title: Scoring patients' risk in differentiated thyroid cancer.
abstract: BACKGROUND
  Despite of excellent long-term results, there is a need for the selection of patients with differentiated thyroid cancer who experience an unfavorable outcome.
  
  
  METHODS
  Between 1980 and 1997, 406 patients underwent thyroidectomy, elective neck dissection if necessary, and radioiodine treatment and/or external beam radiotherapy according to different histologies and TNM stages. Long-term results were analyzed under the comparison of 5 classification systems (TNM, EORTC, AMES, MACIS, and NTCTCSR) to make a selection of patients with high risk and therefore to plead for aggressive treatment.
  
  
  RESULTS
  For 309 TNM stage I-II patients, selected in the low-risk group (LRG), a 20-year cancer-specific survival (CSS) of 96-99% was recorded. A lower CSS of 60-79% was observed for 97 cases (TNM stage III-IV) selected as the high-risk group (HRG) (p = 0.05). The persistence rate for the LRG was 0.9%, compared to 26% for the HRG. The salvage rate after recurrence in the LRG was also significantly higher (84%) than in the HRG (26%) (p = 0.003). The lowest ratio of death rates was scored for AMES (HRG:LRG = 1.2:1), and it is becoming even inverted for papillary cancer (1:2). A higher ratio of death rates (2.6:1) was scored for MACIS and an even higher ratio for EORTC and NTCTCSR (HRG and LRG both 6:1). An analysis of the correlation based on the parameter of cancer-specific mortality reveals that all systems except AMES correlate well with R2 = 0.97-1.0.
  
  
  CONCLUSIONS
  The best validation for our patient cohort was found for classification criteria announced by EORTC, NTCTCSR and TNM, and they might be useful for optimization of the treatment.
authors.affiliation: Radiotherapy Department, University Hospital Queen Giovanna, Faculty of Medicine, Sofia, Bulgaria. rad@cserv.mgu.bg
authors.forename: T
authors.initials: T
authors.lastname: Hadjieva
mesh_terms: D018263:Adenocarcinoma, Follicular / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery; D000328:Adult; D000368:Aged; D002291:Carcinoma, Papillary / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery; D015331:Cohort Studies; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D037981:Neck Dissection; D009367:Neoplasm Staging; D011379:Prognosis; D011446:Prospective Studies; D018714:Radiotherapy, Adjuvant; D018570:Risk Assessment; D016019:Survival Analysis; D013964:Thyroid Neoplasms / Q000401:mortality* / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery; D013965:Thyroidectomy
chemical_list: D007457:Iodine Radioisotopes