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

Abstract

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. 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. 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. 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.