Purpose: To identify the prognostic factors that influence overall survival (OS) in patients with stage III-IV follicular lymphomas and evaluate the clinical usefulness and the prognostic value of the International Prognostic Index (IPI).
Patients and methods: Four hundred eighty-four patients with Ann Arbor stage III-IV follicular lymphomas treated in two phase III trials from 1986 to 1995 were screened for this study. All histologic slides were reviewed by two hematopathologists. The influence of the initial parameters on survival was defined by univariate (log-rank test) and multivariate (Cox model) analyses.
Results: The poor prognostic factors for OS (age > 60 years, "B" symptom(s), > or = two extranodal sites, stage IV disease, tumor bulk > 7 cm, at least three nodal sites > 3 cm, liver involvement, serous effusion-compression or orbital/epidural involvement, and erythrocyte sedimentation rate > 30 mm/h) that were significant in univariate analysis were subjected to multivariate analysis. Three factors remained significant: B symptom(s) (risk ratio = 1.80), age greater than 60 years (risk ratio = 1.60), and at least three nodal sites greater than 3 cm (risk ratio = 1.71). When the IPI was applied to these patients, the score was 1, 2, 3, and 4-5 in 49%, 39%, 11%, and 2%, respectively, and it was significant for progression-free survival (P =.002) and OS (P =.0001).
Conclusion: Three prognostic factors for poor OS were identified: B symptoms, age greater than 60 years, and at least three nodal sites greater than 3 cm. The IPI was prognostic for OS, but in this population, a very low number of patients belonged to the high-risk groups.