Change and Predictors of Body Composition After Gastrectomy for Gastric Cancer During First Postoperative Year.

Purpose: After gastrectomy for gastric cancer, patients often lose significant body weight owing to decreased caloric intake and nutrient absorption. Body weight typically requires approximately 1 year to stabilize. This study aimed to examine the changes and predictors associated with body composition during the first postoperative year.

Methods: Two hundred thirty patients underwent radical gastrectomy for Stage I-III gastric cancer. Body composition was measured using bioelectrical impedance analysis, and changes were analyzed over 1 year. Multiple regression analysis was used to identify predictors of body composition changes.

Results: Body composition changes and significant body weight and body fat mass reductions occurred primarily within the first 6 months postoperatively. Skeletal muscle mass initially decreased but improved by 6 months, without significant changes related to adjuvant chemotherapy. Increased edema was seen at 6 and 12 months postoperatively in patients after total gastrectomy and adjuvant chemotherapy. Gastrectomy type and body mass index significantly affected postoperative body weight changes. Gastrectomy type was also associated with changes in skeletal muscle mass and bone mineral content. Adjuvant chemotherapy significantly affected the whole-body phase angle at 6 and 12 months.

Conclusions: These findings emphasized the initial significant reductions postoperatively and subsequent adjustments over time and elucidate the complex interplay between surgical techniques, adjuvant treatment, and patient characteristics and mid-term changes in body composition.