Association of skeletal muscle loss with the long-term outcomes of esophageal cancer patients treated with neoadjuvant chemotherapy

Purpose To investigate the change in skeletal muscle mass and evaluate the prognostic impact of sarcopenia on esophageal cancer (EC) patients Methods The subjects of this retrospective study were 90 EC patients who were treated with neoadjuvant chemotherapy (NAC) and subsequent esophagectomy. The skeletal muscle index (SMI) was defined according to computed tomography (CT) imaging of the total cross- sectional muscle tissue, measured at the third lumbar level using a volume analyzer before NAC and surgery. The SMI was calculated by normalization according to height, and skeletal muscle loss (SML) was defined as (pre- NAC SMI value - preoperative SMI value) x 100/pre-NAC SMI. Results Sarcopenia was evident in 72 ( 80.0%) patients before NAC and 77 (85.6%) patients before NAC and surgery. The SMI value was decreased in 28 (68.9%) patients and the median SML was 3.3%. The 3-year overall survival rate was 68.9% in the low SML group and 0% in the high SML group (P < 0.001). Sarcopenia before NAC or surgery was not significantly associated with overall survival. Multivariable analysis identified high SML as an independent prognostic factor. Conclusions These results suggest that skeletal muscle loss is associated with a worse long-term outcome for EC patients treated with NAC.