[Hematological neoplasm--how to treat low-grade lymphomas]

Low-grade lymphomas are rare in Japan, comprising about 10% of non-Hodgkin's lymphomas. They are indolent in natural history with median survival of 7-10 years. Despite a good initial response to radiotherapy or chemotherapy, most patients (Pts), being incurable, ultimately die of their disease. Pts with clinical stage (CS) I/II disease are generally treated with locoreginal radiotherapy. Long-term survival of 60% to 70% and disease-free survival (DFS) of 50% to 55% have been reported. The more precise the staging procedures, the better the results. Chemotherapy used as a primary therapy or as an adjuvant to radiotherapy may improve DFS of pts with CS II with many sites of lymph node involvement or bulky disease. For CS III/IV disease there is no accepted standard therapy. There is no survival advantage for any of the different first-line treatment methods ranging from initial deferral of treatment albeit in highly selected pts, an alkylating agent +/- steroid hormone, to combination chemotherapy (C-MOPP, CHOP, ProMace-MOPP etc) +/- irradiation. The international index for prognostication of aggressive lymphoma has also been shown to be applicable to stratification of low-grade lymphomas. In future studies effectiveness of treatment strategies should be investigated with long-term DFS and improved quality of life being set as primary endpoints.