Correlation of contrast-enhanced ultrasound kinetics with prognostic factors in invasive breast cancer

OBJECTIVES: To correlate contrast-enhanced ultrasound (CEUS) kinetic parameters with traditional and molecular prognostic factors in invasive breast cancer. METHODS: Seventy-five invasive breast cancers were evaluated with contrast harmonic imaging after the injection of a bolus dose of 2.4 ml sulphur hexafluoride microbubble contrast agent. The lognormal function was used for quantitative analysis of kinetic data. These parameters correlated with traditional prognostic factors (tumour size, histological type, tumour grade, axillary lymph node status) and immunohistochemical biomarkers (ER, PR and HER2 status). RESULTS: Statistically significant correlation was found between time-to-peak and tumour grade (P value = 0.023), PR status (P value = 0.042) and axillary node status (P value = 0.025). Wash-out ratio, measured at 21 s was significantly associated with ER status (P value = 0.042) and PR status (P value = 0.026). CONCLUSIONS: Invasive breast carcinomas exhibiting earlier peak enhancement and faster elimination of microbubble contrast agent at CEUS are found to be associated with established predictors of poor prognosis. KEY POINTS: * Contrast-enhanced ultrasound (CEUS) can potentially determine the aggressiveness of invasive breast cancers. * Early peak enhancement and accelerated wash-out at CEUS suggest poor prognosis. * CEUS kinetics are similar to that of DCE-MRI in assessing tumour aggressiveness