Predictive Value of Chromogranin A and a Pre-Operative Risk Score to Predict Recurrence After Resection of Pancreatic Neuroendocrine Tumors.

INTRO

Chromogranin A (CgA) may be prognostic for patients with neuroendocrine tumors; however, the clinical utility of this test is unclear.

METHODS

Patients undergoing resection for pancreatic neuroendocrine tumors (pNET) were selected from the eight institutions of the US Neuroendocrine Tumor Study Group database. Cox regression was used to identify pre-operative variables that predicted recurrence-free survival (RFS), and those with p < 0.1 were included in a risk score. The risk score was tested in a unique subset of the overall cohort.

RESULTS

In the entire cohort of 287 patients, median follow-up time was 37 months, and 5-year RFS was 73%. Cox regression analysis identified four variables for inclusion in the risk score: CgA > 5x ULN (HR 4.3, p = 0.01), tumor grade 2/3 (HR 3.7, p = 0.01), resection for recurrent disease (HR 6.2, p < 0.01), and tumor size > 4 cm (HR 4.5, p = 0.1). Each variable was assigned 1 point. Risk-score testing in the unique validation cohort of 63 patients revealed a 95% negative predictive value for recurrence in patients with zero points.

DISCUSSION

This simple pre-operative risk scoring system resulted in a high degree of specificity for identifying patients at low-risk for tumor recurrence. This test can be utilized pre-operatively to aid informed decision-making.