Chromogranin A and the alpha-subunit of glycoprotein hormones in medullary thyroid carcinoma and phaeochromocytoma.
Using specific immunoradiometric assays, we evaluated the clinical usefulness of chromogranin A and the alpha-subunit of glycoprotein hormones in neuroendocrine tumours of neuroectodermic origin. The serum alpha-subunit of glycoprotein hormones was only slightly increased in 2 out of 44 medullary thyroid carcinoma or phaeochromocytoma patients with increased calcitonin or 24-hour urinary metanephrine levels. Serum chromogranin A was increased in 12 of 45 (27%) medullary thyroid carcinoma patients with an elevated calcitonin level and in 4 of 16 medullary thyroid carcinoma patients (25%) with an undetectable calcitonin level, in 5 of 7 phaeochromocytoma patients with increased urinary catecholamine and metabolite excretion, and in 2 of 3 patients with a non-functioning phaeochromocytoma. During follow-up, the course of chromogranin A was found to parallel that of tumour burden and/or 24-hour urinary metanephrine in 5 phaeochromocytoma patients. We conclude that chromogranin A measurement is not recommended for the diagnosis of medullary thyroid carcinoma patients. It may be useful in patients with functioning and non-functioning phaeochromocytomas as a follow-up marker. In neuroendocrine tumour patients with elevated calcitonin secretion, the serum alpha-subunit of glycoprotein hormone measurement may help differentiate medullary thyroid carcinoma or phaeochromocytoma patients from other endodermal-derived neuroendocrine tumour patients in whom it is frequently elevated.
Guignat
L
L
Department of Nuclear Medicine and Endocrine Tumors, Institut Gustave-Roussy, Villejuif, France.
Bidart
J M
JM
Nocera
M
M
Comoy
E
E
Schlumberger
M
M
Baudin
E
E
D000293:Adolescent; D000310:Adrenal Gland Neoplasms / Q000378:metabolism* / Q000473:pathology; D000328:Adult; D000368:Aged; D002116:Calcitonin / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D053379:Chromogranin A; D002864:Chromogranins / Q000378:metabolism*; D005260:Female; D015292:Glycoprotein Hormones, alpha Subunit / Q000378:metabolism*; D006801:Humans; D008297:Male; D008676:Metanephrine / Q000652:urine; D008875:Middle Aged; D010673:Pheochromocytoma / Q000378:metabolism* / Q000473:pathology; D013964:Thyroid Neoplasms / Q000378:metabolism* / Q000473:pathology
C506150:CHGA protein, human; D053379:Chromogranin A; D002864:Chromogranins; D015292:Glycoprotein Hormones, alpha Subunit; D008676:Metanephrine; D002116:Calcitonin