title: Refining calcium test for the diagnosis of medullary thyroid cancer: cutoffs, procedures, and safety.
abstract: BACKGROUND
  Calcitonin (CT) measurement is crucial to the early diagnosis and the follow-up of medullary thyroid cancer (MTC). If the evaluation of stimulated CT levels is required, a provocative test can be performed, being the high-dose Ca test recently reintroduced in clinical practice.
  
  
  OBJECTIVE
  Our objective was to identify gender-specific thresholds for MTC diagnosis in a large series of patients who underwent the Ca test.
  
  
  METHODS
  A total of 91 patients (49 females and 42 males) underwent the Ca test (calcium gluconate, 25 mg/kg) before thyroidectomy and both basal CT (bCT) and stimulated CT (sCT) were compared with histological results by receiver operating characteristic plot analyses. To evaluate possible side effects of Ca administration, cardiac function has been extensively studied.
  
  
  RESULTS
  bCT levels were found to harbor the same accuracy as sCT in the preoperative diagnosis of MTC. The best Ca thresholds for the identification of MTC were >26 and >68 for bCT and >79 and >544 pg/mL for sCT in females and males, respectively. The high tolerability and safety of the Ca test was demonstrated and advice offered to be followed before and during the test.
  
  
  CONCLUSIONS
  Gender-specific bCT and sCT cutoffs for the identification of C-cell hyperplasia and/or MTC have been defined. The bCT and sCT were found to have a similar accuracy, indicating that serum CT assays with improved functional sensitivity may likely decrease the relevance of the stimulation test in several conditions. Finally, systematic cardiac monitoring confirms the safety of the Ca test.
authors.affiliation: Endocrinology (C.M., E.C.) and Surgical Pathology and Cytopathology (G.P.) Units, Department of Medicine; Minimally Invasive Endocrine Surgery Unit (M.I.), Department of Surgery, Oncology, and Gastroenterology; and Departments of Cardiologic, Thoracic, and Vascular Sciences (C.S.) and Surgery, Oncology, and Gastroenterology (M.R.P.), University of Padua, 35122 Padua, Italy; Departments of Clinical Sciences and Community Health (M.P., C.Co., S.D.L., U.V., L.F., C.Ca., G.I.M., L.P.) and Biomedical, Surgical, and Dental Sciences (S.F.), University of Milan, and Endocrine (M.P., C.Co., S.D.L., U.V., L.F.), Division of Pathology (S.F.), and Endocrine Surgery (L.V.) Units, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Ca' Granda, 20122 Milan, Italy; Division of Endocrine and Metabolic Diseases (C.Ca., G.I.M., L.P.), Ospedale San Luca, IRCCS Istituto Auxologico Italiano, 20149 Milan; and Endocrine Surgery Unit (L.D.P.), San Paolo Hospital, 20142 Milan, Italy.
authors.forename: Caterina
authors.initials: C
authors.lastname: Mian
authors.forename: Michela
authors.initials: M
authors.lastname: Perrino
authors.forename: Carla
authors.initials: C
authors.lastname: Colombo
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Cavedon
authors.forename: Gianmaria
authors.initials: G
authors.lastname: Pennelli
authors.forename: Stefano
authors.initials: S
authors.lastname: Ferrero
authors.forename: Simone
authors.initials: S
authors.lastname: De Leo
authors.forename: Cristiano
authors.initials: C
authors.lastname: Sarais
authors.forename: Chiara
authors.initials: C
authors.lastname: Cacciatore
authors.forename: Gloria Irene
authors.initials: GI
authors.lastname: Manfredi
authors.forename: Uberta
authors.initials: U
authors.lastname: Verga
authors.forename: Maurizio
authors.initials: M
authors.lastname: Iacobone
authors.forename: Loredana
authors.initials: L
authors.lastname: De Pasquale
authors.forename: Maria Rosa
authors.initials: MR
authors.lastname: Pelizzo
authors.forename: Leonardo
authors.initials: L
authors.lastname: Vicentini
authors.forename: Luca
authors.initials: L
authors.lastname: Persani
authors.forename: Laura
authors.initials: L
authors.lastname: Fugazzola
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood; D002116:Calcitonin / Q000097:blood*; D002125:Calcium Gluconate; D018276:Carcinoma, Medullary / Q000097:blood / Q000175:diagnosis* / Q000601:surgery; D002648:Child; D003937:Diagnosis, Differential; D005260:Female; D006044:Goiter, Nodular / Q000097:blood / Q000175:diagnosis* / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D013961:Thyroid Gland / Q000473:pathology / Q000601:surgery; D013964:Thyroid Neoplasms / Q000097:blood / Q000175:diagnosis* / Q000601:surgery; D013965:Thyroidectomy
chemical_list: D014408:Biomarkers, Tumor; D002116:Calcitonin; D002125:Calcium Gluconate