The fraction of cancer burden attributable to modifiable lifestyle risk factors in Switzerland

Cancer is the second leading cause of mortality and morbidity in Switzerland, with approximately 17,200 cancer deaths and more than 46,400 incident cases in 2019. Although the age-standardized mortality rates have been decreasing over the past few decades, the burden of cancer is predicted to increase due to demographic ageing. Many cancers caused by lifestyle risk factors are preventable, suggesting the potential of reducing the cancer burden by risk reduction. Quantifying the proportion of preventable cases related to risk factors (i.e., the population attributable fraction [PAF]), especially for those that are modifiable, can assist in identifying rising threats to population health and informing preventative strategies. Previous studies from the United States, the United Kingdom, Germany, Canada, and France have reported their country-specific attributable cancer case estimates. However, in Switzerland, such comprehensive cancer risk factor estimates remain unknown, leaving a void as authorities develop and update cancer control strategies. The aim of this project is to estimate the fraction of cancer burden attributable to modifiable risk factors in adults in Switzerland. These risk factors include alcohol drinking; tobacco (cigarette) smoking; presence of body fatness reflected by body mass index and waist circumference; physical inactivity; red meat consumption; processed meat consumption; diet low in fruit; diet low in non-starchy vegetable; diet low in fibre; diet low in dairy products; coffee consumption. Additionally, as a multilingual country with regional heterogeneity, the exposure prevalence of risk factors in Switzerland is known to vary between the major three major language regions (German, French, and Italian). We also aim to provide estimates of the attributable fraction of cancer burden on both national and regional levels.