Snail transcript levels in diagnosis of pancreatic carcinoma with fine-needle aspirate

Expression of the transcription factor Snail that mediates epithelial-mesenchymal transition is correlated with poor prognosis in many tumour types. The aim of this study is to determine, as a proof of principle, whether Snail messenger RNA (mRNA) could be detected in fine-needle aspirate (FNA) biopsies of pancreatic ductal adenocarcinoma (PDAC) and could accurately differentiate malignant from benign pancreatic tissues. We also investigate the expression of Snail mRNA and its clinical significance in PDAC. FNA (22- or 25-gauge needle) samples were obtained from patients from June 1999 to June 2010. FNA samples that were either benign or chronic pancreatitis or confirmed as PDAC were included in this study. Snail mRNA was detected by quantitative real-time polymerase chain reaction (qRT-PCR). The associations of Snail mRNA expression with various clinicopathological parameters was analysed in addition to the relation between its expression and patient survival. Levels of Snail mRNA were increased in tumour samples in comparison to benign and chronic pancreatitis. Transcript copy numbers for Snail were 0.7 ± 0.21 for tumour, 0.16 ± 0.09 for benign (P = 0.002) and 0.23 ± 0.12 for chronic pancreatitis (P = 0.024). Snail expression was found to be associated significantly with lymph node metastasis (P = 0.001), perineural invasion (P = 0.038) and elevated preoperative serum carcinoembryonic antigen (CEA) level (P = 0.043). Snail mRNA was increased in patients with poor outcome compared with those who remained alive and well. Snail mRNA levels can aid in the pathological evaluation of suspicious cases and may become a valuable asset in obtaining a definitive diagnosis of PDAC. The strong association between Snail expression and lymph node metastasis suggests that Snail mRNA can be used as an adjunct to lymph node positivity to predict survival in pancreatic cancer.