Abstract P2-03-08: Usefulness of sonazoid-enhanced ultrasonography in the evaluation of the biological features of breast cancer
Authors: N Masumoto, A Amioka, K Kajitani, A Emi, H Shigematsu, T Kadoya, R Haruta, T Kataoka, M Okada
Journal: Cancer Research (2013)

Abstract Background: Contrast-enhanced ultrasonography using Sonazoid (CEUS) has gained interest because of its ability to evaluate the vascularity of malignant tumors. This study aimed to investigate the relationship between biological marker expression and time-intensity curve values for signal intensity caused by the contrast effects of Sonazoid used during CEUS for breast cancer. Methods: We evaluated 32 patients with breast cancer (mean age, 45.4 years) using Sonazoid-enhanced ultrasonography between September 2012 and May 2013. Of these, 23 were diagnosed with invasive ductal carcinoma (IDC) and 9 were diagnosed with ductal carcinoma in situ (DCIS). Breast carcinoma was evaluated in terms of nuclear grade (NG), Ki-67 labeling index, and estrogen receptor (ER). Luminal types were categorized using the Ki-67 labeling index as follows: luminal A, ER-positive and Ki-67 &amp;lt; 30%; luminal B, ER-positive and Ki-67 &amp;gt; 30%. The HI VISION ASCENDUS (Hitachi Aloka Medical Corp.) was used for ultrasonography in this study. Tumors were observed 50 s after injection of 0.01 ml/kg of Sonazoid. Time-intensity curves for tumor signal intensity were drawn. The brightness in the tumor was digitized and the curves were created on the basis of changes in brightness over time. To indicate the intensity of brightness of breast cancer lesions on Sonazoid-enhanced ultrasonography, the increase rate of brightness (IRB) was calculated using the following formula: IRB = Maximum intensity x 1/Intensity before contrast. Results IRB was 1.6 ± 0.3 and 3.3 ± 2.2 in patients with DCIS and IDC, respectively, indicating a more significant increase in IDC patients (P &amp;lt; 0.05). Relation of tumour characteristics and brightness intensityCharactersticNo. of PatientsIncreased rate of brightness (IRB)p-valueNG 1, 2122.6 ± 1.00.713113.9 ± 2.9 Ki-67 &amp;lt; 3092.4 ± 0.7P &amp;lt; 0.05≥ 30144.7 ± 2.9 ER status positive213.3 ± 2.2 negative29.1 Sub type Luminal A102.4 ± 0.8P &amp;lt; 0.05Luminal B124.2 ± 2.7 On classification of patients with IDC according to NG, Ki-67, and ER, it was found that IRB values were 2.6 ± 1.0 in patients with NG 1 and 2 tumors and 3.9 ± 2.9 in those with NG 3 tumors, 2.4 ± 0.7 in patients with Ki-67 &amp;lt; 30% and 4.7 ± 2.9 in those with Ki-67 ≥ 30%, and 9.1 in ER-negative patients and 3.3 ± 2.2 in ER-positive patients (table 1). Furthermore, comparison according to luminal subtype revealed that IRB values were 2.4 ± 0.8 and 4.2 ± 2.7 in luminal A and luminal B cases, respectively, indicating a significant difference (P &amp;lt; 0.05) (table 1). Conclusions: The intensity of ultrasound brightness of breast cancer leasions, when digitized and analyzed, can be applied for the differential diagnosis of DCIS and IDC. Furthermore, brightness intensity may also exhibit correlations with NG, Ki-67 index, and luminal subtypes, suggesting that it can be applied in grading of malignancies. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-03-08.