Breast-cancer Incidence in Relation to Height, Weight and Body-fat Distribution in the Dutch "DOM" Cohort

In a cohort of 11,663 participants in a breast-cancer screening program, height, weight, waist circumference and hip circumference were measured, and information about menstrual and reproductive history was obtained by questionnaire. After exclusion of 83 women with unclear menopausal status, the subjects were divided into 3 sub-cohorts: 5,891 women who were pre-menopausal at the time of data collection, 3,521 women who had entered the study after natural menopause, and 2068 women who had been hysterectomized and/or ovariectomized. After a median follow-up of 10.6 years, 147, 76 and 52 incident cases of breast cancer were detected in the 3 respective sub-cohorts. No statistically significant association was found in any of the sub-cohorts between breast-cancer risk and height, weight, body-mass index (BMI) or hip circumference. In the sub-cohort of women with natural menopause, however, risk of breast cancer was positively and significantly associated with the ratio of waist-to-hip circumferences (WHR) (RR = 2.63 for upper vs. lower quartile), and this association did not change after adjustment for variations in disease risk related to body height and weight. Although similar to observations in other cohort studies showing positive associations between obesity and breast-cancer risk in post-menopausal women, our results are different, in that WHR and not BMI appears to be the more specific indicator of breast-cancer risk.