Abstract P2-10-05: Continuous association of a 200-gene prognostic risk score with probability of neoadjuvant chemotherapy response and translation from fresh frozen to FFPE tissue for clinical use.

Abstract

Abstract BreastPRS is a suite of complimentary gene signatures that resolves several of the significant limitations of current gene expression signatures in breast cancer. Notably, BreastPRS can accurately provide prognosis prediction, histological grade resolution and molecular subtyping of invasive breast cancer. The 200-gene prognostic component was previously validated in an independent retrospective series of 1,016 previously published fresh-frozen breast cancers and has now been applied to data from over 6,000 patients. In part one of this study, a meta-analysis of 890 previously published neoadjuvant treated breast cancer patients was performed. A highly significant association was observed between prognosis risk group (high vs low), continuous risk score (0–100), and a patient's probability of achieving complete pathologic response with neoadjuvant chemotherapy. Data from both fine-needle-aspirate and biopsy tissue were included in the cohort. Notably, fewer than 10% of patients with the lowest (most favorable) pre-treatment BreastPRS prognosis scores achieve pCR. Probability of pCR was observed to increase steadily to over 40% for individuals with the highest prognosis scores. In part two of the analysis, 50 paired fresh-frozen and FFPE tumors were profiled on whole genome microarrays containing all three signatures, in a CLIA-certified high throughput genomics laboratory. Results will be presented that highlight the consistency of the prognosis, grade and subtype signatures in clinically relevant FFPE tissue. This suggests that BreastPRS, in addition to identifying 10-year recurrence risk, histologic grade and molecular subtype, may enable physicians to determine a patients benefit from receiving neoadjuvant chemotherapy with more granularity than current clinical or genomic methods. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-10-05.