Tumor expression data from neoadjuvant trial of cisplatin monotherapy in triple negative breast cancer patients

Evidence suggests that BRCA1 mutation associated tumors have increased sensitivity to DNA damaging agents like cisplatin. Sporadic triple negative breast cancers (TNBC) have many phenotypic similarities to BRCA1 tumors and may have a similar sensitivity to cisplatin. We tested the efficacy of cisplatin monotherapy in 28 TNBC patients in a single arm neoadjuvant trial with outcome measured by pathologic treatment response quantified using the Miller-Payne scale. We used microarrays gene expression profiles to determine tumor subtype of each trial tumor sample and to test various expression signatures for association with pathologic response to cisplatin. Pretreatment tumor samples from the clinical trial (N=24 with adequate tissue) were used for RNA extraction, linear amplification, biotin labeling and hybridization to Affymetrix U133 plus 2.0 arrays. A reference set of 51 primary breast tumors representing all subtypes of breast cancer were processed in a similar manner to include linear amplification, and hybridized to Affymetrix arrays.