Younger patients with stage II differentiated thyroid cancer at robustly high risk of mortality

The mortality risk of stage II differentiated thyroid cancer (DTC) is significantly higher in younger patients (aged <45/55 years) and similar to stage III/IVA disease, a study has shown.

The authors performed a retrospective study of DTC in the US Surveillance, Epidemiology and End Results programme for disease-specific mortality risk in different American Joint Committee on Cancer (AJCC) stages, with patient age stratification of stage II disease.

With AJCC staging system 6.0, hazard ratios (HRs) of mortality for stage II DTC in patients aged <45 years and those aged ≥45 years were 46.95 and 4.95, respectively, while the corresponding HRs for stages III, IVA, IVB and IVC compared with stage I were 9.82, 57.37, 222.10 and 468.68. This demonstrated a robustly higher mortality risk in stage II DTC in those aged <45 years vs older patients (p<0.001), comparable with stage IVA (p=0.482).

Results were similar when using AJCC 7.0.

With AJCC 8.0, HRs of mortality for stage II disease in patients aged <55 years and those aged ≥55 years were 75.16 and 11.23, respectively, while the corresponding HRs for stages III, IVA and IVA compared with stage I were 69.45, 134.94 and 235.70. Mortality risk was robustly higher in stage II disease in those aged <55 years vs older patients (p<0.001), comparable with stage III (p=0.57).

A sharp decline was shown in Kaplan-Meier survival curves with stage II disease in patients aged <45/55 years compared with older patients.

“This emphasizes the importance of considering age when managing stage II DTC and not treating it as a uniformly low-risk disease,” the authors said.