NanoString Technologies, Inc., a privately held provider of life science tools for translational research and developer of molecular diagnostic products, today announced positive results from the second clinical validation study of its in vitro diagnostic breast cancer assay based on the PAM50 gene expression signature. The study, which evaluated samples from more than 1,400 patients enrolled in the Austrian Breast & Colorectal Cancer Study Group 8 (ABCSG8) trial, met its primary and secondary objectives and demonstrated the ability of the PAM50 test to indicate the risk of distant recurrence in postmenopausal women with hormone receptor-positive (HR+) early-stage breast cancer treated with endocrine therapy alone. Results were presented by the study's investigators during the 2012 CTRC-AACR San Antonio Breast Cancer Symposium.
NanoString's PAM50-based breast cancer assay can provide a subtype classification based on the fundamental biology of an individual's breast tumor (referred to as intrinsic subtyping), as well as a prognostic score (referred to as the risk of recurrence, or ROR, score). The ROR score indicates the probability of cancer recurrence over 10 years in post-menopausal women with HR+ early-stage breast cancer who have been treated with endocrine therapy alone. Together with studies from the literature, the ROR score and intrinsic subtype have been shown to convey clinically relevant information about a patient's prognosis.
The aim of this study was to assess the performance of the ROR score in indicating distant recurrence for postmenopausal patients with HR+ early-stage breast cancer treated with endocrine therapy alone when the PAM50-based test is performed in a hospital pathology lab. Investigators at the British Columbia Cancer Agency (BCCA) performed NanoString's PAM50-based breast cancer assay on tumor samples from 1,478 participants in the ABCSG8 study that had been stored in formalin-fixed paraffin-embedded (FFPE) format using the nCounter® Analysis System installed in BCCA's Center for Translational and Applied Genomics.
"The nCounter Analysis System is highly automated and fits into the workflow of a hospital pathology laboratory where it can accurately measure RNA extracted from standard FFPE tissue samples with minimal hands-on time," said Torsten Nielson, MD, PhD, Professor of Pathology at the University of British Columbia and lead pathology investigator of this study. "On these clinical specimens, 97% of the breast cancer samples that passed the pre-specified tissue and RNA metrics yielded intrinsic subtype and ROR results."