Cho, E., W. Y. Chen, et al. (2006). "Red meat intake and risk
of breast cancer among premenopausal women." Arch Intern
Med 166(20): 2253-2259.
BACKGROUND:
The association between red meat intake and breast cancer is unclear,
but most studies have assessed diet in midlife or later. Although
breast tumors differ clinically and biologically by hormone receptor
status, few epidemiologic studies of diet have made this distinction.
METHODS: Red meat intake and breast cancer risk were assessed among
premenopausal women aged 26 to 46 years in the Nurses' Health Study
II. Red meat intake was assessed with a food frequency questionnaire
administered in 1991, 1995, and 1999, with respondents followed up
through 2003. Breast cancers were self-reported and confirmed by
review of pathologic reports. RESULTS: During 12 years of follow-up
of 90,659 premenopausal women, we documented 1021 cases of invasive
breast carcinoma. Greater red meat intake was strongly related to
elevated risk of breast cancers that were estrogen and progesterone
receptor positive (ER+/PR+; n = 512) but not to those that were estrogen
and progesterone receptor negative (ER-/PR-; n = 167). Compared with
those eating 3 or fewer servings per week of red meat, the multivariate
relative risks (95% confidence intervals) for ER+/PR+ breast cancer
with increasing servings of red meat intake were 1.14 (0.90-1.45)
for more than 3 to 5 or fewer servings per week, 1.42 (1.06-1.90)
for more than 5 per week to 1 or fewer servings per day, 1.20 (0.89-1.63)
for more than 1 to 1.5 or fewer servings per day, and 1.97 (1.35-2.88)
for more than 1.5 servings per day (test for trend, P = .001). The
corresponding relative risks for ER-/PR- breast cancer were 1.34
(0.89-2.00), 1.21 (0.73-2.00), 0.69 (0.39-1.23), and 0.89 (0.43-1.84)
(test for trend, P = .28). Higher intakes of several individual red
meat items were also strongly related to elevated risk of ER+/PR+
breast cancer. CONCLUSION: Higher red meat intake may be a risk factor
for ER+/PR+ breast cancer among premenopausal women.
