Diagnostic value of chromogranin A in pancreatic neuroendocrine tumors depends on tumor size: A prospective observational study from a single institute

BackgroundChromogranin A has recently been recommended as the most practical tumor marker in patients with pancreatic neuroendocrine tumors. However, the diagnostic effectiveness of circulating chromogranin A levels remains controversial. Here, we aimed to assess the clinical diagnostic value of plasma chromogranin A levels for pancreatic neuroendocrine tumors.MethodsBetween June 2012 and June 2015, 110 consecutive patients with a suspected pancreatic neuroendocrine tumor were prospectively enrolled. We evaluated the diagnostic value of the chromogranin A assay for differentiating pancreatic neuroendocrine tumors from other tumors. The plasma chromogranin A levels in the pancreatic neuroendocrine tumor patients were examined according to various clinicopathologic factors.ResultsA total of 65 patients were diagnosed as having pancreatic neuroendocrine tumors, whereas 45 had other tumors. The median chromogranin A level in pancreatic neuroendocrine tumor cases was higher than that in cases of other tumors (pancreatic neuroendocrine tumors: 126.62 ng/mL, other tumors: 69.82 ng/mL). The sensitivity, specificity, and accuracy of the chromogranin A assay for pancreatic neuroendocrine tumor diagnosis were 49.2%, 77.8%, and 60.9%, respectively. The chromogranin A levels after operative resection were reduced or were confirmed as being within the normal range (78.9%) in most cases. Moreover, the chromogranin A level in pancreatic neuroendocrine tumors cases was correlated with tumor size based on comparisons with other tumors in the pancreas (P = .038). The sensitivity, specificity, and accuracy of the chromogranin A assay for large tumors were greater, at 64.3%, 100.0%, and 81.5%, respectively.ConclusionIn clinical settings, the identification of pancreatic neuroendocrine tumors is vital for the development of therapeutic strategies. In large pancreatic tumors, the measurement of chromogranin A levels is very useful for distinguishing pancreatic neuroendocrine tumors from other tumors in the pancreas.