Ultrasound lags behind MRI for supplemental breast cancer screening
Cancer screening of women with dense breast tissue is a subject of great interest to both the medical community and the press. Dense parenchyma reduces the sensitivity of mammography to half that of fatty breasts. Approximately 40% of women 40 years of age or older have dense breast tissue, making supplemental breast cancer screening essential.
Although supplemental screening via ultrasound is unaffected by breast density, is not associated with ionizing radiation, and does not require IV contrast material, acceptance of this modality has lagged.
According to Ellen B. Mendelson, professor of radiology at Northwestern University Feinberg School of Medicine, and Wendie A. Berg, professor of radiology at Magee-Womens Hospital of UPMC, a significant factor is lack of available intensive training opportunities.
“The most common alternative screening modality, MRI, cannot be used with women who have pacemakers or other devices, severe claustrophobia, or renal insufficiency,” say Drs. Mendelson and Berg.
“To realize ultrasound’s potential to increase the number of cancers detected, intensive training programs need to be put in place for physician performers and interpreters for both handheld and automated breast ultrasound systems.”
Regular breast cancer screening is important for all women, but even more so for those at higher risk. If you are at higher risk of breast cancer, you may need to be screened earlier and more often than women at average risk.
A woman is considered at higher risk if she has one factor that greatly increases risk or several factors that together increase risk. Your health care provider may use different tools to assess your risk and help you make a personalized breast cancer screening plan.
What is breast MRI?
Breast magnetic resonance imaging (MRI) uses magnetic fields to create an image of the breast. Breast MRI is more invasive than mammography because a contrast agent is given through an IV before the test.
Breast MRI and breast cancer screening
At this time, breast MRI is mostly used in breast cancer diagnosis and staging, rather than in screening. However, there is growing evidence that breast MRI in combination with mammography is better than mammography alone at finding breast cancer in certain women at higher risk. ACS and NCCN recommend screening with mammography plus breast MRI for some women at higher risk of breast cancer, including those with:
A BRCA1 or BRCA2 gene mutation
A first-degree relative with a BRCA1/2 mutation, but personally have not been tested for BRCA1/2 mutations
A strong family history of breast or ovarian cancer (for example, two or more first-degree relatives with breast cancer or two or more with ovarian cancer)
Radiation treatment to the chest area before age 30
Li-Fraumeni, Cowden or Bannayan-Riley-Ruvalcaba syndrome (or a first-degree relative with one of these syndromes or family with a known p53 or PTEN gene mutation)
A greater than 20 percent lifetime risk of invasive breast cancer
Certain women have a moderately increased risk of breast cancer. ACS and/or NCCN recommend that a woman at a moderately increased risk talk to her health care provider about the risks and benefits of screening with mammography plus breast MRI. Women who should consider mammography plus breast MRI include those who have:
A personal history of invasive breast cancer or ductal carcinoma in situ (DCIS)
A personal history of lobular carcinoma in situ (LCIS) or atypical hyperplasia
Very dense breast tissue
A 15 to 20 percent lifetime risk of invasive breast cancer
Talk with your health care provider about breast cancer screening. Together, you can come up with a screening plan that is right for you.
The opinion piece appears in the February issue of the American Journal of Roentgenology.
Founded in 1900, ARRS is the first and oldest radiology society in the United States, and is an international forum for progress in radiology. The Society’s mission is to improve health through a community committed to advancing knowledge and skills in radiology. ARRS achieves its mission through an annual scientific and educational meeting, publication of the American Journal of Roentgenology (AJR) and InPractice magazine, topical symposia and webinars, and print and online educational materials. ARRS is located in Leesburg, VA.
A breastultrasound uses sound waves to make a picture of the tissues inside the breast. A breast ultrasound can show all areas of the breast, including the area closest to the chest wall, which is hard to study with a mammogram. Breast ultrasound does not use X-rays or other potentially harmful types of radiation.
A breast ultrasound is used to see whether a breast lump is filled with fluid (a cyst) or if it is a solid lump. An ultrasound does not replace the need for a mammogram, but it is often used to check abnormal results from a mammogram.
For a breast ultrasound, a small handheld unit called a transducercamera.gif is gently passed back and forth over the breast. A computer turns the sound waves into a picture on a TV screen. The picture is called a sonogram or ultrasound scan.
Why It Is Done
Breast ultrasound can add important information to the results of other tests, such as a mammogram or magnetic resonance imaging (MRI). It also may provide information that is not found with a mammogram. A breast ultrasound may be done to:
Find the cause of breast symptoms, such as pain, swelling, and redness.
Check a breast lump found on breast self-examination or physical examination. It is used to see whether a breast lump is fluid-filled (a cyst) or if it is a solid lump. A lump that has no fluid or that has fluid with floating particles may need more tests.
Check abnormal results from a mammogram.
Look at the breasts in younger women because their breast tissue is often more dense, and a mammogram may not show as much detail.
Guide the placement of a needle or other tube to drain a collection of fluid (cyst) or pus (abscess), take a sample of breast tissue (biopsy), or guide breast surgery.
Watch for changes in the size of a cyst or a noncancerous lump (fibroadenoma).
See how far cancer has spread in a breast.
Check your breasts if you have silicone breast implants or dense breasts. In these situations, a mammogram may not be able to see breast lumps.
Lissa D. Hurwitz
American Roentgen Ray Society
American Journal of Roentgenology