Analysis of cancer-specific survival in patients with metastatic colorectal cancer: A evidence-based medicine study

Table 1 Demographic characteristics, n (%)

Variable	Total cohort (n = 15838)	Training cohort (n = 11088)	Validation cohort (n = 4750)	χ2	P value
Race				1.36	0.507
Black people	2303 (14.5)	1590 (14.3)	713 (15.0)
White race	12075 (76.2)	8480 (76.5)	3595 (75.7)
Other	1460 (9.2)	1018 (9.2)	442 (9.3)
Sex				0.027	0.869
Male	8560 (54.0)	5988 (54.0)	2572 (54.1)
Female	7278 (46.0)	5100 (46.0)	2178 (45.9)
Age at diagnosis (yr)				1.73	0.188
< 70	10 735 (67.8)	7480 (67.5)	3255 (68.5)
≥ 70	5103 (32.2)	3608 (32.5)	1495 (31.5)
Primary tumor location				0.264	0.607
Colon	7063 (44.6)	4930 (44.5)	2133 (44.9)
Rectum	8775 (55.4)	6158 (55.5)	2617 (55.1)
Tumor differentiation				0.014	0.906
Ⅰ-Ⅱ	11127 (70.3)	7793 (70.3)	3334 (70.2)
Ⅲ-Ⅳ	4711 (29.7)	3295 (29.7)	1416 (29.8)
T staging				0.08	0.777
1-2	2079 (13.1)	1461 (13.2)	618 (13.0)
3-4	13759 (86.9)	9627 (86.8)	4132 (87.0)
N stage				0.576	0.448
0	4209 (26.6)	2966 (26.7)	1243 (26.2)
1-2	11629 (73.4)	8122 (73.3)	3507 (73.8)
CEA status				2.721	0.099
Masculine	12378 (78.2)	8705 (78.5)	3673 (77.3)
Feminine	3460 (21.8)	2383 (21.5)	1077 (22.7)
Liver metastases				0.286	0.593
No	4731 (29.9)	3298 (29.7)	1433 (30.2)
Yes	11107 (70.1)	7790 (70.3)	3317 (69.8)
Lung metastases				2.202	0.138
No	12673 (80.0)	8838 (79.7)	3835 (80.7)
Yes	3165 (20.0)	2250 (20.3)	915 (19.3)
Bone metastases				0.724	0.395
No	15226 (96.1)	10669 (96.2)	4557 (95.9)
Yes	612 (3.9)	419 (3.8)	193 (4.1)
Brain metastases				1.032	0.31
No	15682 (99.0)	10973 (99.0)	4709 (99.1)
Yes	156 (1.0)	115 (1.0)	41 (0.9)
Surgical				0.014	0.906
No	3495 (22.1)	2444 (22.0)	1051 (22.1)
Yes	12343 (77.9)	8644 (78.0)	3699 (77.9)
Chemotherapy				0.026	0.872
None/unknown	4235 (26.7)	2969 (26.8)	1266 (26.7)
Yes	11603 (73.3)	8119 (73.2)	3484 (73.3)

CEA: Carcinoembryonic antigen.

Table 2 Multivariate analysis of COX based on training cohorts

Variable	Multivariate analysis
	HR (95%CI)	P value
Race
Black people	1
White race	0.894 (0.834-0.959)	0.002
Other	0.835 (0.752-0.928)	0.001
Sex
Male	1
Female	0.965 (0.918-1.015)	0.17
Age at diagnosis (yr)
< 70	1
≥ 70	1.162 (1.099-1.228)	< 0.001
Primary tumor location
Colon	1
Rectum	0.715 (0.678-0.754)	< 0.001
Tumor differentiation
Ⅰ-Ⅱ	1
Ⅲ-Ⅳ	1.721 (1.630-1.817)	< 0.001
T staging
1-2	1
3-4	1.085 (0.999-1.179)	0.053
N stage
0	1
1-2	1.304 (1.226-1.386)	< 0.001
CEA status
Masculine	1
Feminine	0.699 (0.655-0.746)	< 0.001
Liver metastases
No	1
Yes	1.406 (1.326-1.490)	< 0.001
Lung metastases
No	1
Yes	1.341 (1.260-1.426)	< 0.001
Bone metastases
No	1
Yes	1.621 (1.438-1.827)	< 0.001
Brain metastases
No	1
Yes	1.718 (1.370-2.155)	< 0.001
Surgical
No	1
Yes	0.459 (0.429-0.492)	< 0.001
Chemotherapy
None/unknown	1
Yes	0.368 (0.348-0.390)	< 0.001

CEA: Carcinoembryonic antigen; HR: Hazard ratio.

Table 3 Regression coefficients and estimated scores for building a Nomogram prediction model based on a training cohort

Variable	Nomogram
	Regression coefficients	Estimated score
Race
Black people	17.846261	18
White race	6.960746	7
Other	0	0
Age at diagnosis (yr)
< 70	0	0
≥ 70	14.55836	15
Primary tumor location
Colon	32.76881	33
Rectum	0	0
Tumor differentiation
Ⅰ-Ⅱ	0	0
Ⅲ-Ⅳ	54.39289	54
N stage
0	0	0
1-2	27.38794	27
CEA status
Masculine	35.56051	36
Feminine	0	0
Liver metastases
No	0	0
Yes	34.12213	34
Lung metastases
No	0	0
Yes	29.0965	29
Bone metastases
No	0	0
Yes	49.30787	49
Brain metastases
No	0	0
Yes	54.35879	54
Surgical
No	75.074	75
Yes	0	0
Chemotherapy
None/unknown	100	100
Yes	0	0
Range	0-524.474061	0-524
Score	531.434807	531

CEA: Carcinoembryonic antigen.

Table 4 Analyzes tumor-specific survival rates in patients with different risk classes, %

Variable	Low-risk group	Medium-risk group	High-risk group
	(n = 8140)	(n = 4737)	(n = 2013)
1 yr CSS	86.10	63.00	31.50
2 yr CSS	67.30	38.00	16.10
3 yr CSS	49.70	24.60	8.90
5 yr CSS	31.30	14.20	4.30
Median CSS	36 months	18 months	5 months
95%CI	34.987-37.013	17.273-18.727	4.503-5.497

CSS: Cancer-specific survival.