Propensity score-matched outcomes analysis of the liver-first approach for synchronous colorectal liver metastases

Liver resection before primary cancer resection is a novel strategy advocated for selected patients with synchronous colorectal liver metastases (sCRLM). This study measured outcomes in patients with sCRLM following a liver-first or classical approach, and used a validated propensity score.

Clinical, pathological and follow-up data were collected prospectively from consecutive patients undergoing hepatic resection for sCRLM at a single centre (2004-2014). Cumulative disease-free survival (DFS), cancer-specific survival (CSS) and overall survival (OS) were calculated by means of Kaplan-Meier analysis. Survival differences were analysed in the whole cohort and in subgroups matched according to Basingstoke Predictive Index (BPI).

Of 582 patients, 98 had a liver-first and 467 a classical approach to treatment; 17 patients undergoing simultaneous bowel and liver resection were excluded. The median (i.q.r.) BPI was significantly higher in the liver-first compared with the classical group: 8·5 (5-10) versus 8 (4-9) (P = 0·030). Median follow-up was 34 months. The 5-year DFS rate was lower in the liver-first group than in the classical group (23 versus 45·6 per cent; P = 0·001), but there was no difference in 5-year CSS (51 versus 53·8 per cent; P = 0·379) or OS (44 versus 49·6 per cent; P = 0·305). After matching for preoperative BPI, there was no difference in 5-year DFS (37 versus 41·2 per cent for liver-first versus classical approach; P = 0·083), CSS (51 versus 53·2 per cent; P = 0·616) or OS (47 versus 49·1 per cent; P = 0·846) rates.

Patients with sCRLM selected for a liver-first approach had more oncologically advanced disease and a poorer prognosis. They had inferior cumulative DFS than those undergoing a classical approach, a difference negated by matching preoperative BPI.