Validation of the Nccn-Ipi for Diffuse Large B-Cell Lymphoma in Latin American Patients: A Study from the Latin-American Group of Lymphomas (GELL)

Introduction: Diffuse large B-cell lymphoma (DLBCL) is the most frequent subtype of lymphoma in the world and corresponds to a heterogeneous entity, both from the clinical and molecular point of view, being its prognosis of survival very variable The IPI and the NCCN-IPI are powerful risk-stratification tools in patients with DLBCL. Although the IPI risk score is widely used, it doesn't discriminate very high risk patients. In 2014 the NCCN-IPI was published. It has shown a better discrimination of these patients in Asia, Europe and USA. GELL is a recently formed group of study in lymphomas from Latin America that includes eleven countries. The aim of this study was to validate whether the NCCN-IPI is of prognostic value in Latin-American patients with DLBCL. Methods: We included patients with a diagnosis of DLBCL treated at different institution between 2012-2013. IRB approval was obtained before the collection of the data. Pathological samples were reviewed at each participating institution to confirm the diagnosis. Pertinent clinical data were collected through chart review and are presented using descriptive statistics. Survival curves were estimated using the Kaplan-Meier method and compared using the log-rank test. Univariate and multivariate Cox proportional-hazard regression models were fitted to evaluate hazard ratio (HR) for overall survival (OS). Results: A total of 329 patients with the diagnosis of DLBCL were included in this analysis. The median age at diagnosis was 64 years (range 18-83 years) with a slight female predominance (54%). Clinically, 59% of patients were 60 or older, 34% presented with ECOG >1, 29% with elevated serum LDH, and 70% with extranodal disease; 49% had stage I/II and 51% had stage III/IV. The IPI score distribution was low-risk in 36% of patients, low-intermediate in 25%, high-intermediate in 22% and high-risk 17%. The NCCN-IPI score distribution was low risk in 17%, low-intermediate in 42%, high intermediate in 30% and high risk in 11%. 89% of patients received standard R-CHOP, 2% received R-miniCHOP, and 9% received other regimens. The overall response rate was 83%; 69% had complete response and 14% had partial response. The 5-year overall survival (OS) rate was 65%. DLBCL patients with low, low-intermediate, high-intermediate and high risk NCCN-IPI had 5-year OS rates of 89%, 71%, 55% and 38%, respectively (p