Background

Resection of colorectal liver metastasis (CLM) is beneficial when feasible. However, the benefit of second hepatectomy for hepatic recurrence in CLM remains unclear.

Methods

The Colorectal Liver Operative Metastasis International Collaborative retrospectively examined 1004 CLM cases from 2000 to 2018 from a total of 953 patients. Hepatic recurrence after initial hepatectomy was identified in 218 patients. Kaplan-Meier analysis was performed for overall survival (OS) and recurrence-free survival (RFS). Propensity score matching (PSM) was performed to offset selection bias. Cox proportional-hazards regression was performed to identify risk factors associated with OS.

Results

A total of 51 patients underwent second hepatectomy. Unadjusted median OS was 60.1 months in repeat-hepatectomy versus 38.3 months in the single-hepatectomy group (p = 0.015). In the PSM population, median OS remained significantly better in the repeat-hepatectomy group (60.1 vs. 33.1 months; p = 0.0023); median RFS was 12.4 months for the repeat-hepatectomy group, versus 9.8 months in the single-hepatectomy group (p = 0.0050). Repeat hepatectomy was associated with lower risk of death (hazard ratio: 0.283; p = 0.000012). Obesity, tobacco use, and high intraoperative blood loss were associated with significant risk of death (p < 0.05).

Conclusion

In CLM with hepatic recurrence, second hepatectomy was beneficial for OS. With PSM, the OS benefit of performing a second hepatectomy remained significant.

BACKGROUND: Primary laterality of colorectal cancer is thought to be associated with differences in outcomes. Liver metastasis is the most common site of solitary colorectal cancer spread. However, how primary colorectal cancer laterality affects outcomes in colorectal liver metastasis remains unclear. METHODS: The Colorectal Liver Operative Metastasis International Collaborative (COLOMIC) of operative hepatectomy cases for colorectal liver metastasis was compiled from five participating institutions. This included consecutive cases from 2000 to 2018 at all sites. A total of 884 patients were included in this study. Univariate, multivariate, and Kaplan-Meier analyses were performed. RESULTS: Patients with left-sided versus right-sided cancers had significantly better overall survival: 49.4 vs. 41.8 months (p < 0.05). Patients with KRAS mutations had significantly worse median overall survival compared to KRAS wild-type (43.6 vs 56.1 months; p < 0.001). In left-sided cancers, KRAS mutations were associated with significantly worse median overall survival compared to KRAS wild-type cancers (43.6 vs 56.6 months; p < 0.01). This association was absent in patients with right-sided primary tumors. Multivariate Cox regression analysis revealed different variable sets (non-overlapping) were associated with overall survival, when comparing left-sided and right-sided cancers. CONCLUSION: Understanding how primary tumor laterality and related biological aspects affect long-term outcomes can potentially inform treatment decisions for patients with colorectal liver metastases.