Chromogranin A Test: Purpose, Normal Range and Price

The Chromogranin A test is a blood test that measures the level of CgA, an acidic glycoprotein stored in the secretory granules of neuroendocrine cells throughout the body and released into the bloodstream alongside peptide hormones and biogenic amines during neuroendocrine cell activation or tumour-related hypersecretion. CgA is produced by a wide variety of neuroendocrine cells distributed across the gastrointestinal tract, pancreas, adrenal medulla, thyroid C cells, pituitary gland, lung, and prostate, making it the most broadly applicable and widely used general neuroendocrine tumour marker in clinical oncology practice. Neuroendocrine tumours, commonly abbreviated as NETs, are a heterogeneous group of neoplasms arising from neuroendocrine cells that can occur at virtually any anatomical site but most commonly originate in the gastrointestinal tract including the small intestine, appendix, rectum, and stomach, the pancreas, and the lung. NETs range from well-differentiated, slow-growing, functionally active tumours that produce hormonal syndromes to poorly differentiated, highly aggressive neuroendocrine carcinomas with rapid clinical progression. CgA is elevated in the majority of NETs regardless of their site of origin, hormonal activity, or degree of differentiation, making it the single most sensitive and clinically useful general marker across the entire spectrum of neuroendocrine neoplasia. In India, neuroendocrine tumours are increasingly diagnosed as awareness grows among clinicians and diagnostic access to CgA testing and cross-sectional imaging improves. Historically underdiagnosed due to their often indolent presentation and the non-specific nature of early symptoms, NETs are now recognised as a significant oncological challenge requiring specialist multidisciplinary management. The test is performed on a small blood sample drawn from a vein and completed in under five minutes.

Doctors prescribe a CgA test in the following situations: Diagnosing neuroendocrine tumours in patients presenting with episodic flushing, diarrhoea, wheezing, and right-sided cardiac valvular disease consistent with carcinoid syndrome, or with hypoglycaemia, peptic ulcers, and watery diarrhoea from functional pancreatic NETs, where elevated CgA alongside specific hormonal markers and cross-sectional imaging confirms the neuroendocrine origin of the tumour. Screening for neuroendocrine tumours in patients with incidentally discovered hepatic or mesenteric masses, thickening of the small bowel wall on imaging, or unexplained elevated liver enzymes where CgA serves as an initial biochemical screen that, when elevated, directs further investigation with functional imaging including somatostatin receptor scintigraphy or Gallium-68 DOTATATE PET CT. Monitoring treatment response in confirmed NET patients undergoing surgical resection, peptide receptor radionuclide therapy, somatostatin analogue therapy with octreotide or lanreotide, or targeted therapy with everolimus or sunitinib where serial CgA measurements are the primary biochemical endpoint for assessing treatment efficacy and disease control. Detecting disease recurrence after curative surgical resection of a neuroendocrine tumour where a rising CgA during post-operative surveillance is often the earliest detectable indicator of residual disease, hepatic metastases, or locoregional recurrence, frequently preceding radiological detection and enabling earlier salvage intervention. Assessing prognosis in patients with metastatic neuroendocrine disease where baseline CgA level correlates with tumour burden and disease extent, and where very high CgA values indicate a greater hepatic and systemic metastatic load associated with more aggressive disease behaviour and poorer clinical outcomes. Evaluating patients with multiple endocrine neoplasia type 1 syndrome where surveillance for pancreatic NETs, pituitary adenomas, and parathyroid disease includes periodic CgA measurement as a sensitive biochemical screen for emerging neuroendocrine neoplasia within the MEN1 tumour spectrum.

The CgA test measures the concentration of Chromogranin A in the blood serum, expressed in nanograms per millilitre (ng/mL) or Units per litre (U/L) depending on the laboratory platform. The normal reference range for adults is below 100 ng/mL on most commercial platforms, though cut-off values vary between assays and laboratories, making it essential to interpret results against the specific reference range of the laboratory performing the test. Normal (Below 100 ng/mL) A result below the laboratory-specific upper limit of normal indicates no significant CgA elevation at the time of testing. In patients under active NET surveillance after treatment, a consistently normal CgA is a reassuring biochemical marker of disease control, though it does not entirely exclude small volume residual or recurrent disease as a proportion of well-differentiated NETs may produce only modest CgA elevations detectable only by very sensitive assay platforms. Mildly Elevated (100 to 300 ng/mL) A mildly elevated CgA requires careful clinical correlation as this range can be seen in both neuroendocrine tumours and a variety of non-neoplastic conditions that cause false positive elevations. These include proton pump inhibitor use, atrophic gastritis, chronic kidney disease, heart failure, inflammatory bowel disease, and rheumatoid arthritis. Clinical context, medication review, and correlation with imaging and other neuroendocrine markers are essential before attributing mild CgA elevation to a neuroendocrine neoplasm. Markedly Elevated (Above 300 ng/mL) A markedly elevated CgA above 300 ng/mL in a patient not taking proton pump inhibitors and without significant renal or cardiac disease is highly suspicious for a neuroendocrine tumour and warrants comprehensive investigation including specific hormonal markers, cross-sectional imaging, and functional somatostatin receptor imaging. Very high CgA levels above 1000 ng/mL typically indicate metastatic neuroendocrine disease with significant hepatic tumour burden and require urgent specialist oncological evaluation.

Proton pump inhibitors including omeprazole, pantoprazole, rabeprazole, and esomeprazole are the single most important cause of false positive CgA elevation and must be discontinued for at least two weeks before testing wherever clinically safe to do so. PPIs stimulate gastric enterochromaffin-like cell hyperplasia and CgA secretion, producing elevations of two to four times the upper limit of normal that can closely mimic a neuroendocrine tumour and lead to unnecessary invasive investigations. Discuss PPI withdrawal with your doctor before the test. Fasting for 8 to 10 hours before the CgA test is recommended, as food intake stimulates gastrointestinal neuroendocrine cell secretion and can transiently elevate CgA levels. Morning collection after an overnight fast is the standard preferred approach, particularly when CgA is ordered alongside other hormonal NET markers including 5-HIAA, gastrin, glucagon, VIP, and insulin. Inform your doctor about all medications currently being taken, particularly H2 receptor antagonists, antacids, corticosteroids, and any recent acute illnesses, as these can influence CgA levels. Chronic kidney disease and cardiac failure cause CgA elevation through reduced renal clearance and cardiac neuroendocrine activation respectively, and your doctor must be informed of these conditions before testing to ensure results are interpreted with appropriate clinical context. Staying well hydrated before the blood draw facilitates easier venous access and a smooth collection experience.

If you are booking through the SecondMedic platform the Chromogranin A test price starts at approximately Rs. 5665. The exact price will be confirmed at the time of booking through SecondMedic. If your doctor has prescribed multiple tests alongside Chromogranin A, SecondMedic health packages include Chromogranin A as part of a broader neuroendocrine tumour panel at a significantly lower combined price.

SecondMedic offers convenient home sample collection for the CgA test across India, making it easy to get tested without visiting a diagnostic centre. Home collection is available free of charge for orders above Rs. 300. A trained phlebotomist will visit your preferred address between 7 AM and 10 PM, seven days a week, including Sundays and public holidays. Your blood sample is processed at NABL-accredited partner laboratories, and your report is delivered within 24 hours directly to your WhatsApp and email.