Octreotide suppression test in diagnosing and predicting the outcome of therapy in patients with neuroendocrine tumors. Preliminary report.
BACKGROUND
Chromogranin A (CgA) is a non-specific marker of neuroendocrine tumors (NET) and is important in monitoring the disease course and NET treatment.


OBJECTIVE
Usefulness of suppression test of CgA secretion with octreotide in diagnosis and predicting the therapy outcome in NET patients.


METHODS
The study included 32 patients with NET of gastrointestinal tract, lung and of unknown origin. CgA level in blood plasma on fasting, before and 30, 60, 90 and 120 minutes after subcutaneous administration of 100 mug octreotide, was determined in all patients. The subjects were divided into two subgroups with relation to CgA level and to the results of somatostatin receptor scintigraphy (SRS).


RESULTS
Statistically significant CgA decrease after octreotide administration in all study time points and positive results of SRS were found in the patients with the elevated CgA level. No statistically significant decrease of CgA level after octreotide was found in the group with normal CgA levels. In this group, 13 patients had a negative result of SRS, and somatostatin receptors expression was found in one patient. Tolerance of somatostatin analogs (SSA) therapy was very good.


CONCLUSIONS
Octreotide suppression test with CgA level assessment in NET patients is a simple, straightforward examination, providing information on the predicted response to the applied SSA and the data on initial clinical tolerance of those agents. This examination can also be a screening test useful in planning the treatment with SSA in patients with NET.
Kos-Kudła
Beata
B
Division of Endocrinology, Department of Pathophysiology and Endocrinology, Silesian Medical University, Zabrze. bkoskudla@slam.katowice.pl
Zemczak
Anna
A
Foltyn
Wanda
W
Marek
Bogdan
B
Strzelczyk
Janusz
J
Telega
Aleksandra
A
Zajecki
Wojciech
W
Legaszewski
Tomasz
T
Jurecka-Lubieniecka
Beata
B
D000368:Aged; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use; D014408:Biomarkers, Tumor / Q000097:blood*; D053379:Chromogranin A / Q000097:blood*; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000097:blood / Q000175:diagnosis; D006801:Humans; D007279:Injections, Subcutaneous; D008175:Lung Neoplasms / Q000097:blood / Q000175:diagnosis; D008297:Male; D018358:Neuroendocrine Tumors / Q000097:blood* / Q000175:diagnosis*; D015282:Octreotide; D015609:Organotechnetium Compounds; D010190:Pancreatic Neoplasms / Q000097:blood / Q000175:diagnosis; D010865:Pilot Projects; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals; D017481:Receptors, Somatostatin / Q000032:analysis; D013004:Somatostatin / Q000031:analogs & derivatives / Q000627:therapeutic use; D013964:Thyroid Neoplasms / Q000097:blood / Q000175:diagnosis
D018931:Antineoplastic Agents, Hormonal; D014408:Biomarkers, Tumor; D053379:Chromogranin A; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D017481:Receptors, Somatostatin; C487389:technetium 99m EDDA-HYNIC-Tyr(3)-octreotide; D013004:Somatostatin; D015282:Octreotide