title: Survival Analysis of Papillary Thyroid Carcinoma in Relation to Stage and Recurrence Risk: A 20-Year Experience in Pakistan.
abstract: OBJECTIVE
  The aim of this study was to evaluate the overall and progression-free survival of papillary thyroid carcinoma (PTC), comparing the American Thyroid Association (ATA) guideline for risk of recurrence with the TNM staging system with dynamic assessment at 2 years.
  
  
  METHODS
  This study is a retrospective analysis of 689 PTC patients over a 20-year period at a single center. Disease-free survival based on the TNM staging and ATA recurrence risk was calculated using Kaplan-Meier curves. Dynamic response assessment during the first 2 years was compared for both systems. Survival was calculated based on age, baseline resectability, and postthyroidectomy serum tumor marker levels.
  
  
  RESULTS
  Six hundred eighty-nine (72.2%) of the total thyroid cancer patients had PTC. Four hundred sixty-nine patients were females, and 220 patients were males. The age range was 6 to 87 years. Five hundred thirty-five patients were resectable, and 56 patients were unresectable. One hundred fifty-one patients were excluded due to insufficient information on recurrence risk. By ATA categorization, 39% had low risk, no disease-related mortality; 44% had intermediate risk, 3 died; and 17% had high risk, 32 died. The 5-year disease-free survival was 54%, 26%, and 5% in low-, intermediate-, and high-risk groups, respectively. The log-rank test showed a significant difference in the percent survival (P < 0.01). TNM stage wise, in terms of survival, 1.3% in stage I, 2.2% in stage II, 0% in stage III, and 37.5% in stage IV died. The 20-year disease-free survival showed the following: stage I, 43%; stage II, 28%; stage III, 18%; and stage IV, 2%. There is significant difference in survival rate (P < 0.01). Both ATA risk classification and TNM staging were significant predictors of disease-free survival. On bivariate analysis, ATA classification (hazards ratio, 2.1; 95% confidence interval, 1.64-2.67; P = 0.001) was better predictive of overall survival versus TNM classification (hazards ratio, 1.3; 95% confidence interval, 1.11-1.43; P = 0.063).
  
  
  CONCLUSIONS
  The ATA risk stratification and continuous reassessment during the first 2 years predicts disease-free survival better than the TNM staging. Age older than 45 years, unresectable disease, and elevated postthyroidectomy thyroglobulin levels dictate a poorer prognosis.
authors.affiliation: From the Departments of *Nuclear Medicine, and †Surgery, Shaukat Khanum Memorial Cancer Hospital and Research Centre, Lahore, Pakistan.
authors.forename: Aamna
authors.initials: A
authors.lastname: Hassan
authors.forename: Mairah
authors.initials: M
authors.lastname: Razi
authors.forename: Saima
authors.initials: S
authors.lastname: Riaz
authors.forename: Madeeha
authors.initials: M
authors.lastname: Khalid
authors.forename: M Khalid
authors.initials: MK
authors.lastname: Nawaz
authors.forename: Aamir Ali
authors.initials: AA
authors.lastname: Syed
authors.forename: Humayun
authors.initials: H
authors.lastname: Bashir
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001323:Autoantibodies / Q000097:blood; D002277:Carcinoma / Q000097:blood / Q000401:mortality* / Q000473:pathology; D002291:Carcinoma, Papillary; D002648:Child; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000401:mortality* / Q000473:pathology; D009367:Neoplasm Staging; D010154:Pakistan; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012306:Risk; D016019:Survival Analysis; D015996:Survival Rate; D013954:Thyroglobulin / Q000097:blood; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000097:blood / Q000401:mortality* / Q000473:pathology; D055815:Young Adult
chemical_list: D001323:Autoantibodies; C006606:anti-thyroglobulin; D013954:Thyroglobulin