Detecting Breast Cancer: MRIs Can Find Malignancies Missed By More Traditional Methods, a Study Show

Mar 28, 05:06 AM

Current Headlines: By Frank D. Roylance, The Baltimore Sun

Mar. 28--Cancer experts say there is new evidence that women at high risk for breast cancer should undergo magnetic resonance imaging to search for early malignancies typically missed by traditional breast exams and mammography.

A study published this week in The New England Journal of Medicine said MRI exams found previously undetected cancer in the "healthy" breast of 3 percent of women already diagnosed with cancer in the other.

Catching those hidden cancers early allows doctors to treat them and improve patients' chances for survival. It also saves money, they argue, and spares women the trauma of a second diagnosis and a second round of surgery, radiation or chemotherapy.

"Three percent doesn't sound like very much, but ... finding a 3 percent cancer rate is actually high," said Dr. Helen E. Mrose, director of breast imaging at the University of Maryland Medical Center. Mammography typically finds only three cancers in every 1,000 women screened. "I think this is very important information, and it's very exciting for clinicians and patients to have this option," said Mrose, who was not connected to the study.

The risk of cancer's return and spread, and the medical technology available to deal with it, moved into the national spotlight last week when Elizabeth Edwards, wife of Democratic presidential candidate John Edwards, revealed that her breast cancer had returned and settled in her bones. Yesterday, another high-profile case came to light when it was announced that White House spokesman Tony Snow's previously diagnosed colon cancer had returned and spread to his liver.

In a related development today, a panel of experts convened by the American Cancer Society is to issue guidelines recommending doctors use annual MRI scans, in addition to mammography, to look for cancers among women at high risk for breast cancer because of their family history or genetic predisposition.

The ACS panel stopped short of recommending whether women already diagnosed with breast cancer, but without family or genetic risk factors, should get regular MRI screening. But they said a personal history of breast cancer is "relevant in making individualized decisions" about having regular MRI screening.

"MRI is not perfect, and in fact leads to many more false positive results [a finding of cancer when none is actually present] than mammography," Dr. Christy A. Russell, head of the ACS panel, said in a prepared release.

"Those false positives, which can lead to a high number of avoidable biopsies, can create fear, anxiety, and adverse health effects," she said, "making it imperative to carefully select those women who should be screened using this technology."

The lead author of the New England Journal of Medicine study, however, said the ACS panel issued its guidelines before her team's results were available. Dr. Constance D. Lehman, a professor of radiology at the University of Washington Medical Center in Seattle, said the cancer society needs to revisit the issue. "We need to have guidelines not only for how MRIs are used for patients with high genetic or family risk, but how to use MRIs for a patient diagnosed with breast cancer, before she starts her treatment," Lehman said.

Her study was organized by the American College of Radiology Imaging Network and funded by the National Cancer Institute.

Elizabeth Edwards discovered her cancer had returned not with an MRI but when doctors X-rayed a broken rib. She was first diagnosed with breast cancer in 2004; it went into remission after chemotherapy, a lumpectomy and radiation. Experts said Edwards' condition is incurable, but it can be treated -- perhaps for years -- with radiation and drug therapies.

Snow underwent surgery and chemotherapy for colon cancer in 2005. Last year, doctors found another small growth in his lower-right pelvic region. While operating to remove the growth Monday, they discovered it was cancerous. They also found that the cancer had spread to his liver.

Breast cancer is the second-most-common type in women, after lung cancer. The American Cancer Society predicts that more than 178,000 women in the U.S. will be diagnosed with it this year. More than 40,000 will die.

Regular breast exams and mammography are still considered the "gold standard" for detecting breast cancer. Mammograms are relatively inexpensive, and they increase the detection of tumors by 1 percent to 3 percent over breast exams alone, according to previous studies.

But the study in the New England Journal of Medicine notes that up to 10 percent of women diagnosed with cancer in one breast will later develop cancer in the other. Finding evidence of that cancer soon after the initial diagnosis would potentially save lives and prevent a second round of treatment.

Conducted in 2003 and 2004 at 25 academic medical centers across the country -- including the Johns Hopkins University School of Medicine -- Lehman's study found early, hidden growths in the "healthy" breast of more than 3 percent of the nearly 1,000 women they studied.

As sensitive as they are at finding cancers, MRIs -- at up to $2,000 each -- are still too expensive and time-consuming for all healthy women to be screened.

Even breast cancer patients in the U.S. usually don't get MRIs.

"There are centers that use MRIs in patients with a breast cancer diagnosis," Lehman said. "But currently in the U.S., that is the exception rather than the rule."

It is becoming more common, however, especially at major teaching hospitals.

At the University of Maryland hospital, "we recommend MRIs for all of our newly diagnosed breast cancer patients," Mrose said. The aim is to define the cancer's true extent in the affected breast, and then to look for it in nearby lymph nodes and in the second breast.

Dr. Michael J. Schultz, director of the Breast Center at St. Joseph Hospital in Towson, said he has been using MRIs for five years. "We never cease to be amazed about the number of previously undetected things we pick up on MRIs which can substantially alter disease courses," he said.

While there are some frightening false positives and "maybes," he said, the negative findings are reliable. "The MRI does buy you a lot of security when it's negative," he said.

All the women in Lehman's study had been diagnosed with cancer in one breast only. Breast exams and mammography showed their second breast to be cancer-free.

All were given standardized MRI exams within 60 days of their initial diagnoses. Of the 969 who remained in the study at the end, 30 women, or 3.1 percent, were found by the MRI to have hidden growths in their "healthy" breast.

Biopsies were done to confirm the tumors were malignant. All were very small, early cancers.

Of the 30, 18 were "invasive carcinomas" growing beyond the tissues where they developed. Twelve remained in the milk ducts only, the most easily cured stage. None had spread to the lymph nodes.

Women whose MRIs were negative -- finding no sign of cancer in the second breast -- were followed for a year to see whether any malignancies had turned up.

The MRI technology was found to be accurate, flagging 30 of the 33 hidden malignancies later confirmed by biopsies. In 12 percent, the MRIs were false positives -- suspicious readings but with no cancer present.

On the other hand, the MRIs were 99 percent accurate with negative findings for the women whose second breasts were still cancer-free a year after their initial cancer was diagnosed.

Though MRI screening is expensive, and some insurance companies are unwilling to pay for MRIs to watch for breast cancer in high-risk patients, Lehman said she believes the tests will save money in the long run. They allow doctors to spot and treat previously hidden cancers along with the known tumors.

frank.roylance@baltsun.com

Sun reporter Chris Emery contributed to this article.

> Read Frank Roylance's blog on MarylandWeather.com

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