Response to treatment, histologic progression, and survival of 127 patients with follicular lymphoma were analyzed according to histologic, clinical, and biological parameters. Histologic parameters were percentage of large cells (< 10%, 41 patients; 10-25%, 38 patients; 25-50%, 11 patients; greater-than-or-equal-to 50%, 30 patients), percentage of diffuse areas, presence of intrafollicular proliferation or fibrosis, and mitotic scale. Eighty percent of the patients achieved complete remission (CR) with radiotherapy for localized stages and various chemotherapy regimens for disseminted stages. Three patients did not respond to treatment, and 23 were in partial remission (PR) at the end of treatment. Median survival time was 9.25 years. A constant death rate of 8% per year was observed without plateau. Histologic progression was observed in 32 patients; it occurred at a constant rate during the first six years and plateaued thereafter. Factors associated with low response rate were stage IV, B symptoms, high tumor mass, and two or more extranodal sites. Factors associated with histologic progression were bone marrow involvement and two or more extranodal sites. Factors associated with poor survival were advanced stage, two or more extranodal sites, bone marrow involvement, high lactate dehydrogenase level, and absence of interfollicular fibrosis. The percentages of large cells and diffuse areas had no influence on prognosis, nor had the type of treatment. Median survival has not been reached for CR patients and was four years for PR patients (P < 0.0001). The LNH-84 prognostic index for aggressive lymphomas, based on tumor mass, number of extranodal sites, stage, and LDH level, is a clear-cut indicator of prognosis in follicular lymphomas too. This study shows that the prognosis of follicular lymphoma patients is related to clinical and biological parameters of a high tumor mass and to response to treatment, but not to classical histologic parameters.
