Surgical margins during liver resection for colorectal metastases are crucial, especially given tumor genetics.

• R1p margins significantly worsen survival (53% vs. 61% for R0; p < 0.0001), particularly in KRAS-mutated tumors.
• R1p margins also correlate with increased recurrence rates, whereas R1v margins showed no significant risk across molecular groups.

Surgeons should prioritize achieving R0 resection, especially in KRAS mutations, while the need for wider margins in high-risk patients warrants further study.