Breast Cancer in the News
Several high-profile reports about breast cancer have received media coverage in recent weeks, including work on magnetic resonance imaging (MRI), computer-assisted detection, and screening mammography recommendations. With research often reduced to sound bites and headlines, it can be a challenge to distinguish the key points and understand the implications. To help, here are summaries of three recent publications.
MRI Detects Contralateral Breast Cancers
Where: Published in the March 29 New England Journal of Medicine.
Target audience: This study is about breast cancer detection and applies only to women who have been newly diagnosed with breast cancer and want to know whether they have cancer in both breasts.
Findings: MRI plus mammography can help identify hard-to-detect cancers that might be missed by mammography alone. By detecting cancer in both breasts at the same time, women could potentially be treated for both cancers simultaneously rather than having to go through treatment again in the future.
Bottom line: When used in combination with physical examination and mammography, contralateral breast MRI will identify the vast majority of contralateral cancers at the time of diagnosis in women who have an indication such as having very dense breasts or being at high risk for breast cancer.
MRI Screening, Mammograms Urged for High-Risk Women
Where: Published in the March/April CA: A Cancer Journal for Clinicians.
Target audience: This report provides consensus guidelines developed by experts and applies only to women who are at high risk of developing breast cancer.
Findings: In certain groups of high-risk women, conducting both annual MRI scans and screening mammography increases the likelihood of early detection. "High risk" is defined in these guidelines as women who have a 20- to 25-percent lifetime risk of developing breast cancer. This is a very substantial increased risk. Only 1 to 2 percent of women have a risk of breast cancer this high. Risk can be estimated with a risk-assessment tool, and more information can be found on the ACS Web site.
Bottom line: Women should talk to their physicians about whether they fall into the high-risk category and might benefit from MRI scans along with screening mammography.
Comment: "These two publications confirm earlier reports that MRI is a very sensitive technology for detecting breast cancer, and they give us a little more information about when it should be used, including for women who have just been diagnosed with breast cancer and for women who are at high risk," says Dr. Daniel Sullivan, associate director of the Cancer Imaging Program, NCI's Division of Cancer Treatment and Diagnosis.
Mammogram Study Evaluates Computer-Aided Detection
Where: Published in the April 5 New England Journal of Medicine.
Target audience: Researchers and clinicians. This study raises questions about software used at some mammography facilities but does not alter recommendations for women about screening mammograms.
Findings: This was a large-scale analysis of screening mammography performed between 1998 and 2002 at 43 U.S. facilities, some of which adopted computer-aided detection, or CAD. CAD increased the detection of ductal carcinoma in situ but not invasive cancer. It also increased the number of evaluations that resulted in biopsy compared with the period when CAD was not available.
Bottom line: Larger, carefully designed studies are needed to determine whether the potential benefits of CAD outweigh the potential harms.