Comparison of disease-specific survival (DSS) by patient age, primary tumor size, and lymph node involvement. (A) Comparing patients <50 and >50 years of age (hazard ratio [HR], 2.91; 95% confidence interval [CI], 1.14–7.40*; p = .03). (B) Comparing patients with and without lymph node involvement (HR, 2.43; 95% CI, 1.35–4.39*; p = .003). (C) Comparing patients with tumor size of <3 cm and >3 cm (HR, 1.86; 95% CI, 1.05–3.30*; p = .03). (D) Comparing tumor size of <3 cm and >3 cm among patients with lymph node involvement (HR, 2.15; 95% CI, 1.08–4.30*; p = .03). *HR calculated based on Cox regression model after adjusting for age, sex, race, cancer site, and treatment type. [Color figure can be viewed in the online issue, which is available at wileyonlinelibrary.com.]