Breast Cancer Risk with HRT May Be Lower Than Thought

Risk is lowest with estrogen-only therapy, study suggests

THURSDAY, Aug. 4, 2005 (HealthDay News) -- A new study sounds a note of calm in the sea of concern that has surrounded recent findings on the potential risks of hormone replacement therapy for postmenopausal women.

According to this research, a woman's risk of developing breast cancer while taking combined hormone replacement therapy (HRT) is actually fairly low.

"It really confirms what's been known and what good doctors have been attending to since the Women's Health Initiative published their initial results showing that there could be a problem with breast cancer and HRT," said Dr. Julia Smith, director of the Lynne Cohen Breast Cancer Preventive Care Program at New York University Medical Center/Bellevue, in New York City. "[Combined HRT] could be a short-term option after weighing possible risks, but this has to be done as an individual analysis."

The medical community was stunned when, in 2002, investigators pulled the plug on the Women's Health Initiative trial due to evidence that women taking HRT had a higher incidence of heart attacks, stroke, blood clots and breast cancer.

Although HRT is approved to alleviate menopausal symptoms, based largely on observational data, doctors had been prescribing hormones to women to prevent cardiovascular problems.

"For years, doctors told people this medicine prevents heart disease," said Dr. Jay Brooks, chairman of hematology/oncology at the Ochsner Clinic Foundation in New Orleans. "It doesn't. It increases the risk of heart disease."

A more recent study confused matters even more by suggesting that estrogen, when given alone, may not increase the risk of breast cancer.

The authors of the new study, which appears in the Aug. 6 issue of the British Medical Journal, tried to sort through the confusion by assessing risk from an individual perspective.

The researchers, based at the New South Wales Breast Cancer Institute in Australia, estimated the individual breast cancer risk of women up to 79 years of age, something known as cumulative absolute risk.

The cumulative absolute risk of breast cancer declined as a woman aged, as long as she was not taking combined HRT, meaning estrogen and progestin.

For women aged 40 to 79 who are not using HRT, the average risk of breast cancer is 7.2 percent (one in 14); at 50 years of age, it is 6.1 percent (one in 16); and at 60 years, it is 4.4 percent (one in 23).

When combined HRT is added, however, the risk starts to climb. A woman taking HRT for five years starting at age 55 has an additional risk of 0.6 percent. If she takes it for 10 years, the risk climbs to 1.8 percent.

Once the therapy is stopped, however, risk returns to that of a woman of the same age who has never used hormones, the study stated.

The increased risk was even less if the woman used estrogen alone: 6.3 percent (an extra risk of 0.2 percent) at five years.

There are very real, documented problems with using estrogen alone, however.

"If a woman has a uterus, you cannot give estrogen alone because there's no question that it increases uterine cancer," Smith said. "There are also very serious health issues related to giving estrogen, including the risk of stroke."

Once again, it comes down to the individual woman.

"If you have a woman who is going through menopause or has gone through menopause and has severe, severe symptoms and her quality of life is untenable, you look at her other medical problems and you see that she's youngish and has no obvious risk for heart attack, stroke or thromboembolic problems, you may give her a short course of HRT," Smith said.

If not, then you start looking at other ways to alleviate symptoms, such as diet and exercise and other drugs, including certain antidepressants.

"It shows that the risk [revealed in the new study] is small but you have to understand that this is for breast cancer only, not heart disease, which is another risk," Brooks said. "You have to ask yourself, 'Do I want a medicine that may increase my risk for breast cancer, heart disease and stroke to alleviate symptoms that are not going to kill me, that are going to get better in over 85 percent of all women with time.' That's the question individual women have to raise."

More information

To learn more about breast cancer, visit the American Cancer Society.

SOURCES: Jay Brooks, M.D., chairman, hematology/oncology, Ochsner Clinic Foundation, New Orleans; Julia Smith, M.D., Ph.D., director, Lynne Cohen Breast Cancer Preventive Care Program, associate director, cancer screening and prevention program, New York University Medical Center/Bellevue, and clinical assistant professor, New York University School of Medicine, all in New York City; Aug. 6, 2005, British Medical Journal
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