Inclusion Criteria:

- adult patients, >=18 and <=70 years of age;

- unresectable liver metastasis secondary to cancer of colon or rectum;

- scheduled for standard first line chemotherapy;

- ECOG performance score of 0 or 1;

- condition feasible for major abdominal surgery after first line treatment.

Exclusion Criteria:

- diagnosis of metastatic disease >3 months prior to study entry;

- evidence of extrahepatic disease, diffuse peritoneal carcinosis or involvement of
celiac lymph nodes;

- prior systemic or local treatment of metastatic disease;

- prior (neo)adjuvant chemotherapy/radiotherapy completed within 6 months prior to
study entry;

- history or evidence of CNS disease unrelated to cancer.