Stage-modified international prognostic index effectively predicts clinical outcome of localized primary gastric diffuse large B-cell lymphoma

Background: The definition of prognostic parameters in early stages of gastric lymphoma is still controversial. The aim of this retrospective analysis was to assess the value of the stage-modified international prognostic index (IPI) in predicting the outcome of a large, consecutive series of patients with PGL of diffuse large B-cell histology (DLCL). Patients and methods: Three hundred twelve consecutive, newly-diagnosed, patients with localized PGL (stages I-IIE according to the 'Lugano staging system for GI lymphomas') referred from April 1972 to December 1997 to eight Italian and one Swiss centers were reviewed and their outcomes updated to June 1998. One hundred three patients were treated with single-modality therapy, while two hundred four received combined-modality treatment, most of which included surgery and short-term chemotherapy. Results: After a median follow-up of 66 months (range 0.6-300 months), 195 (64%) were alive in first continuous complete remission (CCR). The five-year estimates of overall survival (OS) and event-free survival (EFS) were 75% and 67%, respectively. OS and EFS varied according to IPI, from, respectively, 90% and 82% for patients with 0-1 risk factors, to 40% and 35% for patients with greater than or equal to 3 risk factors (P = 0.00001). Cox regression analysis showed that IPI was the strongest predictor of survival. Conclusions: This study shows that stage-modified IPI is an effective predictive model in patients with primary DLCL of the stomach, enabling identification of patients with significantly different outcomes.