Peak oxygen consumption and long-term all-cause mortality in nonsmall cell lung cancer

BACKGROUND: Identifying strong markers of prognosis is critical to optimize treatment and survival outcomes in patients with nonsmall cell lung cancer (NSCLC). The authors investigated the prognostic significance of preoperative cardiorespiratory fitness (peak oxygen consumption [VO _2peak]) among operable candidates with NSCLC. METHODS: By using a prospective design, 398 patients with potentially resectable NSCLC enrolled in Cancer and Leukemia Group B 9238 were recruited between 1993 and 1998. Participants performed a cardiopulmonary exercise test to assess VO _2peak and were observed until death or June 2008. Cox proportional models were used to estimate the risk of all-cause mortality according to cardiorespiratory fitness category defined by VO _2peak tertiles (<0.96 of 0.96-1.29/>1.29 L/min ^-1) with adjustment for age, sex, and performance status. RESULTS: Median follow-up was 30.8 months; 294 deaths were reported during this period. Compared with patients achieving a VO _2peak <0.96 L/min ^-1, the adjusted hazard ratio (HR) for all-cause mortality was 0.64 (95% confidence interval [CI], 046-0.88) for a VO _2peak of 0.96 to 1.29 L/min ^-1, and 0.56 (95% CI, 0.39-0.80) for a VO _2peak of >1.29 L/min ^-1 (P _trend =.0037). The corresponding HRs for resected patients were 0.66 (95% CI, 0.46-0.95) and 0.59 (95% CI, 0.40-0.89) relative to the lowest VO _2peak category (P _trend =.0247), respectively. For nonresected patients, the HRs were 0.78 (95% CI, 0.34-1.79) and 0.39 (95% CI, 0.16-0.94) relative to the lowest category (P _trend =.0278). CONCLUSIONS: VO _2peak is a strong independent predictor of survival in NSCLC that may complement traditional markers of prognosis to improve risk stratification and prognostication.