ABSTRACT
Background: Alterations in skeletal muscle and visceral adipose mass may occur during neoadjuvant treatment (NAT) for oesophageal cancer. We aimed to explore these changes and sarcopenic visceral obesity (SVO) as a novel composite metric on postoperative outcomes.
Methods: Retrospective cohort study of adults who underwent oesophagectomy following NAT from 2018-2023. Skeletal muscle index (SMI) and visceral fat area (VFA) were measured at L3 vertebral level on pre- and post-NAT Computer Tomography scans using SliceOmatic™ software. SVO was defined as concurrent sarcopenia (SMI Men: Body mass index (BMI) <24.9= <43cm2/m2, BMI>25= <53 cm2/m2, Women= <41cm2/m2) and visceral obesity (VFA Men= >163.8cm2, Women= >80.1cm2). Baseline characteristics, anthropometric measurements and surgical outcomes were collected. Complications explored were anastomotic leaks, chyle leaks and respiratory complications.
Results: Of 74 patients (64.7±8.7 years, 77% male), 66.2% were distal oesophageal adenocarcinomas. Primary treatment was neoadjuvant chemoradiotherapy (84.2%) and subsequent minimally invasive/hybrid oesophagectomy (92%). Significant reductions were observed in SMI (4.65cm2/m2, 95%CI,3.8-5.5; P<0.001) and VFA (19.33cm2, 95%CI,11.3-27.4; P<0.001) following NAT. Patients who experienced respiratory complications lost significantly less VFA (18.4%, 95%CI,1.3-35.5; P=0.035) during NAT. De-novo sarcopenia in isolation did not increase postoperative complications. 17 of 74 (23%) patients developed de-novo SVO post-NAT and higher odds of respiratory complications (OR 3.97 95%CI,1.1-14.3, P=0.035).
Conclusion: Significant reductions in SMI and VFA occurred during NAT. Those who experienced respiratory complications had significantly lower reduction in VFA. Patients who developed de-novo SVO had ~4-fold greater likelihood of postoperative respiratory complications. Targeted prehabilitation, including respiratory, nutritional, and exercise interventions, may benefit at-risk patients.