Cardiorespiratory fitness, incidence and mortality of lung cancer in men: A prospective cohort study.

OBJECTIVES

To evaluate the association between cardiorespiratory fitness (CRF), lung cancer incidence and cancer mortality in men.

DESIGN

Prospective cohort study.

METHODS

Maximal exercise testing was performed in 4920 men (59.2±11.4years) free from malignancy at baseline. Multivariate Cox hazard models adjusted for established cancer risk factors including smoking were analyzed for lung cancer incidence and cancer mortality among those who were diagnosed with lung cancer. Population attributable risks (PAR) of low CRF (<5 METs) were determined.

RESULTS

During 12.7±7.5years follow-up, 105 (2.1%) participants were diagnosed with lung cancer and 83 (79%) of those died from cancer after 3.6±4.6 years from diagnosis. CRF was inversely and independently associated with cancer outcomes. A 1-MET increase and categories of moderate and high CRF were associated with 10%, 47% and 65% reduction in lung cancer incidence (p=0.002), and 13%, 58% and 76% reduction in cancer mortality (p=0.002), respectively. Also, individuals who were diagnosed with lung cancer and were at moderate or high CRF categories at baseline exhibited longer survival time (p<0.001). The PARs% for lung cancer incidence and cancer mortality were 8.7% and 18.5%, respectively.

CONCLUSIONS

Higher CRF is associated with lower lung cancer incidence in men. Among individuals who were diagnosed with lung cancer, higher CRF was associated with reduced cancer mortality and longer survival time. These results support the protective benefits of higher CRF in the prevention of lung cancer outcomes. Eliminating low CRF as a risk factor would potentially prevent considerable lung cancer morbidity and mortality.