Calcitonin Gene‐related Peptide and Calcitonin in Medullary Thyroid Carcinoma

Abstract

We have investigated the levels of serum calcitonin and calcitonin-gene related peptide (CGRP) in 35 patients with well-documented medullary thyroid carcinoma (MTC). Immunohistochemical investigations for calcitonin and CGRP have been performed on tumour tissue from 9 patients to clarify the cellular pattern of production. In four patients with aggressive disease, serum calcitonin and CGRP values have been monitored in relation to progression of disease after surgery. All 35 patients with MTC have elevated calcitonin and 26 elevated CGRP levels. Generally calcitonin values were found to be higher than those of CGRP, although the ratio of the two peptides varied from patient to patient. The immunohistochemical investigations corresponded with these findings, generally showing diffuse staining for calcitonin in MTC tumour-cells and only a small number of CGRP positive cells. Calcitonin and CGRP are produced by alternative processing of the common precursor gene transcript. Our results suggest that absolute values of either calcitonin or CGRP in serum have no direct relationship to aggressiveness of disease. Thus whilst serum CGRP measurements appear to be a useful additional marker for the disease, they can be considered to be only a useful adjunct to serum calcitonin as a marker for tumour progression.

Purification and characterization of a peptide from amyloid-rich pancreases of type 2 diabetic patients.

“…Immunohistochemical localization studies demonstrate CGRP-containing nerve fibers in the central nervous system (33), in nerve fibers throughout the cardiovascular system (35), and in some cells in the thyroid (36) and pancreatic islets (37). However, the similarity of DAP to CGRP raises the possibility that immunohistochemical identification of CGRP in the pancreas may in fact be due to detection of crossreacting determinants on DAP (25).…”

Human alpha‐calcitonin gene‐related peptide (CGRP) is a potent vasodilator in human mesenteric vasculature.

“…Immunocytochemical analysis has localised CGRP in the rat in discrete regions of the central nervous system (Skofitsch & Jacobowitz, 1985a, b) and at nerve endings within the vasculature and heart (Mulderry et al, 1985;Sigrist et al, 1986). In man CGRP has been localised with calcitonin producing cells in the thyroid (Schifter et al, 1986), circulates at low levels in normal plasma (Girgis et al, 1985), and at elevated levels in plasma of patients with lung and medullary thyroid carcinoma (Girgis et al, 1985;Edbrooke et al, 1985). Rat and human have been shown in animal models to be potent inhibitors of gastric acid secretion (Lenz et al, 1985), potent vasodilators (Brain etal., 1985;Holman et al, 1986;Marshall et al, 1986b, c), and can modulate neurotransmission (Al-Kazwini et al, 1986).…”

Circulating Levels of Calcitonin Gene-Related Peptide in Patients with Medullary Thyroid Carcinoma

“…also detected high basal levels of calcitonin gene-related peptide in 26 of 35 patients with medullary thyroid carcinoma, using a radioimmunoassay system with aprotiniü. They observed significantly higher circulating levels of calcitonin than those of calcitonin gene-related peptide in these patients, but they also observed that the ratio of the two peptides varied from patient to patient and that only a small number of eells in tumoürs were stained by änti-cälcitonin geöe-related peptide antibody (21). However, in our study, äl-though the basal level of calcitonin gene-related peptide was high in oüe medullary thyröid carcinoma patient, the mean level in medullary thyroid carcinoma patients was not significantly different ffom that of normal controls.…”