Evaluation of the MD Anderson tumor score for diffuse large B-cell lymphoma in the rituximab era

Abstract

Objectives: Diffuse large B-cell lymphoma (DLBCL) is an aggressive heterogeneous lymphoma with standard treatment. However, 30%-40% of patients still fail, so we should know which patients are candidates for alternative therapies. IPI is the main prognostic score but, in the rituximab era, it cannot identify a very high-risk (HR) subset. The MD Anderson Cancer Center reported a score in the prerituximab era exclusively considering tumor-related variables: Tumor Score (TS). We aim to validate TS in the rituximab era and to analyze its current potential role. Methods From GELTAMO DLBCL registry, we selected those patients homogeneously treated with R-CHOP (n = 1327). Results: Five-years PFS and OS were 62% and 74%. All variables retained an independent prognostic role in the revised TS (R-TS), identifying four different risk groups, with 5-years PFS of 86%, 71%, 50%, and very HR (28%). With a further categorization of three variables of the original TS (Ann Arbor Stage, LDH and B2M), we generated a new index that allowed an improvement in HR assessment. Conclusions: (a) All variables of the original TS retain an independent prognostic role, and R-TS remains predictive in the rituximab era; (b) R-TS and additional categorization of LDH, B2M, and AA stage (enhanced TS) increased the ability to identify HR subsets.