Epidemiology, Treatment, and Outcome of Pancreatic Squamous Cell Carcinoma and Pancreatic Adenocarcinoma: A Propensity Score-Matching Analysis Based on SEER-Database

Background: Pancreatic squamous cell carcinoma (PSCC) is a rare pancreatic malignancy compared to most common pancreatic adenocarcinoma (PAC). Aims: To analyze the prognostics factors of PSCC and compare PAC with PSCC in demographic patterns, clinicopathologic characteristics and treatment modalities. Methods: Data of PSCC and PAC patients from January 1, 2004 to December 31, 2015 were extracted from Surveillance, Epidemiology and End Results (SEER) database for case-control study. Kaplan-Meier method and Cox proportional hazards analysis were used in survival analysis. A 1:3 propensity-score matching (PSM) was performed to compare the overall survival (OS) and cancer specific survival (CSS) between PAC and PSCC in each variable. Results: PAC patients (n = 38 968) and PSCC patients (n = 124) were analyzed. After PSM, 372 PAC patients and 124 PSCC patients were obtained. PSCC tends to happen to elders, white and female with a predilection site of pancreatic head, followed by tail, then body. PSCC have a higher proportion to be poorly differentiated and metastatic when diagnosed. The prognosis of PSCC patients was significantly worse than PAC patients in both univariate and multivariate analyses. Surgery and chemotherapy were independent prognostic factors for PSCC. Conclusions: PSCC patients were identified associated with a worse prognosis than PAC patients. PSCC tend to be poorly differentiated and more easily to be metastatic. Surgery and chemotherapy may be effective therapies to improve the OS of PSCC significantly.