The rates were significantly lower for the entecavir group vs the lamivudine group for HBV-related hepatitis ( 0 % vs 13.3 % , respectively ; difference between groups , 13.3 % [ 95 % CI , 4.7 % to 21.9 % ] ; P = .003 ) , HBV reactivation ( 6.6 % vs 30 % ; difference , 23.4 % [ 95 % CI , 10.2 % to 36.6 % ] ; P = .001 ) , and chemotherapy disruption ( 1.6 % vs 18.3 % ; difference , 16.7 % [ 95 % CI , 6.4 % to 27.0 % ] ; P = .002 ) .