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

BACKGROUND: We 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. METHODS: We 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. RESULTS: Of 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. CONCLUSION: The 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.