Association of p53/p21 expression with cigarette smoking and prognosis in esophageal squamous cell carcinoma patients

Table 1 Distribution of the demographic variables for esophageal squamous cell carcinoma cases and healthy subjects n (%)

	Case	Control	P value1
Age (yr)
< 60	36 (45)	27 (33.8)	NS
≥ 60	44 (55)	53 (66.2)
Gender
Male	45 (56.2)	48 (60)	NS
Female	35 (43.8)	32 (40)
Smoking
Never	52 (65)	28 (35)	0.03
Ever	64 (80)	16 (20)
Opium use
Ever	21 (26.2)	18 (22.5)	NS
Never	59 (73.8)	62 (77.5)
p53 expression
Positive	45 (56.2)	0 (0)	< 0.001
Negative	35 (43.8)	80 (100)
p21 expression
Positive	59 (73.8)	37 (46.2)	< 0.001
Negative	21 (26.2)	43 (53.8)

¹Not statistically significant by χ² test. NS: Not significant.

Table 2 Correlation between p53 and p21 expression in esophageal squamous cell carcinoma cases n (%)

p53 expression	p21 expression			Total number
	Negative (< 10%)	Positive
		Low-expression (10%-49%)	Over-expression (≥ 50%)
Negative (< 5%)	10/80 (12.5)	15/80 (18.7)	9/80 (11.2)	34
Positive
Low-expression (5%-49%)	7/80 (8.75)	7/80 (13.6)	9/80 (11.2)	23
Over-expression (≥ 50%)	4/80 (5)	7/80 (13.6)	12/80 (15)
Total number	21	29	30	80

There was no significant association between p53 and p21 expression among esophageal squamous cell carcinoma cases.

Table 3 Correlation between clinicopathological parameters and p53 and p21 over-expression in esophageal squamous cell carcinoma patients n (%)

	Number	p53 over-expression			p21 over-expression
		Yes	No	P value	Yes	No	P value1
Age (yr)
< 60	36	10 (27.8)	26 (72.2)	NS	14 (38.9)	22 (61.1)	NS
≥ 60	44	13 (29.5)	31 (70.5)		16 (36.4)	28 (63.6)
Gender
Male	45	15 (33.3)	30 (66.7)	NS	20 (44.4)	25 (55.6)	NS
Female	35	8 (22.9)	27 (77.1)		10 (28.6)	25 (71.4)
Smoking
Ever-user	28	13 (46.4)	15 (53.6)	0.01	14 (50)	14 (50)	0.09
Never-user	52	10 (19.2)	42 (80.8)		16 (30.8)	36 (69.2)
Differentiation
Well	46	12 (26.1)	34 (73.9)		20 (43.5)	26 (56.5)
Moderate	23	8 (34.8)	15 (65.2)		6 (26.1)	17 (73.9)	NS
Poor	11	3 (27.3)	8 (72.7)	NS	4 (36.4)	7 (63.6)
Tumor site
Middle	59	19 (32.2)	40 (67.8)	NS	26 (44.1)	33 (55.9)	NS
Lower	20	4 (20)	16 (80)		4 (20)	16 (80)
Size of tumor (cm)
< 3	23	8 (34.8)	15 (65.2)		5 (21.7)	18 (78.3)	0.07
≥ 3	53	15 (28.3)	38 (71.7)	NS	23 (43.4)	30 (56.6)
Operability
Operable	45	12 (26.7)	33 (73.3)	NS	17 (37.8)	28 (62.2)	NS
Inoperable	35	11 (31.4)	24 (68.6)		13 (37.1)	22 (62.9)

¹Not statistically significant by χ² test. NS: Not significant.

Table 4 Log-rank and proportional hazard regression analysis (Cox method) for clinicopathological parameters in esophageal squamous cell carcinoma patients

	Mean survival time (mo)	Log rank P value	Cox-regression
			HR	95% CI	P value1
Operability
Operable	12.68 ± 2.56	0.001	2.27	1.30-3.97	0.004
Inoperable	7.08 ± 1.72
p21 over-expression
Yes	7.41 ± 1.78	0.009	1.82	1.02-3.25	0.04
No	11.71 ± 2.36
p53 over-expression
Yes	8.00 ± 2.06	0.30	1.23	0.67-2.26	NS
No	10.69 ± 2.08
Tumor size (cm)
< 3	12.58 ± 3.28	0.06	1.75	0.92-3.32	0.08
≥ 3	9.43 ± 2.18
Age (yr)
< 60	12.61 ± 2.46	0.006	2.30	1.29-4.09	0.005
≥ 60	8.40 ± 2.14

¹Not statistically significant by χ² test. NS: Not significant; HR: Hazard ratio; CI: Confidence interval.