Objective Skeletal muscle mass (SMM) is an important biomarker for prognosis and health in older patients with cancer. Limited information is available on the recovery course of SMM after oesophagectomy following neoadjuvant chemotherapy (NAC) in older patients. This study was performed to investigate the recovery course of SMM after oesophagectomy following NAC and the preoperative predictors of delayed recovery in older patients with locally advanced oesophageal cancer (LAEC).

Methods This single-centre retrospective cohort study involved older (≥65 years) and non-older (<65 years) patients with LAEC who underwent oesophagectomy following NAC. The SMM index (SMI) was calculated using CT images. One-way analysis of variance and multivariate logistic regression analysis were performed.

Results In total, 110 older patients and 57 non-older patients were analysed. Loss of the SMI after NAC to 12 months postoperatively was significantly greater in older patients than in non-older patients (p<0.01). The significant preoperative predictor of delayed recovery of the SMI 12 months after surgery was loss of the SMI during NAC in older patients (per 1%: adjusted OR 1.249; 95% CI 1.131 to 1.403; p<0.001), but not in non-older patients (per 1%: OR 1.074; 95% CI 0.988 to 1.179; p=0.108).

Conclusions There is an especially large unmet need for preventing the long-term sequelae of SMM loss in older patients with LAEC after oesophagectomy following NAC. In older patients, loss of SMM during NAC is an especially useful biomarker for prescribing postoperative rehabilitation to prevent postoperative loss of SMM.