Abstract
The incidence of thyroid cancer in females is significantly higher than that in males; however, females are more likely to have more favorable outcomes. We aimed to determine the characteristics of differentiated thyroid carcinoma (DTC) subtypes in males and females, and to compare their clinical behavior and survival. A total of 68,337 cases were recruited from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) Program. The disease-specific survival (DSS) of follicular variant papillary thyroid carcinoma (FVPTC) and follicular thyroid carcinoma (FTC) were similar to that of classical variant papillary thyroid carcinoma (CPTC) in male patients (FVPTC vs. CPTC, adjusted hazard ratio (aHR) = 0.947, P = 0.776; FTC vs. CPTC, aHR = 1.512, P = 0.104). In premenopausal female (< 55 years old), FVPTC had better DSS than CPTC (aHR = 0.321, P = 0.038) while FTC had worse DSS than CPTC (aHR = 3.272, P = 0.013); in postmenopausal female, FTC had poorer prognosis than CPTC (aHR = 2.145, P = 0.002), no statistical difference was found between CPTC and FVPTC (aHR = 0.724, P = 0.087). For patients younger than 55 years, women had significantly better DSS compared with men with CPTC (aHR = 0.376, P < 0.001) and FVPTC (aHR = 0.102, P < 0.001). However, no difference was observed in patients older than 55 years. Interestingly, outcomes of FTC were not affected by gender in patients of all ages. These results suggested that different clinical behaviors and outcomes of DTC subtypes should be considered in patients with different genders.