Department of Clinical Oncology, Sir Y.K. Pao Centre for Cancer, Faculty of Medicine, Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong.
Reactivation of hepatitis B virus infection is a known complication during and after anti-cancer therapy. This condition can affect two patient populations: it is most commonly seen in patients who are seropositive for hepatitis B surface antigen (HBsAg), but it is also being increasingly reported among patients who are HBsAg-negative but who have prior infection, as evident by seropositive status for anti-body to hepatitis B core antigen (anti-HBc), irrespective of their anti-HBs (anti-body to HBsAg) status. The clinical course can vary from asymptomatic hepatitis to fulminant hepatic failure that can be potentially fatal. With the increasing use of biological agents in addition to potent cytotoxic chemotherapy in the armamentarium of anti-cancer treatments, reactivation of hepatitis B has become a common clinical situation that is faced by both oncologists and hepatologists especially in HBV endemic areas. In this review, we discuss the clinical course of reactivation in the two HBV-infected sub-populations, and the role of anti-virals in the prevention and management of HBV reactivation in association with cytotoxic chemotherapy and biological therapies.