Mammography and ultrasound features of triple-negative breast cancer

Triple-negative breast cancer is characterized as a cancer with a high malignancy potential and a poor prognosis. Therefore, early detection of this subtype of breast cancer is vital. In this paper, we describe the mammography and ultrasound findings of triple-negative breast cancer in a large population and investigate the specific features of this subtype.

From January 2007 to April 2010, mammography and ultrasound findings of 88 patients with triple-negative breast cancer were retrospectively reviewed. In this cohort, 52 patients underwent neoadjuvant chemotherapy. We compared the pathological chemotherapy effects and radiological findings among these patients. Mammograms were reviewed according to the Japanese mammography guideline. Ultrasound findings were classified as masses, low echoic area, distortions, and calcifications. Noted features included shapes, patterns of internal echoes, posterior echoes, vascularity, and elasticity scores.

On mammography, triple-negative breast cancers frequently presented with a mass (62.4%). Masses with microlobulated margins were the most frequent (39.6%), indistinct (32.0%) and circumscribed (20.8%) were commonly observed, but spiculated margins were rare (4.7%). On ultrasound, cancers were more likely to present as a mass (92.5%), and less likely to show attenuating posterior echoes (8.8%). Of the 40 cases obtained via elasticity imaging, 35 (87.5%) lesions were scored as 4 or 5. There were no significant differences in the mammography or ultrasound findings between the chemotherapy effects.

Mammography and ultrasound imaging together revealed that the morphological features of triple-negative breast cancer include a lobulated mass, with less attenuating posterior echoes, some vascularity, and low elasticity.