Abstract: Objective To analyze the value of signal transducer and activator of transcription 33 in diagnosis and prognosis of pancreatic cancer. Methods From February 2014 to August 2016, specimens from 74 cases of pancreatic cancer, 80 cases of benign pancreatic tumor and pancreatitis （40 cases each） were collected. The expression level of STAT3 in pancreatic cancer and benign disease was detected by immunohistochemical staining, then compared to evaluate the diagnostic efficacy of STAT3 expression. The staging and lymph node metastasis of pancreatic cancer in STAT3 positive and negative subjects were analyzed. STAT3 was compared between 32 patients with poor prognosis （spread, metastasis, recurrence） and 42 patients with good prognosis. Results The expression of STAT3 in pancreatic cancer was higher than that in adjacent tissues, and the difference was statistically significant （P<0.05）. There was significant difference in the expression of p-STAT3 in pancreatic carcinoma tissues, paracancerous tissues and benign pancreatic tissues （P<0. 05）.The sensitivity, specificity, positive predictive value, negative predictive value and coincidence rate of STAT3 in the diagnosis of pancreatic cancer were 70.3% （52/74）, 86.2% （69/80）, 82.5% （52/63）, 75.8% （69/91） and 78.6% （121/154）, respectively. The lymph node metastasis of STAT3 positive pancreatic cancer was higher than that of STAT3 negative pancreatic cancer. STAT3 positive lymph node metastasis in pancreatic carcinoma was higher than that in STAT3 negative group. The clinical stages of STAT3 positive patients in pancreatic carcinoma were statistically different from STAT3 negative ones （P<0. 05）. The positive rate of STAT3 in patients with poor prognosis was significantly higher than that in patients with good prognosis （P<0. 05）. Conclusion STAT3 is valuable in the diagnosis of pancreatic cancer and the prediction of growth and metastasis.

Key words: Pancreatic cancer, Progress, STAT3, Diagnosis