title: Benefit-risk balance of reoperation for persistent medullary thyroid cancer.
abstract: OBJECTIVE
  This investigation aimed at exploring the prospects of a cure for persistent medullary thyroid cancer (MTC) stratified by basal calcitonin levels before reoperation and the number of lymph node metastases previously removed at outside facilities.
  
  
  BACKGROUND
  There is no evidence-based information supporting the balance of surgical benefit and risk in persistent MTC.
  
  
  METHODS
  This retrospective study of 334 patients with persistent MTC referred to a tertiary surgical center, who were compared with 367 patients with previously untreated MTC referred to that institution during the same time period, evaluated biochemical cure rates after systematic lymph node dissection.
  
  
  RESULTS
  The relationship between the incremental serum calcitonin level before reoperation and the number of lymph node metastases at reoperation and biochemical cure was strong after previous removal of 0 (r = 0.74 and 77%-0%) and 1 to 5 lymph node metastases (r = 0.61 and 60%-0%) elsewhere. It disappeared once more than 5 lymph node metastases had been cleared at other hospitals (nonsignificant and 5%). When serum calcitonin levels were 1000 pg/mL or lower before reoperation, biochemical cure rates were 44% (59 of 133 patients) and 18% (12 of 65 patients) after previous removal of 0 and 1 to 5 lymph node metastases, respectively. These rates plummeted to 5% (2 of 43 patients) after a previous clearance of more than 5 lymph node metastases. When serum calcitonin levels exceeded 1000 pg/mL before reoperation, a biochemical cure was exceptional (1%; 1 of 76 patients).
  
  
  CONCLUSIONS
  With serum calcitonin levels of 1000 pg/mL or lower before reoperation and the previous removal of 5 or fewer lymph node metastases, systematic lymph node dissection seems worthwhile for persistent MTC. These findings will need to be validated in independent series before being adopted more widely as a new standard of care.
authors.affiliation: Department of General, Visceral and Vascular Surgery, Martin Luther University Halle-Wittenberg, Ernst-Grube-Str. 40, D-06097 Halle (Saale), Germany. AndreasMachens@aol.com
authors.forename: Andreas
authors.initials: A
authors.lastname: Machens
authors.forename: Henning
authors.initials: H
authors.lastname: Dralle
mesh_terms: D000328:Adult; D014408:Biomarkers, Tumor / Q000097:blood; D002116:Calcitonin / Q000097:blood; D018278:Carcinoma, Neuroendocrine; D005260:Female; D006801:Humans; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D012086:Reoperation; D018570:Risk Assessment; D013964:Thyroid Neoplasms / Q000097:blood / Q000473:pathology / Q000601:surgery*
chemical_list: D014408:Biomarkers, Tumor; D002116:Calcitonin