Next-Generation Sequencing Analysis of Pancreatic Cancer Using Residual Liquid Cytology Specimens from Endoscopic Ultrasound-Guided Fine-Needle Biopsy: A Prospective Comparative Study with Tissue Specimens.

This study evaluated the feasibility and clinical utility of liquid-based cytology (LBC) specimens via endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) for next-generation sequencing (NGS) of pancreatic cancer (PC). We prospectively evaluated the performance of DNA extraction and NGS using EUS-FNB samples obtained from PC. Thirty-three consecutive patients with PC who underwent EUS-FNB at our hospital were enrolled. DNA samples were obtained from 96.8% of the patients. When stratified with a variant allele frequency (VAF) > 10% tumor burden, the NGS success rate was 76.7% (n = 23) in formalin-fixed paraffin-embedded (FFPE), 83.3% (n = 25) in LBC, and 76.7% (n = 23) in frozen samples. The overall NGS success rate was 86.7% (n = 26) using FFPE, LBC, or frozen samples. The detection rates for the main mutated genes were as follows: 86.7% for KRAS, 73.3% for TP53, 66.7% for CDKN2A, 36.7% for SMAD4, and 16.7% for ARID1A. LBC had the highest median value of VAF (23.5%) for KRAS and TP53. PC mutation analysis using NGS was successfully performed using LBC compared with FFPE and frozen samples. This approach provides an alternative and affordable source of molecular testing materials.

Comparison of recurrent biliary obstruction with the use of metal and plastic stents in EUS-guided biliary drainage: A propensity score-matched analysis.

Background and Objectives: In transpapillary biliary drainage, metal stents (MSs) exhibit a lower incidence of a biliary obstruction than plastic stents (PSs). However, few studies have compared recurrent biliary obstruction (RBO) when MSs and PSs are used in EUS-guided hepaticogastrostomy (EUS-HGS) and choledochoduodenostomy (EUS-CDS). We retrospectively evaluated the RBO for both stents in each procedure. Patients and Methods: : Between November 2012 and December 2020, 85 and 53 patients who underwent EUS-HGS and EUS-CDS for unresectable malignant biliary obstruction, respectively, were enrolled. Factors associated with RBO were assessed. Clinical outcomes were compared between the MS and PS groups using propensity score matching. Results: : The clinical success rate and procedure-related adverse events were similar in the MS and PS groups. Multivariate analysis identified the use of PS as a factor associated with RBO (EUS-HGS, P = 0.03; EUS-CDS, P = 0.02). After matching, the median time to RBO in EUS-HGS (MS: 313; PS: 125 days; P = 0.01) in the MS group was longer than that in the PS group. The cumulative incidence of RBO at 1, 3, and 6 months in the MS group was significantly lower than that in the PS group for EUS-HGS (MS: 4.0%, 8.2%, and 8.2%; PS: 12.4%, 24.9%, and 39.5%, respectively, P = 0.01). Conclusions: : MS exhibited a lower rate of RBO than PS for EUS-HGS and EUS-CDS.