Abstract P4-03-07: Angiogenic effect of bevacizumab and paclitaxel in metastatic breast cancer: evaluation by contrast-enhanced ultrasonography using Sonazoid®

Abstract

Agents targeting vascular endothelial growth factor (VEGF) have been validated as breast cancer therapeutics, yet efficacy can differ between tumor types and individual patients. Rapid noninvasive determination of response could provide significant benefits. We tested if response to the VEGF antibody bevacizumab and chemo drug paclitaxel could be detected using contrast-enhanced ultrasound imaging (CEUS). The objective of this study was to evaluate contrast-enhanced ultrasound (CEUS) with contrast agent Sonazoid® injection as a predictor of tumor response. Patients and methods: Ten patients with advanced and metastatic breast carcinomas treated were evaluated. Examinations were performed at baseline, after 2 and 4 weeks and every one month on antiangiogenic drug bevacizumab and chemo drug paclitaxel in tumor targets that were accessible to CEUS. Histological findings were obtained in all cases by ultrasound-guided 14 gauge core needle biopsy or 10 gauge vacuum-assisted biopsy. Each examination included a bolus injection of Sonazoid® and 40–60 seconds of raw linear data with an Aplio (Toshiba), Logiq (GE) and Ascendus (Hitachi-ALOKA) with a 8–12 MHz linear transducer. A low reduced mechanical index (MI) of less than 0.24 was chosen to avoid early gas bubble destruction. The ethic committee of our institution approved this study. An informed consent was signed by each patient for the ultrasound examination and before administering for the contrast medium. Results: A total of 60 examinations were performed. Various intratumoral perfusion parameters changed over time, and the signal intensity was significantly impaired in the treated tumors before the treatment efficacy on tumor size could be observed. Conclusion: CEUS has advantages for real-time visualization and is a new noninvasive imaging technique which might be an effective tool for evaluating antiangiogenic drugs and chemo drugs in breast cancer. The use of a noninvasive ultrasound approach may allow for earlier and more effective determination of efficacy of antiangiogenic therapy. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P4-03-07.

Antiangiogenesis Therapy for Breast Cancer: An Update and Perspectives from Clinical Trials

“…Sonazoid ® is a microbubble contrast that has been studied in hepatocarcinomas ( 72 ). A preliminary study among 10 breast cancer patients has shown that CEUS using Sonazoid ® can be used to assess response to bevacizumab in combination with taxanes ( 73 ). Although well-designed clinical studies are more than necessary to evaluate the accuracy of imaging modalities, assessing tumor vascularity and oxygenation before and during antiangiogenic therapies by new imaging modalities such as photoacoustic mammography ( 74 ) might be a useful tool in providing predictive markers for better selecting patients for antiangiogenic therapies.…”