Association of sarcopenia with relative dose intensity of neoadjuvant chemotherapy in older patients with locally advanced esophageal cancer: A retrospective cohort study

INTRODUCTION:Sarcopenia impacts the toxicity of chemotherapy in patients with cancer, but there is little information on the association of sarcopenia with the relative dose intensity (RDI) of chemotherapy. We investigated the association of sarcopenia with RDI of neoadjuvant chemotherapy (NAC) in older patients with locally advanced esophageal cancer (LAEC). MATERIALS AND METHODS:This was a single-center retrospective cohort study of patients aged ≥65 years who underwent curative esophagectomy after NAC for LAEC between 2016 and 2020. Skeletal muscle mass index (SMI) was calculated from computed tomography images at the L3 level. Sarcopenia was defined using the Youden index of SMI. Average RDI was calculated from delivered-dose intensity and standard-dose intensity of all drugs. The cutoff point of low average RDI was defined as <85%. The multivariate logistic regression model was used for the endpoint. RESULTS:We analyzed 188 patients with a mean age of 71.3 years. The cutoff points of sarcopenia for low average RDI were defined as 42.81 cm2/m2 in males and 37.48 cm2/m2 in females. Sarcopenia significantly affected low average RDI, adjusted for age, sex, body mass index, drug regimen, clinical stage, and creatinine clearance (adjusted odds ratio: 2.195, 95% confidence interval: 1.107-4.411, p = 0.024). Compared with the non-sarcopenia patients, the sarcopenia patients with low average RDI had a higher rate of dose reduction, delayed, or discontinuation after the first cycle because of neutropenia (45% vs. 38%), and decreased performance status (11% vs. 0%). DISCUSSION:Sarcopenia predicted low average RDI (<85%) of NAC in older patients with LAEC. In the future, the information about the mechanism of association of sarcopenia with RDI will progress the development of intervention strategy and novel supportive care.