Pancreatic Gastrointestinal Stromal Tumor Clinicopathologic Features and Prognosis

Goals: The present study aimed to investigate the clinicopathologic features and prognosis of pancreatic gastrointestinal stromal tumor (GIST). Background: Reports on clinicopathologic features and prognosis of pancreatic GIST are limited due to the extremely rare incidence. Study: One case of pancreatic GIST from our center and 44 cases reported in MEDLINE were enrolled in this study. Clinicopathologic features and prognosis of pancreatic GISTs were analyzed and compared with 297 gastric GISTs from our center. Results: The most common location was head of pancreas (38.5%). The majority of pancreatic GISTs exceeded 5 cm (74.4%), displayed cystic or mixed imaging features (56.4%), and were high risk (85.7%). The 5-year disease-free survival (DFS) and disease-specific survival rates were 66.1% and 95.8%, respectively. Mitotic index was the only risk factor for DFS of pancreatic GISTs. The distribution of tumor size, histologic type and National Institutes of Health risk category were significantly different between pancreatic and gastric GISTs. The 5-year DFS rate of pancreatic GISTs was significantly lower than that of gastric GISTs. Multivariate analysis showed that location was an independent prognostic factor for DFS between pancreatic and gastric GISTs. Conclusions: The most common location was head of pancreas. The majority of pancreatic GISTs were large and highly malignant. Pancreatic GISTs differed significantly from gastric GISTs in respect to clinicopathologic features. The DFS of pancreatic GISTs was worse than that of gastric GISTs.