Prognostic value of the CONUT score in newly diagnosed diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin lymphoma and clinical outcomes remain heterogeneous despite standard R-CHOP therapy. The Controlling Nutritional Status (CONUT) score, an immunonutritional index based on serum albumin, total cholesterol and lymphocyte count, has emerged as a potential prognostic marker in this setting. In this retrospective observational study, the prognostic value of the pre-treatment CONUT score was evaluated in 110 adult patients with newly diagnosed DLBCL treated with standard R-CHOP at a tertiary center between October 2022 and September 2025. Patients were categorized into two groups according to their CONUT scores (<5 vs. ≥5), and baseline clinical characteristics, laboratory parameters and prognostic indices [International Prognostic Index (IPI) and National Comprehensive Cancer Network IPI (NCCN-IPI)] were compared. Overall survival (OS) and progression-free survival (PFS) were analyzed using the Kaplan-Meier method, and independent prognostic factors for OS were identified by Cox regression analysis. A CONUT score ≥5 was significantly associated with adverse clinical features, including advanced-stage disease (P=0.021), elevated lactate dehydrogenase (P=0.002), ECOG performance status ≥2 (P=0.021), higher IPI (P=0.015) and higher NCCN-IPI scores (P=0.032). Patients with CONUT ≥5 had significantly inferior OS (log-rank P=0.001) and PFS (log-rank P=0.003) compared with those with CONUT <5. Similar findings were observed in the low/low-intermediate IPI subgroup. In the multivariate analysis, advanced-stage disease (P=0.036) and a CONUT score ≥5 (P=0.042) remained independent predictors of OS. These findings indicate that a high pre-treatment CONUT score is associated with adverse baseline characteristics and predicts inferior survival outcomes in patients with DLBCL. Given its simplicity, low cost and availability in routine clinical practice, the CONUT score may serve as a useful adjunct to established prognostic indices, although prospective validation is warranted.