In light of the recent problem set question on viruses that have oncogenic potential, an article published 2 days ago in the New York Times talks about a major cause of liver cancer. Viruses that cause hepatitis B (HBV of hepadnaviridae) and C (HCV of flaviviridae)can lead to chronic infections that initiate tumorigenesis.
There is a vaccine for Hepatitis B used in this country, but not used as routinely around the world. The frequency of liver cancer is rising in part due to immigration. During the 1960s and 1970s, Hepatitis C was spread among IV drug users. There is no vaccine for Hep C.
Check out the article here: