Expression and role of the long noncoding RNA Linc00909 in chemoradiotherapy for colorectal cancer

Table 1 Baseline characteristics of the 196 patients with colorectal cancer

Variable	Linc00909 expression		P value
	High (n = 98)	Low (n = 98)
Sex			0.770
Male	58 (59.18)	60 (61.22)
Female	40 (40.82)	38 (38.78)
Age, years	61.08 ± 12.08	60.60 ± 11.60	0.777
American Society of Anesthesiologists score			0.793
1	16 (16.33)	19 (19.39)
2	71 (72.45)	70 (71.43)
3	11 (11.22)	9 (9.18)
Tumor location			0.997
Ascending colon	15 (15.31)	15 (15.31)
Transverse colon	10 (10.20)	9 (9.18)
Descending colon	6 (6.12)	7 (7.14)
Sigmoid colon	21 (21.43)	20 (20.41)
Rectum	46 (46.94)	47 (47.96)
Gross type			0.125
Expanding	24 (24.49)	36 (36.73)
Ulcerating	73 (74.49)	61 (62.25)
Infiltrating	1 (1.02)	1 (1.02)
Histopathology			0.461
Adenocarcinoma	78 (79.59)	82 (83.67)
Mucinous adenocarcinoma	20 (20.41)	16 (16.33)
Tumor differentiation			0.902
Well differentiated	4 (4.08)	4 (4.08)
Moderately differentiated	70 (71.43)	74 (75.51)
Poorly differentiated	19 (19.39)	15 (15.31)
Undifferentiated	5 (5.10)	5 (5.10)
Postoperative hospital stay, days	9.11 ± 7.36	8.02 ± 6.80	0.282
Number of lymph nodes retrieved	22.57 ± 12.96	24.04 ± 15.35	0.470
Number of metastatic lymph nodes	1.70 ± 3.46	1.37 ± 2.98	0.466
Tumor size, cm	4.47 ± 2.22	4.20 ± 2.19	0.402
Pathological T stage			0.367
T1	7 (7.14)	5 (5.10)
T2	17 (17.35)	19 (19.39)
T3	60 (61.22)	67 (68.37)
T4	14 (14.29)	7 (7.14)
Pathological N stage			0.214
N0	53 (54.08)	65 (66.32)
N1	28 (28.57)	20 (20.41)
N2	17 (17.35)	13 (13.27)
Pathological M stage			< 0.001
M0	71 (72.45)	93 (94.90)
M1	27 (27.55)	5 (5.10)
Neural invasion			0.610
Yes	21 (21.43)	24 (24.49)
No	77 (78.57)	71 (75.51)
Vascular invasion			0.809
Yes	9 (9.18)	10 (10.20)
No	89 (90.82)	88 (89.80)

Values are presented as n (%) or mean ± SD. P values were calculated using the χ² test for categorical variables and Student’s t-test for continuous variables. Statistical significance was set at P < 0.05.

Table 2 Univariate and multivariate Cox regression analyses of overall survival in the 196 patients with colorectal cancer

Variable	Univariate analysis			Multivariate analysis
	HR	95%CI	P value	HR	95%CI	P value
Sex, male/female	1.176	0.487-2.838	0.719
Age	0.998	0.962-1.036	0.918
American Society of Anesthesiologists	1.092	0.471-2.530	0.837
Postoperative hospital stay	1.011	0.959-1.065	0.695
Tumor size	1.070	0.889-1.287	0.474
Histopathology	0.459	0.106-1.980	0.296
Tumor location			0.686
Ascending colon	Reference	Reference
Transverse colon	1.802	0.253-12.806	0.556
Descending colon	1.168	0.106-12.901	0.899
Sigmoid colon	1.667	0.305-9.105	0.555
Rectum	2.028	0.449-9.152	0.358
Tumor differentiation	0.358	0.083-1.544	0.169
Gross type	0.112	0.015-0.827	0.032	0.188	0.025-1.427	0.106
Pathological T stage	2.928	1.372-6.246	0.005	1.371	0.616-3.053	0.439
Pathological N stage	2.293	1.369-3.841	0.002	1.755	0.987-3.120	0.055
Lymph nodes retrieved	0.982	0.946-1.018	0.326
Metastatic lymph nodes	1.083	0.996-1.178	0.062
Neural invasion	3.775	1.570-9.076	0.003	3.109	1.245-7.764	0.015
Vascular invasion	0.524	0.070-3.925	0.529
Linc00909 expression	4.518	1.510-13.522	0.007	5.067	1.629-15.765	0.005

Univariate analysis was performed for each variable; variables with P < 0.05 in the univariate analysis were entered into the multivariate Cox proportional hazards model (using forward selection). Bold P values indicate statistical significance (P < 0.05). The reference group for Linc00909 expression was low expression. CI: Confidence interval; HR: Hazard ratio.

Table 3 Univariate and multivariate Cox regression analyses of disease-free survival in the 196 patients with colorectal cancer

Variable	Univariate analysis			Multivariate analysis
	HR	95%CI	P value	HR	95%CI	P value
Sex, male/female	0.889	0.496-1.596	0.694
Age	1.004	0.980-1.029	0.754
American Society of Anesthesiologists score	0.971	0.563-1.674	0.916
Postoperative hospital stay	0.984	0.938-1.033	0.516
Tumor size	0.949	0.829-1.087	0.451
Histopathology	0.855	0.400-1.827	0.687
Tumor location			0.686
Ascending colon	Reference	Reference
Transverse colon	0.690	0.178-2.667	0.590
Descending colon	0.656	0.136-3.160	0.599
Sigmoid colon	0.952	0.354-2.555	0.922
Rectum	1.312	0.571-3.013	0.522
Tumor differentiation	0.992	0.506-1.945	0.981
Gross type	0.466	0.228-0.952	0.036	0.681	0.315-1.476	0.331
Pathological T stage	2.202	1.374-3.528	0.001	1.565	0.945-2.593	0.082
Pathological N stage	1.941	1.389-2.712	< 0.001	1.127	0.688-1.846	0.636
Lymph nodes retrieved	0.987	0.957-1.004	0.110
Metastatic lymph nodes	1.115	1.059-1.174	< 0.001	1.069	0.986-1.159	0.104
Neural invasion	1.827	1.002-3.333	0.049	1.365	0.703-2.650	0.357
Vascular invasion	2.164	1.009-4.640	0.047	1.450	0.613-3.429	0.397
Linc00909 expression	5.643	2.638-12.070	< 0.001	5.335	2.467-11.536	< 0.001

Univariate analysis was performed for each variable; variables with P < 0.05 in the univariate analysis were entered into the multivariate Cox proportional hazards model (using forward selection). Bold P values indicate statistical significance (P < 0.05). High Linc00909 expression was used as the reference category. CI: Confidence interval; HR: Hazard ratio.