Preventing chemotherapy-induced hepatitis B reactivation in breast cancer patients: a prospective comparison of prophylactic versus deferred preemptive lamivudine

Prophylactic lamivudine to prevent chemotherapy-induced hepatitis B virus (HBV) reactivation has been widely adopted in hematological cancer patients. We examined the deferred preemptive strategy, upon rising viremia, in breast cancer (BC) patients based on sensitive serum HBV DNA level monitoring in a non-randomized controlled study. Baseline virological profiles before cytotoxic chemotherapy were retrospectively analyzed in historical BC and non-BC patients. A prospective cohort study, including 22 early BC patients (Group I) who were hepatitis B surface antigen (HBsAg)+/- and required adjuvant chemotherapy, were enrolled and had deferred preemptive use of lamivudine upon viremic surge. During the study period, another 23 BC patients, who did not participate in the abovementioned study, received prophylactic use of lamivudine as routine practice (Group 2). Chemotherapy-induced hepatitis events and the lamivudine treatment course were compared. There was no significant difference in the incidence of hepatitis during chemotherapy between these two groups. Patients in Group I had statistically significant shorter duration of lamivudine use during chemotherapy. However, once lamivudine had been initiated, the treatment course is not significantly shorter than those patients given prophylactically. Deferred preemptive strategy is feasible to control HBV replication and prevent its reactivation in BC patients undergoing chemotherapy. However, it may not be superior to prophylactic strategy and clinically practical.