Event free survival at 24 months is a strong surrogate prognostic endpoint of peripheral T cell lymphoma.

Event free survival at 24 months (EFS24) has been described as a powerful predictor for outcome in several subtypes of B cell lymphoma. However, it was limitedly described in T cell lymphoma. We explored the implication of EFS24 as a predictor marker for peripheral T cell lymphoma (PTCL). We reviewed 293 systemic PTCL patients at 13 nationwide major university hospitals in Thailand from 2007 to 2014. The median event free survival (EFS) and overall survival (OS) of PTCL patients in our cohort was 16.3 and 27.7 months with corresponding 2-year EFS and 2-year OS of 45.8% and 51.9%, respectively. A total of 118 patients achieved EFS24 (no events during the first 24 mo). Patients who achieved EFS24 had better OS than patients who did not (2-y OS 92% vs 18.8%; HR, 0.1; P < .001). The standardized mortality ratio of patients achieving EFS24 was 18.7 (95% CI, 14.6-22.8). Multivariable analysis demonstrated performance status, histologic subtype, remission status, and EFS24 achievement as independent predictors for OS. Our study affirmed the value of EFS24 as a powerful prognostic factor for PTCL. Further validation in prospective study setting is warranted.