Treatment evaluation, follow-up and familial screening of medullary thyroid carcinoma by highly specific calcitonin measurements.

BACKGROUND Calcitonin is the most sensitive and specific marker for medullary thyroid carcinoma (MTC). AIMS The aim of this study was to emphasize the role and the limits of plasma basal calcitonin (bCT) measurement in the management of Moroccan MTC patients and their relatives. SETTINGS AND DESIGN This is a retrospective study on 6 MTC patients referred to our institute from January 1996 to December 2004. MATERIALS AND METHODS Serum bCT levels were measured in 36 individuals comprising six known MTC cases, 18 relatives and 12 healthy volunteers, using two-sites immunoradiometric assay method. Five of MTC patients have been followed from 12 to 96 months after surgery. STATISTICAL ANALYSIS USED Calculations were performed using SPSS 10.0 program. Data comparison was done by Student's t -test. RESULTS The circulating preoperative bCT concentrations were elevated for all MTC patients (range, 44,8 -2055 pg/ml, normal <10). Recent postoperative bCT determinations varied from 24.4 to 1972 pg/ml in four patients. In one patient, the bCT value decreased to an undetectable level during a follow-up of 12 months. The mean bCT level of relatives was 4.90 +/- 3.54 pg/ml; two patients had slightly elevated bCT. Five (42%) healthy volunteers had undetectable bCT levels and all had less than 10 pg/ml; the mean bCT value was 3.06 +/- 2.51 pg/ml. CONCLUSIONS Routine plasma bCT measurement still has an important place in the preoperative diagnosis and follow-up treatment of MTC.