of the evolution of viruses, to which an out-of-control cellular growth is clearly advantageous. In fact, recent data indicates that around 15-20% of human cancers are derived from viral infections, either by integration of viral oncogenes, or disruption in the expression of a tumour suppressor gene in the infected cell, among other mechanisms. Despite generally being perceived as a result of environmental and/or genetic factors, it’s important to recognize the impact viral infections can also have in the generation of cancers that afflict the human population.