Age Increased Cancer-specific Mortality Risk of Thyroid Cancer With Lung Metastasis

Abstract Background: To investigate the relationship between age and cancer-specific mortality in thyroid cancer (TC) with lung-metastasis.Methods: 1,418 patients with initial distant metastases from Surveillance, Epidemiology and End Results databases were investigated. Patients with median follow-up time of 8 months [interquartile range (IQR), 2–27] and median age of 66 years (IQR, 55-76) were divided into five groups by age and the association between age and TC-specific mortality was analyzed.Results: The TC-specific mortality rates were 32.78% (118/360), 46.71% (156/334), 53.93% (199/369), 58.96% (158/268) and 82.76% (72/87) for patients with age of ≤55 years,56-65 years, 66-75 years, 76-85 years and >85 years. Kaplan-Meier curves showed that TC-specific mortality rate was associated with increased age (p < 0.001). Compared with patients ≤55 years, patients of 56-65 years, 66-75 years, 76-85 years and >85 years had significantly higher hazard ratios (HRs) of 1.69(1.26-2.26), 1.97 (1.47-2.64), 2.18(1.59-2.99) and 3.24(2.08-5.06) after adjustments for gender, tumor size and radiation therapy (all p < 0.001).In TC with initial lung-metastasis, compared with patients ≤55 years, patients of 56-65 years, 66-75 years, 76-85 years and >85 years had significantly higher adjusted HRs of 1.68(1.20-2.36, p=0.003), 2.18(1.57-3.02), 2.16(1.51-3.08) and 2.91(1.79-4.75) (p < 0.001). Similar results could be obtained in papillary thyroid cancer.Conclusions: The TC-specific mortality increased with age in TC patients with initial lung-metastasis, which suggested that further risk stratification based on age was necessary for TC over 55 years with lung-metastasis. Individual treatment strategy maybe recommended for patients over 85 years.