Early Response Assessed by Contrast-Enhanced Ultrasound in Breast Cancer Patients Undergoing Neoadjuvant Chemotherapy

The study was aimed to investigate the role of contrast-enhanced ultrasound (CEUS) in evaluating the response of patients with breast cancer after receiving neoadjuvant chemotherapy (NAC). A systematic search was conducted in PubMed, Spring, Wanfang, and CNKI databases from 1923 to December 2016. Based on fixed effect model or randomized effects model, standardized mean difference (SMD) with its 95% confidence interval (95% CI) was calculated in accordance with heterogeneity analysis. Cochran Q and I-2 tests were used to measure heterogeneity. Sensitivity analysis was performed to evaluate the strength of the meta-analysis. In total, 8 studies were enrolled in the meta-analysis. Tumor size of breast cancer was obviously decreased when evaluated by CEUS (SMD, 0.96; 95% CI, 0.76-1.15) after NAC. After aggregating the data by the fixed effect model, the CEUS time-intensity curve showed a great reduction in the area under the curve of patients receiving NAC (SMD, 0.38; 95% CI, 0.08-0.69). Based on CEUS, tumor size and area under the CEUS time-intensity curve were both reduced. We suggest that the CEUS is a promising tool for evaluating the response of breast cancer after NAC.