Hepatitis B and cancer: A practical guide for the oncologist.

Hepatitis B virus (HBV) infection is a worldwide disease associated with significant morbidity and mortality and after acute infection, HBV infection can persist in about 1-2% of immunocompetent hosts. Chemotherapy-induced immunosuppression can lead to HBV reactivation and may cause discontinuation of anticancer treatment, fulminant hepatitis with liver failure and death. During immunosuppressive treatments such as chemotherapy, reactivation of HBV infection is a life-threatening complication that can occur in HBV active or inactive carriers but also in patients with OBI. Occult HBV infection (OBI) is defined as the presence of detectable very low levels of HBV DNA in HBsAg-negative patients. Many literature data showed a benefit from prophylactic antiviral treatment in cancer patients at risk for HBV reactivation, however there is no evidence in determining the benefit of routine screening for chronic HBV infection in all patients undergoing cytotoxic and immunosuppressive chemotherapy. Major guidelines recommend HBV screening in HBV-infection high risk patients or if the immunosuppression caused by the treatment is expected to be high.