 - Chemotherapy not including anthracycline such as doxorubicin e.g. SMILE, VIPD The type of salvage treatment will not be a criterion for exclusion. Thus, patients who had received various kinds of salvage treatment including anthracycline-containing regimens can be included. Patients who had undergone autologous or allogeneic stem cell transplantation can also be included in the analysis if they satisfy the above-mentioned inclusion criteria. 