Role of hepatitis B surface antigen in hepatitis B virus relapse after entecavir or tenofovir prophylaxis in patients undergoing cancer chemotherapy.

Abstract

This study investigated whether hepatitis B surface antigen (HBsAg) could predict hepatitis B virus (HBV) relapse after cessation of entecavir or tenofovir disoproxil fumarate (TDF) prophylaxis for chronic hepatitis B cancer patients who are undergoing chemotherapy. The study enrolled 122 hepatitis B e-antigen-negative cancer patients who underwent chemotherapy with entecavir or TDF for antiviral prophylaxis and posttreatment follow-up for at least 6months. Of the 122 patients, 52 and 18 experienced virological and clinical relapse, which had 3-year cumulative incidences of 46.6% and 18.6%, respectively. Multivariate analysis showed that end-of-treatment HBsAg levels and baseline HBV-DNA≥2000IU/mL were independent predictors of virological relapse. The best HBsAg cutoff value was 500IU/mL. An end-of-treatment HBsAg of 500IU/mL was useful for predicting virological relapse in patients with baseline HBV-DNA<2000IU/mL (3-year rate: 21.3% vs 46.4%, P=0.038, in patients with HBsAg <500 and ≥500IU/mL, respectively), but not in patients with baseline HBV-DNA≥2000IU/mL. Of the 52 patients who experienced virological relapse, 13 experienced transient virological relapse. Patients with baseline HBV-DNA level<2000IU/mL experienced a higher rate of transient virological relapse (42.1% vs 15.2%, P=0.031). Three patients experienced hepatic decompensation upon alanine aminotransferase flares, and no patient died after timely retreatment. Ten patients experienced posttreatment HBsAg loss, and the 3-year HBsAg loss rate was 30.7% in patients with end-of-treatment HBsAg<100IU/mL. The baseline HBV-DNA and end-of-treatment HBsAg levels could predict virological relapse after withdrawal of entecavir and TDF prophylaxis for chemotherapy.