Table 4.

p16^INK4a levels by immunohistochemistry among HPV positive and negative HNSCC

	HPV DNA positive			HPV DNA negative
	p16 neg	p16 low	p16 high	p16 neg	p16 low	p16 high
	n (%)	n (%)	n (%)	n (%)	n (%)	n (%)
FCMSCSP
total	14 (70.0)	3 (15.0)	3 (15.0)	49 (66.2)	22 (29.7)	3 (4.1)
oral cavity	4 (100.0)	0 (0)	0 (0)	9 (56.3)	7 (43.7)	0 (0)
oropharynx	0 (0)	0 (0)	1 (100.0)	5 (55.6)	3 (33.3)	1 (11.1)
larynx	5 (62.5)	1 (12.5)	2 (25.0)	35 (71.4)	12 (24.5)	2 (4.1)
ICESP
total	14 (66.7)	2 (9.5)	5 (23.8)	60 (91.0)	5 (7.5)	1 (1.5)
oral cavity	13 (76.4)	2 (11.8)	2 (11.8)	42 (89.3)	4 (8.5)	1 (2.2)
oropharynx	1 (33.3)	0 (0)	2 (66.7)	12 (92.3)	1 (7.7)	0 (0)
larynx	0 (0)	0 (0)	1 (100.0)	6 (100.0)	0 (0)	0 (0)

FCMSCSP-Santa Casa de Sao Paulo, School of Medicine; ICESP-Cancer Institute of São Paulo