Efficacy, toxicity, and prognostic factors of rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone in elderly patients with diffuse large B-cell lymphoma: a single-center retrospective cohort study

Background: Optimizing treatment for elderly patients with diffuse large B-cell lymphoma (DLBCL) remains clinically challenging because curative intent must be balanced against treatment-related toxicity and reduced treatment tolerance. This study aimed to evaluate the efficacy and toxicity of first-line rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP)-based treatment in elderly patients with DLBCL and to identify prognostic factors associated with overall survival. Methods: We conducted a single-center retrospective cohort study of 162 patients aged 60 years or older with newly diagnosed DLBCL who received first-line R-CHOP-based treatment. The main outcomes were overall survival, treatment delivery, and treatment-related toxicity. Relative dose intensity (RDI) was used to assess treatment delivery, and survival was analyzed using Kaplan-Meier methods and Cox proportional hazards regression. A study-specific geriatric-treatment delivery risk model was further evaluated and compared with the International Prognostic Index (IPI) using discrimination analysis. Results: Patients older than 80 years had a significantly lower median RDI than those aged 60 to 80 years (78.2% vs. 93.6%, P = 0.009) and a markedly higher treatment-related mortality rate (33.3% vs. 1.9%, P = 0.015). In multivariable analysis, RDI below 85% (hazard ratio [HR], 2.45; P< 0.001) and albumin below 35 g/L (HR, 2.03; P< 0.001) were independently associated with worse overall survival. The geriatric-treatment delivery risk model showed better discriminative performance than the conventional IPI, with a concordance index of 0.748. Conclusions: In elderly patients with DLBCL, survival outcomes were closely associated with treatment tolerance and baseline nutritional status. These findings suggest that supportive strategies aimed at preserving treatment delivery, rather than empiric age-based dose reduction alone, may improve clinical outcomes in appropriately selected patients.