Burden Of Lung Cancer In Australia Avoidable By Modifications To Lifestyle-Related Risk Factors

Aim: The cancer burden avoidable through risk factor modification can be quantified using the Population Attributable Fraction (PAF) which combines estimates of the prevalence of the risk factor exposure in the population and the strength of the exposure-cancer association. PAF for risk factors causally related to cancer is most accurately estimated from cohort studies, using analytical approaches that account for death as a competing risk. We provide the first such estimates of the lifestyle-related avoidable lung cancer burden. Methods: Seven contemporary Australian cohort studies (N = 367,772), with comprehensive data on exposure to lifestyle-related risk factors, were linked to the Australian Cancer Database and National Death Index to identify lung cancers and deaths from any cause. The risk factors were harmonised across the studies and the data pooled. The strength of the exposure-cancer and exposure-death associations were estimated using a proportional hazards model, adjusting for age, sex and the other lifestyle exposures. Age- and sex-specific exposure prevalence was estimated from the Australian National Health Survey 2011-2012. These estimates were then combined to calculate the PAFs and their 95% confidence intervals (CI) using a newly developed method accounting for competing risk of death. Results: During the first 10-years follow-up, 2,030 incident lung cancers and 20,348 deaths were ascertained as first events. Smoking, physical inactivity and insufficient fruit intake were statistically significantly associated with both lung cancer incidence and death. Most of the lung cancer burden (PAF = 73%, CI = 69-76%) was attributable to current or past smoking, with 31% (CI = 27-35%) of the burden attributable to current smokers. Physical activity below Australian recommendations ( Conclusions: According to these joint PAF estimates, the current lung cancer burden in Australia could be reduced by up to half in 10 years by quitting smoking and increasing physical activity and fruit intake to the recommended levels. As the combined effect of risk factors is rarely additive, knowing both individual and joint effects of risk factors on cancer burden is essential in planning cancer interventions and public health policies and predicting their potential impact. Citation Format: Maarit A. Laaksonen, Maria Arriaga, Peter Hull, Karen Canfell, Robert MacInnis, Emily Banks, Graham Giles, Paul Mitchell, Robert Cumming, Barbara-Ann Adelstein, Julie Byles, Dianna J. Magliano, Jonathan Shaw, Anne Taylor, Kay Price, Vasant Hirani, Claire M. Vajdic. Burden of lung cancer in Australia avoidable by modifications to lifestyle-related risk factors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2280. doi:10.1158/1538-7445.AM2017-2280