Molecular diversity of breast cancers at the time of endocrine resistance [mRNA]. Homo sapiens

Dataset containing whole-genome expression profiles of breast cancers at the time of endocrine resistance. It has been used to identify five distinctive phenotypes with different expression of gene clusters associated with ER-signalling, stromal rearrangement and cytokine-signalling. Pathway-focused analysis suggested individual tumours with active ER-signalling (24/55, 44%), PIK3CA-signalling (18/55, 32%), RAS (12/55, 22%) and MYC-signalling (11/55, 20%). 3 or 4 of the above pathways were simultaneously active in 6/55 (11%) cases. Results provide important information about prevalence of different mechanisms of endocrine resistance in clinical samples of breast cancer. Please note that the tumor samples are clinically quite homogeneous: all are post-menopausal ER+ve breast cancers, endocrine treated and growing on treatment. The main purpose of collecting these data was not to compare transcriptional profiles with clinical parameters, but rather to use the transcriptional profiles of these clinically homogeneous tumours for identifying intrinsic subgroups within endocrine resistance. However, the relevant clinical data was also provided as Series supplementary file (ClinicalData_AL28Jan2014.xlsx). Overall design: Total RNA extracted from 60 fresh-frozen clinical biopsies of breast cancer at the time of endocrine resistance has been profiled with Illumina HT-12 whole-genome expression micro-arrays. The profiles have been analysied using un-supervised and pathway-focused bioinformatics techniques to study diversity between tumours and potential mechanisms of resistance for individual tumours.