Table 1.

Setting of the studies reporting the results of the liver-first approach (LFA) in patients with synchronous colorectal liver metastases including the selection criteria of LFA

Reference	Year of publication	Country	Setting	Study period	Selection criteria of ‘LFA’
Mentha16	2008	Switzerland	Prospective observational study	1998–2007	Advanced synchronous colorectal liver metastasesa Age <70 Performance status <2 Non-occlusive primary tumour At least two liver segments without metastases No or resectable extrahepatic disease Clinical risk score >3
Verhoef17	2009	Netherlands	Retrospective observational study	2003–2007	Synchronous liver metastases Locally advanced rectal cancer and where it is defined as: tumour>5 cm at colonoscopy or MRI (clinically large T3); or clinically fixed tumor or with ingrowth in adjacent organ on MRI (T4); or N + tumor (lymph node>8 mm on CT or MRI)
Brouquet18	2010	United States	Retrospective cohort study	1992–2009	Synchronous colorectal liver metastases Criteria not specifically stated but liver resection is planned as soon as the disease was considered resectable, typically after 3 to 5 cycles of preoperative chemotherapy
De Jong19	2011	Netherlands	Retrospective Observational study	2005–2010	Synchronous colorectal liver metastases Liver remnant post resection includes at least two adjacent liver segments as well as sufficient vascular inflow and outflow and adequate biliary drainage All patients with a primary rectal cancer were considered for the liver-first approach Patients with colorectal cancer located in the colon were selected on a case-to-case basis

^aCriteria of ‘Advanced Synchronous Colorectal Liver metastases’ was not clearly defined.