The North American Menopause Society has recently (www.menopause.org 03-01-2012) updated its 2010 position statement on menopausal hormone replacement therapy. I will summarize the major changes with reference to breast cancer. In today's blog we will discuss only combined estrogen and progesterone therapy (EPT). As you know the menopausal indication for the progestin (progesterone or progestogen) use is to prevent the increase of endometrial cancers seen with estrogen-only treatment. Therefore in this blog we are talking about women who have not had a hysterectomy and do have an intact uterus.
They state that individualized treatment is the key, but still the evidence that they site is mostly from population-based studies. Nevertheless we can and do learn from theses studies. Specifically, EPT does increase the risk of cardiovascular disease, stroke and leg clots. Individualizing care here means taking a history and then not compounding a problem with EPT. Studies point to routes other than oral administration for lowering these risks. Length of treatment recommendations are primarily dictated by breast cancer risk. Timing of treatment is emerging as a variable as well. The effects may not be present for the entire class of estrogen drugs, but just the combined equine estrogens used in most studies.
There is greater safety overall in younger women who use EPT, specifically beginning treatment in the perimenopause or early premenopause period. Interestingly, all adverse effects except breast cancer risk are less with early use and even risk of events for all outcomes is lower in younger women.
Why the beast cancer risk would be different is not yet known, but at least one idea will be discussed next week when we blog about estrogen-alone hormone replacement (ET) for those who have had a hysterectomy.
All three of the large studies used in the analysis showed a greater risk of breast cancer in women beginning EPT shortly after menopause. The Womens' Health Initiative (WHI) initially reported that those who began EPT early in menopause had more breast cancers, but those waiting 5 years did not. Later detailed analysis revealed a delayed increase in those later users. This increase in breast cancers was confirmed in the Million Women Study (MWS) and the French E3N.
BUT, what is the increased risk and when does it present? The absolute risk reported in the WHI was 8 additional cancers per 10,000 women using EPT for 5 years or more. Long term follow up suggests that the increased risk goes away 3 years after hormones are stopped. However, long term follow up also showed an increase in death from breast cancer with 2 additional deaths per 10,000 women followed for 11 years. Specifically, NAMS recommend for EPT use 3 to 5 years of safety from breast cancer.
We will see in blogs next week, that we can further individualize recommendations for EPT with two simple tests. Genetic and histologic information, as well as clinical information is part of the key to an individual treatment recommendation.
This is general medical content and intended, not as treatment for any one person, but to inform and prompt a thorough discussion between a woman and the prescribing physician.
Together we can prevent 75,000 breast cancer cases each year!
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