a strong trendP = 0.095
Evaluation of multivariate analysis when stratifying by histologic subtype revealed that among KSCC patients, the CCI score appeared to be associated with worse OS, with patients with a CCI score of 1 displaying a strong trend to worse OS (HR: 1.253; 95% CI: 0.962–1.633; P = 0.095), and those with a CCI score of 2 displaying a statistically significant association with worse OS (HR: 1.848; 95% CI: 1.199–2.849; P = 0.005) when compared to patients without comorbidity.