Breast cancer awareness campaigns and revelations about the genetic links of the disease have elevated breast cancer concerns among women of all ages in the past 20 years. That increased anxiety often leads younger women—even those with no elevated risk factors who are considered too young for mammography—to discuss early screening efforts with their doctors.
According to National Cancer Institute statistics, this fear isn’t without some foundation. In the United States, roughly 12,150 women under age 40 and 26,393 women under age 45 will receive a breast cancer diagnosis each year. These diagnoses result in approximately 1,000 deaths annually.
However, recent research published in the Israel Medical Association Journal (IMAJ) revealed that, despite the benefits to older women and those with clinical breast findings, conducting a screening breast ultrasound in asymptomatic women under age 40 does not provide any additional information that can proactively augment a physical examination.
“Many young women feel anxious about their breast health and demand breast cancer screening at ages younger than that recommended by national screening programs,” says lead author David Aranovich, MD, professor of general surgery at the Rabin Medical Center in Israel. “The results of our study demonstrate that in the absence of palpable clinical findings during breast examination, the addition of breast ultrasonography will not provide significant yield to complement the physical examination of self-referred women under the age of 40 who do not have major risk factors for the development of breast cancer.”
Previous research, published in the American Journal of Roentgenology, indicates that breast ultrasound is the superior evaluation modality for younger women ages 30 to 39. The results of that study found that breast ultrasound had a 99.9% negative predictive value and a positive predictive value of 13.2%. Mammography had a negative predictive value of 99.2% and a positive predictive value of 18.4%.
However, the findings in the IMAJ study point to a need for breast ultrasound only when suspicious clinical findings are present. This conclusion also supports existing American Cancer Society breast cancer screening guidance that recommends women begin receiving annual mammography screening at age 45.
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To determine the utility of breast ultrasound in younger women, Aranovich and his colleagues identified 3,127 women under age 40 in their breast care clinic who were of average breast cancer risk and who had no breast complaints, such as pain, mass, lactation-related problems, or nipple discharge. Of that group, 220 women underwent a breast ultrasound following their initial clinic visit.
According to electronic medical records data, breast ultrasound identified positive clinical findings in 68 women. Of that group, 30 had simple cysts (BIRADS 2), 15 had solid masses compatible with sonographers fibroadenomas (BIRADS 2), and 15 had suspicious solid masses (BIRADS 4B, BIRADS 4C, BIRADS 3, and BIRADS 4A). Eight women had no sonographic findings. Of the 15 suspicious masses, one was infiltrating ductal carcinoma, and one was ductal carcinoma in situ.
Based on this data, the positive biopsy rate was 13.3% with a corresponding cancer detection rate of 0.9%. Among women with positive clinical findings, the cancer detection rate with ultrasound was 2.9%, making the cumulative cancer detection rate 0.06% for women under age 40 who are also of average risk.
In addition, investigators discovered a substantial number of asymptomatic younger women were actively encouraged to undergo a screening breast ultrasound during their clinical visit. No justifiable reason to support the exam was provided in these patients’ medical records, Aranovich says.
“We assumed that very concerned women were directed to have breast ultrasonography to placate their fears, rather than due to sound medical reasons,” he says.