PREDICTORS OF BREAST CANCER IN WOMEN RECALLED FOLLOWING SCREENING

Abstract

BACKGROUND: Established risk factors are associated with between 25 and 56% of breast cancer cases, but the relative importance and relevance to different age groups is unclear. METHODS: This case-control study examines established risk factors in 298 women with breast cancer and 1926 women without breast cancer aged 40-87 who were recalled for assessment following routine mammography. RESULTS: The cancer group were significantly older than the non-cancer group (F1,222 = 107.6; P < 0.0001). Postmenopausal obesity increased the odds of developing breast cancer (OR: 2.35; CI: 1.33-4.16). The breast cancer group were more likely to have used oral contraceptives (OR: 1.50; CI: 1.09-2.05), and women who used contraceptives for more than 10 years in total were at the highest risk (OR: 1.73; CI: 1.13-2.65). Daily consumption of alcohol was also associated with increased risk of developing breast cancer (OR: 1.62; CI: 1.13-2.33). Reproductive factors and a family history of breast cancer did not affect the odds of developing breast cancer and the reasons for these findings are explored. CONCLUSIONS: Results suggest that the effects of weight reduction in reducing postmenopausal breast cancer risk should be assessed.