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Background: The impact of KRAS mutation testing on pancreatic ductal adenocarcinoma (PDAC) samples by endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) for reducing the need to repeat EUS-FNA has been demonstrated. Such testing however is not part of standard practice for endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB). Objectives: We aim to analyse the proportion of non-contributive samples by EUS-FNB and to evaluate the impact of KRAS mutation testing on the diagnosis, theranostics and survival. Design: In this retrospective study, the impact on diagnosis and survival of KRAS testing for contributive and non-contributive samples by EUS-FNB was analysed. Methods: The EUS-FNB samples, combined with KRAS testing using the Idylla® technique on liquid-based cytology from patients with PDAC between February 2019 and May 2023, were retrospectively reviewed. The cytology results were classified according to the guidelines of the World Health Organization System for Reporting Pancreaticobiliary Cytopathology (WHOSRPC). Results: A total of 85 EUS-FNB specimens were reviewed. In all, 25 EUS-FNB samples did not lead to a formal diagnosis of PDAC according to the WHOSRPC (30.2%). Out of these 25, 11 (44%) could have been considered positive for a PDAC diagnosis thanks to the KRAS mutation test without carrying out further diagnosis procedures. The sensitivity of KRAS mutation testing using the Idylla technique was 98.6%. According to the available data, survival rates were not statistically different depending on the type of mutation. Conclusion: KRAS mutation testing on liquid-based cytology using the Idylla or equivalent technique, combined with the PDAC EUS-FNB sample, should become a standard for diagnosis to avoid delaying treatment by doing another biopsy. Furthermore, knowledge of the KRAS status from treatment initiation could be used to isolate mutations requiring targeted treatments or inclusion in clinical research trials, especially for wild-type KRAS PDAC.
Diagnostic and theranostic interest of searching for a KRAS mutation in echoendoscopic ultrasound biopsies of pancreatic adenocarcinomas The echoendoscopic ultrasound diagnostic of pancreatic adenocarcinomas sometimes remains difficult due to the nature of these tumors with a particular microenvironment. For more than 30 years, several authors have underlined the importance of searching for a KRAS mutation on samples taken by echoendoscopic ultrasound to improve diagnostic performance. However, this research is not common practice. Our retrospective study made it possible to review the files of 85 patients with pancreatic adenocarcinoma in whom an echoendoscopic ultrasound biopsy was performed with a search for the KRAS mutation (with second-generation fine needle biopsy). Forty-four percent could have been considered positive for the diagnosis of PDAC thanks to the search for the KRAS mutation without repeating new samples. Furthermore, knowledge of the KRAS mutation type from diagnosis would make it possible to isolate mutations justifying possible targeted treatments.
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OBJECTIVES: Liver stiffness measurement (LSM) by transient elastography is a noninvasive test of liver fibrosis, but cannot be performed in a significant proportion of obese patients. The aim of this study was to evaluate the performance of the new XL probe in patients with nonalcoholic fatty liver disease (NAFLD). METHODS: Liver biopsy and paired LSM by both the original M probe and XL probe were performed on 193 consecutive NAFLD patients in France and Hong Kong. RESULTS: Compared with M probe, XL probe was more likely to achieve 10 valid measurements (95% vs. 81%; P<0.001) and a success rate of over 60% (90% vs. 74%; P<0.001). The areas under receiver operating characteristics curves of XL probe for F2, F3, and F4 disease were 0.80, 0.85, and 0.91, respectively. XL probe tended to generate lower LSM than M probe in the same patient. At a cutoff of 7.2 kPa, the sensitivity, specificity, positive, and negative predictive values for F3 or greater disease were 78%, 78%, 60%, and 89%, respectively. Discordance of at least two stages between XL probe and histology was observed in 16 (9%) patients. Body mass index (BMI) over 35 kg/m(2) was independently associated with discordance (adjusted odds ratio 9.09; 95% confidence interval 1.10-75.43). Reliable measurements by XL probe were obtained in 75% of the overall population and 65% of patients with BMI over 30 kg/m(2). CONCLUSIONS: LSM by XL probe can be performed successfully in most NAFLD patients, but obesity is associated with less accurate and reliable measurements.