Synchronous colorectal liver metastases: short- and long-term outcome analysis of staged versus simultaneous resection

BACKGROUND: Synchronous colorectal liver metastases (CRLM) are diagnosed in approximately 15-25% of patients with colorectal cancer. The optimal surgical approach - simultaneous versus staged resection - remains an ongoing debate. METHODS: We retrospectively analyzed 138 patients with synchronous CRLM who underwent curative-intent resection between 2005 and 2021 at the University Hospital Duesseldorf. Patients were grouped based on the surgical approach: simultaneous (N.=55) versus staged (N.=83) resection. Outcome analysis included postoperative complications, hospital stay, overall survival (OS), and disease-free survival (DFS). Survival was assessed using Kaplan-Meier analysis and log-rank tests. RESULTS: Baseline patient characteristics were comparable between both groups. Major liver resections were significantly more common in the staged group as compared to simultaneous surgery (48 [57.83%] versus 13 [23.64%]; P=0.001). The rates of major postoperative complications (Clavien-Dindo ≥IIIa) were similar (P=0.728). However, hospital stay was significantly longer following simultaneous resection (37.1 versus 25.7 days; P=0.022). Although median DFS was significantly better in the staged group compared to the simultaneous approach (27.3 versus 14.6 months; P=0.019), median OS did not significantly differ between both groups (44 versus 36 months; P=0.369). CONCLUSIONS: Staged and simultaneous resections for CRLM are both safe and feasible with comparable postoperative morbidity and mortality rates. However, the staged approach was associated with reduced hospital stay and improved DFS. The optimal treatment option for synchronous CRLM should be patient tailored and further validated in larger multi-center cohorts.