Human papillomavirus in upper digestive tract tumors from three countries

Table 6 Clinicopathological features of oral and esophageal carcinomas n (%)

Cancer site	Pathological features	HPV-negative	HPV-positive	1P value
Oral cavity	2Histological grading
	Well-differentiated	17 (81)	20 (77)	0.899
	Moderate differentiation	3 (14)	5 (19)
	Poor differentiation	1 (5)	1 (4)
	3p53
	Positive	13 (45)	16 (48)	0.773
	Negative	16 (55)	17 (52)
	4p16INK4a
	Positive	11 (38)	10 (29)	0.427
	Negative	18 (62)	25 (71)
Esophagus	2Histological grading
	Well-differentiated	42 (31)	10 (32)	0.831
	Moderate differentiation	64 (48)	16 (52)
	Poor differentiation	28 (21)	5 (16)
	3p53
	Positive	59 (44)	11 (35)	0.368
	Negative	74 (56)	20 (65)
	4p16INK4a
	Positive	42 (33)	16 (53)	0.036
	Negative	86 (67)	14 (47)

¹P values were obtained by χ² test.

²Information of histological grading was missing for 10 human papillomavirus (HPV)-negative and 14 HPV-positive oral carcinomas (OCs), and two HPV-negative esophageal carcinomas (ECs). ³Tissue specimens were not enough to examine p53 expression in two HPV-negative and seven HPV-positive OCs, and two HPV-negative ECs. ⁴Tissue specimens were not enough to examine p16^INK4a expression in two HPV-negative and five HPV-positive OCs, and seven HPV-negative and one HPV-positive ECs.