P1.212. Sarcopaenia in Gastrooesophageal Cancer Surgery: Application in Surgical Risk Calculators

Topic Esophageal Cancer: Surgical Treatment of Esophageal Cancer – early outcomes and complications Background Sarcopaenia is prevalent among gastrooesophageal patients and is associated with postoperative complications. Despite the association, no surgical risk calculators have incorporated sarcopaenia as a parameter. This study evaluates the prognostic significance of the preoperative skeletal muscle index (SMI) and assess whether adding SMI into risk calculators increases their accuracy. Methods The retrospective study collected the data of 117 patients between 2019 and 2025 who underwent a gastrectomy or oesophagectomy. Sarcopaenia status was determined using SMI. The SMI was combined with calculator predictions through logistic regressions producing novel calculators. Results Sarcopaenia status was significantly associated with any postoperative complication and Clavien-Dindo complications ≥3 (p=0.037 and p=0.007, respectively). The odds of any complication was 2.39 times higher in the sarcopaenic group (OR=2.39, 95% CI [1.042-5.496], p=0.037). SMI was significantly associated with major complications (OR=0.896, 95% CI [0.813, 0.986], p=0.025). The accuracy of the surgical risk calculators was limited. The O-POSSUM calculator combined with the skeletal muscle index was shown to have improved accuracy for predicting in-hospital mortality and major complications (Original: AUC= 0.693, Novel: AUC= 0.723). Conclusion SMI is significantly associated with major complications. This highlights the need to address sarcopaenia preoperatively and indicates that even incremental improvements may reduce risk. This was the first study to combine SMI with surgical risk calculators. The O-Possum calculator showed improvement, however larger studies are needed to confirm this. The accuracy of surgical risk calculators is limited in gastrooesophageal cancer surgery highlighting the need to incorporate significant prognostic factors to increase their accuracy.