Hepatitis B virus reactivation in breast cancer patients undergoing cytotoxic chemotherapy and the role of preemptive lamivudine administration

Background: Recent data suggest that hepatitis B virus (HBV) reactivation develops in 41% of breast cancer (BC) patients carrying HBV after chemotherapy. Our study aimed to determine the role of preemptive use of lamivudine in BC patients undergoing chemotherapy. Patients and methods: The test group consisted of 11 female patients with BC who were seropositive for hepatitis B surface antigen (HBsAg). Of these, 10 patients were treated in an adjuvant setting and one for metastatic disease. Lamivudine was given from the start of chemotherapy and was maintained until 1 month after the last infusion of chemotherapy. The control group consisted of nine historical BC patients carrying HBV and received similar systemic chemotherapy without preemptive lamivudine. Variables including HBsAg, HBV envelope antigen, anti-HBV envelope antibody, serial serum alanine transaminase (ALT), quantitative HBV viral DNA analysis, and HBV-DNA precore promoter and precore sequence were monitored. Test for emergence of mutant strains, notably nucleotide 550, was performed 6 months after the completion of chemotherapy. Results: All patients tolerated lamivudine well without development of evident HBV reactivation or overt hepatitis. Serum ALT remained unchanged without rebound hepatitis after cessation of chemotherapy and withdrawal of lamivudine. No emergence of lamivudine-selective resistant strain (so-called tyrosine-methionine-aspartate-aspartate mutations) was observed. Conclusions: Our results encourage preemptive use of lamivudine for prevention of HBV reactivation in patients who need short-term chemotherapy.