KRAS and Guanine Nucleotide-Binding Protein Mutations in Pancreatic Juice Collected From the Duodenum of Patients at High Risk for Neoplasia Undergoing Endoscopic Ultrasound

Abstract

BACKGROUND & AIMS Pancreatic imaging can identify neoplastic cysts but not microscopic neoplasms. Mutation analysis of pancreatic fluid following secretin stimulation might identify microscopic neoplasias in the pancreatic duct system. We determined the prevalence of mutations in KRAS and GNAS genes in pancreatic juice from subjects undergoing endoscopic ultrasound for suspected pancreatic intraepithelial neoplasia (PanIN), intraductal papillary mucinous neoplasms, or pancreatic adenocarcinoma. METHODS Secretin-stimulated juice samples were collected from the duodenum of 272 subjects enrolled in Cancer of the Pancreas Screening studies; 194 subjects were screened because of a family history of, or genetic predisposition to, pancreatic cancer and 78 were evaluated for pancreatic cancer (n=30) or other disorders (controls: pancreatic cysts, pancreatitis, or normal pancreata, n=48). Mutations were detected by digital high-resolution melt-curve analysis and pyrosequencing. The number of replicates containing a mutation determined the mutation score. RESULTS KRAS mutations were detected in pancreatic juice from larger percentages of subjects with pancreatic cancer (73%) or undergoing cancer screening (50%) than controls (19%) (P=.0005). A greater proportion of patients with pancreatic cancer had at least 1 KRAS mutation detected 3 or more times (47%) than screened subjects (21%) or controls (6%, P=.002). Among screened subjects, mutations in KRAS (but not GNAS) were found in similar percentages of patients with or without pancreatic cysts. However, a greater proportion of patients over 50 ys old had KRAS mutations (54.6%) than younger patients (36.3%) (P=.032); the older subjects also more mutations in KRAS (P=.02). CONCLUSIONS Mutations in KRAS are detected in pancreatic juice from the duodenum of 73% of patients with pancreatic cancer, and 50% of asymptomatic individuals with a high risk for pancreatic cancer. However, KRAS mutations are detected in pancreatic juice from 19% of controls. Mutations detected in individuals without pancreatic abnormalities, based on imaging analyses, likely arise from small PanIN lesions. ClinicalTrials.gov no: NCT00438906 and NCT00714701

Dynamic landscape of pancreatic carcinogenesis reveals early molecular networks of malignancy

“…In comparison, mature pancreatic epithelial cells are mostly refractory to transformation following activation of oncogenic Kras 5. It has also been demonstrated that Kras mutations appear in the pancreas of healthy individuals 6. This supports the hypothesis that oncogenic Kras alone is not sufficient to induce carcinogenesis, and that a transformation-permissive inflammatory environment is prerequisite.…”

Digital next-generation sequencing identifies low-abundance mutations in pancreatic juice samples collected from the duodenum of patients with pancreatic cancer and intraductal papillary mucinous neoplasms

“…KRAS mutations detected in the pancreatic juice of high-risk individuals without pancreatic imaging abnormalities are thought to arise from small PanIN lesions. 15 These studies used digital melt-curve analysis and pyrosequencing to detect mutations but next-generation sequencing (NGS) is being widely used in clinical laboratories to detect somatic mutations in cancer tissues. 1617 …”

Using an endoscopic distal cap to collect pancreatic fluid from the ampulla (with video)

“…Forty-eight (49.5%) of 97 high-risk patients had a detectable KRAS mutation in their pancreatic juice, including 34 (53.1%) of 64 with and 14 (42.4%) of 33 without cysts suspected to be IPMN, a prevalence very similar to what we reported previously in this population. 17 Patients with KRAS mutations in their pancreatic juice were older on average than those without a KRAS mutation ( P = 0.056). Thirty-six of 106 patients (34.0%) with cysts suspected to be IPMN had GNAS mutation s detected in their pancreatic juice.…”

“…3, 4, 9 Studies using these samples revealed that GNAS mutations detected in pancreatic fluid samples collected from the duodenum are highly correlated with the presence of IPMN, that KRAS mutations are commonly detected in pancreatic fluid samples of patients who are undergoing screening for their family history of pancreatic cancer and that mutation concentrations as well as mutations that are known to arise in high-grade dysplasia and invasive cancer such as in SMAD4 are helpful in distinguishing the presence of pancreatic ductal adenocarcinoma. 12, 14, 16, 17 Since secretin-stimulated pancreatic fluid samples are typically collected from the duodenal lumen, they are admixed with abundant wild-type DNA in duodenal fluid effectively reducing mutation concentrations. 18 The very low concentrations of mutations typically found in these duodenal collections requires that more sophisticated molecular tools be employed for their detection.…”