By: Beth Walsh for Uterus1
MRI scans of women diagnosed with cancer in one breast detected more than 90 percent of cancers in the opposite breast – which were missed by mammography and clinical breast exam, according to recent findings published in the New England Journal of Medicine.
|Breast cancer is the second leading cause of cancer deaths in women. According to the World Health Organization, more than 1.2 million people will be diagnosed with breast cancer worldwide every year. However, thanks to earlier detection and better treatments, breast cancer death rates have been dropping since 1990.|
The exact cause of breast cancer is unknown. Risk factors include early puberty, late childbearing, obesity, and habits such as heavy alcohol use and smoking. The biggest risk factor is age: incidence increases as women gets older. One in eight women will be diagnosed during their lifetime.
Your risk of developing breast cancer increases if a close relative (like mother, sister, or cousin) has had the disease. However, 85 percent of women diagnosed with breast cancer have no known family history.
The most common sign of breast cancer is a new lump or mass in one breast. Some women have swelling in part of the breast, skin irritation or dimpling, nipple pain or the nipple turning inward, discharge or a lump under the arm. See a doctor about any concerns and talk to your provider about conducting monthly breast self-exams as well as when you should begin getting annual mammograms.
Researchers found that adding an MRI scan to breast evaluation can nearly double the number of cancers immediately found in high-risk women. The findings indicate that up to 1.4 million American women should get annual MRIs as well as mammograms, and that all women with newly diagnosed breast cancer should also get MRIs.
This study was released after the American Cancer Society developed new guidelines for breast cancer, which are the first to recommend MRI for screening women who show no signs of cancer. The guidelines are directed at symptom-free women age 30 and older who have a mutation in the BRCA1 or BRCA2 genes; those who were treated for Hodgkin's disease; and those with a strong family history of the disease, such as women with two or more close relatives who had breast or ovarian cancer or who have a close relative who developed breast cancer before age 50.
Mammograms are a type of X-ray that physicians use to detect dense masses such as tumors. Magnetic resonance imaging uses a magnet and radiowaves to create more detailed images. The MRI scan shows increased or abnormal blood flow in the breast, which cannot be seen on a mammogram. MRI scans are more sensitive than mammograms, but they are also more likely to show spots in the breast that may or may not be cancer. Often, a follow-up biopsy is required to determine whether these spots are cancerous. That is why the test is not recommended for women with an average risk of breast cancer, according to the ACS guidelines.
"One in 10 women diagnosed with cancer in one breast will develop the disease in the opposite breast. Having a better technique to find these cancers as early as possible will increase the chances of successful treatment," said National Institutes of Health Director Elias A. Zerhouni, MD.
The American College of Radiology recruited 1,007 women from 25 institutions who had a recent diagnosis of cancer in one breast. All of the women enrolled had a negative mammogram and a negative clinical breast exam of the opposite breast, within 90 days of the MRI. After receiving an MRI, 33 contralateral (in the other breast) breast cancers were diagnosed. The trial was sponsored by the National Cancer Institute.
"This study gives us a clearer indication that if an MRI of the opposite breast is negative, women diagnosed with cancer in only one breast can more confidently opt against having a double, or bilateral, mastectomy," said NCI Director John E. Niederhuber, MD.
"We can now identify the vast majority of contralateral cancers at the time of a woman's initial breast cancer diagnosis," said Constance Lehman, MD, PhD, principal investigator of the ACRIN Breast MRI Trial, professor of radiology and director of breast imaging at the University of Washington and Seattle Cancer Care Alliance. "This means that instead of those women being diagnosed with cancer a second time years later, we can diagnose and treat those opposite breast cancers at the time of the initial diagnosis."
Researchers hope breast MRIs will help avoid unnecessary mastectomies and reassure women that they are disease-free.
Click here for a guide to mammography.