Abstract 2283: Population-level relevance of lifestyle-related risk factors for pancreatic cancer in Australia

Aim: To estimate the proportion of exocrine pancreatic cancers in Australia that can be attributed to the established risk factors, smoking and excess body weight, and the suggested risk factors, excessive alcohol consumption and excessive red and processed meat consumption. Methods: The proportion of pancreatic cancers attributable to lifestyle-related risk factors was quantified using the Population Attributable Fraction (PAF) which combines estimates of the strength of the exposure-cancer association and the exposure prevalence in the population. The study population included seven Australian cohort studies (N=367,772) with comprehensive data on exposure to lifestyle-related risk factors and long-term follow-up. Pancreatic cancer incidence and all-cause mortality were identified through linkage with the Australian Cancer Database and National Death Index, respectively. A proportional hazards model was used to estimate the strength of exposure-cancer and exposure-death associations adjusting for age, sex and other lifestyle exposures. The age- and sex-specific exposure prevalence was calculated from the Australian National Health Survey (NHS) 2011-2012 except for red and processed meat consumption which was not available and was calculated from the latest 45 and Up study. A newly developed method that takes into account the competing risk of death was used to produce PAF estimates and their 95% confidence intervals (CIs). Results: During the first 10-years follow-up to incidence of pancreatic cancer, death or end of follow-up, there were 21,541 deaths and 613 incident exocrine pancreatic cancers. 10% (CI = 1-17%) of pancreatic cancers in Australia could be attributed to current or past smoking. Current smoking explained 8% (CI = 4-13%) of pancreatic cancers. Using cancer incidence projections estimated by the Australian Institute of Health and Welfare, a PAF of 8% translates to 2,700 potentially preventable pancreatic cancers over the next 10 years. The PAF results for excess body weight (≥ 25 kg/m2), excessive alcohol consumption (> 2 drinks/day) and excessive red and processed meat consumption (≥ 4 times/week) were not statistically significant. Conclusion: According to the first pancreatic cancer PAF results from cohort studies, and accounting for competing risk of death, smoking control could reduce the number of pancreatic cancers by one tenth. Further PAF studies should include confidence intervals for the estimates to allow an evaluation of their significance. Citation Format: Maria E. Arriaga, Maarit A. Laaksonen, Karen Canfell, Robert MacInnis, Emily Banks, Graham Giles, Paul Mitchell, Robert Cumming, Barbra-Ann Adelstein, Julie Byles, Dianna J. Magliano, Jonathan Shaw, Anne Taylor, Kay Price, Vasant Hirani, Claire M. Vajdic. Population-level relevance of lifestyle-related risk factors for pancreatic cancer in Australia [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 2283. doi:10.1158/1538-7445.AM2017-2283