Patients with advanced gastroenteropancreatic neuroendocrine tumors (GEP-NET) – rare tumors that develop in the pancreas or gastrointestinal tract – are routinely monitored for disease progression using imaging tests. Circulating chromogranin A (CgA) is an established biomarker for these tumors, but there are mixed results in using serum or plasma CgA to monitor disease progression.
In the prospective, multicenter CASPAR study, Qing Meng, Ph.D., and colleagues examined imaging tests from 153 patients with well-differentiated GEP-NET and validated an automated assay using serum CgA levels. The assay was highly accurate in ruling out tumor progression, with a diagnostic specificity of 93.4% and negative predictive value of 84.3%, but it was not as strong at detecting tumor progression. These results show that serum CgA biomarkers are a valuable tool best used alongside routine monitoring, with imaging tests to improve clinical decision-making for patients with GEP-NET.