RNA Expression Profiling Comparing ER+ Postpartum Breast Cancer with ER+ Nulliparous Breast Cancer

Purpose: To perform RNA-Seq expression profiling from Young Women's Breast Cancer FFPE tissues, comparing ER+ Postpartum Brest Cancer to ER+ Nulliparous Breast Cancer Methods: RNA was extracted and isolated from archival Estrogen Receptor Positive primary breast cancer FFPE tissues ( 9 Postpartum, 7 Nulliparous). RNA species selected for inclusion in library utilzing Illumina-Access bead based oligo library preparation representing > 98% of known protein coding genes. Results: We identified gene pathway differences in estrogen receptor signaling, t-cell immunity and cell cycle between nulliparous and postpartum breast cancer cases. Subset analysis also revealed an enrichment in extra-cellular matrix pathway related genes in postpartum compared to nulliparous and luminal A cases. FFPE derived mRNA from 9 Postpartum and 7 Nulliparous Young Women's Breast Cancer cases generated by 100-cycle, single-ended, sequencing of approxinately 70 million reads per sample using Illumina HiSeq 2500 sequencer. Base call files were converted to fastq format using Bcl2Fastq.