Rosalind Pitpitan Candelaria MD, Presenter: Nothing to Disclose

William Frazer Symmans MD, Abstract Co-Author: Co-founder, Nuvera Biosciences, Inc Scientific Advisor, Nuvera Biosciences, Inc

Maheshwari Ramineni MD, Abstract Co-Author: Nothing to Disclose

Wei Tse Yang MD, Abstract Co-Author: Researcher, Hologic, Inc

The purpose of this study is to determine if ultrasound (US) tumor response measurements during neoadjuvant chemotherapy (NAC) predicts residual cancer burden (RCB), which is a significant predictor of distant relapse-free survival.

Patients with primary invasive breast cancer, who had ultrasound performed before and after NAC, were included in this HIPAA-compliant retrospective study from a single institution. Patients were treated with paclitaxel followed by fluorouracil, doxorubicin and cyclophosphamide (FAC) or fluorouracil, epirubicin and cyclophosphamide (FEC). Human epidermal growth factor receptor 2 positive (HER2+) patients received concomitant trastuzumab. US measurements were obtained in three dimensions. All patients underwent mastectomy or segmentectomy and sentinel node biopsy or axillary node (AXLN) dissection. RCB was calculated based on area of primary tumor bed, overall cancer cellularity as percent (%) of area, % of in situ cancer, number of positive lymph nodes and diameter of largest metastasis. Regression analysis was performed for RCB versus % change in the following tumor measurements: 1) largest dimension, 2) bi-dimension and 3) volume.

160 breast cancer patients [69 triple receptor negative (TRN), 45 estrogen receptor positive (ER+) and 46 HER2+] were included. Median age at diagnosis was 50, range 30-76; median tumor size was 3.4 cm, range 0.9–10.4. 63% of patients were AXLN positive at diagnosis; 30% of this subset became node negative at surgery. TRN tumors showed 38% pCR (pathologic complete response), 9% RCB-I, 32% RCB-II and 22% RCB-III; ER+ 11% pCR, 13% RCB-I, 58% RCB-II and 18% RCB-III; HER2+ 57% pCR, 15% RCB-I, 26% RCB-II and 2% RCB-III. There were significant associations between RCB and % change in tumor largest dimension, bi-dimension and volume for TRN (p<0.001) and ER+ (p<0.05) but not in HER2+ breast cancer (p>0.05).

US tumor response measurements are significant predictors of RCB in TNBC and ER+ but not in HER2+ breast cancers. This may contribute to the monitoring of TNBC and ER+ breast cancer response to targeted therapies and drug development.

US has differential capacities of measuring tumor response based on molecular phenotype; alternate imaging is needed to adequately measure response of HER2+ tumors to better identify chemoresistance.

Candelaria, R, Symmans, W, Ramineni, M, Yang, W, Ultrasound Predicts Residual Disease in Triple Negative and ER+ Breast Cancer but not in HER2+ Breast Cancer.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14045460.html