Resection of colorectal liver metastases after second-line chemotherapy: is it worthwhile? A LiverMetSurvey analysis of 6415 patients

•A heavier tumour burden was found in patients with colorectal liver metastases (CLM) resection after 2nd-line preoperative chemotherapy (PCT).•The 49% 5-year overall survival (OS) from CLM diagnosis in this group was similar to that after 1st-line.•OS or disease-free survival was comparable for the subsets of initially unresectable of two PCT groups.•Surgery of CLM may be proposed to resect CLM ever after 2nd-line chemotherapy.