Table 1 Study subjects.

	No (%)
HNSCC and leukoplakia samples (n = 120)
Male	101 (84.2)
Female	19 (15.8)
Mean age (SD) (y)	46.94 (8.42)
Lymph node positive	46 ( 38.3)
Lymph node negative	60 ( 50)
Unknown	14 (11.6)
Tobacco user	82 ( 68.3)
Tobacco free	22 ( 18.3)
Unknown	16 (13.3)
HNSCC (n = 92)
Oral cavity and oropharyngeal tumours (n = 55)
Buccal mucosa	23 (25.0)
Tongue	19 (20.7)
Cheek	6 (6.5)
Lip	3 (3.3)
Oropharynx	2 (2.2)
Tonsil	1 (1.1)
Palate	1 (1.1)
Laryngeal tumours (n = 12)
Larynx	9 (9.8)
Neck	3 (3.3)
Orofacial tumours (n = 20)
Maxilla	13 (14.1)
Mandible	7 (7.6)
Unknown (n = 5)	5 (5.4)
Histopathology (n = 92)
Stage I	5 (5.4)
Stage II	25 (27.2)
Stage III	34 (37.0)
Stage IV	22 (23.9)
Unknown	6 (6.5)
Leukoplakia (n = 28)
Leukoplakia site (n = 28 )
Buccal mucosa	28 (100.0)
Histopathological stage (n = 28)
Mild dysplasia	3 (10.71)
Moderate dysplasia	12 (42.85)
Severe dysplasia	13 (46.43)

HNSCC, head and neck squamous cell carcinoma.