Cardiorespiratory Fitness and Cancer In Women

Abstract

The preventive role of cardiorespiratory fitness (CRF) in cancer is not well established among women. PURPOSE: The current study sought to evaluate the association between CRF, cancer incidence and cancer mortality in women. METHODS: Maximal exercise testing was performed in pilot cohort of 184 women (59.3±15.2 years) free from malignancy at baseline who were followed for a mean of 12±6.9 years. Multivariate Cox hazard analyses were conducted for all-type cancer incidence and cancer mortality. Population Attributable Risks (PAR) and Number Needed to Treat (NNT) were determined for low CRF (<5 METs). RESULTS: During the follow-up, 11.4% were diagnosed with cancer and 3.2% died from cancer. CRF was inversely associated with cancer outcomes. For every 1 MET higher CRF there was a 19% reduction in cancer incidence [Hazard Ratio (HR) 0.81, 95% Confidence Intervals (CI) (0.68 to 0.96), p=0.016)] and 38% reduction in cancer mortality [HR 0.62, 95%CI (0.42 to 0.92), p=0.017]. The PARs% and NNT of low CRF was 12.3% and 16.6% and 5 and 8 for cancer incidence and cancer mortality, respectively. CONCLUSIONS: Higher CRF is associated with lower risk for cancer incidence and cancer mortality in women, suggesting the possible protective benefits for cancer prevention. Eliminating low CRF as a risk factor would potentially prevent considerable cancer morbidity and mortality and reduce the associated societal-economic burden. Achieving CRF of ≥5 METs could be cost-effective for public health and may play an important role in primary cancer prevention programs. Future large cohorts should ascertain these findings.