Patients with delayed surgery (C3) showed a non-significant trend toward increased risk (HR 5.05; 95% CI 0.53–48.6; p = 0.161), and those who did not undergo indicated surgery (C4) demonstrated borderline significance (HR 7.27; 95% CI 0.92–57.5; p = 0.060).
The wide confidence intervals reflect the small number of events in the G1 category (only one death among 11 G1 patients, resulting in 9% mortality); this limits statistical power but nevertheless demonstrates a clear trend.
Tumor-related factors: Tumor ulceration and necrosis showed a trend toward worse survival but did not reach statistical significance (HR = 0.52 for absence vs. presence; 95% CI: 0.23–1.16 and p = 0.112).