Chromogranin A (CgA) is a protein commonly released by NET cells. A blood test is used to measure CgA. Serial CgA measurements during follow-up should be performed at approximately the same intervals after the administration of a long-acting SSA. False-positive levels of CgA may occur due to several issues such as the use of proton pump inhibitors (medications to treat heartburn).
As better imaging techniques have been developed, there may be less utilization of CgA tests. Chromogranin A is a tumor marker and not a hormone; it is not part of diagnostic testing.
Blood chemistry tests measure certain substances such as glucose (sugar), enzymes, fats, and proteins. Blood chemistry studies give essential information about how well a person’s kidneys, liver, and other organs are working. An unusual (either higher or lower) result can be a sign of disease.
A blood test called the NETest looks for molecular evidence of tumor activity. It is more sensitive than other tumor markers. Recently published results on the NETest following surgery have been promising, showing that a positive NETest following resection can be a predictor of recurrence.
Fasting serum tests measure the amount of gastrin, sugar, glucagon, vasoactive intestinal peptide (VIP), or somatostatin in the blood. For these tests, patients may need to fast for at least 8 hours.
Testing can help your doctor understand the specifics of your tumor and develop a treatment plan for your neuroendocrine cancer.