Breast Cancer Detection Rate of Ultrasound and Mammography Are Comparable
Ultrasound has comparable sensitivity in detecting breast cancer compared with mammography and should be considered when testing for the disease, according to a study published in the JNCI: Journal of the National Cancer Institute (doi:10.1093/jnci/djv367).
Breast cancer cases are increasing worldwide; more than 1.6 million new cases of the disease were diagnosed in 2010, resulting in more than 425,000 deaths. Furthermore, an estimated 2.1 million new diagnoses of breast cancer are expected by 2030. Mammography is proven effective in detecting breast cancer in developed countries; however, it is not commonly available in less developed nations, and alternative methods, such as ultrasound, need to be investigated.
Researchers at Magee-Womens Hospital, in Pittsburgh, Pennsylvania, recruited 2809 women across 20 sites in the United States, Canada, and Argentina to the American College of Radiology Imaging Network protocol 6666 breast cancer screening study. The objective was to determine the effectiveness of US in detecting breast cancer.
Of the participants, 2662 completed 3 annual breast screenings by US and film-screen or digital mammography, then underwent a biopsy or a 12-month follow-up.
Study results show the number of ultrasound screens needed to detect breast cancer was comparable to that of mammography, and found that a greater proportion of invasive and node-negative cancers were found in those who underwent ultrasound. However, they also saw a greater number of false-positives among the women screened with ultrasound. Although the false-positive rate is higher with ultrasound than with mammography, the number of women recalled for extra testing becomes more comparable on incidence screening rounds.
"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," stated the authors.