Chromogranin A, LC/MS/MS

For Specimen Integrity during Extreme Weather see the “Lockbox Usage in Extreme Weather” document at the top of this page.

CHROMA

1 mL serum collected in a red-top tube (no gel)

0.5 mL

Collect blood in a standard red-top serum vacutainer tube. Allow blood to clot at room temperature. Centrifuge and separate the serum from the cells immediately. Do not store refrigerated. (Sample must not reach refrigerator temperature)

Frozen

Room temperature: 7 days
Refrigerated: Unacceptable
frozen: 31 days

Gross hemolysis • Unspun red-top (no gel) tubes • Serum separator tube (SST)

Sets up 6 days a week.

Reports in 3 to 5 days.

Chromogranin-A (CgA) is an acidic glycoprotein expressed in the secretory granules of most normal and neoplastic neuroendocrine (NE) cell types, where it is released together with peptide hormones and biogenic amines. Neuroendocrine tumors (NETs) are a form of cancer that differ from other neoplasia in that they synthesize, store, and secrete peptides, e.g., CgA and amines. CgA is secreted from neuroendocrine-derived tumors including foregut, midgut and hindgut gastrointestinal NETs, pheochromocytomas, neuroblastomas, medullary thyroid carcinomas, some pituitary tumors, functioning and non-functioning pancreatic NETs.
Significantly elevated CgA levels have been found in patients with other diseases, such as impaired renal function, untreated benign essential hypertension, gastritis, prostatic carcinoma, and hyperparathyroidism. The best-characterized circulating biomarker that identifies NETs in general is CgA. Monitoring blood CgA levels may effectively provide information that is helpful in delineating tumor burden and rate of tumor growth, predicting tumor response to therapy and providing some indication as to prognosis.