Menopause: So much increase hormone therapies breast cancer risk

Hot flashes, sweats, sleep disturbances, bleeding from the blood vessels, incontinence: If the female body changes its hormonal balance during menopause, it can cause discomfort. Hormone therapy helps - but also increases the risk of developing breast cancer. This may still be the case even years after stopping the medication, as a recent study shows.

For the study in the journal "The Lancet", an international research team had summarized the results of 58 studies on the subject. Thus, almost every form of hormone therapy increases the risk of breast cancer in the long term. A German expert advises not to panic, but to talk with her doctor about the pros and cons of treatment.

Menopause begins in most women from the age of 45 years. When the ovaries gradually stop functioning, the level of estrogen in the body drops, and progesterone disappears almost completely. In Europe and North America, about 12 million women taking hormone supplements to alleviate the problems of the change, the researchers write.

Data from nearly 500,000 women

The team had evaluated data from nearly 500,000 women who had used menopause. Some of the women had been on hormonal therapy for several periods, others had not taken any hormones. More than 100,000 of these women suffered from breast cancer, most around the age of 65. The analysis showed that almost every form of hormone treatment increased the risk of breast cancer, but to varying degrees:

• Without hormone therapy , 63 out of every 1,000 women of normal weight between the ages of 50 and 69 developed breast cancer.
• A five-year treatment with estrogen and daily gestagen administration resulted in one additional breast cancer case per 50 women.
• If the progestin was not taken daily , but only phased, the risk was slightly lower: one additional case per 70 women.
• When only estrogen was taken, 200 women had an additional case of breast cancer.

If the duration of treatment exceeded five years, the risk of illness increased further. "A treatment period of ten years with hormones doubles the increased risk of breast cancer compared to a five-year treatment," says co-author Gillian Reeves of the University of Oxford in a press release.

"But it seems very low risk to use hormone therapy for less than a year," says Reeves. "The same goes for the local, vaginal estrogen use in the form of ointments or suppositories, which should not get into the bloodstream."

Overweight women: less influence

The results were independent of personal factors that also affect breast cancer risk, such as familial predisposition or alcohol or cigarette consumption. In overweight women who have a higher risk of breast cancer anyway, the risk of hormone therapy increased less. Even a very late onset of hormone therapy, from the age of 60, weakened the risk of disease.

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In a commentary to the study, also published in The Lancet, Joanne Kotsopoulos of Women's College Hospital, Toronto, explains how the increased risk could come about: "Studies show that the increase in breast cancer risk increases with age After menopause, the situation is somewhat milder, and simply put, hormone therapy could de facto keep women in a pre-menopausal state. " They did not benefit from the reduced breast cancer risk after menopause. "

Patients should be informed about the new findings, says Olaf Ortmann from the University Women's Hospital in Regensburg. "We did not know that much about the long-term effects, but until now it has been assumed that the risk of breast cancer returns to normal levels just a few years after the end of hormone treatment."

According to Ortmann, who is jointly responsible for the guideline for hormone therapy during the menopause of the German Society for Gynecology and Obstetrics. "Patients should not panic, but talk to their doctor, and after a few years you should always be able to see if the medication can be reduced or spiked in. Sometimes the symptoms that have led to hormone therapy have already been alleviated."