Bulk RNA-Seq gene expression data for 289 primary and metastatic pancreatic ductal adenocarcinoma (PDAC) tumor samples from FFPE blocks.

Pancreatic Ductal Adenocarcinoma (PDAC) is a deadly disease with a 5 year overall survival rate of 11%. In order to better understand and characterized PDAC we have performed RNAseq on 289 primary and metastatic PDAC tumors collected at our center. Nucleic acids (RNA and DNA) were extracted from formalin fixed paraffin embeded FFPE tumor tissue with tumor enriched regions identified by pathologic analysis. RNA sequencing and resulting gene expression data was then used to study biologic differences in primary PDAC tumors that metastasized to either the liver or to the lung but not liver based on clinical data review. A novel gene expression signature was identified for liver vs lung avid metastatic properties. Samples in the entire cohort were then scored based on this gene signature. Pathway analysis revealed that samples high for this signature (as well as liver cohort patient samples) were enriched for pathways involved in ongoing replication stress response, and this was associated with poorer patient outcome.