From the Guidelines
Elevated Chromogranin A (CgA) indicates the presence of a neuroendocrine tumor (NET), which can be found in various parts of the body, including the gastrointestinal tract, pancreas, and lungs 1, 2, 3, 4, 5.
Key Points
- CgA is a general marker for NETs and is usually elevated in patients with these tumors, regardless of whether they have hormone-related clinical features 1.
- Elevated CgA levels can be associated with recurrence of NETs and shorter survival times in patients with metastatic disease 3.
- CgA levels can be influenced by other factors, such as renal or hepatic insufficiency and proton pump inhibitors, which can cause falsely elevated levels 3, 4.
- CgA is not specific to NETs and can be elevated in other conditions, such as atrophic gastritis and proton pump inhibitor therapy 1, 2.
Clinical Use
- CgA can be used as a tumor marker to monitor patients with NETs and detect recurrence or progression of disease 3, 4.
- CgA levels should be interpreted in conjunction with clinical symptoms and imaging studies to determine the presence and extent of NETs 3, 4.
- CgA can be used in combination with other biochemical markers, such as 5-HIAA and gastrin, to diagnose and monitor NETs 1, 2, 3, 5.
From the Research
Elevated Chromogranin A (CgA) Indications
Elevated Chromogranin A (CgA) levels can indicate several conditions, including:
- Neuroendocrine tumors (NE tumors) 6, 7, 8, 9, 10
- Adenocarcinomas with neuroendocrine differentiation 6
- Atrophic gastritis 6
- Treatment with inhibitors of gastric acid secretion 6
- Renal impairment 6
- Enterochromaffin-like (ECL) hyperplasia secondary to treatment with acid secretion inhibitors or atrophic gastritis 6
Neuroendocrine Tumors
Elevated CgA levels are commonly found in patients with neuroendocrine tumors, including:
- Gastrinomas 7
- Pheochromocytomas 7
- Carcinoid tumors 7, 10
- Non-functioning tumors of the endocrine pancreas 7
- Medullary thyroid carcinomas 7
- Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) 8
Clinical Utility
CgA is considered a useful marker for the diagnosis and monitoring of neuroendocrine tumors, with elevated levels correlating with tumor burden and recurrence 7, 8, 9, 10. Effective treatment is often associated with a decrease in CgA levels 9, 10. However, proton pump inhibitors can falsely increase CgA levels, which normalize with therapy cessation 9.