Combined modality therapy in malignant lymphomas

The treatment of patients with non-Hodgkin's lymphomas remains controversial. The Rappaport classification system has established its clinical value in distinguishing relatively favorable disease (ie, nodular or follicular lymphoma) from relatively unfavorable disease (ie, diffuse lymphoma). Despite the problems of multiple histologies in a given patient posed by the existence of composite lymphomas and by a spectrum of nodularity in a given node, no newer classification has yet proved superior to the Rappaport system. The relative roles of radiotherapy and chemotherapy are reviewed. The primary role of radiation appears to be the control of detectable disease, when adequate doses and volumes are employed. The primary role of chemotherapy appears to be the eradication of microfoci of tumor. Randomized studies of combined modality approaches have produced no definitive evidence of benefit from adjuvant chemotherapy in stage I and II disease of unfavorable histology. The addition of adjuvant radiotherapy in stage III and IV disease of unfavorable histologic types appears to produce some improvement. Aggressive treatment regimes have yet to show any significant advantage over more conservative treatment in patients with favorable histologic types of stage IV extent. This paper emphasizes the need for expert hematopathologic interpretation in every study of non-Hodgkin's lymphoma.