Table 4.

Detection of HPV, p16, and EBV in Pathology Specimens.

	No. of Patients (%) with Positive Results			P value†
	All* (n = 30)	WHO Type I (n = 8)	WHO Type II/III (n = 22)
HPV type 16 by PCR
E6 positive	13/28 (46.4)	4/6 (66.7)	9/22 (40.9)	.372
E7 positive	15/28 (53.6)	5/6 (83.3)	10/22 (45.5)	.173
Both E6 & E7 positive	12/28 (42.9)	4/6 (66.7)	8/22 (36.4)	.354
HPV type 18 by PCR
E6 positive	0 (0)	0 (0)	0 (0)	1.0
E7 positive	0 (0)	0 (0)	0 (0)	1.0
Both E6 & E7 positive	0 (0)	0 (0)	0 (0)	1.0
HPV positive by ISH‡	5/28 (17.9)	4/8 (50.0)	1/20 (5.0)	.015
p16 positive by IHC	25/28 (89.3)	7/8 (87.5)	18/20 (90.0)	1.0
HPV positive by PCR & ISH‡ and p16 positive	4/26 (15.4)	3/6 (50.0)	1/20 (5.0)	.028
EBV positive by ISH	14/28 (50.0)	2/8 (25.0)	12/20 (60.0)	.209

PCR = polymerase chain reaction, ISH = in situ hybridization, and IHC = immunohistochemistry.

^*PCR was not successful for 2 WHO-I cases and ISH was not successful for 2 WHO-II/III cases.

^†Fisher's exact test comparing WHO type I to WHO type II/III.

^‡ISH probe detects high-risk HPV types (16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, & 66).