Strategies to reduce the risk of virus-related cancers

Experimental and epidemiological evidence has established an association between at least eight viruses and various cancer sites. Recent estimates (at least 10% of cancer worldwide) have revealed that viruses, together with tobacco and diet, account for the largest proportion of cancer in the world.

Improvements in the detection of viruses and biomarkers of chronic infection have led to the identification of strong associations with cancer, particularly for human papillomavirus (HPV), hepatitis B virus (HBV), and human immunodeficiency virus (HIV). For some cancer viruses (e.g., HIV and hepatitis C virus, HCV), the spectrum of malignancies involved has still to be well defined. For HBV and HPV, vaccination aimed at cancer prevention is already a reality or a possibility. Whereas HBV vaccination already emerged as one of the most cost-effective ways to reduce adult cancer mortality, for HPV vaccination some technical problems still await a solution. For other infectious agents (e.g., HCV, HIV) prospects for a vaccine are not immediate.

In order to apply new knowledge on viruses to cancer prevention, large vaccination trials are warranted. These will have to be large (many thousands of people), prolonged (5-10 years), and match scientific excellence with a feasible design. Mistrust between scientists and the public will have to be prevented by means of absolute openness in scientific information and economical interests involved.