Doctors recommend an MRI for women who have a genetic trait associated with breast cancer or a family history of the disease. An MRI, which uses powerful magnetic fields, radio waves and a computer to produce detailed pictures, tends to work better than mammograms in detecting abnormalities in women with dense breast tissue.
The Mayo Clinic study examined 5,414 women with early-stage breast cancer who had surgery at the hospital between 1997 and 2006. The study noted which women had received a pre-operative MRI, which Mayo began using in 2003.
The women who had an MRI before surgery had already been diagnosed with breast cancer, and doctors were typically trying to see if there was additional cancer - either elsewhere in the cancerous breast or in the other breast.
Florida's Grobmyer said the use of an MRI in this manner "helps us better select patients for breast conservation."
Still, the technology has its detractors. They say that the MRI is so new that it finds many lumps that are unlikely to develop into cancer. But once identified, those lumps may lead to unnecessary treatment and anxiety.
At the same time, some cancers found only by MRI may be in a different quadrant of the breast than the original cancer, making mastectomy the correct treatment.
Dr. Julie Gralow, a medical oncologist at the Fred Hutchinson Cancer Research Center in Seattle who specializes in breast cancer, said yesterday that much of the surgery is probably appropriate.
But, she added, "What would be a real shame is if women are choosing mastectomy based on MRI findings that are benign ... and they end up having more aggressive surgery than they need."
The discussion is similar to a debate over high-powered CT scans for lung screening. CT scans find smaller cancers, but many are relatively harmless, and the jury is still out on whether a CT scan actually improves survival rates.
In other breast cancer research released yesterday, Canadian researchers found that breast cancer patients with a vitamin D deficiency were 94 percent more likely to have their cancer spread and 73 percent more likely to die, compared with women with adequate vitamin D levels.
More than one-third of the 512 breast cancer patients studied had a vitamin D deficiency, and another third had "insufficient" levels of vitamin D.
Dr. Pamela Goodwin, a medical oncologist at Mount Sinai Hospital in Toronto, said there is growing evidence that women should get more vitamin D. The body normally produces vitamin D when it's exposed to sunshine, but the vitamin is also available in supplements.
stephanie.desmon@baltsun.com
