title: Prognostic evaluation of patients with multicentric papillary thyroid microcarcinoma.
abstract: OBJECTIVE
  Patients with papillary thyroid microcarcinoma (PTMC) often have an excellent prognosis. We hypothesize that patients with multicentric PTMC are associated with good clinical outcome, although multicentricity in papillary thyroid carcinoma may be associated with poor prognosis.
  
  
  METHODS
  Retrospective analysis of multicentric PTMC cases in one medical center enrolled from 1987 to 2008 was conducted. At the end of follow-up, patients were classified as "recurrence-free" or "recurrence or persistent disease". The tumor-node-metastasis (TNM) staging system was used, and (T1, N0, M0) was regarded as "early clinical stage", whereas (T3-4, any N, any M) or (any T, N1, or M1) was regarded as "advanced clinical stage".
  
  
  RESULTS
  There were 61 patients with a median age of 45 years. After a median follow-up period of 7.3 years (range: 2.1-22.1 years), the overall cause-specific survival rate was 98.36%. The patients with tumor diameters < 0.5 cm were all recurrence-free. Advanced clinical stage, especially distant metastasis, was highly associated with recurrence or persistent disease.
  
  
  CONCLUSIONS
  Our results demonstrate excellent prognosis in multicentric PTMC patients. No patients with tumor diameter < 0.5 cm had recurrence or persistent disease. Tumor size is an important risk factor in patients with multicentric PTMC.
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Chang Gung Memorial Hospital, Keelung, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Sheng-Fong
authors.initials: SF
authors.lastname: Kuo
authors.forename: Tzu-Chieh
authors.initials: TC
authors.lastname: Chao
authors.forename: Hung-Yu
authors.initials: HY
authors.lastname: Chang
authors.forename: Chuen
authors.initials: C
authors.lastname: Hsueh
authors.forename: Chung-Han
authors.initials: CH
authors.lastname: Yang
authors.forename: Jen-Der
authors.initials: JD
authors.lastname: Lin
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D044963:Biopsy, Fine-Needle; D002291:Carcinoma, Papillary / Q000473:pathology* / Q000601:surgery*; D016009:Chi-Square Distribution; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D015996:Survival Rate; D013964:Thyroid Neoplasms / Q000473:pathology* / Q000601:surgery*; D013965:Thyroidectomy