title: Early changes in carcinoembryonic antigen but not in calcitonin levels are correlated with the progression-free survival in medullary thyroid carcinoma patients treated with cytotoxic chemotherapy.
abstract: BACKGROUND
  The prognostic value of serum calcitonin (CT) and carcinoembryonic antigen (CEA) doubling time has been recently demonstrated in medullary thyroid carcinoma (MTC) patients. No study has yet validated the surrogate role of these markers for survival during treatment. The aim of this study was to evaluate, in patients with advanced MTC treated with cytotoxic chemotherapy, the relationship between early changes of serum CT or CEA levels and progression-free survival (PFS).
  
  
  METHODS
  The files of 28 consecutive metastatic MTC patients with progressive disease, treated with cytotoxic chemotherapy in a single tertiary referral center between 2000 and 2010, were retrospectively reviewed. Serum CT and CEA measurements and radiological Response Evaluation Criteria in Solid Tumors (RECIST) evaluations were collected every 3 months. The relationship between changes in serum CT and CEA levels at 3 months, defined by an increase or a decrease of at least 20%, and PFS according to RECIST 1.0, was estimated using Kaplan-Meier curves and log-rank test.
  
  
  RESULTS
  The median follow-up for the 28 patients was 68 months. According to RECIST, a partial response, a stabilization or a progression was observed in 14, 43, and 43% of cases respectively. Median PFS from the initiation of cytotoxic chemotherapy was 4.5 months. Median PFS among patients with and without significant CT increase at 3 months was 4.6 and 3.3 months respectively (P=0.75). Median PFS among patients with a significant CEA increase at 3 months was 2.7 months, whereas it was 19.1 months in patients in whom CEA did not increase (P=0.02).
  
  
  CONCLUSIONS
  At 3 months, an increase of serum CEA but not of CT levels appears as a valuable surrogate marker of short PFS in MTC patients treated with cytotoxic chemotherapy. A prospective validation is expected.
authors.affiliation: Department of Nuclear Medicine and Endocrine Tumors, Institut Gustave Roussy, University Paris Sud, 39 Rue Camille Desmoulins, 94805 Villejuif Cedex, France. hajjgeorges@hotmail.com
authors.forename: G
authors.initials: G
authors.lastname: Hajje
authors.forename: I
authors.initials: I
authors.lastname: Borget
authors.forename: S
authors.initials: S
authors.lastname: Leboulleux
authors.forename: C
authors.initials: C
authors.lastname: Chougnet
authors.forename: A
authors.initials: A
authors.lastname: Al Ghuzlan
authors.forename: H
authors.initials: H
authors.lastname: Mirghani
authors.forename: C
authors.initials: C
authors.lastname: Caramella
authors.forename: D
authors.initials: D
authors.lastname: Hartl
authors.forename: M
authors.initials: M
authors.lastname: Schlumberger
authors.forename: E
authors.initials: E
authors.lastname: Baudin
mesh_terms: D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D002116:Calcitonin / Q000097:blood*; D002272:Carcinoembryonic Antigen / Q000097:blood*; D018276:Carcinoma, Medullary / Q000097:blood* / Q000188:drug therapy / Q000401:mortality; D018450:Disease Progression; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D013964:Thyroid Neoplasms / Q000097:blood* / Q000188:drug therapy / Q000401:mortality
chemical_list: D002272:Carcinoembryonic Antigen; D002116:Calcitonin