Primary Tumor Versus Liver-First Approach for Synchronous Colorectal Liver Metastases: An Association Française de Chirurgie (AFC) Multicenter-Based Study with Propensity Score Analysis

Objectives: Multicenter studies comparing the reverse strategy (RS) with the classical strategy (CS) for the management of stage IVA liver-only colorectal cancer (CCR) are scarce. The aim of this study was to compare long-term survival and recurrence patterns following use of the CS and RS. Method: This retrospective multicenter review collected data from all consecutive patients with stage IVA liver-only CCR who underwent staged resection of CCR and liver metastases (LM) at 24 French hospitals between 2006 and 2013 and were retrospectively analyzed. Patients who underwent simultaneous liver and CCR resection, those with synchronous extrahepatic metastasis, and those who underwent emergent CCR resection were excluded. Overall survival (OS) and recurrence-free survival (RFS) rates and recurrence patterns were investigated before and after propensity score matching (PSM). Results: A total of 653 patients were included: 587 (89.9%) in the CS group and 66 (10.1%) in the RS group. Compared with the CS patients, RS patients were more likely to have rectal cancer (43.9 vs. 24.9%; p = 0.006), larger liver tumor size (52.5 ± 38.6 vs. 39.6 ± 30 mm; p = 0.01), and more positive lymph nodes (62.1 vs. 44.8%; p = 0.009). OS was not different between the two groups (75 vs. 72% at 5 years; p = 0.77), while RFS was worse in the RS group (24 vs. 33% at 5 years; p = 0.01). Time to recurrence at any site (1.8 vs. 2.4 years, p = 0.024) and intrahepatic recurrence (1.7 vs. 2.2 years, p = 0.014) were significantly shorter in the RS group than in the CS group. After PSM (63 patients in each group), no significant difference was found between the two groups in OS (p = 0.35), RFS (p = 0.62), time to recurrence at any site (p = 0.19), or intrahepatic recurrence (p = 0.13). Conclusions: In this study, approximately 10% of patients with CCR and synchronous LM were offered surgery with the RS. Both strategies ensured similar oncological outcomes.