Reducing breast cancer risk: what we’ve learned from the Women’s Health Initiative


IStock_000003885695XSmallTen years ago, the medical world was rocked by the discovery that estrogen-progestin hormone-replacement therapy increased the risk of breast cancer and other diseases in post-menopausal women. Hundreds of thousands of women came off HRT and within a few years we saw the first-ever documented decrease in breast cancer rates.

The discovery was made by the government-funded Women's Health Initiative, a study designed to explore the benefits and risks of combined estrogen-progestin HRT in post-menopausal women. The study was halted in 2002 when researchers saw a 26 percent increase in the relative risk of breast cancer in women taking the combined estrogen-progestin HRT compared with those taking a placebo. There were also significant increases in the risk of heart disease, stroke and blood clots.

A follow-up study done three years later showed increases in invasive cancers in women who had been on HRT. But while breast cancer rates remained elevated in this group, there was a trend towards lower rates similar to those in the placebo group, suggesting that the increased risk for breast cancer from combined HRT is reversible within a fairly short period.

As we look at other chemical exposures linked to breast cancer, the WHI study and the resulting drop in breast cancer incidence should give us great hope. The study showed us that by eliminating an avoidable exposure to chemicals we can reduce breast cancer risk. It gave us a tangible example of why we do the work we do—why we work every day to reduce our exposure to toxic chemicals and radiation linked to the disease. So on this 10th anniversary, we are thankful to the researchers and women who were part of the study. Because of their contribution, millions of women now have clear information about the risks of estrogen-progestin HRT, and all of us working to prevent breast cancer have a case study for why we must continue to call for more research on the causes of breast cancer and for action—by individuals, corporations and government—to prevent exposure to toxic chemicals and radiation linked to the disease.


4 thoughts on “Reducing breast cancer risk: what we’ve learned from the Women’s Health Initiative

  1. I am in disbelief when a woman tells me that she is doing “x” because her doctor told her to, and then she knows almost nothing about “x”.
    We are smart strong women, with community and family….and the internet. The doctors do the best they can do, yet none of us, even doctors, knows what we don’t know until we know it.
    I suggest understanding the objectives of a treatment and then researching with the objective of finding the healthiest way to achieve the objective, with the least side effects. Taking drugs or potentially harmful treatments are only options.
    I believe it’s about prevention, and finding the causes….at the least, about changing the terrain of the body, that gave rise to the cancer.
    Many women live the same lifestyle after discovering BC. The saying goes, how could anyone expect a different outcome if they keep doing the same thing over and over.
    I understand, having been there, that it’s terrifying. That’s what friends, family and doctors are for, in addition to ourselves.
    Your intuition is your best friend….and works best with knowledge. Don’t drown in the knowledge, just find good sources, like this site, and others.
    And remember, to envision what we DO want to see. The word “not” is not understood by the brain, ie I don’t want to be sick…is understood by the brain as I want to be sick.
    I have more to say and hope I haven’t overstepped boundaries. We each have to choose what’s best for us, and yet all of us,
    has intuition.
    Sleep early and well,

  2. Just want to thank you for all that you do . Please keep checking into the chemicals for us all.

  3. Having been dealing with breast cancer for a year now and trying to understand the “why” I find there are still no real answers. There seems to be no ryhme nor reason to it. I have known so many who did everything right, lived as healthy a life as could be and still became afflicted with this disease. I know many who are obese, don’t take care of themselves, don’t exercise, are older than me and do not have it. I still try to pay attention to the risk factors but after obsessing over every little thing I put in my mouth since being diagnosed, I have finally come to the realization that I want to live my life however long I have and don’t want to always be worried or obsessed over this. Easier said than done however.

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