TUESDAY, April 3 (HealthDay News) -- New research suggests that
adding an ultrasound or MRI scan to breast cancer screening if a
woman has dense breasts and at least one other risk factor for
breast cancer would increase the number of cancers found.
Dense breast tissue increases a woman's risk of developing
breast cancer, and it also makes screening for breast cancer more
difficult with standard mammography, previous research has
The addition of ultrasound to screening resulted in the
detection of an additional 4.3 cancers per 1,000 women screened,
and MRI resulted in an additional 14.7 cancers detected per 1,000
screened on average, according to the results of the new study.
These cancers were found before they had spread to nearby lymph
"This is a very important time in breast cancer screening. Breast cancer is becoming more treatable, and now we have these extra tools to find cancers," said the study's lead author, Dr. Wendie Berg, a professor of radiology at the University of Pittsburgh School of Medicine, Magee-Womens Hospital.
But, she added that women need to be informed that while MRI and
ultrasound are more sensitive tests that detect more breast
cancers, these tests also come with the risk of false positives.
"You have to be willing to accept the risk of extra testing," she
Results of the study are published in the April 4 issue of the
Journal of the American Medical Association. Funding for the study was provided by the Avon Foundation and the U.S. National Cancer Institute.
The study included almost 2,700 women who underwent annual
mammography and ultrasound for three years. At the end of three
years, the women were offered the chance to undergo MRI screening,
which requires the use of a special dye (injected through an
intravenous line) and lying still in the enclosed MRI machine,
which can be a problem for people who are uncomfortable in confined
spaces. Just 58 percent of the women decided to undergo MRI.
All of the women included in the study had dense or extremely
dense breast tissue. Berg noted that about 40 percent of women
under 50 years old and 30 percent of women over 50 have dense
The women in the study also had at least one additional risk
factor for breast cancer, according to Berg. Risk factors that
indicate an intermediate risk of breast cancer include a personal
history of breast cancer, a previous unusual breast tissue biopsy
or an intermediate family history of breast cancer (meaning not
someone in the immediate family).
Factors that indicate a high risk of breast cancer include
having a known breast cancer gene, prior radiation treatment to the
chest or an immediate family history of the disease. In women with
a high risk, which is about 1 percent to 2 percent of women
according to Berg, it's already recommended that they undergo MRI
in addition to mammography.
What's been less clear is how best to screen women with dense
breast tissue and an intermediate risk of cancer.
After three years, a total of 7,473 mammograms and ultrasounds
were completed, and 612 women had completed MRIs. There were 111
breast cancers detected. Thirty-three were detected by mammogram
alone, while 32 were found by ultrasound alone, and another 26 were
found by both. Nine cancers were detected by MRI after women had
already undergone mammography and ultrasound. Eleven cancers
weren't detected by any of the screening methods -- they were found
either by the women or their doctors discovering a lump.
As for false positive rates, Berg said that ultrasound resulted
in an additional 7 percent recall rate, and 5 percent of those
women had to have a biopsy. Only 7 percent of the biopsies detected
cancer, she said. But for MRI, the recall rate was 20 percent and 7
percent of those women needed a biopsy. Just 19 percent of these
biopsies found cancer, said Berg.
Berg pointed out that insurers may or may not pay for ultrasound
screenings, and that requests for MRI screenings are often denied
because of the significant cost of the test.
Commenting on the study findings, Dr. Stephanie Bernik, chief of
surgical oncology at Lenox Hill Hospital in New York City, said:
"Insurance companies probably won't pay for an MRI unless a woman
is high risk. And, cost isn't always the bottom line. MRI does
generate false positives, which aren't innocuous. They have their
risks and complications."
Bernik recommended that women ask their doctors whether or not
their mammography showed dense breast tissue. If you have dense
breast tissue, she recommended asking your doctor if you should be
getting a screening ultrasound as well. "There are risk factors
other than dense breast tissue that factor into the decision, so
ask your doctor if you need it," said Bernik.
Both Bernik and Berg noted that ultrasound screening for breast
cancer isn't yet available everywhere, and that the quality of the
test depends a lot on who's doing it.
Learn more about breast cancer detection techniques from the
American Cancer Society.
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
Copyright © EBSCO Publishing. All rights reserved.