Impact of sarcopenia on outcomes of locally advanced esophageal cancer patients treated with neoadjuvant chemoradiation followed by surgery

Abstract

Background: Sarcopenia is an independent predictor of clinical outcomes in multiple gastrointestinal cancers. Total psoas area (TPA), as measured on a single cross-sectional CT image at the L4 vertebral body level, has been correlated with sarcopenia. We sought to evaluate whether TPA was predictive of acute grade ≥3 toxicity, pathologic response, and overall survival in patients with locally advanced esophageal cancer receiving tri-modality therapy. Methods: An institutional database of esophageal cancer patients treated with neoadjuvant chemoradiation followed by surgery was queried. Of 77 patients treated from 2008 to 2012 with intensity modulated radiation therapy (IMRT) and image guided radiation therapy (IGRT), 56 patients were eligible based on having CT imaging that included the L4 vertebral body. The L4 vertebra was identified on axial CT and the psoas muscle was manually contoured bilaterally to determine the skeletal muscle index. Sarcopenia was defined by the presence of the psoas area less than the median of the cohort. Acute toxicity was defined as within 3 months of radiotherapy based on Common Terminology Criteria for Adverse Events. ROC curve, logistic regression, and Kaplan Meier estimates were used when appropriate. Results: Sarcopenia was associated with increased acute grade ≥3 toxicity from chemoradiation by ROC analysis using a cut off of 841.5 mm2/m2 (P=0.003, AUC 0.709, sensitivity 60.9%, specificity 78.8%) and logistic regression (P=0.002). Patients with TPA < 841.5 mm2/m2 were 5.78 times more likely to develop grade 3 or higher toxicity (P=0.004). Sarcopenia did not predict a difference in overall survival (P=0.217) and was not significant for pathologic complete response or favorable pathologic response (TRG 0/1). Conclusions: In our cohort of patients, sarcopenia was associated with a significant increase in acute grade =3 toxicity with chemoradiation, suggesting a potential role for neoadjuvant patient selection strategies. There was no difference in pathologic response or overall survival.