No abstract

To perform real-time whole genome sequencing (WGS) and RNA sequencing (RNASeq) of advanced pancreatic ductal adenocarcinoma (PDAC) to identify predictive mutational and transcriptional features for better treatment selection. Patients with advanced PDAC were prospectively recruited prior to first-line combination chemotherapy. Fresh tumor tissue was acquired by image-guided percutaneous core biopsy for WGS and RNASeq. Laser capture microdissection was performed for all cases. Primary endpoint was feasibility to report WGS results prior to first disease assessment CT scan at 8 weeks. The main secondary endpoint was discovery of patient subsets with predictive mutational and transcriptional signatures. Sixty-three patients underwent a tumor biopsy between December 2015 and June 2017. WGS and RNASeq were successful in 62 (98%) and 60 (95%), respectively. Genomic results were reported at a median of 35 days (range, 19-52 days) from biopsy, meeting the primary feasibility endpoint. Objective responses to first-line chemotherapy were significantly better in patients with the classical PDAC RNA subtype compared with those with the basal-like subtype ( = 0.004). The best progression-free survival was observed in those with classical subtype treated with m-FOLFIRINOX. expression in tumor measured by RNA hybridization was found to be a robust surrogate biomarker for differentiating classical and basal-like PDAC subtypes. Potentially actionable genetic alterations were found in 30% of patients. Prospective genomic profiling of advanced PDAC is feasible, and our early data indicate that chemotherapy response differs among patients with different genomic/transcriptomic subtypes. .

S 2020, 'GATA6 expression distinguishes classical and basal-like subtypes in advanced pancreatic cancer. ', Clinical Cancer Research.

Highlights d Cities possess a consistent ''core'' set of non-human microbes d Urban microbiomes echo important features of cities and city-life d Antimicrobial resistance genes are widespread in cities d Cities contain many novel bacterial and viral species

Graphical Abstract Highlights d Higher cell cycle progression in PDAC metastases; increases with driver gene loss d Half of PDACs are hypoxic and are associated with subtypes and treatment response d Paired tumors show molecular conservation and Halstedian progression d Multiple PDACs arising in the same pancreas are intraparenchymal metastases In Brief Connor et al. molecularly characterize primary and metastatic PDAC and show conserved alterations between primary and metastatic lesions. Clinical features outperform molecular alterations in survival analyses, but cell cycle progression and hypoxia signatures may inform clinical practice. SUMMARYWe integrated clinical, genomic, and transcriptomic data from 224 primaries and 95 metastases from 289 patients to characterize progression of pancreatic ductal adenocarcinoma (PDAC). Driver gene alterations and mutational and expression-based signatures were preserved, with truncations, inversions, and translocations most conserved. Cell cycle progression (CCP) increased with sequential inactivation of tumor suppressors, yet remained higher in metastases, perhaps driven by cell cycle regulatory gene variants. Half of the cases were hypoxic by expression markers, overlapping with molecular subtypes. Paired tumor heterogeneity showed cancer cell migration by Halstedian progression. Multiple PDACs arising synchronously and metachronously in the same pancreas were actually intra-parenchymal metastases, not independent primary tumors. Established clinical co-variates dominated survival analyses, although CCP and hypoxia may inform clinical practice. SignificancePancreatic ductal adenocarcinoma has dismal prognosis due to rapid metastatic dissemination. This rigorous study of paired and unpaired tumors informs both progression mechanisms and therapy. First, there was no evidence of discrete metastases enabling genes. Second, greater CCP in metastases may explain aggressive behavior and correspond to treatment response. Third, hypoxia signature was associated with chemotherapy resistance. Fourth, comparing mutations in paired samples revealed sequential progression from primary to lymph node to distant metastases, and sequencing synchronous and metachronous lesions distinguished these as recurrences rather than separate primaries, resolving this clinical conundrum. Finally, clinical features outperformed and were independent of molecular alterations in survival analyses, implying greater insight is needed before molecular profiling broadly informs therapy.