Health: WebMD

Study: Mammogram Expectations Too High

May 5, 2006 / 1:43 PM EDT / WebMD

Many women overrate their risk of breast cancer. But many also think mammograms detect tumors better than they truly do.

The finding comes from a survey of 397 women getting screening mammograms at an outpatient clinic. University of Michigan radiologist Marilyn Roubidoux, M.D.; Tricia Tang, Ph.D., and colleagues quizzed the women on their expectations.

They found that many of the women had more fears about cancer — and more confidence in mammograms — than they should.

Yet:

30 percent of the women thought they personally had a 50-50 lifetime risk of getting breast cancer. Two-thirds of the women thought the national lifetime breast cancer risk was more than 20 percent. The real risk is no higher than 1 in 8 — 12 percent. And for women with no breast cancer risk factors, the risk is even lower.
14 percent of the women thought it was likely — a better than 50 percent chance — that the mammogram they were about to get would find they had breast cancer. The real risk for women getting a routine screening mammogram is less than 1 percent. About half the women knew this.
A third of the women did not disagree with the statement "A mammogram can detect all breast cancers, even if they are extremely small." Actually, there's a 20 percent chance a breast cancer won't be seen on a mammogram. And size isn't the only issue.

"The issue isn't that these cancers are small, but that they are hard to see," Roubidoux tells WebMD. "Some breast cancers just hide. You can't see a seagull in a cloudy sky."

Roubidoux today reported the findings at the annual meeting of the American Roentgen Ray Society in Vancouver, British Columbia.

Mammograms Still Save Lives

Roubidoux's findings come as no shock to radiologist Mary S. Newell, M.D., assistant director of breast imaging at Emory University in Atlanta.

"There has been a lot of good work in educating women about breast cancer," Newell tells WebMD. "Because of this, it takes on more of a specter in women's lives than it needs to."

The same thing goes for mammograms.

"I think we have oversold mammography to some degree," Newell says. "It is a good test. It has decreased breast cancer deaths in women who get annual screening, but it is not a perfect test. We need to be very upfront with people about that."

Better tests with newer technology are on the way. In the meantime, Roubidoux and Newell both urge women to continue to get their recommended annual mammograms.

"Annual screening is critically important to detecting breast cancer at an early stage," Roubidoux says. "If a woman has no lump, and it's truly a screening test, if we do detect breast cancer it is likely to be at a low stage — treatable, and likely curable with lumpectomy."

"Breast cancer is no doubt the No. 1 cancer in women and the No. 2 killer of women behind lung cancer," Newell says. "We need to pay attention to it, but it doesn't have to overwhelm our lives. And mammography isn't perfect, but it is the best thing we have right now to aid in the detection of breast cancer. While it is not perfect, it does work."

Sources: Annual meeting of the American Roentgen Ray Society, Vancouver, British Columbia, April 30-May 5, 2006. Roubidoux, M. American Journal of Roentgenology, April 2006; Vol. 186: pp A63-64. Marilyn Roubidoux, M.D., professor of radiology, University of Michigan, Ann Arbor. Mary S. Newell, M.D., assistant director of breast imaging, Emory University, Atlanta.

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