Experience with a provocative test of calcitonin release as a prospective screening for preclinical medullary thyroid carcinoma in men type 2A family members
✍ Scribed by J. J. M. van Lathem; W. J. H. Vermaak; J. M. Kuyl; W. Mollentze; S. Jansen; L. Wolmaran; H. Pelser; R. Barry; A. J. Kruger; M. Wolfaardt; C. J. C. Nel
- Publisher
- John Wiley and Sons
- Year
- 1992
- Tongue
- English
- Weight
- 564 KB
- Volume
- 6
- Category
- Article
- ISSN
- 0887-8013
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✦ Synopsis
We report our experience with a provocative test of calcitonin (CT) release using a combined stimulus of intravenous 10% CaCI, solution and pentagastrin on 34 normal adults (1 5 females: age 41 2 12.3 years and range 22-65 years; and 19 males: age 43 k 9.1 years and range 23-60 years) and in 44 family members of three proven multiple endocrine neoplasia type 2A syndrome (MEN 2A) patients. A commercial radioimmunoassay was used to determine the serum CT levels. Peak CT levels were reached within 2 to 5 minutes after administration of the stimulus in all subjects tested. In the group of normal subjects there was no significant difference in the mean basal CT levels between males (54.8 2 21.7pg/ml)andfemales(56.5 2 34.8 pg/ml), whilst the mean peak response val-uesformaleswas146.3 2 120.6pg/ml, which was significantly different from the mean value of females, namely 71.6 k 39.0 pg/ml. We did not find significant correlations between the basal CT level, peak CT response, and age.
Of the 44 family members tested, 9 showed an exaggerated CT response to the combined stimulus and subsequently had a total thyroidectomy. Histological examination confirmed C-cell hyperplasia (CCH) in one and medullary thyroid carcinoma (MTC) in the other 8. Three of the 9 had high basal plasma CT levels. The 9 patients were retested postoperatively and all showed a flat response to the combined stimulus. Those family members with histological proof of MTC or CCH were screened for genetic linkage to the disease gene for MEN 2A using probe MCK2, and showed correlation in each instance. Eight other members were identified as highrisk genotypes. They are still asymptomatic and calcitonin negative.
Our study shows that the provocative test and the commercial calcitonin radioimmunoassay used is reliable in detecting family members of MEN type 2A patients having preclinical MTC or CCH. We found that peak response values higher than 250 pg/ml were highly suggestive of preclinical MTC in family members of MEN 2A cases (sensitivity 100% and specificity 94%). The test had minor side effects which did not last more than 2 minutes. o 1992 Wiley-Liss, Inc.