Patients, Doctors Overrate DCIS Risk

Ductal Carcinoma in Situ: High Anxiety Over Small Risk of Invasive Breast Cancer

From the WebMD Archives

Feb. 12, 2008 -- Far too many women successfully treated for DCIS -- an early, noninvasive breast cancer -- suffer from greatly overrating their risk of getting deadly cancer.

Despite DCIS treatment, 39%of patients think that in the next five years they have at least a 25% to 35% chance of invasive breast cancer. More than half of these patients fear their lifetime risk is this large. Yet experts put the real risk at less than 10% after breast-conserving surgery and 1% after mastectomy.

"Most strikingly, we find that a substantial minority of patients -- 28% -- harbor inaccurate, heightened perceptions of the risks they face with regard to future breast cancer spreading to other places in their bodies," says Ann Partridge, MD, MPH. Her team looked at women's breast cancer fears after DCIS treatment.

The true risk of this happening is less than 1%, says Partridge, a medical oncologist at the Dana-Farber Cancer Institute and Brigham and Women's Hospital and assistant professor at Harvard Medical School. Partridge and colleagues gathered data from 487 women at the time of their DCIS treatment and at nine and 18 months later.

"Some women are paralyzed by their diagnosis of DCIS," Partridge says. "In another study, where we actually compared the risk perceptions of women with DCIS to those with invasive cancer, they had a very similar perception of their risk of dying. But of course women with invasive cancer have a much, much higher risk."

What has women so frightened? Part of the answer is that a common treatment for DCIS -- partial or full removal of the breast -- is so drastic. And part of it is doctor-patient communication.

"Anxiety is the biggest predictor of inaccurate risk perception," Partridge says. "For most of these women, we think it is a combination of not clearly hearing what the doctor says and not getting clear information from the doctor."

Doctors may not be clear because they don't fully understand DCIS. Where facts are few, fears flourish.

In a study presented to the 2005 San Antonio Breast Cancer Symposium, Partridge and colleagues found that different doctors hold very different ideas about even the most basic DCIS facts.

For example, Partridge's team found that while 40% of doctors "always" refer to DCIS as cancer, 22% of doctors "never" or "almost never" call DCIS cancer. And while 63% of doctors rate DCIS as a "1" or "2" on a 5-point risk scale, 36% rate this risk as a "3" or "4."

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Low-Risk Breast Cancer -- Except When It's Not

DCIS is ductal carcinoma in situ. The "carcinoma" part is truly scary. Just as it sounds, it means cancer. But the "in situ" part is every bit as important. It means that this cancer isn't going anywhere. DCIS is, by definition, confined to the breast ducts. It does not invade the rest of the breast, or the rest of the body.

It's very unusual for either women or their doctors to feel DCIS, as it rarely is large enough to cause a lump. Nearly all DCIS is detected during routine screening mammograms.

This doesn't mean DCIS is never a problem. About one in 100 women with DCIS actually has invasive cancer cells lurking in her breast ducts, says Partridge. So why are virtually all women with DCIS treated?

"Until you take it all out, you can't know it is only DCIS," Partridge tells WebMD. "In some ways it is incumbent on us as oncologists to take it out to prove it is only DCIS. It is hard to predict who is just DCIS and who is having invasive cancer cells hiding in the DCIS."

And if DCIS comes back, which happens less than 10% of the time, Partridge says there's a 50-50 chance it will come back as invasive cancer.

This makes it sound as though doctors fully understand DCIS. They don't. Doctors treat DCIS when they see it, so nobody is really sure what happens to untreated DCIS.

One thing that is sure is that some women treated for DCIS would never have had serious breast cancer if their DCIS had not been detected, notes H. Gilbert Welch, MD, MPH, director of the VA outcomes group at the Veterans Affairs Medical Center in White River Junction, Vt.

"We know that mammography detects more cancers than would ever become clinically evident," Welch tells WebMD. "You cast a wide net to find early cancers, and that net catches a lot more women than ever would have clinically significant cancers."

How many?

"For every 1,000 women in their 50s who undergo a 10-year course of annual mammography, under a best-case scenario, two would avoid a breast cancer death or have a breast cancer death delayed -- that is the credit side of the balance sheet," Welch says. "On the debit side, 250 to 500 of these women will have at least one false-positive result they will worry about. And about four of these women will be diagnosed with breast cancer unnecessarily -- four women will be overdiagnosed."

DCIS is the poster child for this dilemma, Welch suggests in an editorial accompanying the Partridge report in the Feb. 20 issue of the Journal of the National Cancer Institute. He says women with DCIS are anxious because doctors really don't know what to tell them. He suggests there should be a clinical trial of withholding biopsy until DCIS lesions are large enough to feel.

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Real Women, Real Breast Cancer Decisions

Women diagnosed with DCIS face a difficult treatment decision. Welch suggests that women should prepare themselves for these decisions not at the time of diagnosis, but much earlier -- when they decide to undergo regular mammograms.

Whether or not a woman has done this, it's very difficult for a woman to hear she has DCIS -- and even harder for her to get a firm grasp on her real risk. That's why Partridge advises women to take their time.

"When women are diagnosed with DCIS, it is not a medical emergency," she says. "They should take the time they need to truly understand what they have and the risks they face and the treatments they are being offered. They should try to make as educated and as non-emotion-driven a decision as possible for their survivorship and care."

WebMD Health News Reviewed by Louise Chang, MD on February 12, 2008

Sources

SOURCES:

Partridge, A. Journal of the National Cancer Institute, Feb. 20, 2008; vol 100: pp 243-251.

Welch, H.G. Journal of the National Cancer Institute, Feb. 20, 2008; vol 100: pp 2228-229.

National Cancer Institute web site: "Ductal Carcinoma in Situ," last modified Feb. 1, 2008.

2005 San Antonio Breast Cancer Symposium.

Ann H. Partridge, MD, MPH, medical oncologist, Dana-Farber Cancer Institute and Brigham and Woman's Hospital; and assistant professor, Harvard Medical School, Boston.

H. Gilbert Welch, MD, MPH, director, VA outcomes group, Veterans Affairs Medical Center, White River Junction, Vt.

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