Is the International Prognostic Index for aggressive lymphomas useful for low-grade lymphoma patients? Applicability to stage III-IV patients

Background The International Prognostic Index (IPI) is widely used to predict outcome of patients with aggressive lymphomas. Our goal was to assess the prognostic value of this index for low-grade lymphoma. Patients and methods: One hundred eighty-two patients with disseminated (stage III or IV) low-grade lymphoma were enrolled in a prospective multicenter trial. According to the initial features, treatment either was started immediately or was deferred until indicated by disease progression. Patients received the same polychemotherapy regimen, given monthly for six cycles. They were assigned to one of four risk groups according to the number of presenting risk factors: low-risk (0 or 1), low-intermediate-risk (2), high-intermediate-risk (3), high-risk groups (4). Results: Survival curves (Kaplan-Meier method) demonstrated a high significant difference for the four groups (log-rank: P < 0.0001). Median survival for the low-risk group has yet to be reached, while that for the three other groups are, respectively, 65, 34, and 12 months. Conclusions: In this study, the IPI has been found to be an important prognostic tool in low-grade lymphoma and may be used in the selection of appropriate therapeutic approaches for individual patients.