p16, Cyclin D1, and HIF-1α Predict Outcomes of Patients with Oropharyngeal Squamous Cell Carcinoma Treated with Definitive Intensity-Modulated Radiation Therapy

Table 2

Patient demographics.

Overall	p16 negative	p16 positive	𝑃 value
𝑛	106	36	70
Mean age (years)	58.1	59.2	57.5	0.461^*
Median followup (months)	27.2	26.9	37.2
Gender
Male	83 (78.3%)	25 (69.4%)	58 (82.9%)	0.113^†
Female	23 (21.7%)	11 (30.6%)	12 (17.1%)
Received chemotherapy (%)	65 (61.3%)	18 (50.0%)	47 (67.1%)	0.086^†
Habits (%)
Tobacco use	83 (78.3%)	35 (97.2%)	48 (68.6%)	0.000^††
Alcohol use	68 (64.2%)	29 (80.6%)	39 (55.7%)	0.011^†
Primary site (%)				0.002^††
Tonsil	58 (54.7%)	20 (55.6%)	38 (54.3%)
Base of tongue	41 (38.7%)	10 (27.8%)	31 (44.3%)
Soft palate	6 (5.7%)	6 (16.7%)	0 (0.0%)
Pharyngeal wall	1 (0.9%)	0 (0.0%)	1 (1.4%)
Primary tumor classification				0.467^††
T1	29 (27.4%)	9 (25.0%)	20 (28.6%)
T2	52 (49.1%)	16 (44.4%)	36 (51.4%)
T3	12 (11.3%)	4 (11.1%)	8 (11.4%)
T4	13 (12.3%)	7 (19.4%)	6 (5.6%)
Lymph node classification				0.393^††
N0	14 (13.2%)	7 (19.4%)	7 (10.0%)
N1	21 (19.8%)	8 (22.2%)	13 (18.6%)
N2a	9 (8.5%)	1 (2.8%)	8 (11.4%)
N2b	40 (37.7%)	15 (41.7%)	25 (35.7%)
N2c	18 (17.0%)	4 (11.1%)	14 (20.0%)
N3	4 (3.8%)	1 (2.8%)	3 (4.3%)
Stage group				0.711^††
I	0 (0.0%)	0 (0.0%)	0 (0.0%)
II	10 (9.4%)	5 (13.9%)	5 (7.1%)
III	23 (21.7%)	7 (19.4%)	16 (22.9%)
IVA	69 (65.1%)	23 (63.9%)	46 (65.7%)
IVB	4 (3.8%)	1 (2.8%)	3 (4.3%)
IVC	0 (0.0%)	0 (0.0%)	0 (0.0%)
Histology				0.007^††
Well differentiated	5 (4.7%)	2 (5.6%)	3 (4.3%)
Moderately differentiated	33 (31.1%)	15 (41.7%)	18 (25.7%)
Poorly differentiated	29 (27.4%)	12 (33.3%)	17 (24.3%)
Not otherwise specified	9 (8.5%)	5 (13.9%)	4 (5.7%)
Basaloid	26 (24.5%)	2 (5.6%)	24 (34.3%)
Lymphoepithelioma	1 (0.9%)	0 (0.0%)	1 (1.4%)
Papillary	3 (2.8%)	0 (0.0%)	3 (4.3%)

^*𝑡-test.
^†Chi-square test.
^††Fisher’s exact test.