Hormone Replacement Therapy, Family History, and Breast Cancer Risk Among Postmenopausal Women

Abstract

Background Evidence is mixed regarding how familial predisposition to breast cancer affects the relation between hormone replacement therapy and risk of postmenopausal breast cancer. We investigated whether the risk difference for invasive breast cancer attributable to estrogen plus progesterone replacement therapy is greater among women with a first-degree family history of the disease. Methods This study is a longitudinal follow-up of 16,608 postmenopausal women aged 50–79 years who were enrolled between 1993 and 2002 in the Women’s Health Initiative randomized trial of estrogen plus progesterone replacement therapy versus placebo. Results Three hundred forty-nine cases of invasive breast cancer occurred during a mean follow-up period of 5.6 years. The invasive breast cancer risk difference attributable to the hormone therapy was 0.007 among women with first-degree family history and 0.005 among the others, resulting in a negligible interaction contrast (IC = 0.002; 95% confidence interval = −0.014 to 0.018). The interaction contrast restricted to estrogen-receptor-positive invasive breast cancers was also negligible (IC = −0.006; 95% CI = −0.021 to 0.008). Conclusion Family history and estrogen plus progesterone replacement therapy have independent and noninteracting effects on the risk of invasive breast cancer among participants in the Women’s Health Initiative randomized trial.

A retrospective study on breast cancer presentation, risk factors, and protective factors in patients with a positive family history of breast cancer

“…Shah et al reported a 39% increase in the risk of breast cancer with postmenopausal combined estrogen and progesterone hormone therapy with OR = 1.35 (95%CI:1.16‐1.57) and OR = 1.63 (95%CI:1.22‐2.18) for less than and more than 5 years of use, respectively . However, HRT use in women with a positive family history of breast cancer was not associated with a greater incidence of breast cancer . The noninteracting effect of family history and HRT on the incidence of breast cancer was similarly demonstrated in this study also.…”

“…13 However, HRT use in women with a positive family history of breast cancer was not associated with a greater incidence of breast cancer. 14 two or more was marginally significant (P = .057) and protective (B = −0.540) of a positive family history of breast cancer (adjusted OR = 0.583, 95%CI:0.334, 1.016).…”

Menopausal Hormone Therapy for the Primary Prevention of Chronic Conditions: A Systematic Review to Update the U.S. Preventive Services Task Force Recommendations

“…In the WHI estrogen plus progestin trial, breast cancer incidence did not significantly differ on the basis of age, BMI, Gail risk score (18,20), or first-degree family history (26), but increased with previous use of oral contraceptives (20) or menopausal therapy with estrogen plus progestin (18,20) and with current smoking (20). Age also had no effect on the relationship between hormone therapy and breast cancer incidence in the WHI estrogen-only trial (2), but risks were significantly reduced in women without a previous biopsy indicating benign breast disease or a family history of breast cancer (63).…”

Comparison of annual percentage change in breast cancer incidence rate between Taiwan and the United States—A smoothed Lexis diagram approach

“…Since the 1960s, Taiwan has become increasingly industrialized . The Westernization of the citizens’ lifestyle has been suggested as a plausible cause of the rapid increase in FIBC incidence rates in Taiwan .…”