This topic deals specifically with viruses of any kind that cause cancer of any kind. There are many viruses that cause cancer, including the following: Rous sarcoma virus (1) is a retrovirus and is the second oncovirus to have been described. It causes sarcoma in chickens; Human Papilloma Viruses (HPV) (2) which cause virtually all cervical cancers, with just two HPV types, 16 and 18, responsible for about 70 percent of all cases.
References:
1. Wikipedia: http://en.wikipedia.org/wiki/Rous_sarcoma_virus
1. National Cancer Institute: http://www.cancer.gov/cancertopics/causes-prevention/risk/infectious-agents/hpv-fact-sheet