Chromogranin A, Serum
Also known as: CGA
Use
This test aids in the monitoring of neuroendocrine tumors, particularly nonsecretory sympathetic and parasympathetic neuroendocrine tumors. It is not recommended for the diagnosis of carcinoid tumors. The test measures changes in Chromogranin A levels over time, providing diagnostic information about tumor progression. Increases in CgA serum concentrations can indicate a higher probability of tumor progression, while smaller increases or stable levels may indicate a lower probability.
Special Instructions
It is recommended to stop proton pump inhibitor (PPI) treatment for at least 14 days prior to testing, as PPIs can cause non-tumor related elevations of Chromogranin A.
Limitations
The test is performed using the BRAHMS CGA II Kryptor kit, and results obtained with different methods or kits cannot be used interchangeably. Results should not be interpreted as definitive evidence for or against malignant disease and must be considered alongside clinical symptoms, diagnostic evidence, and other laboratory parameters. Nontumor related elevations of Chromogranin A can occur in gastrointestinal, cardiovascular, and renal disorders, as well as in cancers other than neuroendocrine tumors.
FDA ApprovedNew York Approved
Methodology
Immunoassay (Quantitative Immunofluorescence)
Biomarkers
LOINC Codes
- 9811-1
Result Turnaround Time
1-4 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.5 mL
Container
ARUP standard transport tube
Collection Instructions
Allow serum specimen to clot completely at room temperature before transferring to the transport tube.
Patient Preparation
Collection should occur after a 14-day washout period for PPIs.
Causes for Rejection
Plasma
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 48 hours |
| Refrigerated | 3 days |
| Frozen | 3 months |