Common in the endocrine tissues and its measurement is considered the gold standard biochemical test for the diagnosis of carcinoid and neuroendocrine tumors.
It is a useful marker for following the course of illness in carcinoid and neuroendocrine tumors.
A correlation exists between tumor burden and serum levels.
High levels in carcinoid patients indicate a high tumor burden.
In patients with midgut carcinoid tumors and elevated level is an independent predictor of death (Taupenot L).
Five-year survival in patients with high levels is 22%, while it is 63% in patients with low levels (Ardill JE).
Serial measurements can provide monitoring of the disease process and can be used to follow the results of treatment of carcinoid tumors.