Abstract
Prognostic factors for long‐term survival of 312 patients with diffuse large cell or immunoblastic non‐Hodgkin's lymphoma are presented based on analysis of the multi‐institution clinicopathologic study sponsored by the National Cancer Institute. At the time of analysis, 75% of the patients had died and the median follow‐up for patients still alive was 11 years. The distribution of Ann Arbor stages was 21% stage 1, 32% stage 11, 17% stage III, and 30% stage IV. Factors of prognostic significance for survival included age, stage, histologic subtype, presence of B symptoms, size of the largest lesion, number of extra‐lymphoid organs involved, and extent of lymphatic involvement. Recursive partitioning analysis suggested a prognostic classification system based on stage, age, size of the largest lesion, and presence of mediastinal involvement. Stage I patient <50 years of age had a 10 year survival rate of 65% compared to 36% for older stage I patients. Stage II patients <65 years old without bulky lesions or mediastinal involvement had a 10 year survival rate of 45% compared to 10% for the poorer risk stage II patients. Although statistically significant prognostic factors were identified for the stage III/IV patients, they were not strong discriminants of 5–10 year survival rate. Because of the correlation among potential prognostic factors, there is no uniquely best classification system. Reasons for discrepancies among reported prognostic factor analyses are discussed, and a prognostic grouping that synthesizes our results with those of others is proposed.