Table 3. Correlation between DNMT1 expression and clinicopathological factors of ccRCC.

Parameter	n	DNMT1 expression		P value
		Negative	Positive
Gender
Female	35	16	19	0.772
Male	54	23	31
Age at diagnosis
≤55	50	21	29	0.695
>55	39	18	21
Tumor size
≤4	15	10	5	0.04
>4	74	28	46
Tumor pathology stage
pT1-pT2	67	34	33	0.022
pT3-pT4	22	5	17
Grading
G1	23	16	7	0.004
G2	30	15	15
G3	24	5	19
G4	12	3	9
Lymph node metastasis
pNx	26	8	18	0.029
pN0	50	28	22
pN1/2	13	3	10
Vascular invasion
No	80	38	42	0.037
Yes	9	1	8
Tobacco smoking
No	32	16	16	0.379
yes	57	23	34

ccRCC, clear cell renal cell carcinoma; DNMT1, DNA methyltransferase 1.