[The diagnostic value of plasma chromogranin A in neuroendocrine tumors].

OBJECTIVE: To investigate the value of plasma chromogranin A (CgA) in the diagnosis of neuroendocrine tumors (NETs), and to evaluate the diagnostic efficacy of plasma CgA in different gastrointestinal pancreatic neuroendocrine tumors (GEP NETs). To investigate the role of monitoring plasma CgA in the progress of GEP NETs.

METHODS: ELISA kits were used to measure the CgA plasma level in 56 cases of GEP NETs, 52 cases of pheochromocytoma, and 7 cases of small cell lung cancer (SCLC) and 52 cases of normal controls respectively. The sensitivity and specificity of plasma CgA in diagnosis of gastrointestinal pancreatic endocrine tumor; pheochromocytomas and SCLC were calculated. The group of GEP NETs included 13 cases of gastrointestinal carcinoid tumors, 13 cases of gastrinomas, 12 cases of islet cell tumors and 18 cases of other type tumors of GEP NETs. The differences of plasma CgA levels and various sensitivities were compared in different types tumors of GEP NETs. Meanwhile the value of plasma CgA in the diagnosis of metastatic and nonmetastatic tumors in GEP NETs was determined.

RESULTS: The median CgA levels and quartile of the groups of GEP NETs, pheochromocytomas and SCLCs were 84.5 U/L and 38.3 - 175.5 U/L, 154.0 U/L and 53.3 - 243.8 U/L, and 55.0 U/L and 19.0 - 79.0 U/L respectively, which were significantly higher than that of (18.5 U/L and 12.3 - 25.8 U/L) normal controls (P < 0.001). The sensitivities of CgA in diagnosis of GEP NETs, pheochromocytomas and SCLCs were 82.1%, 88.5% and 57.1% respectively, and the specificities were all 96.2%. In the group of GEP NETs, the CgA level of gastrinoma was significant higher than the groups of carcinoid, islet cell tumor, and other type tumors of GEP NETs. The sensitivities of CgA in diagnosis of gastrinoma, carcinoid tumors, and islet cell tumors were 92.3%, 84.6% and 50.0% respectively. In the group of GEP NETs, it showed significant differences in CgA levels in patients with metastatic and non-metastatic tumors.

CONCLUSION: The plasma CgA levels were elevated significantly in the GEP NETs, and showed a high sensitivity and specificity particularly in the diagnosis of gastrinoma. CgA also can be used as a marker in monitoring tumor development and evaluating prognosis during the clinical application.