title: Calcitonin and carcinoembryonic antigen doubling times as prognostic factors in medullary thyroid carcinoma: a structured meta-analysis.
abstract: BACKGROUND
  In the management of patients with medullary thyroid carcinoma (MTC), calcitonin doubling time (dt) has gained interest as an independent predictor of recurrence and survival.
  
  
  OBJECTIVE
  To perform a structured meta-analysis of the diagnostic value of calcitonin dt, carcinoembryonic antigen (CEA) dt and the combination and to define dt strata with the highest predictive power. Design The study was a meta-analysis using individual data.
  
  
  METHODS
  Ten studies containing data on the post-operative kinetics of tumour marker(s) and (recurrence free) survival were included.
  
  
  RESULTS
  Calcitonin- and CEA-dt are significant indicators for survival (hazard ratios (HR) 21.52 respectively infinite for dt 0-1 year compared to dt >1 year) and recurrence (HR 5.33 respectively 6.80 for dt 0-1 year compared to dt >1 year). The highest predictive power was found for the dt classification 0-1 year vs. >1 year. CEA dt has a higher predictive value than calcitonin dt in the subgroup of patients for which both parameters were available.
  
  
  CONCLUSIONS
  The dts of both calcitonin and CEA are strong prognostic indicators for MTC recurrence and death. CEA dt has a higher predictive value than calcitonin dt and therefore measuring both tumour markers is essential for proper risk stratification.
authors: Department of Endocrinology, Walaeus Library, Leiden University Medical Centre, Leiden, The Netherlands. j.a.a.meijer@lumc.nl
authors: Johannes A A
authors: JA
authors: Meijer
authors: Saskia
authors: S
authors: le Cessie
authors: Wilbert B
authors: WB
authors: van den Hout
authors: Job
authors: J
authors: Kievit
authors: Johannes W
authors: JW
authors: Schoones
authors: Johannes A
authors: JA
authors: Romijn
authors: Johannes W A
authors: JW
authors: Smit
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002116:Calcitonin / Q000378:metabolism*; D002272:Carcinoembryonic Antigen / Q000378:metabolism*; D018276:Carcinoma, Medullary / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D011237:Predictive Value of Tests; D011379:Prognosis; D013964:Thyroid Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D016896:Treatment Outcome
chemical_list: D002272:Carcinoembryonic Antigen; D002116:Calcitonin