Abstract A90: The attribution of lifestyle related risk factors in middle age on breast cancer incidence in The Netherlands: Preliminary results

Abstract

Abstract Background: Breast cancer, especially postmenopausal, is one of the most common cancers in Western women. Although therapeutic options have improved, there still is a high mortality rate. Several of the known risk factors for breast cancer are lifestyle related and modifiable, providing an opportunity for primary prevention. Middle-aged women still have the chance to modify these factors to lower nearby breast cancer risk. We estimated the fraction of postmenopausal breast cancer cases that is attributable to lifestyle factors as currently present in middle-aged Dutch women. Methods: We estimated population attributable fractions (PAFs) of five potentially modifiable risk factors for Dutch women aged 45-54 years. Risk factors included overweight and obesity, alcohol use, physical inactivity, current use of hormone replacement therapy (HRT) and oral contraceptives. We based relative risks on literature search including meta-analyses and expert group consensus. Current prevalence rates of the risk factors were derived from several Dutch registration databases and national surveys (2009-2011). Results: Of all 45-54 year old contemporary Dutch women, 46% are estimated to be physically inactive, 43% to be overweight or obese, 42% to drink alcohol, 1% to use HRT and 17% to use contraceptives. These risk factors jointly account for an estimated 20.2% of all future breast cancer cases in these women. Physical inactivity and alcohol use are responsible for the highest population attributable fraction (PAF of 7.0% and 6.8% respectively), followed by overweight and obesity (4.3%), oral contraceptive use (3.4%) and hormone replacement therapy (0.6%). Conclusion: On a population level, lifestyle related factors play an important role in the development of postmenopausal breast cancer. Considering current prevalence rates in the Netherlands, our findings imply that modifiable risk factors present at middle-age are jointly responsible for 1 out of every 5 future breast cancer cases. This is in concordance with other studies in European countries. Our findings thus suggest that incidence rates can be lowered substantially by changing lifestyle habits, even in a woman's later life. Citation Format: WAM van Gemert, SG Elias, RA Bausch-Goldbohm, PA van den Brandt, HG Grooters, E Kampman, LALM Kiemeney, FE van Leeuwen, EM Monninkhof, E De Vries, PHM Peeters. The attribution of lifestyle related risk factors in middle age on breast cancer incidence in The Netherlands: Preliminary results. [abstract]. In: Proceedings of the Eleventh Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2012 Oct 16-19; Anaheim, CA. Philadelphia (PA): AACR; Cancer Prev Res 2012;5(11 Suppl):Abstract nr A90.