Background: Triple-negative (TN) breast cancers have high malignancy potential and are often characterized by early systemic relapse. Early detection is vital, but there are few comprehensive imaging reports. Here we describe mammography, ultrasound, and magnetic resonance imaging (MRI) findings of TN breast cancers, investigate the specific features of this subtype, and compare the characteristics of TN breast cancers with those of hormone receptor (HR)-positive/human epidermal growth factor receptor (HER)-2-negative breast cancers.
Materials and methods: From July 2009 to June 2011, mammography and ultrasound findings of 210 patients with pathologically confirmed TN (n = 105) and HR-positive/HER-2-negative breast cancers (n = 105) were retrospectively reviewed from our institutional database. Ultrasound vascularity was notified in 88 cases and elasticity scores were notified in 49 cases overall. Thirty-five patients underwent MRI (22 TN and 13 HR-positive/HER-2-negative). Mammograms, ultrasound, and MRI were reviewed according to the Breast Imaging-Reporting and Data System (BI-RADS) lexicon and classification.
Results: TN breast cancers were more likely to show round, oval, or lobulated masses with indistinct margins on mammography than HR-positive/HER-2-negative breast cancers. On ultrasound, TN tumors were more likely than HR-positive/HER-2-negative breast cancers to show circumscribed or microlobulated margins and no posterior acoustic features or posterior enhancement-positive. On MRI, TN cancers exhibited suspicious aspects more often than HR-positive/HER-2-negative cancers, often with rim enhancement-positiveHER-2 (84.6% of masses were classified BI-RADS 5).
Conclusion: This study is the first to describe findings on mammography, ultrasound, and MRI for TN breast cancers with a matched HR-positive/HER-2-negative control group. Several distinctive morphological features of these aggressive tumors are identified that can be used for earlier diagnosis and treatment, and ultimately to improve outcomes.
Keywords: Breast neoplasms; Diagnosis; Magnetic resonance imaging; Mammary; Mammography; Triple-negative breast cancer; Ultrasonography; Ultrasound.