Impact of obesity on outcomes following surgery for gastric adenocarcinoma: A European multi-institutional study.

Introduction: The impact of overweight and obesity on pathological outcomes, complications, and oncologic outcomes following surgery for gastric adenocarcinoma has been poorly reported in Western populations. This study aimed to better understand the impact of overweight and obesity on both surgical and oncological outcomes in patients who underwent surgery for gastric cancer.

Methods: Data were retrospectively collected from a multi-institutional European database. 1589 patients underwent surgery for gastric adenocarcinoma between 2007 and 2017. Patients were divided into three groups according to their body mass index (BMI): 722 normoponderal patients (45.4 %), 585 overweight patients (36.8 %), and 282 obese patients (17.7 %).

Results: The tumor stage, administration of perioperative chemotherapy, number of harvested lymph nodes, and reoperation rates were similar. Tumor location differed between the groups, with more distal locations in normoponderal patients than in overweight patients (51.4 % vs. 44.1 %, p = 0.04). Surgical complications were more frequent in obese patients than in normoponderal patients (34.8 % vs. 24.2 %, p = 0.005), and severe postoperative complications too. The medical complication rate was higher in overweight and obese patients (31.5 % and 32.6 % vs. 24.1 %, p = 0.003). There was no difference in the overall survival.

Conclusions: Obesity was not related to tumor stage, pre- or intraoperative strategies, or survival in patients undergoing surgery for gastric adenocarcinoma. However, postoperative morbidity increases in patients with obesity. Surgery for gastric adenocarcinoma should be proposed for all patients and should be performed as usual, regardless of their BMI. However, obese patients should be counseled regarding the higher risk of postoperative complications.