Clock Genes Expression In Breast Cancers (Bc) From Patients (Pts) Treated With Neoadjuvant Chemotherapy (Nac) In A Randomized Multicenter Phase Ii Trial.

e11528 Background: Circadian clocks control cellular metabolism and proliferation. Circadian disruption could affect BC development and treatment efficacy. Purpose: To determine the relevance of 17 core clock genes as prognostic factors and their predictive value for pathological complete response (pCR) to NAC and disease-free survival. Methods: Tumor biopsies from 189 BC pts in a randomized Phase II trial were available for DNA microarrays (Pierga, BCRT, 2010; De Cremoux, Breast 2013). Transcriptome was determined with Affymetrix chip. Three metagenes were identified using Non negative Matrix Factorization. Genes recapitulating a metagene were defined by r u003e 0.7 (Pearson). Principal component analysis (PCA) discriminated groups according to clock genes expression. Differential analysis using LIMMA’s package scrutinized clock genes according to BC characteristics, pCR and DFS. Results: No clock gene expression was correlated to the metagenes. PCA did not discriminate any group according to individual cloc...