Impact of increased resection rates and a liver parenchyma sparing strategy on long-term survival after surgery for colorectal liver metastases. A population-based study.

Background and aims: Expanded criteria for resection of colorectal liver metastases (CRLM) have led to a more aggressive surgical attitude. The aim is to evaluate any impact of expanded criteria on perioperative mortality and long-term survival. Materials and methods: A population based study from 2001 to 2015 for patients undergoing surgery for CRLM. The cohort was divided into three 5-year periods.
Results: A total of 341 patients underwent resection of CRLM. Relative to the number of colorectal primaries, patients resected for CRLM increased from 82/2520 (3.3%) in 2001-2005 to 151/3071 (4.9%) in 2011-2015 (p = .007). The proportion of patients who underwent formal resections declined from 62% to 21%. There was a substantial increase in resections of synchronous liver metastases, portal vein embolizations, two-stage resections, and the share of octogenarians who underwent resection. The proportion of patients undergoing reresections of new liver recurrences increased from 6% to 24%. The 90-d postoperative mortality for 2001-2005, 2006-2010, and 2011-2015 were 7.9%, 0.8%, and 2.0%, respectively. The median overall survival was 47 months during the two first periods, for the last period not reached. The 5-year overall survival remained at 40% from 2001 to 2010, and estimated at 55.2% from 2011 to 2015. The 5-year disease-free survival was well above 30%. The 5-year overall survival following liver reresection was 52.6%.
Conclusion: Postoperative mortality remained at approximately 2%, and the 5-year overall survival at 40% in the first 10 years, but increased to 55% in the last 5 years under study, despite a marked increase in resection rates.