Kuo MT, et al. - This study was conducted if hepatitis B surface antigen (HBsAg) predicts HBV relapse after cessation of entecavir or tenofovir disoproxil fumarate (TDF) prophylaxis for chronic hepatitis B (CHB) cancer patients who were undergoing chemotherapy. An end-of-treatment HBsAg of 500 IU/mL was useful for predicting virologic relapse in patients with baseline HBV DNA<2000 IU/mL. Therefore, it was concluded that the baseline HBV DNA and end-of-treatment HBsAg levels could speculate virologic relapse following withdrawal of entecavir and TDF prophylaxis for chemotherapy.