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Breast cancer

The puzzle of why more women don't take preventive drugs

For women at higher risk of developing breast cancer, two well-established drugs, tamoxifen and raloxifene, can do what statins do for heart attacks and strokes: drive down the odds. But these two drugs are virtually invisible on the U.S. pharmaceutical landscape.

October 04, 2010|By Melissa Healy, Los Angeles Times
  • For women at higher risk of developing breast cancer, two well-established drugs -- tamoxifen and raloxifene -- can do what statins do for heart attacks and strokes: drive down the odds.
For women at higher risk of developing breast cancer, two well-established… (Bill Branson / National…)

The millions of Americans who take a pill each day to drive down their cholesterol or blood pressure do not generally think of themselves as "sick." They believe that they are treating one thing — high cholesterol or blood pressure — and helping to prevent something worse: a heart attack or stroke.

For women who worry about becoming the oft-quoted "1 in 8" who will develop breast cancer in her lifetime, two well-established drugs can do for breast cancer what statins and blood pressure drugs do for heart attacks and strokes: drive down their odds of happening.

Cardiovascular medications are aggressively advertised, widely prescribed and talked about freely among friends and co-workers. Breast cancer prevention drugs are virtually invisible on the American pharmaceutical landscape.

Those contrasting pictures are a puzzle to many physicians and researchers who have spent their careers working to eradicate the scourge of invasive breast cancer — a diagnosis handed down to more than 192,000 American women last year. In 2009, about 40,000 women died of breast cancer in the United States.

"It has surprised me continuously," says Dr. Rowan T. Chlebowski, a breast cancer expert at Harbor- UCLA Medical Center in Torrance. "Physicians get more women asking about medication to increase their eyelashes than they do about drugs that can reduce breast cancer risk."

This is in spite of the fact that a raft of respected studies has shown that in certain women with higher-than-average risk for breast cancer, two widely available drugs — tamoxifen and raloxifene — can cut that probability roughly in half. Tamoxifen is a chemotherapy drug for breast cancer patients; raloxifene, marketed since 1998 as Evista, is better known as an osteoporosis drug that women can take after menopause.

In the coming years, researchers expect a new class of drugs — aromatase inhibitors — may prove even more effective than raloxifene and tamoxifen at driving down breast cancer risk, cutting it by 70%.

So why, given the fear so many women feel about this particular disease, aren't people flocking to the drugs? The reasons are various — involving optimism, mistrust and a misunderstanding of how breast cancer risk is calculated.

Neither of the drugs now approved for prevention is a wonder drug that's perfectly effective and side-effect free. Both raise the risk of strokes, blood clots, endometrial cancers and, with tamoxifen, cataracts. Both can come with bothersome side effects such as hot flashes and vaginal dryness. Taking either drug for years is not, therefore, a slam-dunk decision, even for a woman who by virtue of age, family history and past breast disease is more likely than most to develop invasive breast cancer. But for the right woman, one whose lifetime risk is well above average, many breast cancer specialists say these drugs look like a pretty easy call.

Yet, among women who are aware they have a higher-than-average risk and consult a specialist about it, just a little over 3 in 10 opt for medicine to lower their risk.

"These medications have been underutilized to this point by anyone's standards," says Dr. Larry Wickerham, a professor of oncology at Drexel University School of Medicine in Philadelphia.

That's particularly surprising, experts say, given that women typically overestimate their breast cancer risk. Most women have heard advocacy groups cite the alarming statistic that a woman in the U.S. has a 1 in 8 — or 12.5% — chance of developing breast cancer over her lifetime. And everyone knows someone — a relative, friend, neighbor or celebrity — who's recently gotten a diagnosis. Such factors tend to inflate women's perceptions of their personal risk.

In one telling 2009 study, 632 women considered to be at high risk of developing breast cancer in the next five years received a comprehensive assessment of the risks and benefits they could expect from tamoxifen. While 29% said they would probably speak to their doctor about the drug, only 6% said they thought they would take it. Three months later, fewer than 1% had started to take it, and just 6% had asked their doctor about it.

"People weren't always convinced the benefits were real or that those benefits would apply to them," says study co-author Angela Fagerlin, a University of Michigan psychologist. And then there is suspicion. Fagerlin says she was struck recently by online comments posted in response to a newspaper editorial she wrote about the medications.

"They said, 'Look at hormone replacement therapy — they claimed it was going to help us, and look what happened,' "Fagerlin says. "The hatred and mistrust of the pharmaceutical companies was just astounding."

Relying on optimism

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