MRI better at spotting precancerous growths: study

MRI scans are far better than mammograms at spotting a type of precancerous growth before it becomes invasive breast cancer, a German researcher said on Sunday.
Dr. Christiane Kuhl of the University of Bonn suggested the costly scans should be used routinely to screen for breast cancer.
"MRI is better than mammography. You cannot recommend a woman wait for an MRI study to be done," said Kuhl, who presented results from her study at the annual meeting of the American Society of Clinical Oncology in Chicago.
Kuhl studied a kind of precancerous growth that forms in the lining of the milk duct called ductal carcinoma in situ, or DCIS, which accounts for up to 25 percent of all growths found on a mammogram -- a type of X-ray.
"Mammography is considered the mainstay for diagnosing DCIS," she said at the conference. But her study found that magnetic resonance imaging, or MRI, was more likely to spot high-grade DCIS, an aggressive type of growth that increases the chances a woman would get breast cancer by about 40 percent.
Some 17 percent of the more than 52,000 cases of DCIS diagnosed in the United States each year are considered to be high grade. About 180,000 U.S. men and women will be diagnosed with breast cancer in 2007.
In her study, Kuhl screened more than 5,000 women. Of those, 167 were diagnosed with DCIS. Those women got both an MRI and a mammogram. The MRI found nearly double the amount of growths, and half of the most aggressive high-grade growths were only seen on MRI.
If found early, high-grade DCIS is easily removed by surgery, but untreated, it can develop into invasive breast cancer. Kuhl believes the MRI test is better and should be used as part of routine screening, but others at the conference disagreed.
"We do not recommend use of MRI for women of average risk," said Dr. Len Lichtenfeld, deputy chief medical officer of the American Cancer Society, which does recommend MRI screening plus mammography for certain women at higher risk for breast cancer.
Dr. Julie Gralow, assistant professor of oncology at the University of Washington in Seattle, said, "This is not something that is ready for prime time around the country."
She said it is too early to recommend widespread screening using MRI because the technology has not yet become standardized enough in breast cancer to offer uniformly reliable results. She said efforts are under way to standardize breast MRI tests.
But the biggest stumbling block is cost, Gralow said. MRI costs about 15 times the cost of a mammogram. "If this were cheap it would be an easier discussion," she said.