Worried about menopausal hormone therapy?

The number one reason women avoid hormone therapy after menopause is the fear of breast cancer. But what if I told you that estrogen use does NOT increase your risk of developing breast cancer? I know. You might not believe me. But, fortunately, you don’t have to believe me. Here are the facts.

The Women’s Health Initiative (WHI), which was the largest study on menopausal hormones for a long period of time, is responsible for most of the confusion about breast cancer. The headlines blared “Study halted. Estrogen increases the risk of breast cancer!!” And when women read that, they abandoned hormones quicker than Ted Cruz boarded a plane to Cancun after an ice storm. And, it makes sense. 

Here’s the problem: Those headlines weren’t accurate. 

And, there’s another problem: That study was reported twenty years ago, and many of you–doctors and patients alike–still believe it. 

What did the Women’s Health Initiative really say? It said that women who took estrogen and synthetic progestin (the only combination tested) had a 26% increase in developing breast cancer over women who didn’t take hormones. Sounds scary right? But, a 26% increase in risk does not mean 26 in 100 will get breast cancer. In absolute numbers, it translated to less than one additional breast cancer case, per 1,000 women, per year. Not so scary. And, it gets better. For women in the WHI who had hysterectomies and took estrogen only (instead of an estrogen/progesterone combo), the breast cancer risk actually decreased. But, most people missed that part.

It gets even better. 

There’s a brand new study from the United Kingdom. The study looked at 43,183 newly diagnosed cases of breast cancer from 1995-2014 and compared them to 431,830 controls who had never used hormones. And what did they find? Turns out they confirmed the WHI results. Women who used estrogen only did not have an increased risk of developing breast cancer over nonusers. And it didn’t matter if the estrogen was taken orally or transdermally. There was no increase in breast cancer attributable to the estrogen alone. 

The only group of women who had an increased risk of breast cancer were those who took estrogen and a synthetic progestin. Women who took estrogen and bioidentical progesterone had NO increased risk of breast cancer. I’ll repeat that. Women who took estrogen and bioidentical progesterone had NO increased risk of breast cancer. Why didn’t the WHI find that bioidentical progesterone had no effect on breast cancer? BECAUSE THEY DIDN’T STUDY IT!! 

In summary, here’s the take-home message. Estrogen itself does not increase the risk of breast cancer. Period. But, if you have a uterus, you should take estrogen and progesterone. Synthetic progestins slightly increase the risk of breast cancer. Study after study has shown no increase in breast cancer in women who take bioidentical hormones, and all of Alloy’s menopausal hormone therapy is bioidentical. That includes progesterone. And those are the facts. 

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