Fig. 1

Kaplan–Meier recurrence-free survival curves showing a significantly lower time to recurrences in patients with T4 (mean RFSs were 60.8 vs 74.4 months, Log-Rank test P = 0.022, panel A), positive cervical lymph nodes (Mean RFSs were 53.9 vs 78.3 months, Log-Rank test P < 0.001, Panel B), positive lympho-vascular invasion (Mean RFSs were 52.3 vs 74.9 months, Log-Rank test P = 0.015, Panel C), and older age more than 65 years (Mean RFSs were 54.9 vs 74.8 months, Log-Rank test P = 0.001, Panel D)