The 6-min walk test in the functional evaluation of patients with lung cancer qualified for lobectomy

The American College of Chest Physicians guidelines recommend low-technology exercise tests in the functional evaluation of patients with lung cancer considered for resectional surgery. However, the 6-min walk test (6MWT) is not included, because the data on its clinical value are inconsistent. Our goal was to evaluate the 6MWT in assessing the risk of cardiopulmonary complications in candidates for lung resection.

We performed a retrospective assessment of clinical data and pulmonary function test results in 947 patients, mean age 65.3 (standard deviation 9.5) years, who underwent a single lobectomy for lung cancer. In 555 patients with predicted postoperative values ≤60%, the 6MWT was performed. The 6-min walking distance (6MWD) and the distance-saturation product (DSP), which is the product of the 6MWD in metres, and the lowest oxygen saturation registered during the test were assessed.

A total of 363 patients with predicted postoperative values <60% and a 6MWT distance (6MWD) ≥400 m or DSP ≥ 350 m% had a lower rate of cardiopulmonary complications than patients with shorter 6MWD or lower DSP values [odds ratio (OR) 0.53, 95% confidence interval (CI) 0.35-0.81] and 0.47 (95% CI 0.30-0.73), respectively. This result was also true for patients with predicted postoperative values <40%, ORs 0.33 (95% CI 0.14-0.79) and 0.25 (95% CI 0.10-0.61), respectively.

The 6MWT is useful in the assessment of operative risk in patients undergoing a single lobectomy for lung cancer. It helps to stratify the operative risk, which is lower in patients with 6MWD ≥400 m or DSP ≥350 m% than in patients with a shorter 6MWD or lower DSP values.