SP 7.08 Predictive Value of Body Composition Parameters for Pathological Response to Neoadjuvant Immunochemotherapy in Locally Advanced Gastric
Xinglong Lu, Jianling Zhang, Xiang Cui, Yongjiang Yu, Wenzhen Yuan, Fanghui DingAbstract
Background
The predictive value of body composition for pathological response to neoadjuvant immunochemotherapy (NICT) in locally advanced gastric cancer (LAGC) is unclear. This study aimed to investigate its impact.
Methods
This retrospective study included 261 LAGC patients admitted to the First Hospital of Lanzhou University from January 1, 2021, to December 31, 2024, who received NICT and subsequently underwent radical gastrectomy. Based on postoperative pathological evaluation, patients were divided into the Major Pathological Response group (MPR, n=84) and the Incomplete Pathological Response group (IPR, n=177). Utilizing pre- and post-NICT abdominal CT images, various body composition parameters were measured at the level of the third lumbar vertebra (L3). Various statistical methods were employed to systematically screen for independent predictive factors of pathological response after NICT.
Results
Skeletal muscle density (SMD) decreased most significantly (38.9±6.6 vs. 29.7±3.8 HU, P<0.001). Multivariate logistic regression analysis revealed that the absolute decrease in SMI during treatment was an independent negative predictor for MPR (OR: 1.116, 95% CI: 1.015-1.225, P=0.023). Diagnostic analysis confirmed that both pre-treatment sarcopenia (22.6% vs 39.0%, P=0.009) and post-treatment sarcopenia (20.2% vs 44.1%, P<0.001) were significantly associated with poorer pathological response. Nutritional and body composition parameters decreased post-NICT.
Conclusion
Progressive muscle loss during NICT independently predicts pathological response in LAGC. Dynamic monitoring of body composition could help identify patients with poor prognosis early, informing potential interventions.
Keywords
Gastric cancer, Neoadjuvant immunochemotherapy, Skeletal muscle index, Sarcopenia, Pathological response, Body composition