TY - JOUR
T1 - Menstrual risk factors and early-onset breast cancer
AU - Butler, Lesley M.
AU - Potischman, Nancy A.
AU - Newman, Beth
AU - Millikan, Robert C.
AU - Brogan, Donna
AU - Gammon, Marilie D.
AU - Swanson, Christine A.
AU - Brinton, Louise A.
PY - 2000
Y1 - 2000
N2 - Objectives: Epidemiologic studies provide evidence for increased breast cancer risk among women with prolonged exposure to endogenous estrogens and progesterone. Menstrual cycle characteristics, such as early menarche, rapid initiation of regular ovulatory cycles, short cycle length, and more days of flow, all potentially contribute to higher cumulative ovarian hormone exposure. Methods: We assessed the associations between these characteristics and breast cancer risk in a population-based, case-control study of 1505 controls and 1647 newly diagnosed cases, all younger than 45 years of age. Results: Compared to women with menarche at ≥ 15 years, we observed some increase in risk for women with younger ages at menarche, although those with very early ages were not at particularly high risk [odds ratio (OR) = 1.5, 95% confidence interval (CI) = 1.1-1.9 for menarche at age 12 and OR = 1.2, 95% CI = 0.9-1.7 for menarche at age ≤ 10]. Women who reported having regular menstrual cycles within 2 years of menarche were at increased breast cancer risk (OR = 1.7, 95% CI = 1.2-2.3), compared to those never having regular cycles. Stratification by current body mass index revealed slightly stronger associations with menstrual characteristics among thinner women (< 22.0 kg/m2) compared to heavier women (> 28.8 kg/m2). Conclusions: These findings suggest that future studies should focus on clarifying how the interrelated effects of body size and menstrual factors, such as age at menarche and cycle regularity, contribute to breast cancer etiology.
AB - Objectives: Epidemiologic studies provide evidence for increased breast cancer risk among women with prolonged exposure to endogenous estrogens and progesterone. Menstrual cycle characteristics, such as early menarche, rapid initiation of regular ovulatory cycles, short cycle length, and more days of flow, all potentially contribute to higher cumulative ovarian hormone exposure. Methods: We assessed the associations between these characteristics and breast cancer risk in a population-based, case-control study of 1505 controls and 1647 newly diagnosed cases, all younger than 45 years of age. Results: Compared to women with menarche at ≥ 15 years, we observed some increase in risk for women with younger ages at menarche, although those with very early ages were not at particularly high risk [odds ratio (OR) = 1.5, 95% confidence interval (CI) = 1.1-1.9 for menarche at age 12 and OR = 1.2, 95% CI = 0.9-1.7 for menarche at age ≤ 10]. Women who reported having regular menstrual cycles within 2 years of menarche were at increased breast cancer risk (OR = 1.7, 95% CI = 1.2-2.3), compared to those never having regular cycles. Stratification by current body mass index revealed slightly stronger associations with menstrual characteristics among thinner women (< 22.0 kg/m2) compared to heavier women (> 28.8 kg/m2). Conclusions: These findings suggest that future studies should focus on clarifying how the interrelated effects of body size and menstrual factors, such as age at menarche and cycle regularity, contribute to breast cancer etiology.
KW - Breast neoplasm
KW - Menstruation
KW - Risk factors
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U2 - 10.1023/A:1008956524669
DO - 10.1023/A:1008956524669
M3 - Article
C2 - 10877338
AN - SCOPUS:0034094912
VL - 11
SP - 451
EP - 458
JO - Cancer Causes and Control
JF - Cancer Causes and Control
SN - 0957-5243
IS - 5
ER -