The Association Between Cruciferous Vegetables Intake and Breast Cancer Risk among Women with Familial Breast Cancer

Background The effect of cruciferous vegetables consumption on breast cancer risk is controversial. Cruciferous vegetables are a primary source of glucosinolates that have shown anticarcinogenic effects in etiological studies. Some prior epidemiological and intervention studies suggested the protective effect of crucifers on breast cancer risk but the results were inconsistent. This study evaluated the effect of crucifers on breast cancer risk among women from a familial risk cohort. Methods To address this issue, a hospital-based case-control study was conducted among 200 cases and 200 controls matched on age at baseline and enrollment year, from the same familial risk cohort. A self-developed food frequency questionnaire was applied to assess the consumption of 25 subtypes of crucifers. Adjusted odds ratios (ORs) and 95% confidence intervals (95% CI) were estimated from conditional logistic regression. Cases and controls were stratified by menopausal status and body mass index (BMI, cutoff point 25 kg/m2) and unconditional logistic regression was used in stratified analyses. Results The median consumption of total crucifers was 1 serving/day in cases and less than one serving/day in controls. Total crucifers intake was not associated with breast cancer risk after adjusting for breast cancer risk factors. Broccolini showed a protective effect that closed to significance on the development of breast cancer (adjusted OR=0.51, 95% CI = [0.25, 1.01], and P = 0.06). BMI modified the association between total crucifers consumption and breast cancer risk (P = 0.015). Most subtypes non-significantly decreased the odds of developing breast cancer among normal BMI women while non-significantly increased the odds of developing breast cancer among overweight/obese women. Conclusions To the best of our knowledge, this is the first study to examine the impact of cruciferous vegetables on breast cancer risk among women with a familial breast cancer risk and one of the few studies that has collected detailed information on crucifer intake. Total cruciferous vegetables intake was not associated with breast cancer risk among women with a familial risk. Our results suggested that BMI may modify the association between the cruciferous vegetables and breast cancer risk among the high-risk population