Preoperative exercise Vo2 measurement for lung resection candidates:: Results of Cancer and Leukemia Group B protocol 9238

Introduction: A stepwise approach to the functional assessment of lung resection candidates is widely accepted, and this approach incorporates the measurement of exercise peak Vo(2) when spirometry and radionuclear studies suggest medical inoperability. A new functional operability (FO) algorithm incorporates peak exercise Vo(2) earlier in the preoperative assessment to determine which patients require preoperative radionuclear studies. This algorithm has not been studied in a multicenter study. Methods: The CALGB (Cancer and Leukemia Group 13) performed a prospective multi-institutional study to investigate the use of primary exercise Vo(2) measurement for the prediction of surgical risk. Patients with known or suspected resectable non-small cell lung cancer (NSCLC) were eligible. Exercise testing including measurement of peak oxygen uptake (Vo(2)), spirometry, and single breath diffusion capacity (DLCO) was performed on each patient. Nuclear perfusion scans were obtained on selected high-risk patients. After surgery, morbidity and mortality data were collected and correlated with preoperative data. Mortality and morbidity were retrospectively compared by algorithm-based risk groups. Results: Three hundred forty-six patients with suspected lung cancer from nine institutions underwent thoracotomy with or without resection,- 57 study patients did not undergo thoracotomy. Patients who underwent surgery had a median survival time of 30.9 months, whereas patients who did not undergo surgery had a median survival time of 15.6 months. Among the 346 patients who underwent thoracotomy, 15 patients died postoperatively (4%), and 138 pa-tients (39%) exhibited at least one cardiorespiratory complication postoperatively. We found that patients who had a peak exercise Vo(2) of <65% of predicted (or a peak Vo,/kg <16 ml/min/kg) were more likely to suffer complications (p = 0.0001) and were also more likely to have a poor outcome (respiratory failure or death) if the peak Vo(2) was < 15 ml/min/kg (p = 0.0356). We also found a subset of 58 patients who did not meet FO algorithm criteria for operability, but who still tolerated lung resection with a 2% mortality rate. Conclusions: Our data provide multicenter validation for the use of exercise Vo(2) for preoperative assessment of lung cancer patients, and we encourage an aggressive approach when evaluating these patients for surgery.