Wei Tse Yang MD, Presenter: Consultant, Naviscan, Inc

Jenny Chang, Abstract Co-Author: Nothing to Disclose

Massimo Cristofanilli MD, Abstract Co-Author: Nothing to Disclose

Wei Wei, Abstract Co-Author: Nothing to Disclose

Savitri Krishnamurthy MD, Abstract Co-Author: Nothing to Disclose

Eric Michael Rohren MD, PhD, Abstract Co-Author: Nothing to Disclose

Naoto Ueno MD,PHD, Abstract Co-Author: Nothing to Disclose

Vicente Valero MD, Abstract Co-Author: Nothing to Disclose

Thomas A. Buchholz MD, Abstract Co-Author: Nothing to Disclose

We report the utility of PEM to evaluate clinical and pathologic response to targeted neoadjuvant (NA) therapy.  

The correlation with pre-treatment PEM and early changes in PEM are reported for breast cancer patients treated on two NA clinical trials. In the first study, patients with newly diagnosed HER2+ inflammatory breast cancer (IBC) received lapatinib [LP] (EGFR/HER2 tyrosine kinase inhibitor) at 1500 mg PO QD for 14 days as a single agent, followed by sequential NA chemotherapy (CT) (paclitaxel [PT] followed by FEC75), in combination with LP. In the second study, triple receptor negative (TRN) patients received dasatinib [DB] (multitargeted Src inhibitor ) at 100 mg PO QD for 21 days as a single agent, followed by sequential NA PT. PEM was performed prior to treatment and repeated after run-in with single agent targeted therapy (LP or DB). PEM results were correlated with subsequent pathologic complete response (pCR) in the LP study (defined as no residual cancer in the histological evaluation of surgical specimens after completion of NA LP/CT), and with clinical partial response (cPR) by RECIST criteria in the DB study. Statistical analyses included Wilcoxon rank sum test and Spearman’s correlation test.

A total of 10 HER2+ IBC patients (median age 59 years, range, 41-71), and 8 TRN patients (median age 46 years, range, 30-61), who were imaged with PEM, and had corresponding imaging and pathology results were included in this analysis. In the LP group, the median tumor size was 10 cm (range 5-14 cm), and 30% (3/10) patients achieved a pCR. Higher baseline PEM uptake value (PUV), and change in PUV values from baseline to day 14, were both significantly associated with pCR to LP (p<0.05). In the DB group, the median tumor size was 5 cm (range 2-11 cm), and only 12.5% (1/8) patients achieved cPR. There were no significant changes in PUV values with DB treatment.

This is the first functional study to demonstrate that baseline PUV and change in PUV values are strongly correlated with pCR to NA LP and CT. In addition, lack of change in PUV values is associated with low clinical efficacy of DB.

Correlating PUVs as a measure of early response to targeted therapy with pCR, changes in proliferation, and downstream markers may aid drug discovery in the era of personalized medicine.

Yang, W, Chang, J, Cristofanilli, M, Wei, W, Krishnamurthy, S, Rohren, E, Ueno, N, Valero, V, Buchholz, T, Evaluation of Response to Targeted Therapy Using Positron Emission Mammography (PEM).  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11004772.html