Can Breast MRI Help Evaluate Cancer?
Study Weighs the Benefits, Risks of Routine Breast MRIs for Cancer Evaluation
Breast MRI Study Findings
Among the findings:
Breast MRI was associated with a 22-day delay in the start of treatment. "We don't know why," Bleicher says. It could be because of the scheduling of the MRI itself, or perhaps MRI prompts other biopsies." Three weeks should not change a patient's survival chances, he says, but waiting can clearly add to a patient's anxiety.
- Those who got the breast MRI were nearly twice as likely to have a mastectomy as breast-conserving surgery, even after controlling for size and stage of the tumor. One reason, he says, may be that the MRI, being highly sensitive, picked up something that looked like cancer but turned out not to be -- a false positive.
- Those who got the breast MRI were slightly more likely to have what surgeons call positive margins, although this finding could have been a chance finding. The goal is negative margins. "The goal is to excise out the tumor so there is a margin of normal tissue around it, reassuring us the cancer has been completely removed," he says.
- Younger women were more likely than older women to have MRIs, but the use of the MRI did not correlate with other factors such as family history of breast or ovarian cancer.
Breast MRI Research Evolving
Another expert, Constance Lehman, MD, PhD, professor and vice chair of radiology and head of breast imaging at the University of Washington Medical Center and director of imaging at the Seattle Cancer Care Alliance, reviewed the study for WebMD. She says the new study is "not the kind of study we need to make firm conclusions."
She points out that the study was small and that only 130 women had breast MRIs.
Research on the value of breast MRI when used in cancer treatment decision is evolving, she says, and not all the answers are in.
The Bleicher study has inherent limitations, she says, because it wasn't a study that randomized people to get one treatment or not. Rather, it was a study that took a look backward, and it lacked some information, such as why some women got MRIs and others didn't.