Family History of Breast Cancer and HRT

The evidence shows that  having a Family history of Breast Cancer does not increase your risk of BC  if taking HRT. Having a family history of breast cancer means there is a higher risk of breast cancer anyway,  but taking HRT won’t increase that risk. It may actually reduce the risk. See following evidence for this:
Ann Intern Med. 1997 Dec 1;127(11):973-80.

The role of hormone replacement therapy in the risk for breast cancer and total mortality in women with a family history of breast cancer.


Division of Epidemiology, University of Minnesota, Minneapolis 55454, USA.



The risks and benefits of hormone replacement therapy (HRT) are of considerable interest and importance, especially in terms of whether they differ among subsets of women.


To determine whether HRT is associated with increased risks for breast cancer and total mortality in women with a family history of breast cancer.


Prospective cohort study.


Population-based sample of midwestern post-menopausal women enrolled in an observational study of risk factors for cancer.


Random sample of 41,837 female Iowa residents 55 to 69 years of age.


Incidence rates of and relative risks for breast cancer (n = 1085) and total mortality (n = 2035) through 8 years of follow-up were calculated by using data from the State Health Registry of Iowa and the National Death Index.


A family history of breast cancer was reported by 12.2% of the cohort at risk. Among women with a family history of breast cancer, those who currently used HRT and had done so for at least 5 years developed breast cancer at an age-adjusted annual rate of 61 cases per 10,000 person-years (95% CI, 28 to 94 cases); this rate was not statistically significantly higher than the rate in women who had never used HRT (46 cases per 10,000 person-years [CI, 36 to 55 cases]). Among women with a family history, those who used HRT had a significantly lower risk for total mortality than did women who had never used HRT (relative risk, 0.67 [CI, 0.51 to 0.89]), including total cancer-related mortality (relative risk, 0.75 [CI, 0.50 to 1.12]). The age-adjusted annual mortality rate for women using HRT for at least 5 years was 46 deaths per 10,000 person-years (CI, 19 to 74 deaths); this is roughly half the rate seen in women who had never used HRT (80 deaths per 10,000 person-years [CI, 69 to 92 deaths]).


These data suggest that HRT use in women with a family history of breast cancer is not associated with a significantly increased incidence of breast cancer but is associated with a significantly reduced total mortality rate.

Comment in

  • ACP J Club. 1998 May-Jun;128(3):74.
[PubMed – indexed for MEDLINE]
Climacteric. 2006 Dec;9(6):404-15.

Is HRT justified for symptom management in women at higher risk of developing breast cancer?


King’s Breast Care, King’s College Hospital NHS Trust, London, UK.


Hormone replacement therapy (HRT) is the most efficacious intervention for the treatment of estrogen-deficiency symptoms. Prescriptions for HRT have fallen over the last 3 years due to anxiety provoked about breast cancer risk and recurrence that has been generated by recent clinical trials. In women at population risk of breast cancer, these trials have not shown risks greater than estimates from clinical trial evidence that predated them. For women at increased breast cancer risk due to a family history or high-risk benign breast conditions, clinical trial data are limited but suggest a lack of an additive effect of HRT on risk. In symptomatic breast cancer survivors, observational data suggest no increase in recurrence but these data are open to bias. Interim analyses of large, randomized trials have shown contradictory outcomes and, as a result, three large HRT randomized trials have now been closed. The randomized LIBERATE trial evaluating tibolone in breast cancer survivors is fully recruited and continuing. The current clinical climate is ‘HRT adverse’ but, due to a lack of effective alternatives for symptom relief, women at higher breast cancer risk and breast cancer survivors are still requesting information about HRT. In this situation, discussion of the current clinical uncertainty surrounding the use of HRT must be undertaken to ensure that women are adequately informed.

[PubMed – indexed for MEDLINE]
Epidemiology. 2009 Sep;20(5):752-6.

Hormone replacement therapy, family history, and breast cancer risk among postmenopausal women.


Department of Epidemiology, Boston University School of Public Health, Boston, MA, USA.



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.


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.


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).


Family history and estrogen plus progesterone replacement therapy have independent and non-interacting effects on the risk of invasive breast cancer among participants in the Women’s Health Initiative randomized trial.

[PubMed – indexed for MEDLINE]
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