Equivalent survival in patients with and without steatosis undergoing resection for colorectal liver metastases following pre-operative chemotherapy

BackgroundWe previously reported that the presence of steatosis did not adversely influence survival in patients undergoing resection for colorectal liver metastases (CLM) without pre-operative chemotherapy. Here, this hypothesis is tested in patients undergoing resection for CLM following pre-operative chemotherapy.MethodsWe assessed the effects of background liver pathology, categorized as ‘normal’, ‘steatosis’ and ‘other’, on perioperative mortality, overall survival (OS) and cancer-specific survival (CSS) in LiverMetSurvey patients. Survival analyses included log-rank tests and multivariate Cox models, incorporating well-established prognosticators. In secondary analyses, re-populating the model with non-chemotherapy patients, the effect modification of chemotherapy on the impact of steatosis on survival was tested.ResultsOf 4329 patients undergoing first-time liver resection following pre-operative chemotherapy, histologies were normal in 1913 (44%), steatosis in 1675 (39%), and other abnormal pathologies in 741 (17%). For normal, steatosis and other, 90-day mortalities were 2.1%, 2.3%, and 3.5% (P = 0.103). For the three histo-pathological groups, 5-year OS rates were 39%, 42%, and 36% (Plogrank = 0.363); 5-year CSS rates were 43%, 45% and 41% (Plogrank = 0.496), respectively. The associations of steatosis with OS and CSS were materially unchanged in the multivariate models. Chemotherapy did not interact with the effect of steatosis on survival.ConclusionThe findings of equivalent survivals challenge the common perception that steatosis in CLM patients after pre-operative chemotherapy is associated with increased peri-operative mortality and poorer long-term survival.