Table 4. Major changes from the seventh to the eighth editions of TNM [12].

Edition of TNM	Main characteristics
7Th edition	1-presence of T0 and Tis
	2-no emphasis on extra-capsular extension
	3-division of T4 into a and b
	4-stage IV for disease T4, N2, N3 and M1
	5-number of metastatic lymph nodes differed from N2a to N2b
8Th edition	1-absence of T0 in negative p16 and absence of Tis for positive p16
	2-creation of extra-capsular extension (N3b) only for 16 negatives
	3-absence of T4b for positive p16
	4-stage IV only for M1 disease in positive p16 5-without distinction of number of lymph nodes in positive p16