Prognostic Factors and Survival in 324 Patients with Pancreatic Endocrine Tumor Treated at a Single Institution

Abstract

Unequivocal pathologic markers for the prognosis of pancreatic endocrine tumors are often lacking. Suggestions for prognostic guidance include the WHO classification. Recently, a tumor-node-metastasis (TNM) staging system was proposed. We evaluate this system, as well as assess other potential prognostic factors such as tumor Ki67, size, endocrine syndrome, heredity, body mass index (BMI), and plasma chromogranin A, in a large patient material treated at a single institution. A total of 324 patients with pancreatic endocrine tumor, consecutively diagnosed and treated at a tertiary referral center, were retrospectively evaluated. Median follow-up was 54 months (range, 1-423 months). Patient and tumor data were extracted from medical records. Univariate and multivariate analyses were done to recognize factors of prognostic value. The median overall survival was 99 months (95% confidence interval, 81-117). Five- and 10-year survival rates were 64% and 44%, respectively. In univariate analysis, TNM stage, radical surgery, WHO classification, nonfunctioning tumor, Ki67 > or = 2%, chromogranin A > or = 3 times the upper normal limit, BMI < 20 kg/m2, sporadic tumor, tumor size, and referral from our primary uptake area had a significant prognostic effect. In multivariate analysis, TNM stage, WHO classification, radical surgery, and Ki67 > or = 2% retained their significance. Having a nonfunctioning tumor was not an independent marker of poor prognosis and neither was heredity. The recently suggested TNM staging system emerged as a useful clinical tool.