Breast Cancer and the Hormone Therapy Question

When women abandoned hormone therapy en masse, breast cancer rates dropped. Could this actually be a bad sign?

By Tara Parker Pope

Breast Cancer DeclineLast year, Texas researchers announced a surprising decline in breast cancer cases, and it seemed like a reason to celebrate: The most recent findings showed an estimated 14,000 women had been spared the diagnosis. At first the decline was attributed to the fact that many women had abruptly stopped using hormones for menopause in 2002, after the Women’s Health Initiative linked the drugs with breast cancer, heart attacks, and other illnesses. But now medical experts say there is likely far more to the story. "I, and some of my colleagues, feel that those breast cancers did not just go away," says Len Lichtenfeld, MD, deputy chief medical officer for the American Cancer Society. Here’s what the latest numbers say — and what they really mean for your health.Why Hormones Aren’t the Whole StoryBreast cancer rates fell most in women over 50, the same age group that uses hormones for menopause, says Peter Ravdin, MD, a research professor at the M.D. Anderson Cancer Center, in Houston, part of the team that first reported the trend. And the biggest declines were in estrogen-receptor-positive tumors, the type fueled by estrogen. From 2001 to 2004, overall breast cancer cases dropped 8.6 percent; estrogen-receptor-positive breast cancers fell by about 15 percent, building a compelling case that changes in hormone use had something to do with the trend.Some doctors, however, believe it’s not just that women stopped taking hormones but that they also stopped having regular breast exams. "Stopping HT alone is unlikely to produce a sudden, statistically significant drop in breast cancer incidence overnight,’‘ says Marisa Weiss, MD, founder of the Web site, which provides information about research and treatment. "More likely, it’s the drop off of doctor visits and less compliance with mammography. There are fewer reasons to see your doc if he’s no longer prescribing HT.’‘ There’s another piece of evidence that hormones aren’t the only factor: Cancer rates actually started declining nine years ago. According to Ahmedin Jemal, PhD, American Cancer Society epidemiologist the decrease was seen in several age groups and was greatest for small tumors and early-stage cancers — the ones most commonly detected by mammography.Fewer Mammograms, Greater RiskThe disturbing trend in mammography rates emerged in 2005: "Rates for women overall had dropped to about 66 percent, nearly four percent lower than the peak of 70 percent in 2000," says Nancy Breen, PhD, of the National Cancer Institute. Even more troubling is that the biggest drop occurred in women who could be counted on to get regular mammograms: highly educated women with access to regular medical care and private health insurance. Mammography use also fell seven percent among women who have the most to gain from screening — those 50 to 64, the group with the largest number of breast cancer cases in the United States.What’s behind the drop? Perhaps higher insurance copayments or long waits for appointments, or it may be that some women aren’t convinced mammograms make much difference in their health. But if the decline in breast cancer is linked, even in part, to women getting fewer mammograms, "it means you’re not finding cancers you would normally find early,’‘ says Robert Smith, MD, PhD, director of cancer screening for the American Cancer Society. "When those cancers are eventually found, they’re going to be bigger and have a worse prognosis."Back to the Hormone Therapy QuestionHow does this new thinking affect you if you’re contemplating taking replacement hormones? The most recent guidelines from the FDA and major medical groups haven’t changed: Women who want to treat hot flashes and other symptoms should use hormones in the lowest dose for the shortest time possible. "I wouldn’t want the WHI study findings and our analysis of the data to be something that caused all women to stop hormone therapy," Ravdin says. In fact, stopping hormones doesn’t dramatically change your risk for breast cancer. Based on the latest analysis, a woman with no special risk factors who stops hormones would, at best, reduce her individual risk by about 1.7 percent.

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