Loss of Skeletal Muscle Mass During Neoadjuvant Chemoradiotherapy Predicts Postoperative Mortality in Esophageal Cancer Surgery

Esophageal surgery is associated with complications and mortality. It is highly important to develop tools predicting unfavorable postoperative outcome. Esophageal cancer and neoadjuvant chemoradiotherapy (CRT) induce skeletal muscle wasting, which leads to diminished physiologic reserves. The purpose of this study was to investigate whether the degree of muscle mass lost during neoadjuvant CRT predicts postoperative mortality. A total of 123 consecutive patients undergoing surgery for esophageal malignancy in the period 2008-2012 were included, of whom 114 received neoadjuvant CRT. Skeletal muscle mass was measured on routinely performed CT scans by assessing L3 muscle index (according to the Prado method) before and after neoadjuvant CRT, and the amount of muscle mass lost during neoadjuvant CRT (muscle loss index) was calculated. It was investigated whether this amount was associated with postoperative 30-day or in-hospital mortality and morbidity. In the complete cohort, no significant association between loss of muscle mass and mortality was found. However, skeletal muscle mass was significantly lower in patients with stage III-IV tumors compared with stage I-II tumors, prior to neoadjuvant CRT. In the stage III-IV subgroup, the amount of muscle mass lost during neoadjuvant CRT was predictive of postoperative mortality: -13.5 % (standard deviation 6.2 %) in patients who died postoperatively compared with -5.0 % (standard deviation 8.3 %) in surviving patients, p = 0.02. Measurement of muscle mass loss during neoadjuvant chemoradiotherapy may provide a readily available and inexpensive assessment to identify patients at risk for developing unfavorable postoperative outcome after resection of esophageal malignancies, especially in patients with stage III-IV tumors.