Prognostic scoring system for synchronous brain metastasis at diagnosis of colorectal cancer: A population-based study

Table 1 Characteristics of patients with brain metastasis from colorectal cancer, n (%)

Variable	No. of patients
Age (yr)
< 60	144 (38.8)
60-74	157 (42.3)
≥ 75	70 (18.9)
Race
White	295 (79.5)
Black	45 (12.1)
Other	31 (8.4)
Gender
Male	199 (53.6)
Female	172 (46.4)
Primary tumor site
Colon	215 (58.0)
Rectosigmoid/rectum	112 (30.2)
Unknown	44 (11.9)
Tumor grade
Well/moderately differentiated	152 (41.0)
Poorly/undifferentiated	101 (27.2)
Unknown	118 (31.8)
Histology types
Adenocarcinoma	320 (86.3)
Mucinous carcinoma	13 (3.5)
Signet ring-cell carcinoma	10 (2.7)
Other	20 (5.4)
Unknown	8 (2.2)
CEA level
Negative	46 (12.4)
Positive	206 (55.5)
Unknown	119 (32.1)
T stage
T1/T2	57 (15.4)
T3/T4	164 (44.2)
Unknown	150 (40.4)
N stage
N0	119 (32.1)
N1/N2	172 (46.4)
Unknown	80 (21.6)
Liver metastasis
No	166 (44.7)
Yes	199 (53.6)
Unknown	6 (1.6)
Lung metastasis
No	184 (49.6)
Yes	177 (47.7)
Unknown	10 (2.7)
Bone metastasis
No	276 (74.4)
Yes	81 (21.8)
Unknown	14 (3.8)
Extracranial metastasis to liver, lung or bone
No	97 (26.1)
Yes	270 (72.8)
Unknown	4 (1.1)

CEA: Carcinoembryonic antigen.

Table 2 Univariate analysis of prognostic factors in patients with brain metastasis from colorectal cancer

Variable	Median survival (mo)	HR	95%CI	P value
Age (yr)
< 60	8	1	-	-
60-74	4	1.398	1.082-1.807	0.010
≥ 75	3	2.434	1.787-3.315	< 0.001
Race
White	5	1	-	-
Black	6	0.990	0.703-1.395	0.955
Other	4	1.309	0.889-1.926	0.172
Gender
Male	4	1	-	-
Female	6	0.932	0.743-1.169	0.543
Primary tumor site
Colon	5	1	-	-
Rectosigmoid/Rectum	6	0.849	0.656-1.098	0.211
Unknown	3	1.451	1.025-2.053	0.036
Tumor grade
Well/moderately differentiated	8	1	-	-
Poorly/undifferentiated	5	1.185	0.895-1.569	0.236
Unknown	4	1.527	1.170-1.994	0.002
Histology types
Adenocarcinoma	5	1	-	-
Mucinous carcinoma	8	0.761	0.416-1.394	0.377
Signet ring-cell carcinoma	4	0.923	0.451-1.888	0.826
Other	4	1.314	0.814-2.122	0.264
Unknown	3	2.416	1.133-5.149	0.022
CEA level
Negative	8	1	-	-
Positive	5	1.964	1.331-2.896	0.001
Unknown	4	2.149	1.431-3.225	< 0.001
T stage
T1/T2	4	1	-	-
T3/T4	6	0.942	0.669-1.326	0.731
Unknown	4	1.125	0.798-1.585	0.502
N stage
N0	5	1	-	-
N1/N2	6	0.952	0.733-1.238	0.715
Unknown	4	1.239	0.907-1.691	0.178
Extracranial metastasis to liver, lung or bone
No	6	1	-	-
Yes	4	1.400	1.071-1.831	0.014
Unknown	7	1.544	0.566-4.269	0.392

CEA: Carcinoembryonic antigen; HR: Hazard ratio.

Table 3 Multivariate analysis of prognostic factors in patients with brain metastasis from colorectal cancer

Variable	HR	95%CI	P value
Age (yr)
< 60	1	-	-
60–74	1.395	1.075-1.809	0.012
≥ 75	2.497	1.818-3.430	< 0.001
CEA level
Negative	1	-	-
Positive	1.613	1.078-2.413	0.020
Unknown	1.865	1.229-2.829	0.003
Extracranial metastasis to liver, lung or bone
No	1	-	-
Yes	1.383	1.045-1.831	0.023
Unknown	1.280	0.461-3.551	0.636

CEA: Carcinoembryonic antigen; HR: Hazard ratio.

Table 4 Scoring system

Variable	Point
Age (yr)
< 60	0
60-74	1
≥ 75	2
CEA level
Negative	0
Positive	1
Extracranial metastasis to liver, lung or bone
No	0
Yes	1

CEA: Carcinoembryonic antigen.

Table 5 Median survival of patients with brain metastasis according to different scoring groups

Variable	n	Median survival (mo)	HR	95%CI	P value1
Group I (score 0-1)	44	14	1	-	-
Group II (score 2-3)	172	5	2.050	1.363-3.083	0.001
Group III (score 4)	32	2	3.721	2.225-6.225	< 0.001

¹Group II vs Group III: P = 0.003 (Hazard ratio = 0.551, 95%CI: 0.374-0.812). HR: Hazard ratio.