Detecting breast cancer

MRIs can find malignancies missed by more traditional methods, a study shows

March 28, 2007|By Frank D. Roylance | Frank D. Roylance,sun reporter

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.

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