Diet patterns and breast cancer risk in Hispanic and non-Hispanic white women: the Four-Corners Breast Cancer Study.

BACKGROUND: There is a lower incidence of breast cancer among Hispanic women than among non-Hispanic white women. Little is known about the role of diet in this difference.
OBJECTIVE: We examined the associations of dietary patterns (Western, Prudent, Native Mexican, Mediterranean, and Dieter) with risk for breast cancer in Hispanic women (757 cases, 867 controls) and non-Hispanic white women (1524 cases, 1598 controls) from the Four-Corners Breast Cancer Study.
DESIGN: Dietary intake, physical activity, and other exposures were assessed by using interviews. Dietary patterns were defined via factor analysis. Risk was assessed by using logistic regression with adjustment for age, center, education, smoking, total activity, calories, dietary fiber, dietary calcium, height, parity, recent hormone exposure, family history of breast cancer, menopausal status, and body mass index x recent hormone exposure.
RESULTS: The Western (odds ratio for highest versus lowest quartile: 1.32; 95% CI: 1.04, 168; P for trend < 0.01) and Prudent (1.42; 1.14, 1.77; P for trend < 0.01) dietary patterns were associated with greater risk, and the Native Mexican (0.68; 0.55, 0.85; P for trend < 0.01) and Mediterranean (0.76; 0.63, 0.92; P for trend < 0.01) dietary patterns were associated with lower risk of breast cancer. Body mass index modified the associations of the Western diet and breast cancer among postmenopausal women and those of the Native Mexican diet among premenopausal women.
CONCLUSIONS: Associations of dietary patterns with breast cancer risk varied by menopausal and body mass index status, but there was little difference in associations between non-Hispanic white and Hispanic women.