I am eager to see the new information that will come out in 2007! Will there be bombshells or breakthroughs? Hard to say. I certainly hope so! I do think that we will continue to see ways to determine which breast cancer treatment is best for which patients. This will probably do more to improve survival than anything else. I also expect that we will see more biological therapies that target angiogenesis, growth factors, and other biological mechanisms cancer cells use to grow and spread.
Undoubtedly, the most significant womenâ€™s health-related news story of 2006 occurred right at yearâ€™s end, when researchers announced that not only had they found a striking decline in new breast cancer cases in the United States in 2003 (the most recent year for which statistics are available), but that their analysis had determined that this rapid decrease had come about because millions of postmenopausal women has abruptly stopped taking hormone replacement therapy (HRT).
The analysis, which was reported on December 14 at the San Antonio Breast Cancer Symposium, found that the breast cancer rate dropped by 7 percent between August 2002 and December 2003. Even more striking was the finding that the biggest drop was in women between the ages of 50-60 who had tumors that were hormone sensitive (ER or PR positive).
Why were the researchers so certain the decline was linked to womenâ€™s decreased use of HRT? As you probably recall, in July 2002 we awoke one morning to the news that the Womenâ€™s Health Initiative (WHI), a large randomized trial comparing HRT to a placebo, was being stopped because an interim analysis had found that the women taking HRT hadmore risks than benefitsâ€”including an increased risk for breast cancer. Virtually overnight, women threw out their HRT and stopped refilling prescriptions. As more women stopped taking HRT, more women stopped getting breast cancer. And as far as we can tell, nothing else of the same magnitude occurred that could explain the decreased breast cancer rate.
News, of course, brings questionsâ€”and our Foundationâ€™s website received many, many questions as this story made headlines worldwide. Questions like:
1. How could stopping HRT reduce breast cancer rates so quickly, given that cancer takes years to develop?
2. Is this only true for the drug used in the study (Prempro). Can I still use natural bioidentical hormones?
3. What if Iâ€™m only taking estrogen because I had a hysterectomy? Is that also a problem?
4. What about the estrogen Iâ€™m taking for vaginal dryness?
Breast cancer does take years to develop. That hasnâ€™t changed. But our understanding of the relationship between the local tissue around the cancer (stroma) and the cancer cells has. In the past, we blamed everything on the cancer cell, as if it were a criminal that functioned autonomously. But we now know that the neighborhood (stroma) that the cancer cells live in also plays a critical role in determining whether a cancer or even a precancer like ductal carcinoma in situ (DCIS) will remain dormant or become invasive. Estrogen and progesterone are two of the major influences on the stroma. As soon as a woman starts taking HRT, her breasts will appear denser on a mammogram. And as we know from the WHI, breast cancer increases as well. This is because of the impact the hormones have on the stroma, making it more inviting and supportive to cancer cells. In essence, the stroma is providing a nurturing environment for the cells to function criminally. Likewise, as soon as a woman starts to take tamoxifen to reduce her breast cancer risk, her breasts appear less dense on a mammogram. In this case, itâ€™s because tamoxifen is keeping estrogen away from the stroma. In this case, the stroma is providing an environment that is, in essence, rehabilitating those criminal cancer cells.
Some experts have suggested that when women stopped taking HRT it just delayed breast cancer development and that we will see a rise in cancer statistics again. However, we know that when women take tamoxifen to reduce their breast cancer risk the benefit persists long after the drug is stopped. So, itâ€™s certainly biologically plausible that the effect of stopping HRT would not only be fast but that it will also persist, which would mean we would not see rates increase again.
Time Will Tell
Natural hormone replacement therapy is promoted on the Internet and elsewhere as an alternative to synthetic forms of HRT. Typically the advertisements and supporting literature claim that natural HRT is better because it is made from plant sources and because it is “bioidentical.” There is no reason to believe that this is true. Studies show that women with high levels of their own estrogen and testosterone have an increased risk of breast cancer and that progesterone (not progestin) blockers may actually work to prevent breast cancer in BRCA 1 mice. You cannot get more bioidentical than your own hormones, and if your own hormones increase risk, so would all others. The bottom-line: regardless of what type of HRT you use, you should only take it for menopause symptom management and for as short a time as needed not longer than three to five years.
There is one exception to this: women who began taking estrogen after having a hysterectomy that includes removal of the ovaries. When a woman has a hysterectomy that includes removal of the ovaries before she has naturally entered menopause, she undergoes what we refer to as surgical menopause. These women are typically prescribed estrogen to help maintain bone health and many are on estrogen for ten years or more. We know from the WHI that women who had had a hysterectomy and who took estrogen did not have an increased breast cancer risk. However, that doesnâ€™t mean women should stay on estrogen forever. It is now recommended that women who have had a hysterectomy that included removal of their ovaries stay on estrogen until the time they would have naturally entered menopauseâ€”around age 50.
What about estrogens that are used vaginally or are for vaginal dryness? It depends what type of estrogen product you are using. The Femring is actually a form of HRT. Both Premarin and Estrace raise your blood levels of estrogen much the same as estrogen pills, while sustained release products, like Estring and Vagifem, contain estrogen doses so low that very little if any is absorbed into the rest of the body. You can learn more about all of these options here.
As we learn more, weâ€™ll tell you more. So expect to find more pieces that address these topics on our website soon. Also, be sure to check out my blog from San Antonio. This is the first time weâ€™ve had a blog on the site, and Iâ€™m interested in learning what you think about it and what types of issues youâ€™d like me to address in the future.
Weâ€™ll also be regularly updating you on our Foundationâ€™s own research projects. We are always looking for volunteers in the Southern California area who are willing to take part. To learn more about these research projects or about the information sessions we will be hosting at the Foundation throughout the month of January, please email us here.
As we enter the New Year, I want to take this opportunity to thank you for all the support you gave to the Foundation in 2006. Without our research volunteers and all your support and donations, we could not do the research we need to do to move us closer to eradicating breast cancer once and for all.