Prognostic and Predictive Significance of Body Mass Index in Locally Advanced Gastric Cancer Receiving Neoadjuvant...

Background/Objectives: Gastric cancer remains a leading cause of cancer-related mortality worldwide, with a significant number of patients diagnosed at locally advanced stages. While perioperative chemotherapy and surgical resection are the standard treatments, patient outcomes remain heterogeneous. This study aimed to investigate the prognostic and predictive effects of Body Mass Index (BMI) on pathological response, progression-free survival (PFS), and overall survival (OS) in patients receiving neoadjuvant chemotherapy. Methods: This retrospective, observational cohort study included 192 patients with locally advanced gastric cancer who underwent curative gastrectomy and neoadjuvant chemotherapy between 2018 and 2023. Patients were categorized based on an optimal BMI cutoff value of 24.9 kg/m². Results: Patients with a BMI ≥ 24.9 kg/m² demonstrated a 41% lower 5-year mortality risk compared to those with a lower BMI (HR = 0.59; 95% CI: 0.35-0.99; p = 0.044). The high BMI group had a significantly longer average PFS (54.1 months) compared to the low BMI group (41.4 months). High BMI was associated with a significantly reduced risk of progression (HR: 0.61; 95%CI: 0.38-0.97; p = 0.038. Log-linear regression confirmed that the complete response rate was 73.7% lower in patients with low BMI. Conclusions: BMI threshold of ≥24.9 kg/m² is associated with improved pathological response and long-term survival in patients with locally advanced gastric cancer receiving neoadjuvant chemotherapy. These findings suggest that BMI potentially reflects the impact of nutritional status on treatment tolerability and oncological outcomes.