Preoperative maximum oxygen consumption is associated with prognosis after pulmonary resection in stage I non-small cell lung cancer.
BACKGROUND
The objective of this investigation was to evaluate whether maximum oxygen consumption (VO2max) is a reliable prognostic factor after lung resection for pathologic stage I non-small cell lung cancer (NSCLC).


METHODS
Observational analysis of 157 patients undergoing pulmonary lobectomy or segmentectomy for pathologic stage I (T1 or T2-N0 only) NSCLC, with preoperative measurement of Vo2max and complete follow-up (2006-2011). Survival was calculated by the Kaplan-Meier method. The log-rank test was used to assess differences in survival between groups. The relationships between survival and several baseline and clinical variables were determined by Cox multivariate analyses.


RESULTS
The median follow-up time was 40 months. The average preoperative Vo2max was 16.1 mL/kg · min and 69% of predicted value. Sixty-two (40%) patients had a Vo2max below 60%. The median and 5-year overall survivals of patients with preoperative Vo2max above 60% were significantly longer than in those with Vo2max below 60% (median not reached vs 48 months: 73% vs 40%, p=0.0004). Cox regression model showed that an age older than 70 years (p=0.005, hazard ratio 2.3) and Vo2max below 60% (p=0.001, hazard ratio 2.4) were independent prognostic factors significantly associated with overall survival. Cancer-specific survival was also longer in patients with Vo2max above 60% (81% vs 61%, p=0.01).


CONCLUSIONS
Exercise tolerance may influence the physiologic outcomes associated with cancer that can potentially affect survival. Physical rehabilitation aimed at improving exercise tolerance can possibly improve the long-term prognosis after operations for lung cancer.