Adiposity, hormone replacement therapy use and breast cancer risk by age and hormone receptor status: a large prospective cohort study

作者：Ritte Rebecca; Lukanova Annekatrin; Berrino Franco; Dossus Laure; Tjonneland Anne; Olsen Anja; Overvad Thure Filskov; Overvad Kim; Clavel Chapelon Francoise; Fournier Agnes; Fagherazzi Guy; Rohrmann Sabine; Teucher Birgit; Boeing Heiner; Aleksandrova Krasimira; Trichopoulou Antonia; Lagiou Pagona; Trichopoulos Dimitrios; Palli Domenico; Sieri Sabina; Panico Salvatore; Tumino Rosario; Vineis Paolo; Ramon Quiros Jose; Buckland Genevieve; Sanchez Maria Jose; Amiano Pilar

来源：Breast Cancer Research, 2012, 14(3): R76.

DOI：10.1186/bcr3186

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. %26lt;br%26gt;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. %26lt;br%26gt;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 %26lt;= 49 years (per 5 kg/m(2) increase, HR = 0.79 (95%CI 0.68 to 0.91)), and positively associated with risk among women %26gt;= 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 (P-het = 0.035). The association of HRT was significantly stronger in the leaner women (BMI %26lt;= 22.5 kg/m(2)) than for more overweight women (BMI %26gt;= 25.9 kg/m(2)) 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. %26lt;br%26gt;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.

• 出版日期2012