Preoperative exercise capacity as a predictor of postoperative pulmonary complications in patients with esophageal cancer: a multicenter observational cohort study

BACKGROUND: Postoperative pulmonary complications (PPCs) after esophageal cancer surgery remain a major concern. Preoperative exercise capacity has emerged as an important predictor. This study examined the clinical use of practical predictors-the 30-s chair stand test (CS-30) and the 6-min walk test (6MWT). METHODS: We retrospectively analyzed patients with esophageal cancer from three institutions who underwent preoperative physical therapy between July 2021 and June 2023. Data completeness for the CS-30 and 6MWT was compared using McNemar's test. Three logistic regression models predicting PPCs were developed: Model 1 (established risk factors), Model 2 (risk factors plus CS-30), and Model 3 (risk factors plus 6MWT). PPCs were defined as pneumonia or sputum retention requiring intervention (Clavien-Dindo grade ≥ 2). Model performance was evaluated using the area under the curve (AUC), and incremental predictive value was assessed using net reclassification improvement (NRI) and integrated discrimination improvement (IDI). RESULTS: Among 213 patients (median age 68 years; 83% male), PPCs occurred in 57 (26.8%). Data completeness was significantly higher for the CS-30 (195/213, 91.5%) than the 6MWT (178/213, 83.6%; p < 0.001). The AUCs (95% confidence interval) were 0.775 (0.708-0.842) for Model 1, 0.786 (0.716-0.857) for Model 2, and 0.779 (0.712-0.846) for Model 3. NRI and IDI analyses showed that adding the CS-30 significantly improved reclassification and discrimination abilities. CONCLUSIONS: The CS-30 was more feasible than the 6MWT and significantly improved PPCs prediction. A perioperative management model for high-risk patients based on the CS-30 is recommended.