Postoperative skeletal muscle loss is associated with high fat mass in patients undergoing Esophagectomy for esophageal cancer.

OBJECTIVE

Esophageal cancer is one of the most lethal cancers worldwide. Loss of skeletal muscle after esophagectomy worsens prognosis; however, it remains unclear which musculoskeletal factors, such as muscle and fat mass, are associated with this loss. We investigated factors associated with postoperative skeletal muscle mass decrease in patients undergoing esophagectomy for esophageal cancer.

METHODS

Fifty-two patients who underwent radical subtotal esophagectomy from 2021 to 2023 were reviewed. Changes in skeletal muscle mass index (SMI) were compared using multifrequency bioelectrical impedance analysis conducted at ~1 month and 3 months after surgery. Statistical analyses, including univariable and multivariable logistic regression, were performed to identify risk factors for decreased SMI.

RESULTS

The analysis divided patients into increased and decreased SMI groups (32 and 20 patients, respectively). Multivariable logistic regression analysis identified risk factors for decreased SMI as fat mass (OR = 1.290, 95%CI: 1.080-1.540, P = .004), clinical stage, and forced expiratory volume in 1 s. Models incorporating other body composition variables showed that % body fat, visceral fat area, and body mass index (BMI) were also associated with decreased SMI. Patients with higher fat mass tended to have lower postoperative energy surplus (total caloric intake minus basal metabolic rate) (r = -0.538 P < .001). Patients in the decreased SMI group had significantly lower overall survival (log-rank, P = .048).

CONCLUSIONS

These findings indicate that postoperative skeletal muscle loss is associated with body composition characteristics beyond body weight or BMI, including fat mass. Prospective studies are needed to evaluate individualized muscle preservation programs based on comprehensive body composition assessment.