INCIDENCE, PREDICTIVE FACTORS, AND OUTCOME OF LYMPHOMA TRANSFORMATIONIN FOLLICULAR LYMPHOMA PATIENTS

Purpose: To assess the incidence of lymphoma transformation in the nat ural history of follicular lymphoma (FL) patients and the factors that are predictive of this event. Patients and Methods: Two hundred twent y patients with FL treated in our institution between 1975 and 1990, w ith alpha median follow-up duration of 9 years, were included in this retrospective analysis. Results: Transformation was proven by histolog y in 34 patients or by cytology in 13 patients and was considered as h ighly probable on clinical arguments in five patients for an overall i ncidence of 24%. The probability of transformation was 22% at 5 years and 31% at 10 years and tended to plateau after 6 years. Predictive fa ctors for transformation were nonachievement of complete remission (CR ) after initial therapy (P < 10(-4)), low serum albumin level (< 35 g/ L) (P = .001), and beta(2)-microglobulin level greater than 3 mg/L (P = .02) at diagnosis. In a multiparametric analysis, only beta(2)-micro globulin level retained prognostic significance for freedom-from-trans formation (FFT) survival (P = .04). Transformation accounted for 44% o f deaths and was associated with a poor outcome, with alpha median sur vival time of 7 months. Conclusion: Transformation is on early event i n the course of the disease and is mainly observed in patients with kn own adverse prognostic factors or those who do not achieve CR after in itial treatment. These findings may be useful to select follicular lym phoma patients for intensive therapeutic approaches. (C) 1997 by Ameri can Society of Clinical Oncology.