A Novel Nanoprobe-Based Assay For Detecting K-Ras Mutations In Plasma And Stool Samples From Patients With Pancreatic Cancer: Value In Diagnosis And Prognosis Evaluation

Background: To develop a novel nanoprobe-based assay for detecting K-ras mutations in plasma and stool samples from patients with pancreatic cancer, and assess its value in the diagnosis and prognosis evaluation of this malignancy.Methods: Fifty-eight pancreatic cancer, 18 chronic pancreatitis, 7 pancreatic cystadenoma, 5 pancreatic cyst, 2 solid pseudopapillary tumor of the pancreas patients, who were treated at the Second Affiliated Hospital of Jiaxing University from June 2013 to October 2015. Thirty-one healthy volunteers were as normal controls. Blood and stool samples were collected from these subjects to detect the K-ras mutation status using a novel nanoprobe-based assay, assess its diagnostic accuracy and analysis the relation between the clinicopathological characteristics and survival in pancreatic cancer.Results: The detection rates of K-ras mutations in stool and plasma samples from patients with pancreatic cancer were 79.3% and 43.1%, respectively, both of which were significantly higher than those for patients with benign pancreatic diseases (15.6% and 6.3%, respectively; P<0.05) and normal controls (0% for both; P<0.05). The sensitivity and specificity of stool K-ras mutation status alone, plasma K-ras mutation status alone, and the combination of both in the diagnosis of pancreatic cancer were 79.3% and 84.4%, 43.1% and 93.8%, and 86.2% and 96.9%, respectively. Plasma K-ras mutation status was significantly associated with 1-year survival and TNM stage in patients with pancreatic cancer (P<0.05).Conclusions: The developed novel nanoprobe-based assay allows for the detection of K-ras mutations in trace amounts of plasma and stool DNA.