Table 1. Clinicopathologic characteristics and SMAD4 expression of patients with OL.

		Oral leukoplakia
	No. of Patient	MT(%)	UT(%)	p value
All patients	88	22 (25.0)	66 (75.0)
Age (years)
≤55	47	11 (23.4)	36 (76.6)	0.711
>55	41	11 (26.8)	30 (73.2)
Sex
Male	37	6 (16.2)	31 (83.8)	0.105
Female	51	16 (31.4)	35 (68.6)
Grade of dysplasia
High	22	9 (40.9)	13 (59.1)	0.047
Low-moderate	66	13 (19.7)	53 (80.3)
Lesion site
Nontongue	31	9 (29.0)	22 (71.0)	0.519
Tongue	57	13 (22.8)	44 (77.2)
Smoking
Never	64	19 (29.7)	45 (70.3)	0.214
Past and present	16	2 (12.5)	14 (87.5)
Unknown	8
Alcohol intake
Never	64	18 (28.1)	46 (71.9)	0.538
Past and present	17	3 (17.6)	14 (82.4)
Unknown	7
SMAD4 expression
Strong	43	17 (39.5)	26 (60.5)	0.002
Weak	45	5 (11.1)	40 (88.9)

Abbreviations: MT, malignant-transformed oral leukoplakia; UT: untransformed oral leukoplakia.

Bold indicates values that are statistically significant (p<0.05).