Chemotherapy of non-Hodgkin's lymphoma: 10 years' experience in the Southwest Oncology Group.

The Southwest Oncology Group (SWOG) has completed five studies of high-dose intermittent combination chemotherapy for the management of advanced (stage III and IV) non-Hodgkin's lymphoma involving 1143 patients from May 1966 to September 1974. Lack of uniform histopathologic interpretation precludes precise analysis of these data. Although there has been little change in complete response duration over the years of this study, there has been an overall improvement in response rate and survival though there is no statistically significant improvement in the best overall survival when compared to the Stanford experience in stage III and IV disease (1960-71). The response rate and survival in diffuse histiocytic lymphoma have improved since the first study. There is definite evidence of a plateau in the survival curve beyond 2 years. The percentage of survival at which the plateau appears has increased over the years to 40% in the most recent studies, and the survival is suggestively better than the Stanford experience (P = 0.09). Over the years there has been a distinct improvement in response rate and survival of patients with nodular lymphocytic lymphoma, although the best SWOG survival is no different than the Stanford experience (P = 0.36).