Evaluation of clinical significance of claudin 7 and construction of prognostic grading system for stage II colorectal cancer

Table 1 Clinicopathological features of the patients with stage II colorectal cancer, n (%)

Variable	No. of patients
Age in yr
Median (range)	60 (30-79)
≤ 60	124 (53.7)
> 60	107 (46.3)
Gender
Male	140 (60.6)
Female	91 (39.4)
CEA level
Negative	119 (51.5)
Positive	54 (23.4)
Unknown	58 (25.1)
Tumor location
Colon	130 (56.3)
Rectum	101 (43.7)
Tumor differentiation
Well/moderate	209 (90.5)
Poor	22 (9.5)
T stage
T3	189 (81.8)
T4	42 (18.2)
Lymphovascular invasion
Negative	200 (86.6)
Positive	31 (13.4)
Perineural invasion
Negative	191 (82.7)
Positive	40 (17.3)
Postoperative chemotherapy
No	147 (63.6)
Yes	84 (36.4)
Recurrence
No	204 (88.3)
Yes	27 (11.7)

CEA: Carcinoembryonic antigen.

Table 2 Relationship between the expression of claudin 7 and clinicopathological features, n (%)

Variable	No. of patients	Claudin 7 expression		P value
		High	Low
Age in yr
≤ 60	124	97 (78.2)	27 (21.8)	0.158
> 60	107	75 (70.1)	32 (29.9)
Gender
Male	140	99 (70.7)	41 (29.3)	0.106
Female	91	73 (80.2)	18 (19.8)
CEA level
Negative	119	91 (76.5)	28 (23.5)	0.708
Positive	54	40 (74.1)	14 (25.9)
Unknown	58	41 (70.7)	17 (29.3)
Tumor location
Colon	130	96 (73.8)	34 (26.2)	0.809
Rectum	101	76 (75.2)	25 (24.8)
Tumor differentiation
Well/moderate	209	159 (76.1)	50 (23.9)	0.082
Poor	22	13 (59.1)	9 (40.9)
T stage
T3	189	143 (75.7)	46 (24.3)	0.374
T4	42	29 (69.0)	13 (31.0)
Lymphovascular invasion
Negative	200	150 (75.0)	50 (25.0)	0.632
Positive	31	22 (71.0)	9 (29.0)
Perineural invasion
Negative	191	144 (75.4)	47 (24.6)	0.477
Positive	40	28 (70.0)	12 (30.0)
Recurrence
No	204	157 (77.0)	47 (23.0)	0.017
Yes	27	15 (55.6)	12 (44.4)

CEA: Carcinoembryonic antigen.

Table 3 Univariate and multivariate prognostic analyses of patients with stage II colorectal cancer

Variable	Univariable analysis		Multivariate analysis
	HR (95%CI)	P value	HR (95%CI)	P value
Age in yr
≤ 60	Reference
> 60	1.310 (0.616-2.788)	0.483
Gender
Male	Reference
Female	0.903 (0.413-1.971)	0.797
CEA level
Negative	Reference
Positive	1.224 (0.488-3.067)	0.667
Unknown	1.133 (0.452-2.842)	0.789
Tumor location
Colon	Reference
Rectum	1.384 (0.651-2.945)	0.399
Tumor differentiation
Well/moderate	Reference
Poor	1.228 (0.370-4.080)	0.737
T stage
T3	Reference		Reference
T4	2.558 (1.147-5.701)	0.022	1.817 (0.771-4.285)	0.172
Lymphovascular invasion
Negative	Reference
Positive	1.984 (0.800-4.919)	0.139
Perineural invasion
Negative	Reference		Reference
Positive	3.190 (1.457-6.985)	0.004	2.586 (1.121-5.966)	0.026
Postoperative chemotherapy
No	Reference
Yes	0.859 (0.386-1.913)	0.710
Claudin 7 expression
High	Reference		Reference
Low	2.578 (1.206-5.509)	0.015	2.366 (1.100-5.091)	0.028

CEA: Carcinoembryonic antigen; CI: Confidence interval; HR: Hazard ratio.

Table 4 Prognostic stratification analysis based on different grades

Variable	HR	95%CI	P value
Grade A (claudin 7-high and PNI-)	1	-	-
Grade B (claudin 7-high and PNI+, claudin 7-low and PNI-)	2.512	1.084-5.817	0.032
Grade C (claudin 7-low and PNI+)	7.963	2.704-23.452	< 0.001

Grade C vs Grade B, P = 0.040 (HR = 2.987; 95%CI: 1.051-8.489). HR: Hazard ratio. Claudin 7-high: Claudin 7 high expression; claudin 7-low: Claudin 7 low expression; PNI-: Perineural invasion negative; PNI+: Perineural invasion positive. CI: Confidence interval; HR: Hazard ratio.