ABSTRACT
Objective:To study whether male was the risk factor for prognosis of patients with differentiated thyroid cancer (DTC) after 131I treatment based on propensity score matching (PSM) method. Methods:From April 2016 to January 2021, 1 677 patients (age: 11-84 (43.9±12.5) years) with DTC who underwent total thyroidectomy and received 131I treatment in Tianjin Medical University General Hospital were retrospectively enrolled and patients were divided into male group ( n=546) and female group ( n=1 131). The evaluation results of patients were divided into excellent response (ER), indeterminate response (IDR), biochemical incomplete response (BIR) and structural incomplete response (SIR). Among them, ER and IDR were divided into good prognosis group, and BIR and SIR were divided into poor prognosis group. The PSM method was adopted to process all data to reduce the influence of data bias and confounding variables. χ2 test was used for data analysis. Multivariate logistic regression was used to analyze the risk factors affecting prognosis, and ROC curve was used to analyze the relationship between stimulated thyroglobulin (sTg) level and poor prognosis. Results:Before PSM, the proportion of male patients with poor prognosis was significantly higher than that of female patients (21.2%(116/546) vs 14.0%(158/1 131); χ2=17.53, P=0.001). After PSM, there was no difference in the proportion of poor prognosis between male and female groups (19.9%(107/537) vs 15.6%(84/537); χ2=5.43, P=0.143). Multivariate logistic regression analysis showed that male (odds radio ( OR)=1.439 (95% CI: 1.016-2.038), P=0.040), high T stage(T3+ T4 stage)( OR=1.816 (95% CI: 1.273-2.590), P=0.001), N1b stage ( OR=1.766 (95% CI: 1.233-2.530), P=0.002), M1 stage ( OR=9.833 (95% CI: 3.190-30.309), P<0.001) and sTg level ( OR=1.035 (95% CI: 1.029-1.042), P<0.001) were risk factors for poor prognosis before PSM, while high T stage (T3+ T4 stage)( OR=1.870 (95% CI: 1.212-2.886), P=0.005), M1 stage ( OR=8.993 (95% CI: 2.434-33.225), P=0.001), sTg level ( OR=1.040 (95% CI: 1.030-1.049), P<0.001) were still risk factors, and N1b stage ( OR=1.459 (95% CI: 0.938-2.270), P=0.094), male ( OR=1.383 (95% CI: 0.912-2.096), P=0.127) were no longer risk factors for poor prognosis after PSM. ROC curve analysis showed that the cut-off value of sTg was 10.25 μg/L, with the sensitivity of 81.0%(222/274) and the specificity of 84.2%(1 181/1 403). Conclusions:After reduction of selection bias by PSM, male is no longer a risk factor for prognosis after 131I treatment of DTC. In addition, high T stage(T3+ T4 stage), M1 stage and sTg≥10.25 μg/L were risk factors for poor prognosis.