FORCE’s eXamining the Relevance of Articles for Young Survivors (XRAYS) program is a reliable resource for breast cancer research-related news and information. XRAYS reviews new breast cancer research, provides plain-language summaries, and rates how the media covered the topic. XRAYS is funded by the CDC.
Breast cancer survivors
Women under 45
Women over 45
Men with breast cancer
Metastatic breast cancer
Triple negative breast cancer
BRCA mutation carriers
Her2+ breast cancer
Special populations: Women with dense breasts; women at high risk for breast cancer
Mammography has been shown to reduce breast cancer deaths; however, women in developing countries don’t have easy access to mammography. Ultrasound screening, on the other hand, is portable and less expensive, and could be an alternative to mammography. This study compared mammography to ultrasound in women with dense breasts and found the two techniques have similar cancer detection rates, although the false positive rate is higher with ultrasound.
The study looks at the effectiveness of ultrasound as compared to mammography for breast cancer screening.
In general, the number of breast cancer cases worldwide is increasing. Women in developing countries do not have easy access to mammography, and some lack breast cancer screening entirely. Ultrasound has many advantages: it does not use ionizing radiation, the machinery is portable and not as expensive as mammography, making it a more viable alternative for women in developing countries.
Ultimately, this study finds that ultrasound and mammography have similar cancer detection rates, although there are more false positives found through ultrasound. However, this finding does not mean that ultrasound should replace mammography. According to the study authors, “…these results suggest that screening [ultrasound] could be a viable alternative to mammography in countries lacking organized screening, particularly with availability of low-cost, portable [ultrasound] systems. Where mammography is available, [ultrasound] should be seen as a supplemental test for women with dense breasts who do not meet high-risk criteria for screening MRI and for high-risk women with dense breasts who are unable to tolerate MRI.” National guidelines recommend that women who have mutations in BRCA or other genes that increase their risk of breast cancer undergo increased surveillance for breast cancer using both MRI and mammography. It is important to remember that this study looked at women at high risk for breast cancer. The results may not apply to women with an average lifetime risk of breast cancer.
Previous work has shown that mammograms reduce the number of breast cancer deaths. In women from age 40-49, researchers have seen a 15% reduction in breast cancer deaths; a 22% reduction has been seen in women from age 50 -74. It is believed that older women benefit more from mammography because their breasts are not as dense as those of younger women. In addition to ultrasound’s portability and cost benefits, the quality of ultrasound images are not as limited by breast density as are mammography images.
In January 2016, Wendie Berg and colleagues at the Magee-Womens Hospital of University of Pittsburgh Medical Center and other institutions published a study in the Journal of the National Cancer Institute that compared all aspects of cancer detection from ultrasound and mammography.
Is ultrasound a viable alternative to mammography?
This study included 2,662 women who did not have breast cancer, but did have dense breasts. These women also had to have one other risk factor for breast cancer (for example, a BRCA mutation, an atypical breast biopsy, or high risk scores through the Gail test for Breast Cancer Risk Assessment).
In order to participate in this study, women had to have dense breasts and at least one other risk factor for breast cancer, meaning that they were all at greater risk for breast cancer than women in the general population. Therefore, the results of this study may be more applicable to young breast cancer survivors. Had study participants been at average risk for breast cancer, the results may have been different. For now, the results apply only to women at high risk of breast cancer.
This study suggests that ultrasound may be a viable alternative to mammography for women in countries that do not have access to mammography. Ultrasound should not be a replacement, however, for women who can access mammography. The researchers saw that more invasive cancers were detected by ultrasound as compared to mammography; however, they write, “a larger study is needed to statistically support greater sensitivity of ultrasound to invasive cancers.”
Berg WA, Bandos AI, Mendelson EB, et al. “Ultrasound as the Primary Screening Test for Breast Cancer: Analysis from ACRIN 6666.” Journal of the National Cancer Institute. Published online first on December 28, 2015.
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