ASO Visual Abstract: Prognostic Impact of the Loss of Skeletal Muscle Mass during Neoadjuvant Chemotherapy on Older Patients with Esophageal Cancer

Background In older adults, skeletal muscle mass is an important factor for health and prognosis. The loss of SMM during neoadjuvant therapy affects the prognosis of patients with locally advanced esophageal cancer. However, information is limited regarding this possibility in older patients. This study aimed to establish the prognostic impact of SMM loss during neoadjuvant chemotherapy on older patients with locally advanced esophageal cancer. Methods This was a single-center retrospective cohort study. Patients age 65 years or older had undergone R0 curative esophagectomy after NAC. The skeletal muscle mass index before and after NAC was calculated from computed tomography images. The percentage change in the SMI during NAC (SMI%) was calculated from the SMI before and after NAC. Results The study analyzed 150 patients with a mean age of 71.1 ± 3.7 years. The mean value of the SMI was 42.7 ± 7.2 cm 2 /m 2 before NAC, and the SMI% was − 6.4% ± 5.9%. The cutoff of SMI% for overall survival was defined by the log-rank test as − 12%. The Cox proportional hazard model showed that major loss of the SMI (≥ 12%) significantly influenced OS (hazard ratio, 2.490; 95% confidence interval, 1.121–5.529; p = 0.025) independently of age, sex, pathologic T and N factors, or treatment regimen. Conclusions Major SMI loss has an impact on OS after R0 curative esophagectomy for older patients with locally advanced esophageal cancer.