ANNUAL MRI MAMMOGRAPHY BENEFITS HIGH RISK WOMEN

November 30, 2010 (Chicago, Illinois) — Women with a personal history of breast cancer should be screened annually with magnetic resonance imaging (MRI), according to a new study presented here at Radiological Society of North America 96th Scientific Assembly and Annual Meeting.

"Annual screening MRI is recommended by the American Cancer Society as an adjunct to mammographic screening for individuals who have sufficient genetic or family history, defined by a greater than 20% lifetime risk of developing cancer," according to Wendy B. DeMartini, MD, from the University of Washington Medical Center and Seattle Cancer Care Alliance. However, "there is currently insufficient evidence to support screening MRI for women with a personal history of treated breast cancer."

Dr. DeMartini and her colleagues compared the diagnostic performance of screening MRI in women at high risk for breast cancer with that of women who have already had breast cancer.

They performed a retrospective review of initial breast MRI screening exams of 1025 women from January 2004 to June 2009. Of these women, 327 had a genetic or family history of breast cancer and 646 had a personal history of treated breast cancer.

Overall, MRI testing identified 25 of 27 cancers, for a sensitivity rate of 92.6%.

However, cancer yield was significantly greater in women with a personal history of breast cancer than in those with a genetic or family history (3.1% vs 1.5%; P < .0001); the same was true for specificity (93.6% vs 86.3%; P = .0003).

The researchers also found that biopsy was recommended in fewer women with a personal history than in those with genetic risk factors or a family history (9.3% vs 15.0%), and that the positive predictive value of biopsy was greater in the personal history group than in the genetic or family history group (35.7% vs 12.2%; P = .009).

"The diagnostic performance of screening MRI in patients with a personal history of treated breast cancer supports consideration of this tool as an adjunct to screening mammography," Dr. DeMartini concluded.

In an interview after her talk, Dr. DeMartini told Medscape Medical News that these data add to other data that have recently been published in this area. "We think that women with a personal history of breast cancer should consider breast MRI screening, and we hope that the American Cancer Society will consider this in the future," she said.

She cautioned that her study results are from a single institution, and she would like to see them replicated at other centers. "Studies from other institutions would be important. In addition, although our study is the largest study to date in this patient population, there are a total of only 27 breast cancers in the study, so we do have this small numbers phenomenon, and that is going to be the case even in a larger study."

Commenting on this study for Medscape Medical News, Stamatia Destounis, MD, from the University of Rochester School of Medicine and Dentistry in New York, said: "This study is very important and reinforces many of the findings that breast imagers see in their daily practice. Women with a personal history of breast cancer are at risk of developing a recurrence or a new cancer in either breast, and breast MRI can be very useful in detecting occult cancer that may otherwise not be found with standard screening techniques."

Dr. Destounis, who was not part of the study, added that mammography "is a great screening tool. But for women postsurgery and postradiation, . . . the breast tissue becomes more difficult to interpret, and it also becomes more difficult to detect a new cancer. Breast MRI gives us anatomical and functional information, allowing us to detect subtle small cancers that could be missed otherwise."

This study is a good starting point for open discussions with current policy makers about the utility of MRI screening in this group of women, she said.

Dr. DeMartini and Dr. Destounis have disclosed no relevant financial relationships.

Radiological Society of North America (RSNA) 96th Scientific Assembly and Annual Meeting: Abstract SSAO1-01. Presented November 28, 2010.