Fig. 1
a and b (left to right): Kaplan Meier curves demonstrating probability of overall survival of patients with HPV associated oropharyngeal cancer according to a 7th Edition TNM staging system with no significant difference between any stage groups and b 8th Edition TNM staging system with a statistically significant difference between stage I and II (p < 0.0001), but not between stages II and III. The 5 year probability of overall survival was 96.9% for stage I, 77.1% for stage II and 60.3% for stage III