The value of the K-ras mutations in FNA samples of pancreas on the diagnosis of pancreatic cancer

Abstract

Objective To investigate the diagnostic value of the K-ras mutations in FNA samples for early detection of pancreatic cancer. Methods FNA samples of 27 patients with pancreatic cancers, 9 patients with other malignant tumors and 14 patients with non malignant pancreatic mass (NMPM) were collected. DNA was extracted, and K-ras gene was amplified through PNA-mediated PGR clamping, the products were sequenced to determine the mutation type. Results The positive rate of K-ras mutations in pancreatic cancers,other malignant tumors and NMPM were 88.9%, 44.4%, 35.7%. There was significant difference in K-ras gene mutations in FNA samples between pancreatic cancer and other malignant tumors ( P = 0. 013 ) and NMPM ( P = 0. 001 ). The sensitivity, specificity, positive predictive value, negative predictive value,accuracy of K-ras mutations in FNA samples of pancreatic cancers were 88.9%, 55.6%, 85.7%, 62.5%,80.6% when compared with other malignant tumors, and the difference between the two groups was significant (P =0. 013) ;Those were 88.9%, 64.3%, 82.8%, 75.0%, 80. 5% when compared with NMPM, and the difference between the two groups was significant ( P = 0. 001 ). When cytology of FNA samples and K-ras mutations was combined, the positive rate of pancreatic cancer was up to 96.3%. Conclusions The detection of K-ras mutations in EUS-FNA samples helped improve the positive diagnostic rate of pancreatic cancer. Key words: Pancreatic neoplasms; K-ras gene; Peptide nucleic acids; Gene diagnosis