Correlation between ultrasound descriptors and histopathological prognostic markers (Ki-67 score, Nottingham grade, and tumor subtype) in triple-negative breast cancers

Objectives: To determine whether ultrasound (US) features correlated with high (>14%) or low (<14%) Ki-67 score or other histopathological prognostic markers in TNBC.Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer. Alarmingly, TNBC can often masquerade as a benign mass on imaging, and benign appearing TNBCs can be highly aggressive. It is important for radiologists to understand the prognostic features of “benign” imaging appearances of TNBC, so that they are cautious while imaging seemingly benign masses. Materials and Methods: We retrospectively searched our institutional Picture archiving and communication system for patients who had undergone US-guided core needle biopsy at our institution (n=50) and were proven to have TNBCs. Ki-67 scores, TNBC subtype (basal-like/non-classified), Nottingham’s grade, and score were documented from the histopathology report. Statistical analysis was done using chi-square and T-tests. Results: Circumscribed margins were significantly associated with higher Nottingham’s score ( p = 0.046) and younger age ( p = 0.006). Circumscribed masses showed higher Ki-67 than non-circumscribed masses ( p = 0.206). Masses with posterior enhancement were significantly associated with higher Nottingham’s Score ( p = 0.041) and Grade ( p = 0.032). High ki67 score was significantly associated with BL subtype ( p < 0.001). Conclusion: The combination of circumscribed margins and posterior enhancement on imaging, classically described in fibroadenomas, warrants caution since it is also seen in high-grade TNBCs.