title: Long-term outcomes for older patients with papillary thyroid carcinoma: should another age cutoff beyond 45 years be added?
abstract: BACKGROUND
  Although an age cutoff of 45 years has often been adopted to stratify cancer risk in papillary thyroid carcinoma (PTC), both cancer-specific survival (CSS) and disease-specific survival (DFS) continue to worsen beyond this cutoff. This study aimed to determine whether advanced age (i.e., >60 years) at diagnosis was an independent predictor of CSS and DFS in older (≥45 years) patients.
  
  
  METHODS
  This study analyzed 407 PTC patients with a minimal follow-up period of 7 years. Standard protocol was followed. Both CSS and DFS were estimated using the Kaplan-Meier method and compared with the log-rank test. Variables shown to be significant by the log-rank test were entered into the Cox regression analysis.
  
  
  RESULTS
  During a median follow-up period of 15.1 years, 51 patients (12.5 %) died of PTC, whereas 80 (20.5 %) experienced at least one recurrence. For CSS, age beyond 60 years (hazard ratio [HR], 3.027; 95 % confidence interval [CI] 1.369-6.690; p = 0.006), tumor size greater than 4 cm (HR 2.043; 95 % CI 1.141-4.255; p = 0.049), central nodal metastases (HR 2.726; 95 % CI 1.198-6.200; p = 0.017), lateral nodal metastases (HR 5.247; 95 % CI 2.987-9.216; p < 0.001), and distant metastases (HR 4.297; 95 % CI 1.726-2.506; p = 0.002) were independent predictors. For DFS, only tumor size greater than 4 cm (HR 1.733; 95 % CI 1.030-3.058; p = 0.049), central nodal metastases (HR 2.362; 95 % CI 1.010-5.523; p = 0.047), and lateral nodal metastases (HR 4.383; 95 % CI 2.388-8.042; p < 0.001) were independent predictors.
  
  
  CONCLUSIONS
  Advanced age was an independent predictor of CSS, and cancer-related death risk showed a continuing increase beyond the age of 60 years. However, advanced age was not an independent predictor of DFS. Therefore, having another age cutoff appears justifiable for stratifying risk of cancer-related death but less justifiable for disease recurrence. Tumor size as well as central and lateral nodal metastases independently predicted CSS and DFS.
authors.affiliation: Department of Surgery, The University of Hong Kong, Hong Kong, Hong Kong SAR, China, blang@hku.hk.
authors.forename: Brian Hung-Hin
authors.initials: BH
authors.lastname: Lang
authors.forename: Chung-Yau
authors.initials: CY
authors.lastname: Lo
authors.forename: Kai Pun
authors.initials: KP
authors.lastname: Wong
authors.forename: Koon Yat
authors.initials: KY
authors.lastname: Wan
mesh_terms: D000367:Age Factors; D002291:Carcinoma, Papillary / Q000401:mortality* / Q000473:pathology; D005260:Female; D006801:Humans; D008875:Middle Aged; D015999:Multivariate Analysis; D016019:Survival Analysis; D013964:Thyroid Neoplasms / Q000401:mortality* / Q000473:pathology