Comprehensive Outcomes of On- and Off-Antiviral Prophylaxis in Hepatitis B Patients Undergoing Cancer Chemotherapy: A Competing Risks Analysis

Although antiviral prophylaxis is essential in hepatitis B patients in the context of cancer chemotherapy, there is little evidence-based consensus regarding the appropriate prevention strategy depending on the underlying type of cancer and viral status. This retrospective study included a comprehensive cohort of 302 hepatitis B surface antigen-positive patients with various cancers undergoing chemotherapy and antiviral prophylaxis. The rates of hepatitis B virus (HBV) reactivation during antiviral therapy (>1 log(10)IU/mL increase or positive conversion of serum HBV DNA) and relapse when off antivirals ([re] appearance of HBV DNA>2,000 IU/ml with related alanine aminotransferase elevation) were evaluated, together with the associated risk factors, in a competing risks analysis where cancer death was considered as the competing event. During antiviral prophylaxis, HBV was reactivated in six patients (1.9%), who had leukemia (n = 4) or lymphoma (n = 2) and were treated with lamivudine (n = 4) or entecavir (n = 2). The incidence rate of HBV relapse in 127 off-prophylaxis patients was 21.3% during a median post-antiviral period of 11.7 months. Lymphoma, pre-prophylactic HBV DNA >= 2,000 IU/ml, and age >= 50 years were independent predictors of off-treatment HBV relapse (adjusted hazard ratios 5.25, 3.07, and 0.34, respectively; Ps<0.05). Antiviral and anticancer drugs, duration of consolidation on antiviral prophylaxis, and HBeAg positivity were not independent predictors. In conclusion, hepatitis B flare-ups are not rare in patients receiving cancer chemotherapy during and after anti-HBV prophylaxis, even when potent antivirals are used. Patients with hematopoietic or lymphoid neoplasms or high viral burdens should receive prolonged and powerful HBV prophylaxis. (C) 2016 Wiley Periodicals, Inc.