Description

Test Criteria

Chromogranin A (CgA) is a protein commonly secreted by neuroendocrine tumor cells. A blood test measures CgA as a tumor marker. In patients treated with somatostatin analogs, CgA tests should be timed carefully with their somatostatin analog treatment. False-positive levels of CgA, due to several issues, including the use of proton pump inhibitors (medications used to treat heart burn), may occur.¹⁶