title: Progression of medullary thyroid carcinoma: assessment with calcitonin and carcinoembryonic antigen doubling times.
abstract: OBJECTIVE
  The progression of medullary thyroid cancer is difficult to assess with imaging modalities; we studied the interest of calcitonin and carcinoembryonic antigen (CEA) doubling times and of Ki-67 labeling and mitotic index (MI).
  
  
  METHODS
  Fifty-five consecutive medullary thyroid carcinoma (MTC) patients with elevated calcitonin levels underwent repeated imaging studies in order to assess tumor burden and progression status. We looked for relationships between tumor burden and levels of calcitonin and CEA and between progression status according to the response evaluation criteria in solid tumors (RECIST) and calcitonin and CEA doubling times, and Ki-67 labeling and MI.
  
  
  RESULTS
  The calcitonin and CEA levels were correlated with tumor burden. Ten patients with calcitonin levels below 816 pg/ml had no imaged tumor foci. Among the 45 patients with imaged tumor foci, 19 had stable disease and 26 had progressive disease, according to the RECIST. The calcitonin and CEA doubling times were strongly related to disease progression, with very few overlaps: 94% of patients with doubling times shorter than 25 months had progressive disease and 86% of patients with doubling times longer than 24 months had stable disease. Ki-67 labeling and MI were not significantly associated with disease progression.
  
  
  CONCLUSIONS
  For MTC patients, the doubling times of both calcitonin and CEA are efficient tools for assessing tumor progression.
authors.affiliation: Department of Nuclear Medicine and Endocrine Oncology, Institut Gustave Roussy and University Paris Sud, 94805 Villejuif Cédex, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Laure Giraudet
authors.forename: Abir
authors.initials: A
authors.lastname: Al Ghulzan
authors.forename: Anne
authors.initials: A
authors.lastname: Aupérin
authors.forename: Sophie
authors.initials: S
authors.lastname: Leboulleux
authors.forename: Ahmed
authors.initials: A
authors.lastname: Chehboun
authors.forename: Frédéric
authors.initials: F
authors.lastname: Troalen
authors.forename: Clarisse
authors.initials: C
authors.lastname: Dromain
authors.forename: Jean
authors.initials: J
authors.lastname: Lumbroso
authors.forename: Eric
authors.initials: E
authors.lastname: Baudin
authors.forename: Martin
authors.initials: M
authors.lastname: Schlumberger
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood*; D002116:Calcitonin / Q000097:blood*; D002272:Carcinoembryonic Antigen / Q000097:blood*; D002277:Carcinoma / Q000097:blood*; D018450:Disease Progression; D005260:Female; D006801:Humans; D019394:Ki-67 Antigen / Q000097:blood; D008297:Male; D008875:Middle Aged; D013964:Thyroid Neoplasms / Q000097:blood*; D013997:Time Factors
chemical_list: D014408:Biomarkers, Tumor; D002272:Carcinoembryonic Antigen; D019394:Ki-67 Antigen; D002116:Calcitonin