Objectives: This study aimed to investigate the association between physical activity and site-specific cancer incidence.
Methods: UK Biobank is a prospective population-based cohort study. 364,899 adults (51.6% females, mean age 56.0 years) were included. The exposure variable was physical activity level derived from the International Physical Activity Questionnaire-Short Form (IPAQ-SF). Participants were categorised at 'high' (=1,500 MET-minutes/week), 'moderate' (=600 MET-minutes/week) or 'low' levels of activity following standardised IPAQ-SF scoring guidance. Primary outcome measures included incident cancers at 20 sites. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) showing relationships between physical activity and cancer.
Results: 21,816 incident cancers were identified. Significant associations were identified between high physical activity levels and lower risk of lung (HR 0.81, 95% CI: 0.70, 0.94), breast (female only) (HR 0.85, 95% CI: 0.77, 0.94), hepatobiliary tract (HR 0.72, 95% CI: 0.53, 0.97), and colon (HR 0.86, 95% CI: 0.74, 0.99) cancers compared to low physical activity levels. Moderate levels of physical activity were associated with significantly lower risk of oropharyngeal (HR 0.71, 95% CI: 0.55, 0.93), and lung cancer (HR 0.86, 95% CI: 0.74, 0.99) compared to low physical activity levels. Sensitivity analyses showed associations of higher physical activity with lower oesophageal and higher prostate cancer incidence.
Conclusions: Regular physical activity is significantly associated with reduced risk for lung, breast, hepatobiliary tract, colon and oropharyngeal cancers. Our findings highlight the importance of physical activity promotion, particularly high levels of physical activity, in cancer prevention.
A multi-level approach to better understand the association between physical activity and sedentary behaviour, and cancer risk
Our aims are to investigate physical activity behaviour and sedentary behaviour, and cancer risk, including better estimations of the magnitude of risk by different cancer sites.
Specifically, we aim:
1) To evaluate correlations between physical activity and sedentary behaviour data and relevant biomarkers related to physical activity/sedentary behaviour and cancer
2) To analyse the association between physical activity and sedentary behaviour data and relevant genetic variants identified within GWAS data and cancer risk.
3) To analyse factors related to the built environment, physical activity, sedentary behaviour, and cancer risk. The aim of UK Biobank is to improve the prevention, diagnosis and treatment of serious and life-threatening illnesses, including cancer. The proposed research will elucidate the role of physical activity and sedentary behaviour in cancer prevention. The study will provide insight into biological mechanisms by which physical activity and sedentary behaviour may impact on different cancer sites, the role of individual modifiable and non-modifiable characteristics, and built environment factors in influencing the association between physical activity, sedentary behaviour, and cancer risk. Results will help inform the development of future physical activity/sedentary behaviour related interventions for cancer prevention. Linkage between UK Biobank and cancer registries provides information on cohort members who have been diagnosed with cancers. Using appropriate statistical techniques, we will compare physical activity and sedentary behaviour amongst cohort members who have developed cancer with those who have not developed these cancers, examining questionnaire and accelerometer (measure of physical activity/sedentary behaviour) data. We will also evaluate the associations with relevant biomarkers from the panel of blood/urinary markers and genetic analyses to be undertaken on all cohort members. The full cohort will be included in all analyses to be undertaken.
|Lead investigator:||Dr Ruth Hunter|
|Lead institution:||Queen's University Belfast|