The timing of liver resection in patients with colorectal cancer and synchronous liver metastases: a population-based study of current practice and survival.

AIM: There is uncertainty regarding the optimal sequence of surgery for patients with colorectal cancer (CRC) and synchronous liver metastases. This study was designed to describe temporal trends and inter-hospital variation in surgical strategy, and to compare long-term survival in a propensity score-matched analysis. METHOD: The National Bowel Cancer Audit dataset was used to identify patients diagnosed with primary CRC between 1 January 2010 and 31 December 2015 who underwent CRC resection in the English National Health Service. Hospital Episode Statistics data were used to identify those with synchronous liver-limited metastases who underwent liver resection. Survival outcomes of propensity score-matched groups were compared. RESULTS: Of 1830 patients, 270 (14.8%) underwent a liver-first approach, 259 (14.2%) a simultaneous approach and 1301 (71.1%) a bowel-first approach. The proportion of patients undergoing either a liver-first or simultaneous approach increased over the study period from 26.8% in 2010 to 35.6% in 2015 (P < 0.001). There was wide variation in surgical approach according to hospital trust of diagnosis. There was no evidence of a difference in 4-year survival between the propensity score-matched cohorts according to surgical strategy: bowel first vs simultaneous [hazard ratio (HR) 0.92 (95% CI: 0.80-1.06)] or bowel first vs liver first [HR 0.99 (95% CI: 0.82-1.19)]. CONCLUSION: There is evidence of wide variation in surgical strategy in dealing with CRC and synchronous liver metastases. In selected patients, the simultaneous and liver-first strategies have comparable long-term survival to the bowel-first approach.