title: High recurrent rate of multicentric papillary thyroid carcinoma.
abstract: BACKGROUND
  Multicentric papillary thyroid carcinoma (PTC) is not unusual in patients with PTC. However, its clinical features concerning cancer recurrence and mortality are not well described.
  
  
  METHODS
  A total of 1682 PTC patients at a single institution who underwent total thyroidectomy were retrospectively reviewed; the mean follow-up period was 7.7 +/- 0.1 years. Postoperative radioactive iodide ablation for thyroid remnant was performed after surgery for most patients.
  
  
  RESULTS
  Of all the PTC cases reviewed, 337 cases (20.0%) were categorized as multicentric PTC. Compared with patients with unifocal PTC, multicentric PTC patients demonstrated older age, advanced TNM staging, and higher recurrence. A higher recurrence rate for multicentric PTC (20.2%) was observed compared with that for unifocal PTC; 45.8% of multicentric PTC cases with >or= 5 foci experienced cancer recurrence. Mean tumor size of the largest nodule in patients with multicentric PTC was significantly smaller than that found in unifocal PTC. Patients with multicentric papillary microcarcinoma (<or=1 cm) had higher recurrence rate and cancer mortality than those with unifocal papillary microcarcinoma. Of the recurrent multicentric PTC cases, 52.9% were persistent or diagnosed within the first year of thyroidectomy and had a cancer-related mortality of 27.8%. The 5-, 10-, and 20-year survival rates of multicentric PTC patients were 97.7%, 94.4%, and 84.7%, respectively, which were not statistically different from those of unifocal PTC patients.
  
  
  CONCLUSIONS
  Multicentric PTC warrant postoperative adjuvant therapy and close surveillance within the first year. Patients with multicentric papillary thyroid microcarcinoma need to be treated as high-risk patients.
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Chang Gung Memorial Hospital, Chang Gung University, Kweishan County, Taoyuan Hsien, Taiwan ROC. einjd@adm.cgmh.org.tw
authors.forename: Jen-Der
authors.initials: JD
authors.lastname: Lin
authors.forename: Tzu-Chieh
authors.initials: TC
authors.lastname: Chao
authors.forename: Chuen
authors.initials: C
authors.lastname: Hsueh
authors.forename: Sheng-Fong
authors.initials: SF
authors.lastname: Kuo
mesh_terms: D018263:Adenocarcinoma, Follicular / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D000328:Adult; D002291:Carcinoma, Papillary / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis* / Q000401:mortality / Q000601:surgery; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate; D013964:Thyroid Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D013965:Thyroidectomy; D016896:Treatment Outcome
chemical_list: D007457:Iodine Radioisotopes