Malignant Nonfunctioning Endocrine Tumors of the Pancreas: Predictive Factors for Survival after Surgical Treatment

Background There are scant studies that have analyzed the prognostic factors for malignant nonfunctioning endocrine tumors of the pancreas. We identified the predictive factors associated with long‐term survival after surgical resection for malignant nonfunctioning endocrine tumors. Methods Among the 25 patients seen at our hospital with a diagnosis of malignant nonfunctioning endocrine tumor, a review was performed on 22 of these patients who were surgically treated at our institution over the last 10 years. The following factors were evaluated for disease‐specific mortality: age, gender, tumor location, tumor size, histological differentiation, status of the resection margin, and status of lymph node involvement. Results Tumor recurrence was noted in 9 cases (40.9%) among the 22 operated patients. Of the 9 recurrent cases, 7 patients (77.8%) had liver metastases. The median follow‐up period was 24.8 (range: 3.7–121.4) months. The overall actuarial 1‐, 2‐ and 5‐year survival rates were 84.1%, 72.5%, and 52.8%, respectively. The factor shown to have a favorable independent prognostic significance was a negative resection margin (odds ratio = 19.44, 95% confidence interval = 1.22–310.54, P = 0.036). Conclusions Definitive surgical resection of the primary tumor was a predictor of long‐term survival after surgical resection for malignant nonfunctioning endocrine tumor.