Background: Obesity and metabolic syndrome are associated with inflammatory hepatic parenchymal disease (HPD) and increased risk for recurrence after resection of colorectal liver metastases (CRLM). The independent impact of HPD on recurrence patterns has not been well defined.
Methods: The nonalcoholic fatty liver disease activity score (NAS) was used to quantify HPD including steatosis and fibrosis for all patients with completely resected CRLM between April 2003 and March 2007. Clinicopathologic factors, perioperative history, and outcomes were compared with the NAS. Fisher's exact test was used to examine the association between severe HPD (NAS ≥ 3) with clinical and perioperative characteristics. Kaplan-Meier methods were used to estimate recurrence-free survival (RFS). The cumulative incidences of recurrence [any intrahepatic recurrence (IHR), extrahepatic recurrence only (EHR), and death without recurrence (DWR)] were estimated using competing risks methods.
Results: Among the 357 patients included in this study, microsteatosis was noted in 124 (35%) patients, severe HPD in 31 (9%), steatohepatitis in 14 (4%), and sinusoidal injury in 36 (10%). After median follow-up of 127 months (range 4-175 months), 10-year RFS was 22% [95% confidence interval (CI) 17-27%]. Ten-year cumulative incidence for IHR, EHR, and DWR was 37%, 30%, and 12%, respectively. After controlling for confounders, NAS ≥ 3 was independently associated with higher risk of IHR [hazard ratio (HR) 1.76, 95% CI 1.07-2.90, p = 0.027] and lower risk of EHR (HR 0.18, 95% CI 0.04-0.75, p = 0.019) on multivariable analysis.
Conclusions: Severe HPD was associated with increased IHR risk and decreased EHR risk. Future investigation into whether improving HPD from reversible etiologies can reduce the risk for IHR is warranted.