Prognostic significance of chromogranin A in small pancreatic neuroendocrine tumors.

Abstract

375 Background: Theincidence of non-functional pancreatic neuroendocrine tumors (PNETs) < 2 cm is rising. The biologic behavior of these tumors is variable and therefore their management remains controversial. We hypothesized that chromogranin A (CgA) levels are prognostic in these patients and may help guide management. Methods: Patients with PNETs measuring < 2 cm, without distant metastases were identified from the National Cancer Database (NCDB) over a ten-year period (2004-2014). Patients were categorized as CgA high (> 36.4 ng/ml) or CgA low (<36.4 ng/ml), and those lacking data on CgA levels were excluded from the study. Univariate and multivariate analyses were performed using Cox proportional hazards model. Results: Of the 445 eligible patients, 149 (33.5%) were CgA Low and 296 (66.5%) were CgA High. Median CgA level was 71 (Inter-quartile range, IQR 24-294) ng/ml. On multivariate analysis, CgA levels independently predicted overall survival after controlling for tumor size, grade, clinical nodal status and academic status of the facility (p = 0.001). At a median follow up of 26.5 months there were no deaths in the CgA Low group whereas 8% of the patients in CgA High group had died (p = 0.0068). Only CgA High patients benefited from surgical resection (HR 0.31, 95% CI 0.11-0.86, p = 0.025). Conclusions: Serum CgA levels can be incorporated in surgical decision making for patients with small PNETs. Patients with a high CgA should be strongly considered for resection.