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

Abstract

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.

• Authors: Rebecca Ritte, Annekatrin Lukanova, Franco Berrino, Laure Dossus, Anne Tjønneland, Anja Olsen, Thure Filskov Overvad, Kim Overvad, Françoise Clavel-Chapelon, Agnès Fournier, Guy Fagherazzi, Sabine Rohrmann, Birgit Teucher, Heiner Boeing, Krasimira Aleksandrova, Antonia Trichopoulou, Pagona Lagiou, Dimitrios Trichopoulos, Domenico Palli, Sabina Sieri, Salvatore Panico, Rosario Tumino, Paolo Vineis, José Ramón Quirós, Genevieve Buckland, Maria-José Sánchez, Pilar Amiano, María-Dolores Chirlaque, Eva Ardanaz, Malin Sund, Per Lenner, Bas Bueno-de-Mesquita, Carla H van Gils, Petra Hm Peeters, Sanda Krum-Hansen, Inger Torhild Gram, Eiliv Lund, Kay-Tee Khaw, Nick Wareham, Naomi E Allen, Timothy J Key, Isabelle Romieu, Sabina Rinaldi, Afshan Siddiq, David Cox, Elio Riboli, Rudolf Kaaks
• Journal: Breast cancer research : BCR (Breast Cancer Res) Vol. 14 Issue 3 Pg. R76 (May 14 2012) ISSN: 1465-542X [Electronic] England
• PMID: 22583394 (Publication Type: Journal Article, Multicenter Study, Research Support, Non-U.S. Gov't)

Chemical References

• Receptors, Estrogen
• Receptors, Progesterone

Topics

• Adiposity
• Adult
• Age Factors
• Aged
• Aged, 80 and over
• Body Mass Index
• Breast Neoplasms (etiology, metabolism)
• Cohort Studies
• Estrogen Replacement Therapy
• Female
• Humans
• Middle Aged
• Postmenopause
• Premenopause
• Prospective Studies
• Receptors, Estrogen (metabolism)
• Receptors, Progesterone (metabolism)
• Risk
• Risk Factors
• Young Adult