Associations of Subcutaneous and Visceral Fat Areas with Progression-Free Survival in Patients with Diffuse Large B-Cell Lymphoma

Background: Body composition, particularly adipose tissue distribution, may modulate cancer progression and therapeutic outcomes.This study investigated the associations of subcutaneous fat area (SFA) and visceral fat area (VFA) with progression-free survival (PFS) in patients with diffuse large B-cell lymphoma (DLBCL).Methods: This retrospective study included 110 patients with DLBCL diagnosed between 2010 and 2019.SFA and VFA were quantified from baseline computed tomography images using a previously validated automated deep learning-based segmentation system and analyzed as continuous variables standardized to 1-standard deviation (SD) increments.Associations with PFS were evaluated using Cox proportional hazards regression adjusted for the International Prognostic Index (IPI), with joint modeling, sensitivity analyses, restricted cubic spline analysis, and bootstrap internal validation.Overall survival (OS) was additionally evaluated in exploratory analyses.Results: During a mean follow-up of 63.5 ± 45.2 months, 46 PFS events (41.8%) were observed.In separate IPI-adjusted models, each 1-SD increase in SFA was associated with poorer PFS (hazard ratio [HR], 1.34; 95% confidence interval [CI], 1.00-1.79;p = 0.047), whereas VFA was not significantly associated with PFS (HR, 1.09; 95% CI, 0.82-1.44;p = 0.552).In the joint model, the SFA estimate remained similar (HR, 1.33; 95% CI, 0.99-1.79;p = 0.057), whereas the VFA estimate remained close to the null (HR, 1.03; 95% CI, 0.76-1.38;p = 0.868); the standardized coefficients did not differ significantly (p = 0.265).Adding SFA to the IPI yielded a small increase in the apparent C-index (0.618 to 0.632; ΔCindex, 0.014; bootstrap 95% CI, -0.013 to 0.069).In exploratory analyses, neither SFA nor VFA was significantly associated with OS.Conclusion: Higher SFA was associated with poorer PFS after adjustment for the IPI, whereas VFA showed little evidence of an association; however, the difference between their associations was not statistically significant, and neither adipose tissue compartment was significantly associated with OS.The incremental prognostic value of SFA beyond the IPI was limited.Larger studies with external validation are needed to confirm these findings.