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Type: Journal Article × Start date: 2010 × End date: 2015 × Author: Ritte, Rebecca ×

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    Reproductive factors and risk of hormone receptor positive and negative breast cancer: a cohort study
    Ritte, R ; Tikk, K ; Lukanova, A ; Tjonneland, A ; Olsen, A ; Overvad, K ; Dossus, L ; Fournier, A ; Clavel-Chapelon, F ; Grote, V ; Boeing, H ; Aleksandrova, K ; Trichopoulou, A ; Lagiou, P ; Trichopoulos, D ; Palli, D ; Berrino, F ; Mattiello, A ; Tumino, R ; Sacerdote, C ; Ramon Quiros, J ; Buckland, G ; Molina-Montes, E ; Chirlaque, M-D ; Ardanaz, E ; Amiano, P ; Bueno-de-Mesquita, HB ; van Gils, CH ; Peeters, PHM ; Wareham, N ; Khaw, K-T ; Key, TJ ; Travis, RC ; Weiderpass, E ; Dumeaux, V ; Lund, E ; Sund, M ; Andersson, A ; Romieu, I ; Rinaldi, S ; Vineis, P ; Merritt, MA ; Riboli, E ; Kaaks, R (BMC, 2013-12-09)
    BACKGROUND: The association of reproductive factors with hormone receptor (HR)-negative breast tumors remains uncertain. METHODS: Within the EPIC cohort, Cox proportional hazards models were used to describe the relationships of reproductive factors (menarcheal age, time between menarche and first pregnancy, parity, number of children, age at first and last pregnancies, time since last full-term childbirth, breastfeeding, age at menopause, ever having an abortion and use of oral contraceptives [OC]) with risk of ER-PR- (n = 998) and ER+PR+ (n = 3,567) breast tumors. RESULTS: A later first full-term childbirth was associated with increased risk of ER+PR+ tumors but not with risk of ER-PR- tumors (≥35 vs. ≤19 years HR: 1.47 [95% CI 1.15-1.88] p(trend) < 0.001 for ER+PR+ tumors; ≥35 vs. ≤19 years HR: 0.93 [95% CI 0.53-1.65] p(trend) = 0.96 for ER-PR- tumors; P(het) = 0.03). The risk associations of menarcheal age, and time period between menarche and first full-term childbirth with ER-PR-tumors were in the similar direction with risk of ER+PR+ tumors (p(het) = 0.50), although weaker in magnitude and statistically only borderline significant. Other parity related factors such as ever a full-term birth, number of births, age- and time since last birth were associated only with ER+PR+ malignancies, however no statistical heterogeneity between breast cancer subtypes was observed. Breastfeeding and OC use were generally not associated with breast cancer subtype risk. CONCLUSION: Our study provides possible evidence that age at menarche, and time between menarche and first full-term childbirth may be associated with the etiology of both HR-negative and HR-positive malignancies, although the associations with HR-negative breast cancer were only borderline significant.
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    Adiposity, hormone replacement therapy use and breast cancer risk by age and hormone receptor status: a large prospective cohort study
    Ritte, R ; Lukanova, A ; Berrino, F ; Dossus, L ; Tjonneland, A ; Olsen, A ; Overvad, TF ; Overvad, K ; Clavel-Chapelon, F ; Fournier, A ; Fagherazzi, G ; Rohrmann, S ; Teucher, B ; Boeing, H ; Aleksandrova, K ; Trichopoulou, A ; Lagiou, P ; Trichopoulos, D ; Palli, D ; Sieri, S ; Panico, S ; Tumino, R ; Vineis, P ; Ramon Quiros, J ; Buckland, G ; Sanchez, M-J ; Amiano, P ; Chirlaque, M-D ; Ardanaz, E ; Sund, M ; Lenner, P ; Bueno-de-Mesquita, B ; van Gils, CH ; Peeters, PHM ; Krum-Hansen, S ; Gram, IT ; Lund, E ; Khaw, K-T ; Wareham, N ; Allen, NE ; Key, TJ ; Romieu, I ; Rinaldi, S ; Siddiq, A ; Cox, D ; Riboli, E ; Kaaks, R (BMC, 2012)
    INTRODUCTION: Associations of hormone-receptor positive breast cancer with excess adiposity are reasonably well characterized; however, uncertainty remains regarding the association of body mass index (BMI) with hormone-receptor negative malignancies, and possible interactions by hormone replacement therapy (HRT) use. METHODS: Within the European EPIC cohort, Cox proportional hazards models were used to describe the relationship of BMI, waist and hip circumferences with risk of estrogen-receptor (ER) negative and progesterone-receptor (PR) negative (n = 1,021) and ER+PR+ (n = 3,586) breast tumors within five-year age bands. Among postmenopausal women, the joint effects of BMI and HRT use were analyzed. RESULTS: For risk of ER-PR- tumors, there was no association of BMI across the age bands. However, when analyses were restricted to postmenopausal HRT never users, a positive risk association with BMI (third versus first tertile HR = 1.47 (1.01 to 2.15)) was observed. BMI was inversely associated with ER+PR+ tumors among women aged ≤49 years (per 5 kg/m2 increase, HR = 0.79 (95%CI 0.68 to 0.91)), and positively associated with risk among women ≥65 years (HR = 1.25 (1.16 to 1.34)). Adjusting for BMI, waist and hip circumferences showed no further associations with risks of breast cancer subtypes. Current use of HRT was significantly associated with an increased risk of receptor-negative (HRT current use compared to HRT never use HR: 1.30 (1.05 to 1.62)) and positive tumors (HR: 1.74 (1.56 to 1.95)), although this risk increase was weaker for ER-PR- disease (Phet = 0.035). The association of HRT was significantly stronger in the leaner women (BMI ≤22.5 kg/m2) than for more overweight women (BMI ≥25.9 kg/m2) for, both, ER-PR- (HR: 1.74 (1.15 to 2.63)) and ER+PR+ (HR: 2.33 (1.84 to 2.92)) breast cancer and was not restricted to any particular HRT regime. CONCLUSIONS: An elevated BMI may be positively associated with risk of ER-PR- tumors among postmenopausal women who never used HRT. Furthermore, postmenopausal HRT users were at an increased risk of ER-PR- as well as ER+PR+ tumors, especially among leaner women. For hormone-receptor positive tumors, but not for hormone-receptor negative tumors, our study confirms an inverse association of risk with BMI among young women of premenopausal age. Our data provide evidence for a possible role of sex hormones in the etiology of hormone-receptor negative tumors.