The combined influence of multiple sex and growth hormones on risk of postmenopausal breast cancer: a nested case-control study
Couplée aux données de la cohorte "Nurses' Health Study", cette étude (265 cas et 541 témoins) évalue l'association entre des hormones sexuelles, des hormones de croissance et le risque de cancer du sein après la ménopause
INTRODUCTION:Sex and growth hormones are positively associated with postmenopausal breast cancer risk. However, few studies have evaluated the influence of multiple hormones simultaneously.METHODS:We considered the role of estrone, estradiol, estrone sulfate, testosterone, androstenedione, dehydroepiandrosterone (DHEA), DHEA sulfate, and prolactin, and secondarily insulin-like growth factor (IGF-1) and c-peptide, in postmenopausal breast cancer risk, among 265 cases and 541 controls in the prospective Nurses' Health Study (NHS). We created several hormone scores, including ranking women by the number of hormones above the age- and batch-adjusted geometric mean as well as weighting hormone values by their individual associations with breast cancer risk.RESULTS:Women in the top versus bottom quintile of individual estrogen or androgen levels had approximately a doubling of postmenopausal breast cancer risk. Having 7-8 vs. 0 hormones above the geometric mean level was associated with total (RR=2.7, 95%CI=1.3-5.7, p-trend<0.001) and ER+ (RR=3.4, 95%CI=1.3-9.4, p-trend<0.001) breast cancer risk. When comparing the top vs. bottom quintile of the score weighted by individual hormone associations, the RR for total breast cancer was 3.0 (95%CI=1.8-5.0, p-trend<0.001) and for ER+ disease was 3.9 (95%CI=2.0-7.5, p-trend<0.001); the risk further increased when including IGF-1 and c-peptide to the scores. Results did not change with adjustment for BMI.CONCLUSIONS:Overall, this study suggests that having multiple hormones with high circulating levels substantially increases risk of breast cancer, particularly for ER+ disease. Additional research should consider the potential impact to developing risk prediction scores incorporating hormones and prevention strategies.