title: Progression of medullary thyroid cancer in RET carriers of ATA class A and C mutations.
abstract: BACKGROUND
  There is no histopathological or radiological information on the natural course of tumor growth and lymph node metastasis in medullary thyroid cancer (MTC).
  
  
  OBJECTIVE
  This investigation aimed at determining annual rates of tumor growth and lymph node metastasis in hereditary MTC at the surgical pathology level.
  
  
  METHODS
  This was a retrospective analysis.
  
  
  METHODS
  The setting was a tertiary referral center.
  
  
  METHODS
  Included were 172 carriers of American Thyroid Association (ATA) class C (95 patients) and class A rearranged during transfection (RET) mutations (77 patients) with MTC.
  
  
  METHODS
  The intervention was compartment-oriented surgery.
  
  
  METHODS
  Comparisons of means between index and nonindex patients yielded incremental primary tumor diameter and incremental number of lymph node metastases, which were divided by incremental patient age at tissue diagnosis.
  
  
  RESULTS
  Annual primary tumor growth was 0.4-0.5 mm in node-negative carriers of ATA class A and C mutations. In node-positive carriers, annual primary tumor growth was 2.6 mm (ATA class C mutations) and 1.2 mm (ATA class A mutations), more than 6-fold (2.6 vs 0.4 mm) and more than 2-fold greater (1.2 vs 0.5 mm) than in their node-negative peers. Node-positive carriers revealed an annual rate of lymph node metastasis of 0.6-0.7 nodes independent of ATA class.
  
  
  CONCLUSIONS
  Small MTCs may take longer than 10 years to become big enough to visualize on imaging. These slow growth rates highlight the importance of following up on patients for very long time periods to uncover at least some tumoral sources of persistent calcitonin production.
authors.affiliation: Department of General, Visceral, and Vascular Surgery, Martin Luther University Halle-Wittenberg, D-06097 Halle (Saale), Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Machens
authors.forename: Kerstin
authors.initials: K
authors.lastname: Lorenz
authors.forename: Henning
authors.initials: H
authors.lastname: Dralle
mesh_terms: D000293:Adolescent; D000328:Adult; D018276:Carcinoma, Medullary / Q000235:genetics* / Q000473:pathology / Q000601:surgery; D018450:Disease Progression; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009154:Mutation; D051096:Proto-Oncogene Proteins c-ret / Q000235:genetics*; D012189:Retrospective Studies; D013961:Thyroid Gland / Q000473:pathology / Q000601:surgery; D013964:Thyroid Neoplasms / Q000235:genetics* / Q000473:pathology / Q000601:surgery
chemical_list: D051096:Proto-Oncogene Proteins c-ret