Chronic infections and infestations represent major causes of
cancer. Overall, Helicobacter pylori, HPV, HBV, and HCV are estimated to account for 15% of all human
cancers. We have estimated that
cancers associated with 6 pathogens in Italy account for 31,000 yearly cases, 42.0%of which is attributable to H. pylori, 34.7%to HBV and HCV, 19.8%to HPV, 2.9%to KSHV, and 0.2% to EBV. These figures represent 8.5% of all incident cases of
cancer in Italy. The implementation of anti-HBV vaccination programs in countries with high endemicity resulted in a significant impact on the incidence of
hepatocellular carcinoma, and the availability of
antiviral drugs is a real opportunity to drastically reduce the cases attributable to HCV. Primary prevention of
cervical cancer mainly involves HPV vaccination; two
vaccines (bivalent and quadrivalent) are available and a new
vaccine (9-valent) has recently been approved by the FDA.
Secondary prevention is based on screening programs that include Pap smear cytology and/or HPV test. To reduce the burden of HIV-associated
cancers, prevention programs include primary prevention of
HIV infection, early diagnosis and treatment, restoration of immune function, reduction in the prevalence of associated
infections and risk factors, and
secondary prevention. To date, anti-HBV and anti-HPV vaccinations, eradication of H. pylori
infection, treatment of HCV and HIV carriers with
antivirals, and HPV-related
cancer screening prove to be the most effective strategies for the prevention of
infection-associated
cancers.