Hepatitis B in immunosuppressed cancer patients: pathogenesis, incidence and prophylaxis.

Hepatitis B virus (HBV) reactivation in immunosuppressed cancer patients is a serious clinical problem for HBV carriers undergoing chemotherapy, because it may result in severe liver injury and prevent completion of life-saving treatment of the underlying malignant disease.We reviewed the literature on the incidence, pathogenesis and management of hepatitis B in immunosuppressed cancer patients. The role of primary prophylaxis has also been reviewed.Patients with a previous HBV infection (negative for hepatitis B surface antigen [HBsAg], and positive for both hepatitis B core antibody [anti-HBc] and/or hepatitis B surface antibody [HBsAb]) can experience HBV reactivation. All guidelines support screening of patients with cancer who are about to undergo potentially immunosuppressive therapy, even if the ASCO provisional clinical opinion considers the screening for patients at heightened risk for chronic HBV infection or if undergoing highly immunosuppressive therapy, as hematopoietic cell transplantation and regimens including rituximab. Several meta-analyses support the prophylactic role of lamivudine in preventing HBV reactivation. Most of studies evaluated retrospectively or, if prospectively designed, compared the effect of prophylactic antiviral therapy against historical controls.Screening for HBV should be considered before chemotherapy. Prophylaxis with lamivudine can reduce the incidence of HBV reactivation as well as HBV-related morbidity and mortality. Unsolved issues include the role of antiviral agent with higher potency and less resistance, how to monitor patients for reactivation and when to stop prophylaxis.