BRCA1 and cancer: In addition, FDA approval was granted for BRCA analysis CDx (Myriad Genetics) as a companion diagnostic test to facilitate the identification of BRCA mutant PDAC patients who may be eligible for olaparib.31 Along with BRCA1/2 deficiency, pancreatic cancers that harbor other DNA repair defects also show a trend toward improved OS when compared with DNA repair-proficient cancers.