Estrogen-Only HRT May Reduce Breast Cancer Risk for Women With Hysterectomies

A new study published in Lancet Oncology states that estrogen-only hormone replacement therapy (HRT) may protect a small group of women against breast cancer. The findings of this study are in direct contradiction to multiple other studies that state estrogen can cause breast cancer. Should women consider taking estrogen to prevent breast cancer? The findings of the study indicate they should not.

The study

The latest edition of Lancet Oncology contains an article authored by Garnet L. Anderson Ph.D., titled "Conjugated equine oestrogen and breast cancer incidence and mortality in postmenopausal women with hysterectomy: extended follow-up of the Women's Health Initiative randomised placebo-controlled trial." The article details the results of a follow-up study done on 7,645 women, ages 50-79 years of age, who have undergone a hysterectomy and were using estrogen-only HRT for menopausal symptoms. The results of the study showed that for women with an average risk for breast cancer, the estrogen-only HRT seemed to offer protection against breast cancer when taken over an average time period of 5.9 years.

The Lancet article further states that women in the same group who had a higher risk of breast cancer due to behavioral, genetic or family history did not receive any cancer protection benefits from estrogen-only HRT.

Premarin

The Seattle Times mentions that Premarin was the estrogen-only HRT drug used in the study. Premarin is manufactured by Pfizer Pharmaceuticals, Inc. On the Premarin website, it states clearly that this drug should not be used if you have had breast or cervical cancers or if you have had a stroke, heart attack or bleeding disorders.

Another opinion

In his article "Oestrogen and breast cancer: results from the WHI trial", author Anthony Howell states "The present results of WHI should be seen in the context of the update of the study in 2011 reporting the effects of estrogen on overall health. No overall difference was noted in participants' global index of health (including cardiovascular disease, thrombosis and embolism, breast and colorectal cancer, hip fracture, and death from all causes). However this null result masks an unexpected but significant interaction with age (p=0009) with health improvements in young women and health decrements in older women. Young women (50-59 years) taking estrogen were significantly less likely to have coronary heart disease, myocardial infarction, and death from all causes, not only with respect to older women but also placebo controls of the same age. The reasons for such an interaction with age deserve further investigation."

Hormone replacement therapy

HRT is used to help women of any age deal with serious symptoms caused by menopause. Sometimes menopause is chemically induced due to chemotherapy or hormone therapy used to treat cancer. Other times, women can be put into menopause due to surgical procedures like a hysterectomy or an oophorectomy (removal of the ovaries).

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Estrogen-Only HRT May Reduce Breast Cancer Risk for Women With Hysterectomies