Screening of prognosis-related clinical characteristics by Kaplan-Meier analysis. (A) Kaplan-Meier curves based on different age groups, where Q1, Q2, Q3, and Q4 represent quartiles. (B) Kaplan-Meier curves based on gender. (C) Kaplan-Meier curves based on different N stages. (D) Kaplan-Meier curves based on different M stages. (E) Kaplan-Meier curves based on new events. (F) Kaplan-Meier curves based on different tumor stages.