Strategies for Recurrent Colorectal Liver Metastases Based on Prognostic Factors and Resectability: Potential Benefit of Multidisciplinary Treatment.

Background: Colorectal liver metastasis (CLM) is classified into technical and oncologic categories, with recommended treatments for each resectability category. However, the classification of recurrent CLM has not been established to date.

Methods: This study evaluated patients with CLM who underwent initial liver resection between 2006 and 2020 and subsequently experienced liver recurrence. Long-term outcomes and prognostic factors associated with recurrent CLM were investigated.

Results: From 949 patients who underwent an initial liver resection, the analysis included 392 patients with liver recurrence. Repeat liver resection was associated with a significantly longer prognosis than non-resection (5-year overall survival [OS] from initial liver resection: 66.3 % vs 27.2 %, p < 0.0001). Multivariable analysis indicated the following independent prognostic factors: four or more recurrent tumors (p = 0.015), tumor 5 cm or larger in size (p = 0.004), and presence of extrahepatic diseases (p = 0.003). The patients were stratified into resectable, borderline resectable, and unresectable recurrent CLM groups based on these criteria. The prognosis varied significantly across the groups, with 5-year OS rates of 67.3 % for resectable recurrent CLM, 30.8 % for borderline resectable recurrent CLM, and 2.6 % for unresectable recurrent CLM (p < 0.0001). Patients with borderline resectable recurrent CLM who did not receive adjuvant chemotherapy after initial liver resection had a positive prognostic impact of preoperative chemotherapy (p = 0.049).

Conclusion: The significant independent predictors of recurrent CLM prognosis were four or more tumors, tumor size of 5 cm or larger, and the presence of extrahepatic diseases at recurrence. It is critical to onsider the current condition and tumor resectability at the time of recurrence, and tailored treatments could further improve recurrent CLM outcomes.