Predictive value of preoperative subcutaneous and intramuscular adipose tissue for the occurrence of postoperative liver metastasis in gastric cancer patients undergoing radical gastrectomy.

[BACKGROUND] Body compositions were associated with the clinical outcomes of patients with malignant tumors. Our study aimed to explore the predictive value of preoperative body compositions for liver metastasis after radical gastrectomy in gastric cancer (GC).

[METHODS] GC patients undergoing radical gastrectomy in the single center from January 2012 to December 2023 were retrospectively included. Patients with distant metastases or other malignant tumors before the surgery were excluded. Included patients were divided into the liver metastasis and control groups according to the presence of liver metastasis within the 3-year follow-up. Body compositions including skeletal muscle (SM), visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and intramuscular adipose tissue (IAT) were estimated using preoperative computed tomography (CT) images at the L3 level. Multivariate logistic regression analysis was used to identify the independent risk factors of liver metastasis. Receiver operating characteristic curve was used to evaluate the predictive performance of significant factors.

[RESULTS] A total of 300 patients were included for the final analysis with 223 in the control group and 77 in the liver metastasis group. Compared with the control group, the liver metastasis group contained more males (P<0.001), presented older age (P=0.004), higher T and N stages (P<0.001 for both), higher incidence of moderately-poorly and poorly differentiated cell grade (P<0.001), increased lymphovascular and perineural invasions (P<0.001 and P=0.01, respectively), higher incidence of abnormal carcinoembryonic antigen (CEA), carbohydrate antigen 199 (CA199) and alpha-fetoprotein (AFP) (P=0.01, 0.01 and 0.003, respectively), smaller SAT area (SATA) (P=0.009) and larger IAT area (IATA) (P=0.002). Multivariate logistic regression analysis demonstrated that the N stage (P=0.03), cell grade (P=0.01), AFP (P=0.04), and IATA (P=0.04) were independent risk factors for liver metastasis. The combination of SATA and IATA exhibited good predictive performance for liver metastasis [area under the curve (AUC) =0.687, 95% confidence interval (CI): 0.621-0.754].

[CONCLUSIONS] The preoperative SATA and IATA at the L3 level were significant predictors of postoperative liver metastasis in GC patients undergoing radical gastrectomy.