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New Breast Cancer Risk Found With Hormone Replacement Therapy


Lead author Catherine Schairer, PhD, an epidemiologist with the National Cancer Institute, tells WebMD she does not support completely abandoning long-term HRT based on her research. "I think one study is never definitive. There need to be other studies confirming these results. On the other hand, I feel reasonably confident of my results. I think a woman may still consider the use of estrogen alone if she has a uterus. If a woman still feels she wants HRT, she should be carefully monitored. She should at least get what is recommended in terms mammograms and clinical exams."

While Walter Willett, MD, DrPH, and his colleagues at the department of epidemiology and nutrition at the Harvard School of Public Health call "strong" the "evidence that the addition of progestin to estrogen increases the risk of breast cancer," they write in an accompanying editorial that the cause-and-effect remains unproven. Still, they urge a pointed review of the reasons why menopausal women would be placed on hormone therapy, and they admonish clinicians and patients for overlooking lifestyle interventions.

Felicia Cosman, MD, urges a measured response to the research.

"I think it would be a mistake for women who are taking estrogen to stop taking it based on this study," Cosman says. "Women should not indiscriminately go on estrogen because they go through menopause. If they and their doctors feel that the heart disease data and the osteoporosis data and the preventive effects for Alzheimer's disease data are strong, and they have a history of those diseases, then I think it is reasonable" to be on HRT long-term. Cosman, who is clinical director for the National Osteoporosis Foundation and an endocrinologist and director of osteoporosis programs at Helen Hayes Hospital in New York, reviewed the study for WebMD.

"What I don't like, and I see this every day, is women who've been on estrogen for years for no specific reason," Cosman says. "I ask them why, and they say, 'I don't know, my doctor put me on it.' The conclusion is that we all should have a reason for being on hormones. And if we take them, we should be on the lowest possible dose of [progestin]."

Schairer and her colleagues stop short of offering guidelines for HRT use, but Willett and his colleagues at Harvard attempt to sort out this controversial and perplexing issue. They write that short term use to quell menopausal symptoms, with a two to three-year course of treatment, "should not be influenced by fear of cancer risks." Secondly, for women without a uterus, the combination therapy is unwarranted anyway, because there is no need for the progestin and its beneficial effects on the uterus.

But for the third group of menopausal women with a uterus, who comprise the vast majority of HRT users, the questions of benefit vs. risk doesn't have such tidy answers. "[R]educing the risks of fractures and heart disease will rarely provide sufficient justification because avoidance of smoking, performance of regular exercise, and consuming a good diet are effective preventive measures," they write. They point out that there are many new medications that can be used for heart disease and osteoporosis prevention that were not available in the past.

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