Table 1.

Clinicopathological characteristics.

	Primary CRC (n = 315 patientsa)		Metastatic CRC (n = 176 patientsa)
	No. of patients	%	No. of patients	%
Age at surgery
Below 65 years	94	30	81	46
65–75 years	105	33	76	43
Above 75 years	116	37	19	11
Gender
Male	169	54	110	62
Female	146	46	66	38
Primary tumor location
Left/rectum	181	57	133	76
Right	126	40	35	20
Synchronous	7	2	1	1
Unknown	1	0.3	7	4
Cancer stage at first diagnosis
I	65	21	2	1
II	117	37	15	9
III	90	29	112	64
IV	41	13	31	18
Unknown	2	1	16	9
Diagnosis of liver metastasis
Synchronous (within 6 months of initial diagnosis)	–	–	138	78
Metachronous	–	–	38	22
Systemic oncological treatment prior to sampling of metastases
Neoadjuvant chemotherapy for this metastatic situation	–	–	134	76
Previous chemotherapy only	–	–	27	15
No previous systemic treatment (naive)	–	–	15	9

^aFourteen patients with matched primary and metastatic tumor samples.