At the time when viruses lead to an infection,they spread their
DNA( Deoxyribonucleic acid),influencing the healthy cell's genetic
composition and likely leading them to change into cancer.
The HPV infections, lead the virus DNA to merge with host's
DNA,damaging the standard activity of cells.
The HIV virus and Hepatitis C virus might enhance a
individual's risk of forming cancer by attacking the body's immune
system.
Mostly in every cases,particular viruses only attack particular
cells in the human body,like the common cold viruses which effect
the throat and nose lining.That is why some viruses are only
associated with particular types of cancer.