Comparison of MammaPrint and TargetPrint with clinical parameters in patients with breast cancer: Findings from a prospective U.S. cohort.

e11094 Background: The MammaPrint 70-gene expression profile (MP) is a powerful predictor of disease outcome in early stage breast cancer. In addition, TargetPrint (TP), a microarray-based test that measures the mRNA expression level of ER, PR and HER2 was developed. In the present study, MP was measured in a prospective U.S. breast cancer patient cohort to determine how MP compares to treatment advice according to NCCN consensus guidelines and how TargetPrint results compare to IHC/FISH. Methods: MP results were evaluated in fresh tumor samples from 111 breast cancer patients (T1-4N0-2; median age 62 [39 -97 yr]) collected by core needle biopsy or from a surgical specimen between July 2008 and November 2010. We compared treatment advice as recommended by NCCN guidelines and classification according to MP. A direct comparison was also made between MP and the Oncotype DX (ODX) assay in a small subset of patients. In addition, we compared IHC/FISH ER, PR and HER2 assessments with TP. Results: According to N...