Age interaction in associations between geriatric nutritional risk index and prognosis in diffuse large B-cell lymphoma

To evaluate the effect modification of age on associations between geriatric nutritional risk index (GNRI) and overall survival (OS) in ≥18-year-old patients with newly diagnosed diffuse large B-cell lymphoma (DLBCL), we conducted a multi-centre retrospective study of 552 analysable patients. Multivariable Cox modelling with restricted cubic spline (RCS) modelling showed that GNRI correlated significantly with OS, but the relationship is non-linear ( P for non-linearity = 0.0158). According to a multivariable three-dimensional Cox-RCS model, older patients show higher mortality risk. The trend toward higher mortality risk with worse GNRI was consistent across age groups, including in younger patients. Normal albumin concentration (Alb) and body mass index (BMI) in a low-GNRI state (< 92) was the most common pattern of malnutrition, accounting for approximately 40% of low-GNRI patients in both younger and older adults, using any of the age thresholds of 65, 70, or 75 years. Survival curves revealed that regardless of the GNRI component (Alb or BMI), a low-GNRI (< 92) population shows poor prognosis. Age had no effect modification on the prognostic ability of GNRI for de novo DLBCL. Irrespective of age, patients are equally affected by adverse effects of malnutrition.