Breast Ultrasound vs. Mammography
But ultrasound has more false positives, researchers find
By Kathleen Doheny
MONDAY, Dec. 28, 2015 (HealthDay News) -- Ultrasound and mammography appear equally likely to detect breast cancer, a new study says.
The finding is good news, particularly for women who live in developing countries that typically have more access to ultrasound than to mammography, the researchers said.
While the detection rate with ultrasound was comparable to that of mammography, "it looks like ultrasound does better than mammography for node-negative invasive cancer," said study leader Dr. Wendie Berg, professor of radiology at Magee-Womens Hospital of UPMC in Pittsburgh. Node-negative invasive cancer is cancer that hasn't invaded the lymph nodes, but has grown past the initial tumor, according to the U.S. National Cancer Institute.
"The downside [to ultrasound] is, there were more false positives," Berg said.
At least one expert doesn't expect this study to change current screening practice in the United States.
"For U.S. patients, what [this study] really confirms is, ultrasound should be used as a supplemental screening exam in dense breast patients," said Dr. Lusi Tumyan, a radiologist and assistant clinical professor at the City of Hope Cancer Center, in Duarte, Calif. She reviewed the findings but was not involved in the study.
"At this time we do not have enough data to support or refute ultrasound as a screening tool for average-risk patients," Tumyan said. The take-home message for women in the United States, she added, is to discuss their specific risks with their physician and decide together which screening test is best for them.
The study was published Dec. 28 in the Journal of the National Cancer Institute.
Ultrasound is generally used as a follow-up test once a potential breast tumor has been discovered through a mammogram or a physical exam, according to the American Cancer Society (ACS). The ACS says that ultrasound is a valuable tool that's widely available and noninvasive.
The new study involved 2,600 women living in the United States, Canada and Argentina who had ultrasound and mammogram annually for three years. They had no symptoms of breast cancer at the study's start, but they did have dense breast tissue -- considered a risk factor for breast cancer -- plus at least one other risk factor for breast cancer.