Prognosis of follicular lymphoma: a predictive model based on a retrospective analysis of 987 cases

Patients (n-987) with a histologically confirmed diagnosis of follicular ly mphoma were studied with the aim of developing a prognostic model specifica lly devised for this type of lymphoma. We collected information on age, sex , Ann Arbor stage, number of extranodal disease sites, bone marrow (BM) inv olvement, bulky disease, B symptom criteria (fever, night sweats, and weigh t loss), performance status (PS), serum lactate dehydrogenase (LDH) level, serum albumin level, hemoglobin level, and erythrocyte sedimentation rate ( ESR). In the training sample of 429 patients with complete data, multivaria te analysis showed that age, sex, number of extranodal sites, B symptoms, s erum LDH level, and ESR were factors predictive for overall survival. Using these 6 variables, a prognostic model was devised to identify 3 groups at different risk. The 5- and 10-year survival rate was 90% and 65% for patien ts at low risk, respectively; 75% and 54% for patients at intermediate risk ; and 38% and 11% for those at high risk (log-rank test, 86.62; P < .0001). The model was also predictive (P = .0001) in the validation sample of 265 patients with complete data only for the 6 variables used in the developmen t of the model and even in the group of 210 patients from the validation sa mple uniformly treated with doxorubicin-containing regimens (P = .0001). Th e prognostic model appears to be very useful in identifying patients with f ollicular lymphoma at low, intermediate, or high risk. (C) 2000 by The American Society of Hematology.