 If third-line chemotherapy is needed, the use of lamivudine will be at the 2.2 Arm II Patients are treated with CHOP alone. If the patients develop clinical hepatitis, as defined in section 7.2, lamivudine 100 mg, P.O., qd., will be given, and continued until hepatitis is resolved. Prophylactic lamivudine is not to be given in subsequent chemotherapy. Our previous study has indicated that nearly all clinical hepatitis developed in HBV carriers during systemic chemotherapy is caused by HBV reactivation. Therefore, for practical reason, the investigators are not advised to wait for the results of HBV DNA serology examination before starting lamivudine treatment. 