Persistence of the Postoperative Change in the Six-minute Walking Distance of Lung Cancer Patients with Chronic Obstructive Pulmonary Disease

OBJECTIVES: The aim of this prospective follow-up study was to investigate the difference before and after surgery in the six-minute walking distance (6MD) of lung cancer patients with chronic obstructive pulmonary disease (COPD) and to examine the long-term effect of the change in 6MD in the early postoperative period. METHODS: This was a retrospective analysis of 25 COPD patients who underwent lung cancer surgery and perioperative rehabilitation in our department. Assessments of 6WD were carried out preoperatively and at 1, 3, and 6 months postoperatively. The changes in 6MD at 1, 3, and 6 months postoperatively compared with the preoperative value were designated the 1-month Δ6MD, the 3-month Δ6MD, and the 6-month Δ6MD, and the associations between them were investigated. RESULTS: The mean 6MD distance was 412.0±27.3 m (95% confidence interval) preoperatively, 369.0±33.8 m at 1 month, 395.6±32.2 m at 3 months, and 400.0±38.2 m at 6 months, with a significant difference between the preoperative and 1-month values (P<0.01). There were strong correlations between 1-month and 3-month Δ6MDs (r =0.74, P<0.0001) and between 1-month and 6-month Δ6MDs (r =0.88, P<0.0001). CONCLUSIONS: In lung cancer patients with COPD, the 1-month Δ6MD was strongly associated with both the 3-month Δ6MD and the 6-month Δ6MD. These findings suggest that the decrease in exercise tolerance of patients whose 6MD is low at 1 month postoperatively may be prolonged, and such patients may therefore be in greater need of postoperative outpatient rehabilitation.