Changes of bone, adipose, and muscle-related body compositions in gastric cancers after gastrectomy using deep learning based automatic segmentation.

BACKGROUND: To investigate bone, adipose, and muscle-related body compositions changes in gastric cancers (GCs) 12 months after gastrectomy utilizing an artificial intelligence (AI) based segmentation tool and to conduct subgroup analyses based on clinicopathological characteristics. METHODS: This retrospective study included 146 GCs who underwent gastrectomy. Body compositions of GCs at baseline and 12 months after surgery were automatically measured utilizing the AI-based segmentation tool. The differences in body compositions at baseline and 12 months after surgery were assessed. Subgroup analyses of body composition changes stratified by clinicopathological characteristics were conducted. Benjamini-Hochberg false discovery rate (FDR) correction was utilized for all subgroup analyses. RESULTS: All body composition parameters, including bone mineral density (BMD), adipose tissue, and muscle, decreased significantly 12 months after surgery (all p < 0.001). The greatest losses were observed in adipose-related compositions. The proportions of sarcopenia (from 37.7% to 55.5%) and osteoporosis (from 13.7% to 26.7%) showed significant increases. Subcutaneous and visceral adipose tissues, abdominal wall muscle, and skeletal muscle losses indicated significant differences in gender and body mass index (BMI) subgroups (all FDR p < 0.05). Adipose- and muscle-related losses differed significantly in GCs underwent different types of gastrectomy (all FDR p < 0.05), while BMD loss showed no significant difference. Subgroup analyses based on pathological stages showed no significant difference for body composition changes. CONCLUSIONS: BMD, adipose-related, and muscle-related body compositions showed significant losses over 12 months in GCs underwent gastrectomy. The greatest losses were observed in adipose-related compositions. The proportions of sarcopenia and osteoporosis showed significant increases. Gender, baseline BMI, and gastrectomy differences affected adipose- and muscle-related body composition losses but showed no significant effect on BMD.