Developing a multivariable prognostic model for pancreatic endocrine tumors using the clinical data warehouse resources of a single institution

Objective: Current staging systems are not accurate for classifying pancreatic endocrine tumors (PETs) by risk. Here we developed a prognostic model for PETs and compared it to the WHO classification system. Methods: We identified 98 patients diagnosed with PET at NewYork-Presbyterian Hospital/Columbia University Medical Center (1999 to 2009). Tumor and clinical characteristics were retrieved and associations with survival were assessed by univariate Cox analysis. A multivariable model was constructed and a risk score was calculated the prognostic strength of our model was assessed with the concordance index. Results: Our cohort had median age of 60 years and consisted of 61.2% women median follow-up time was 10.4 months (range: 0.1-99.6) with a 5-year survival of 61.5%. The majority of PETs were non-functional and no difference was observed between functional and non-functional tumors with respect to WHO stage age pathologic characteristics or survival. Distant metastases aspartate aminotransferase- AST and surgical resection (HR=3.39 95% CI: 1.38-8.35 p=0.008 HR=3.73 95% CI: 1.20-11.57 p=0.023 and HR=0.20 95% CI: 0.08-0.51 p<0.001 respectively) were the strongest predictors in the univariate analysis. Age perineural and/or lymphovascular invasion distant metastases and AST were the independent prognostic factors in the final multivariable model a risk score was calculated and classified patients into low (n=40) intermediate (n=48) and high risk (n=10) groups. The concordance index of our model was 0.93 compared to 0.72 for the WHO system. Conclusion: Our prognostic model was highly accurate in stratifying patients by risk novel approaches as such could thus be incorporated into clinical decisions.