# Evaluating the role of BMI in survival and complications in older esophageal squamous cell carcinoma following esophagectomy

## TL;DR

This study examines how body mass index affects survival and complications in older patients with esophageal cancer after surgery.

## Contribution

The study reveals a U-shaped relationship between BMI and survival in elderly esophageal cancer patients post-surgery.

## Key findings

- No significant differences in overall or disease-free survival among BMI groups.
- A U-shaped association between BMI and survival, with protective ranges identified.
- Low BMI is linked to specific serious complications, highlighting the need for nutritional support.

## Abstract

To evaluate the impact of Body Mass Index (BMI) on survival and postoperative complications in older patients with esophageal squamous cell carcinoma (ESCC) following esophagectomy, we designed this study.

We retrospectively analyzed 469 patients aged ≥70 years with thoracic ESCC who underwent esophagectomy at Sichuan Cancer Hospital (May 2016–August 2021). Patients were grouped by WHO BMI categories: underweight (<18.5 kg/m2), normal (18.5–24.9 kg/m2), and overweight/obese (≥25 kg/m2). Primary outcomes were overall survival (OS) and disease-free survival (DFS); secondary outcomes included Clavien-Dindo grade III–IV complications. Kaplan-Meier, Cox models, and restricted cubic splines (RCS) were used.

Median follow-up was 47.5 months; R0 resection was achieved in 96.4%. BMI distribution: 7.3% low, 76.8% normal, 16.0% high. Median OS was 44.9 months overall, with no significant OS or DFS differences among BMI groups. RCS demonstrated a significant U-shaped association between continuous BMI and survival: protective ranges were approximately 21.9–27.0 kg/m2 for OS (P non-linearity = 0.014) and 20.2–27.2 kg/m2 for DFS (P non-linearity = 0.033).

In elderly ESCC patients after esophagectomy, BMI does not independently influence OS or DFS, though low BMI is associated with specific serious complications. Perioperative optimization—particularly nutritional support for underweight patients—remains essential.