Long-term outcomes for older patients with papillary thyroid carcinoma: should another age cutoff beyond 45 years be added?

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.