Perioperative chemotherapy shows a survival edge for patients undergoing hepatectomy for colorectal liver metastases, but use is declining.

• Among 3,752 patients who had surgery, 54% received some form of perioperative chemotherapy.
• Survival improved significantly with both pre- and postoperative regimens (hazard ratio, 0.54).

Complication risks and patient selection remain crucial; higher use is seen in rectal primaries and synchronous disease.

• The use of perioperative chemotherapy has modestly declined over the past two decades (odds ratio per year, 0.97).