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The success of personalized medicine depends on the discovery of biomarkers that allow oncologists to identify patients that will benefit from a particular targeted drug. Molecular tests are mostly performed using tumor samples, which may not be representative of the tumor's temporal and spatial heterogeneity. Liquid biopsies, and particularly the analysis of circulating tumor DNA, are emerging as an interesting means for diagnosis, prognosis, and predictive biomarker discovery. In this study, the amplification refractory mutation system (ARMS) coupled with high-resolution melting analysis (HRMA) was developed for detecting two of the most relevant KRAS mutations in codon 12. After optimization with commercial cancer cell lines, KRAS mutation screening was validated in tumor and plasma samples collected from patients with pancreatic ductal adenocarcinoma (PDAC), and the results were compared to those obtained by Sanger sequencing (SS) and droplet digital polymerase chain reaction (ddPCR). The developed ARMS-HRMA methodology stands out for its simplicity and reduced time to result when compared to both SS and ddPCR but showing high sensitivity and specificity for the detection of mutations in tumor and plasma samples. In fact, ARMS-HRMA scored 3 more mutations compared to SS (tumor samples T6, T7, and T12) and one more compared to ddPCR (tumor sample T7) in DNA extracted from tumors. For ctDNA from plasma samples, insufficient genetic material prevented the screening of all samples. Still, ARMS-HRMA allowed for scoring more mutations in comparison to SS and 1 more mutation in comparison to ddPCR (plasma sample P7). We propose that ARMS-HRMA might be used as a sensitive, specific, and simple method for the screening of low-level mutations in liquid biopsies, suitable for improving diagnosis and prognosis schemes., (© 2023. The Author(s).)

Background and Aims: Pancreatic cystic fluid (PCF) analysis is useful to distinguish between different cyst types and to guide management. The aim of our study was to compare the diagnostic accuracy of glucose level with carcinoembryonic antigen (CEA) in PCF for mucinous cyst diagnosis., Methods: We identified studies with PCF obtained by EUS before surgery, with cysts classified as mucinous and nonmucinous according to surgical specimens. A random-effects model was used for quantitative meta-analysis. Pooled sensitivities, specificities, and summary receiver operating characteristic (ROC) curve analysis were conducted., Results: For CEA, we included 31 studies with 5268 patients, of which 2083 were referred for surgery. For glucose, we included 4 studies with 345 patients, of which 275 were referred for surgery. Glucose performed better than CEA for mucinous cysts diagnosis (premalignant and malignant) with sensitivities of .90 (95% confidence interval [CI], .85-.94) and .67 (95% CI, .65-.70), specificities of .82 (95% CI, .72-.89) and .80 (95% CI, 0.76-0.83), and areas under the ROC curve of .96 and .79, respectively. Glucose had a higher sensitivity (90%), with uncommon false-negative results, making it an excellent biomarker to exclude a mucinous cyst. Sensitivity analysis demonstrated that the findings of the current meta-analysis are robust., Conclusion: Glucose level in PCF is more accurate than CEA for preoperative diagnosis of mucinous cysts. It may become a useful first-line test, particularly in small cysts with a limited volume of PCF. Larger studies are awaited to confirm glucose as the single test for mucinous cyst diagnosis., (Copyright © 2021 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.)

Background: Endoscopic ultrasound with fine-needle aspiration (EUS-FNA) is recommended for diagnosis of pancreatic cystic lesions (PCLs). Its role in surveillance is unclear. Our goal was to determine if a second EUS-FNA changes diagnosis or management of PCLs., Methods: A retrospective analysis of an EUS database, searching for EUS-FNAs in PCLs from 2007 to 2017 was performed. Demographics, cyst characteristics, and FNA results were compared in patients under surveillance, performing a single or two consecutive EUS-FNAs., Results: Of 203 PCLs referred for EUS-FNA, surveillance was decided in 128 (63%). Data of 105 (82%) patients with a single EUS-FNA were compared with 23 (18%) with two EUS-FNAs during surveillance. Patients were younger in this latter group (P = .055), whereas CEA levels were marginally higher (P = .078) and a mass/nodule were more frequent (P = .006). The mean time between EUS-FNAs was 38 months (4.7-118.8) for 18 patients maintaining surveillance vs 18 months (2.9-56.9) in the four referred for surgery (P = NS) after two EUS-FNAs (two NETs, one IPMN-HGD, and one MCN-LG). A high correlation in CEA level between consecutive EUS-FNAs (r 2 = 0.945, P < .01) was present, with a change of category observed (cut-off level = 192 ng/mL) in two patients only. Of four patients with a second EUS-FNA with conclusive cytology, two had NETs confirmed on resection., Conclusions: Repeating EUS-FNA in surveillance of PCLs with clinical suspicion of malignancy increased neoplasm diagnoses, changing decision toward surgery in almost 20% of patients while excluding IPMNs with mucin nodules from unnecessary resections. A second EUS-FNA for cytology appears justified in some PCLs, particularly for diagnosing NETs., (© 2020 Wiley Periodicals LLC.)

Background: In current guidelines, endoscopic ultrasound with fine-needle aspiration (EUS-FNA) is recommended in pancreatic cystic lesions (PCLs) with worrisome features (size ≥ 3 cm, mural nodule, or Wirsung dilation)., Objective: To evaluate the diagnostic ability and assess the accuracy of EUS-FNA in PCLs smaller than 3 cm., Methods: Retrospective study of PCLs < 3 cm (2007-2016) undergoing EUS-FNA. Clinical, EUS and pancreatic cystic fluid (PCF) data were prospectively registered. Performance of EUS-FNA with PCF analysis for the detection of malignancy and accuracy in surgical cohort were analyzed., Results: We evaluated 115 patients with PCLs < 3 cm who underwent EUS-FNA. 19 patients underwent surgery, 7 had malignant, 8 pre-malignant, and the remaining 4 benign lesions. Mass/mural nodule was present in 27% of the cysts, CEA level was higher than 192 ng/mL in 39.4% of patients, and only 35% of cytologic samples were informative. Nevertheless, additional FNA for PCF analysis improved the diagnostic performance of EUS imaging-AUC = 0.80 versus AUC = 60., Conclusion: EUS-FNA has good accuracy in PCLs < 3 cm. It confirmed malignancy even in lesions without worrisome features (nodule/mass), with two in every five resections showing high-risk/malignant lesions. EUS-FNA was also useful to diagnose benign cysts, possibly allowing surveillance to be stopped in one in every five patients.

Background: CEA in pancreatic cystic fluid (PCF) is standard for mucinous cysts diagnosis. Glucose is an alternative, but its accuracy remains poorly described., Aims: To evaluate PCF glucose using a glucometer and compare its accuracy with CEA for mucinous cysts diagnosis., Materials and Methods: In frozen PCF obtained by EUS-FNA, glucose was evaluated using a glucometer. CEA and cytology were available as standard of care. The accuracy of glucose and CEA was calculated using receiver operator (ROC) curves. Definitive diagnoses were surgical or clinicopathological., Results: We evaluated 82 patients with a mean age of 61.3 ± 14.8 years (25-91), predominantly (59%) females. Diagnoses included 17 serous cystadenomas, five pseudocysts, 20 intraductal papillary mucinous neoplasms, three mucinous cystic neoplasms, five adenocarcinomas, four neuroendocrine tumors, two other types, 26 non-defined. The median glucose levels (interquartile range) were 19 mg/dL (19-19) in mucinous and 105 mg/dL (96-127) in non-mucinous cysts (p < 0.0001). The median CEA level was 741 ng/mL (165-28,567) in mucinous and 9 ng/mL (5-19) in non-mucinous cysts (p < 0.0001). For mucinous cyst diagnosis, a CEA > 192 ng/mL had a sensitivity of 72% (95% CI 51-88) and a specificity of 96% (95% CI 82-100), and ROC analysis showed an area under the curve (AUC) of 0.842 (95% CI 0.726-0.959), while glucose < 50 mg/dL had a sensitivity of 89% (95% CI 72-98), a specificity of 86% (95% CI 67-96), and an AUC of 0.86 (95% CI 0.748-0.973). Pseudocysts presented low glucose, identically to mucinous cysts, with CEA allowing differential diagnosis., Conclusion: Glucose measured by a glucometer is accurate for mucinous cyst diagnosis, with significantly higher levels in non-mucinous cysts, except pseudocysts.

Background: Carcinoembryonic antigen (CEA) and cytology in pancreatic cystic fluid are suboptimal for evaluation of pancreatic cystic neoplasms. Genetic testing and microforceps biopsy are promising tools for pre-operative diagnostic improvement but comparative performance of both methods is unknown., Aim: To compare the accuracy of genetic testing and microforceps biopsy in pancreatic cysts referred for surgery., Methods: We performed a literature search in Medline, Scopus, and Web of Science for studies evaluating genetic testing of cystic fluid and microforceps biopsy of pancreatic cysts, with endoscopic ultrasound with fine-needle aspiration (EUS-FNA) prior to surgery and surgical pathology as reference standard for diagnosis. We evaluated the diagnostic accuracy for: 1- benign cysts; 2- mucinous low-risk cysts; 3- high-risk cysts, and the diagnostic yield and rate of correctly identified cysts with microforceps biopsy and molecular analysis. We also assessed publication bias, heterogeneity, and study quality., Results: Eight studies, including 1206 patients, of which 203 (17%) referred for surgery who met the inclusion criteria were analyzed in the systematic review, and seven studies were included in the meta-analysis. Genetic testing and microforceps biopsies were identical for diagnosis of benign cysts. Molecular analysis was superior for diagnosis of both low and high-risk mucinous cysts, with sensitivities of 0.89 (95%CI: 0.79-0.95) and 0.57 (95%CI: 0.42-0.71), specificities of 0.88 (95%CI: 0.75-0.95) and 0.88 (95%CI: 0.80-0.93) and AUC of 0.9555 and 0.92, respectively. The diagnostic yield was higher in microforceps biopsies than in genetic analysis (0.73 vs 0.54, respectively) but the rates of correctly identified cysts were identical (0.73 with 95%CI: 0.62-0.82 vs 0.71 with 95%CI: 0.49-0.86, respectively)., Conclusion: Genetic testing and microforceps biopsies are useful second tests, with identical results in benign pancreatic cysts. Genetic analysis performs better for low- and high-risk cysts but has lower diagnostic yield., Competing Interests: Conflict-of-interest statement: The authors have no conflict of interest to disclose.

To evaluate the diagnostic accuracy of KRAS mutation in pancreatic cystic fluid and compare it with carcinoembryonic antigen and cytology, we identified studies with cyst fluid obtained by endoscopic ultrasound prior to surgery. We classified cysts as malignant, premalignant, and benign. A random-effects model was used for quantitative meta-analysis. Pooled sensitivities, specificities, and summary receiver operating characteristic curve analysis were conducted. We analyzed 16 studies, with 3429 patients, including 731 referred for surgery. Carcinoembryonic antigen was better for clinically significant cysts (premalignant and malignant) with sensitivity = 0.58 (95% confidence interval [CI], 0.53-0.65), specificity = 0.9 (95% CI, 0.76-0.97), and area under the curve (AUC) = 0.69. Cytology performed better in malignant cysts, with sensitivity = 0.37 (95% CI, 0.27-0.48), specificity = 0.96 (95% CI, 0.93-0.98), and AUC = 0.78. Isolated, KRAS mutation failed the diagnosis of malignant and significant cysts, with sensitivities = 0.43 (95% CI, 0.34-0.43) and 0.46 (95% CI, 0.42-0.51), specificities = 0.62 (95% CI, 0.56-0.68) and 0.97 (95% CI, 0.92-0.99), and AUCs = 0.56 and 0.53, respectively. Carcinoembryonic antigen and cytology are more accurate than KRAS. Additional studies are lacking to recommend KRAS as a single diagnostic test.

Background: Pancreatic cysts are common incidental findings with malignant potential, raising diagnostic and treatment dilemmas., Aims: To determine the added value of KRAS and GNAS mutation analysis on cyst classification and decision making., Methods: We analyzed 52 frozen samples of pancreatic cystic fluid obtained by EUS-FNA between 2008 and 2014. In addition to cytology and CEA, mutations of GNAS (exons 8 and 9) and KRAS (exons 2 and 3) genes were analyzed using Sanger sequencing., Results: There were 52 patients, 67% females, with a mean age of 59 ± 15 years (29-91). Cysts were classified as mucinous in 21 patients (40%) (14 low-risk, seven malignant) and non-mucinous in 31 patients (60%). After EUS-FNA, 11 patients had surgery, six had chemotherapy or palliation, one had endoscopic drainage, and 34 are on follow-up after a mean of 57 months. KRAS mutation was detected in nine and GNAS in two samples. Patients harboring cysts with KRAS mutations were older (p = 0.01), cysts were more commonly mucinous (p = 0.001) and malignant (p = 0.01). KRAS mutations were present in both low-risk and malignant mucinous lesions. For identifying mucinous lesions, CEA > 192 ng/mL performed better (AUC ROC = 93%), whereas for malignant/high-risk mucinous lesions, EUS imaging had the best accuracy (AUC ROC = 88%). After molecular analysis, a modification in cyst classification occurred in ten patients, but was correct in only two, a pseudocyst re-classified as IPMN and a malignant cyst as a non-mucinous cyst., Conclusions: In this cohort of patients with pancreatic cysts, KRAS and GNAS mutations had no significant diagnostic benefit in comparison with conventional testing.