Clinical Effectiveness of Serum Chromogranin A (CgA) Levels on Diagnostic Relevance, Response After Surgical Resection and Recurrence of Pancreatic Endocrine Tumors (PET)

Chromogranin A (CgA) is a glycoprotein with a molecular weight of 49 to 52 kDa produced by chromaffin cells of the adrenal medulla, enterochromaffin-like (ECL) cells, and endocrine cells of the stomach and pancreas, and it is the precursor to several functional peptides including vasostatin and pancreastatin.

Importantly, CgA can be measured in the serum or plasma or detected within the secretory vesicles as a general diagnostic biomarker for neuroendocrine tumors (NETs), and plasma CgA levels also provide information regarding tumor burden and response to treatment. It has a sensitivity and specificity between 27% and 81%.

Some studies have noted an association between CgA concentrations and tumor location or degree of differentiation. It has also been proposed that plasma CgA levels are more frequently elevated in well-differentiated tumors compared with poorly differentiated tumors of the midgut. Some other clinical series have provided evidence of an association between plasma CgA levels and the extent of disease, tumor burden, or presence of metastases, and high baseline levels of CgA are suggestive of a poor prognosis.

However, there exist still controversies the effectiveness of serum CgA levels on diagnostic relevance, treatment response after surgical resection or sandostatin analog, clinicopathologic features of pancreatic neuroendocrine tumors (PNETs).

To date, moreover, a precise association between CgA levels and survival has not been clearly demonstrated, although a number of studies suggest that this relationship may exist. There, especially, is no relevant data on value of serum CgA level for clinical usefulness in Korean population.