Table 1.

Patient characteristics of the primary patient set, according to CTC count and mRNA cluster, and the second independent patient set.

Patient characteristics	Primary patient set								Second independent patient set
	No. of pts	%	mRNA cluster		P‐value	CTC count		P‐value	No. of pts	%	P‐value
			1	2		<3	≥3
All patients	98	100%	36	62		74	24		35
Sex
Female	40	41%	10	30	0.060	24	16	0.004	12	34%	0.550
Male	58	59%	26	32		50	8		23	66%
Age at time of surgery
<60	35	36%	14	21	0.665	25	10	0.625	12	34%	1.000
≥60	63	64%	22	41		49	14		23	66%
Presentation of metastasis
synchronous	62	63%	19	43	0.129	48	14	0.629	24	69%	0.682
metachronous	36	37%	17	19		26	10		11	31%
Primary tumor in situ at time of surgery
yes	26	27%	8	18	0.636	21	5	0.598	7	20%	0.502
no	72	73%	28	44		53	19		28	80%
Elapsed time between primary tumor and metastasis resectiona
<6 months	22	22%	7	15	0.612	19	3	0.257	6	17%	0.802
≥6 months	64	65%	26	38		47	17		22	63%
CTC count
<3	74	76%	29	45	0.486				29	83%	0.482
≥3	24	24%	7	17					6	17%
Primary tumor characteristics
Locationb
right hemicolon	16	16%	4	12	0.299	12	4	1.000	7	20%	0.716
left hemicolon	50	51%	17	33		38	12		18	51%
rectum	32	33%	15	17		24	8		9	26%
Tumor sizeb
T0	1	1%	1	0	1.000	1	0	1.000	0	0%	0.243
T1	0	0%	0	0		0	0		0	0%
T2	13	13%	4	9		10	3		1	3%
T3	64	65%	25	39		50	14		24	69%
T4	9	9%	3	6		7	2		7	20%
Lymph node involvementb
N0	33	34%	18	15	0.091	25	8	0.545	10	29%	0.6746
N1	29	30%	8	21		25	4		13	37%
N2	20	20%	7	13		15	5		9	26%
Dukes classificationb
A	1	1%	0	1	0.11	0	1	0.303	0	0%	0.8964
B	16	16%	10	6		11	5		5	14%
C	16	16%	6	10		14	2		5	14%
D	62	63%	19	43		48	14		24	69%
Gradeb
1 (well differentiated)	3	3%	1	2	1000	3	0	0.179	3	9%	0.2871
2 (moderately differentiated)	58	59%	23	35		41	17		18	51%
3 (poorly differentiated)	7	7%	3	4		7	0		3	9%
Neoadjuvant chemotherapyb
yes	10	10%	6	4	0.086	9	1	0.444	4	11%	0.5049
no	71	72%	22	49		54	17		19	54%
Adjuvant chemotherapyb
yes	9	9%	3	6	1000	8	1	0.676	4	11%	0.4646
no	74	76%	25	49		57	17		18	51%
Induction chemotherapy before liver resectionb
yes	52	53%	15	37	0.017	38	14	0.813	22	63%	0.4291
no	44	45%	21	23		34	10		13	37%
Site of metastasis
liver‐only	89	91%	33	56	1000	68	21	0.684	32	91%	1000
liver and other sites	9	9%	3	6		6	3		3	9%

Detailed clinicopathologic characteristics of the 98 patients from the primary patient set with pathology‐confirmed colorectal liver metastases and mRNA data available, depicted according to CTC‐count (<3 vs. ≥3, the clinically relevant prognostic cut‐off level and according to mRNA (cluster 1 vs. 2). The last column depicts the clinicopathologic characteristics of the independent second patients set, which were included in the same study at a later time point and used to validate some of our findings in the primary patient set. Significant P‐values as obtained by the Fisher's exact test are depicted in italics and P‐values are depicted in bold if the value is <0.05.

^aNumbers do not add up to 100% because patients undergoing primary tumor resection after liver resection, and patients who have not undergone primary tumor resection at all, were left out.

^bNumbers do not add up to 100% because of missing data.