Background: The risk stratification value of the 6-min walk test (6MWT) to decide the feasibility of surgical resection is not well elucidated in patients with non-small cell lung cancer (NSCLC) and moderately decreased lung function.

Objective: This study aimed to determine the role of the 6MWT in predicting postoperative cardiopulmonary complications in patients with NSCLC who underwent lobectomy and had moderately decreased lung function.

Methods: The data were obtained from a prospective cohort study called Coordinate Approach to Cancer Patient's Health for Lung Cancer (CATCH-LUNG). Patients who underwent lobectomy for NSCLC were classified into two groups according to predicted postoperative pulmonary function (low-risk group or moderate-risk group); each group was then further classified into short-distance (< 400 m) or long-distance (≥ 400 m) groups according to a 6-min walk distance. The main end point of this study was the incidence of postoperative cardiopulmonary complications occurring within the first 30 postoperative days. A multivariable logistic regression model was used to compare the postoperative cardiopulmonary complications among the four groups.

Results: The adjusted ORs for any postoperative pulmonary complications, postoperative cardiac complications, and postoperative cardiopulmonary complications in patients with moderate-risk/short-distance relative to those with low-risk/long-distance were 10.26 (95% CI, 2.37-44.36), 5.65 (95% CI, 1.39-22.90), and 7.84 (95% CI, 2.24-27.46), respectively. However, these complications were not different between the patients with moderate-risk/long-term distance and those with low-risk/long-distance. Among patients in the moderate-risk group, those in the short-distance group had a significantly higher risk of postoperative cardiopulmonary complications compared with those in the long-distance group (adjusted OR, 4.95; 95% CI, 1.37-17.93).

Conclusions: Patients with NSCLC with moderate-risk/short-distance were at greater risk of developing postoperative cardiopulmonary complications; it may be feasible, however, for patients with NSCLC and moderate-risk/long-distance to undergo lobectomy compared with those with low-risk/long-distance. Our study suggests that the 6MWT could provide additional information in identifying optimal candidates for lung resection surgery of NSCLC.

Trial registry: ClinicalTrials.gov; No.: NCT03705546; URL: www.clinicaltrials.gov.