(RxWiki News) The technology used to screen for breast cancer has improved greatly in recent years. In addition to traditional mammography, advanced imaging techniques such as MRIs (magnetic resonance imaging) are being used to find breast cancer. Is this a good thing?
A new study found that the use of MRIs to screen for breast cancer has increased substantially among older women.
And women who had MRIs were more likely to be diagnosed with cancer in both breasts and have both breasts removed.
"Ask your doctors about the purpose of the medical tests you have."
Cary Gross, MD, associate professor of internal medicine at Yale School of Medicine and director of the Cancer Outcomes, Public Policy, and Effectiveness Research (COPPER) Center at Yale Cancer Center, was this study’s lead author.
"These data are concerning because the long-term benefits associated with bilateral [both breasts] mastectomy for older women with breast cancer are unclear," Dr. Gross said in a prepared statement.
Using the Surveillance, Epidemiology and End Results–Medicare database, the researchers looked at the use of MRI breast screenings and surgical care of 72,461 women between the ages of 67 and 94 who were diagnosed with breast cancer between 2000 and 2009. All of the women were Medicare beneficiaries.
The investigators examined the use of MRI and the type of surgery these women received. These surgeries included breast-conserving surgery, also known as a lumpectomy, in which only the tumor and surrounding tissue are removed, and mastectomy.
Researchers also looked at bilateral versus unilateral (single) mastectomy, along with the contralateral prophylactic mastectomy — the removal of the other breast to lower the risks of cancer development in the second breast.
More women who had MRIs had one or both breasts removed than women who received only mammograms.
Here are the specifics of what the research team learned:
- Among the 72,461 women, 10.1 percent had a breast MRI.
- Use of breast MRI increased from 0.8 percent in 2001 to 25.2 percent in 2008-2009.
- Among the whole group, 43.3 percent of the women received mastectomies and 56.7 had lumpectomies.
- Women who had breast MRIs had about a 21 percent greater chance of having a mastectomy instead of lumpectomy compared to women who had only a mammogram.
- Of the women who had MRIs prior to surgery, 9.7 percent were diagnosed with cancer in both breasts, compared to 3.7 percent who didn't have MRIs.
- 12.5 percent of the MRI-screened women had bilateral mastectomies, compared to 4.1 percent of the women who did not have MRIs.
- Of the women who had mastectomies, 6.9 percent of those who had been screened with MRI had contralateral prophylactic mastectomy, compared to 1.8 percent of those who did not have an MRI.
“The fundamental problem with studies such as this is that it is not known why women in the MRI group were evaluated using MRI,” Daniel B. Kopans, MD, Professor of Radiology at Harvard Medical School, told dailyRx News.
“It is entirely possible that women who were evaluated with MRI appeared to have more extensive disease on clinical evaluation or mammography, and they were studied with MRI as a consequence,” said Dr. Kopans, who is Senior Radiologist in Breast Imaging Division of Massachusetts General Hospital.
The author of the textbook Breast Imaging, Dr. Kopans, pointed out that MRIs are finding smaller cancers than traditional screening methods.
“Now when MRI is used the hidden cancer foci are found, and this has led to an increased rate of mastectomies. The fundamental question remains: Does the use of preoperative breast MRI only increase the mastectomy rate with no mortality benefit, or does its use actually reduce deaths from breast cancer?” said Dr. Kopans, who was not involved in this study.
MRIs cost between $1,000 and $2,000 depending on the geographic location. A standard mammogram costs about $200.
Mastectomies are actually less expensive than lumpectomies. Removing only the tumor is a more complicated surgery, and radiation is often used following a lumpectomy, whereas radiation is generally not used after a mastectomy.
This study was published August 14 in Breast Cancer Research and Treatment.
The research was supported by the National Cancer Institute and the P30 Cancer Center Support Grant at the Yale Comprehensive Cancer Center. No conflicts of interest were reported.