423. POSTOPERATIVE SKELETAL MUSCLE MASS IN ESOPHAGEAL CANCER SURGERY PATIENTS AFTER NEOADJUVANT CHEMOTHERAPY

Abstract Recently, the significant decrease in skeletal muscle mass after esophagectomy in patients who underwent neoadjuvant chemotherapy, which in turn has been reported to affect long-term survival. The results of JCOG1109 have been published, and while DCF has become the standard of care as neoadjuvant chemotherapy, its toxicity has also been pointed out. In this study, we analyzed the relationship between changes in body composition before and after neoadjuvant chemotherapy and postoperative complications after esophagectomy. Among esophageal cancer patients who underwent esophagectomy after preoperative chemotherapy from September 2018 to May 2020, 74 patients were included, excluding patients with recurrence within 1 year after surgery and patients with gastrointestinal fistula. The relationship between body composition and postoperative complications, and changes in body weight and skeletal muscle mass were analyzed. The male-to-female ratio was 60:14, and the median age was 65.0 years. When the subjects were divided into DCF and Others, there was a significant difference in skeletal muscle loss in the Others group. There was no significant difference in the incidence of postoperative complications by chemotherapy, nor an incidence of postoperative complications between the DCF and Others. There was no significant difference in weight loss between the DCF group and the Others group, but a significant decrease in skeletal muscle mass in the DCF group at one year. The decrease up to 4 months after surgery was particularly large. In the present analysis, DCF therapy as preoperative treatment had no effect on the occurrence of postoperative complications, but was associated with a long-term decrease in skeletal muscle mass, suggesting that the toxicity of DCF therapy may have a long-term effect. Although the tumor suppression effect of preoperative treatment was proven, long-term nutritional and rehabilitative interventions were considered necessary to establish a truly favorable long-term prognosis for the patients.