{Reference Type}: Multicenter Study
{Title}: Calcium-stimulated calcitonin test for the diagnosis of medullary thyroid cancer: results of a multicenter study and comparison between different assays.
{Author}: Faggiano A;Giannetta E;Modica R;Albertelli M;Barba L;Dolce P;Motta C;Deiana MG;Martinelli R;Zamponi V;Sesti F;Patti L;Scavuzzo F;Colao A;Monti S;
{Journal}: Minerva Endocrinol (Torino)
{Volume}: 48
{Issue}: 3
{Year}: 2023 Sep 16
{Factor}: 3.757
{DOI}: 10.23736/S2724-6507.23.04017-4
{Abstract}: <B>BACKGROUND: </B>A basal serum calcitonin (Ct) increase >100 pg/mL in patients with a thyroid nodule is consistent with the diagnosis of medullary thyroid cancer (MTC). In cases where the CT test have a slight to moderate increase, the calcium gluconate stimulation test is helpful to increase diagnostic accuracy. However, reliable cut-offs for calcium-stimulated Ct are still lacking. The aim of this study was to evaluate the sex-specific calcium-stimulated Ct cutoffs for the diagnosis of MTC in a multicenter series. A comparison between different Ct assays has been also performed.<BR><B>METHODS: </B>90 subjects undergone calcium-stimulated Ct for a suspected MTC in 5 Endocrine Units between 2010-2021 were retrospectively analyzed. Serum Ct concentrations were assessed by immunoradiometric (IRMA) or chemiluminescence (CLIA) assays.<BR><B>RESULTS: </B>MTC was diagnosed in 37 (41.1%) and excluded in 53 (58.9%) patients. The best calcium-stimulated Ct cut-off to identify MTC was 611 pg/mL in males (AUC =0.90, 95% CI (0.76;1) and 445 pg/mL in females (AUC=0.79, 95% CI (0.66;0.91). Logistic regression analysis showed that both basal (OR 1.01, P=0.003) and peak Ct after stimulation (OR 1.07, P=0.007) were significantly associated with MTC, together with sex (OR=0.06, P<0.001). The "Ct assay" variable was also considered in the logistic regression model, but it was not significantly associated with MTC (OR=0.93, P=0.919).<BR><B>CONCLUSIONS: </B>This study indicates that calcium test could be helpful to identify patients with early-stage MTC and those without MTC. A Ct value of 611 pg/mL in males and 445 pg/mL in females are proposed as the optimal Ct cut-offs at the stimulation test.