Hormone Therapy Raises Odds of Breast Biopsy

Among hormone users, mammograms are more likely to raise false alarms over cancer.

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Though hormone replacement therapy works well to alleviate menopausal symptoms, that relief comes at a price in the form of a slightly elevated risk of breast cancer. Well, now the price just got a bit steeper. A study out today in the Archives of Internal Medicine shows that HRT boosts the likelihood of having an abnormal mammogram or a breast biopsy.

Let's look at the numbers: In the study, some 35 percent of HRT users had an abnormal mammogram compared with 23 percent of those taking placebos, and 10 percent had biopsies based on their mammograms compared with 6 percent of those on placebos. Adding insult to injury, more breast cancers were diagnosed in the hormone takers even though mammograms were also more likely to miss tumors in this group. (The researchers used data from the Women's Health Initiative trial, which randomly assigned more than 16,000 women to get either HRT or a placebo.) The effects last for at least a year after women go off hormones.

"I think this finding could influence women considering hormone therapy," says study author Rowan Chlebowski, a medical oncologist at the Los Angeles Biomedical Research Institute. After all, no woman wants to have a breast cancer scare, and biopsies themselves can cause tissue damage that in rare cases can lead to malignancies. One possible explanation for the missed cancers is that hormones increase the density of breast tissue, thus masking tumors, which are also dense; an increase in density can also create a friendly environment for cancer cells to grow.

What about opting for other imaging tests? Digital mammograms tend to be more accurate in women with dense breasts, and magnetic resonance imaging might have benefits in high-risk women, but the research article says that whether these can improve the diagnostic performance of imaging in HRT users "remains to be determined." In other words, the studies are lacking.

Should you instead try those "natural" bioidentical hormones to combat hot flashes, sleeplessness, and mood swings? They're certainly hot right now. Amazon has seven books for sale on these products (including one written by former TV star Suzanne Somers), generally touting these pills as safer and more effective than traditional HRT. Chlebowski, though, points out that the devil you know is probably better than the devil you don't. "I don't think there's any reason to think they'd behave differently in the breast than synthetic hormones," he tells me, "and we don't even have data on whether they're safe." The Food and Drug Administration agrees. Last month, the agency sent seven letters to companies selling "BHRT," warning them that claims made on the products are unsupported by medical evidence and are considered false and misleading. Some of the manufacturers claim that BHRT is identical to hormones made by the body and can stave off Alzheimer's, stroke, and cancer.

The bottom line is that women with severe menopause symptoms might still be better off spending a few years on HRT than suffering through the transition without it. Those with mild discomfort, however, should weigh the new finding into their decision. Above all, women older than 50 should continue to get yearly mammograms regardless of whether they take HRT. The screening tool, though far from perfect, reduces the risk of dying of breast cancer by up to 30 percent.