Higher cardiorespiratory fitness tied to lower risk for colorectal cancer

  • Hillreiner A & al.
  • Eur J Epidemiol
  • 9 Nov 2019

  • curated by Sarfaroj Khan
  • UK Clinical Digest
Access to the full content of this site is available only to registered healthcare professionals. Access to the full content of this site is available only to registered healthcare professionals.

Takeaway

  • High level of cardiorespiratory fitness was associated with reduction in the risk for colorectal cancer.
  • The reduction in risk was more evident in men than women, although the sex difference was not statistically significant.

Why this matters

  • Findings indicate that achieving a high level of fitness by individuals who are currently unfit represents a significant individual-level and public health opportunity to lower the risk for colorectal cancer.

Study design

  • Prospective analysis of cardiorespiratory fitness in relation to colorectal cancer in 59,191 UK Biobank participants (aged 39-70 years) without prevalent cancer.
  • Cardiorespiratory fitness was defined as physical work capacity at 75% of the maximum heart rate, standardised to body mass (PWC75%).
  • Funding: UK Biobank was supported by the Wellcome Trust and others.

Key results

  • 232 cases of colorectal cancer (151 colon cancers; 79 rectal cancers) were reported during a mean follow-up of 4.6 years.
  • The adjusted HR of colorectal cancer per interquartile increase in cardiorespiratory fitness was 0.78 (95% CI, 0.62-0.97).
  • This inverse association was more pronounced for colon cancer (HR, 0.74; 95% CI, 0.56-0.97) and was weakest for rectal cancer (HR, 0.88; 95% CI, 0.62-1.26).
  • Cardiorespiratory fitness showed an inverse association with colorectal cancer in men (HR, 0.72; 95% CI, 0.55-0.94) but not in women (HR, 0.99; 95% CI, 0.71-1.38), although the interaction by sex was not statistically significant (P=.192).

Limitations

  • Relatively short follow-up period; limited number of cases, especially in the subsite analyses.