Comprehensive molecular profiling of pancreatic ductal adenocarcinoma in FNA, biopsy, and resection specimens.

Abstract

Molecular testing to identify molecular alterations in pancreatic ductal adenocarcinoma (PDAC) has been increasingly requested because of potential therapeutic implications. In this study, we compared the performance of PDAC fine-needle aspiration (FNA), fine-needle biopsy (FNB), and resection specimens for comprehensive molecular analysis. A next-generation sequencing-based Oncomine Comprehensive Assay (OCA) was used to analyze molecular alterations in FNA, FNB, or resection specimens. We examined adequacy and success rates for completion of molecular testing and catalogued molecular alterations in these specimen types. The cohort included 23 FNA, 20 FNB, and 27 resection cases. Gene mutation or amplification analysis was successful in 18 (78%) FNA and 16 (80%) FNB specimens, whereas gene fusion assessment succeeded in 12 (52%) FNA and 12 (60%) FNB samples. All 27 (100%) resection specimens were adequate for complete OCA. There were significant differences in success rates for mutation and amplification analysis between resection and FNA or FNB specimens (P< .01) but not between FNA and FNB samples (P> .05). Manual microdissection was less likely to be performed for FNA specimens than FNB or resection specimens (P< .01). KRAS mutation was the most common mutation identified (90%), followed by mutations in TP53 (64%), CDKN2A (25%), and SMAD4 (15%) genes. Our study demonstrated similar success rates for comprehensive molecular analysis using FNA and FNB specimens of PDAC, suggesting that FNA material could serve as an alternative source for comprehensive molecular testing. The molecular alterations identified in these specimens may have potential diagnostic and therapeutic implications.