CHEMOTHERAPY - THE MORE, THE BETTER IN MALIGNANT-LYMPHOMA

Several clinical trials have demonstrated that high-dose chemotherapy (HDC) with autologous hematopoietic stem-cell transplantation is more effective than conventional-dose chemotherapy in some subsets of patie nts with malignant lymphoma, such as relapsed aggressive lymphoma pati ents showing a response to salvage chemotherapy and those with Hodgkin 's disease who fail primary initial chemotherapy. This paper summarize s recent findings and the following issues remaining to be resolved: ( 1) whether HDC is superior to conventional-dose chemotherapy as initia l therapy for aggressive lymphoma in unfavorable risk groups, (2) whet her single HDC or multiple semi-HDC is better, (3) whether HDC has cur ative potential in indolent lymphoma or mantle-cell lymphoma, and (4) the HDC regimen that is most useful. To clarify these controversial is sues, well-designed clinical trials are needed. To evaluate whether th e concept ''the more chemotherapy, the better in malignant lymphoma'' is valid, the Lymphoma Study Group of the Japan Clinical Oncology Grou p is conducting two kinds of clinical trials in high-and high-intermed iate-risk aggressive lymphoma patients, focusing on the dose intensity of key agents. One is a randomized phase II trial of dose-escalated c yclophosphamide, doxorubicin, vincristine, and prednisolone (high CHOP ) versus shortened CHOP (biweekly CHOP) with prophylactic use of granu locyte colony-stimulating factor. The other is a phase II trial of HDC with peripheral blood stem-cell transplantation as a part of the init ial therapy. If promising results are obtained from these trials a ran domized phase III trial will be considered to compare the best dose-in tensive regimen with standard CHOP.