Impact of body composition on dose modifications and prognosis in patients with locally advanced gastric cancer - undergoing neoadjuvant chemotherapy.

BACKGROUND

Despite advances in treatment, locally advanced gastric cancer (GC) continues to be associated with poor prognosis. Body composition, specifically the distribution of skeletal muscle and adipose tissue, has emerged as a key factor influencing cancer prognosis, yet its impact on neoadjuvant chemotherapy (NACT) dose modifications and long-term survival in GC remains unclear. The primary aim of this study was to assess the relationship between body composition and dose delay/reduction during preoperative NACT in patients with locally advanced GC. The secondary aim was to evaluate the impact of body composition on overall and disease-free survival (DFS).

METHODS

This retrospective study included 97 patients with locally advanced gastric adenocarcinoma treated with NACT at Liv Bona Dea Hospital, Baku, Azerbaijan, between 2018 and 2024. Body composition parameters-skeletal muscle index, visceral adipose tissue (VAT), and subcutaneous adipose tissue-were analyzed using before and after NACT computed tomography imaging. Dose delay and reduction were defined as treatment delays of ≥5 days and dose reductions of ≥10% owing to chemotherapy-related side effects. Survival outcomes were assessed using Kaplan-Meier analysis.

RESULTS

Of the 97 patients (mean age, 63 years), 33% experienced dose delays and 15% had dose reductions. Multivariate analysis revealed that lower pre-NACT VAT measurements were associated with both dose delay (P =.01; odds ratio [OR], 7.31) and dose reduction (P =.01; OR, 8.87). No significant correlation was found between body composition parameters and overall survival (OS) or DFS. However, neural (P =.013; hazard ratio [HR], 1.88) and venous invasions (P =.03; HR, 1.43) were independent predictors of poor OS, whereas poor histologic grade (P =.008; HR, 2.01) and neural invasion (P =.039; HR, 1.61) independently predicted poor DFS.

CONCLUSION

This study is the first to demonstrate that lower pre-NACT VAT is a significant predictor of dose reduction and delay in patients with locally advanced GC. Although body composition did not predict survival outcomes, tumor histologic grade and invasion factors were significant for prognosis. These findings suggest that monitoring body composition, particularly VAT, could aid in optimizing chemotherapy dosing and improving treatment outcomes for patients with GC undergoing NACT. Further prospective studies are needed to validate these results.