The timing of chemotherapy and surgery for the treatment of colorectal liver metastases.

Combining surgery and chemotherapy in the treatment of patients with colorectal hepatic metastases is increasingly becoming the standard of care. However, controversy remains regarding the juxtapositioning of chemotherapy and surgery, the duration of chemotherapy, and particularly, the use of preoperative chemotherapy in the treatment of patients with initially resectable metastases. The arguments for and against the different approaches presented are based on the data published in the medical literature and on the data presented at the most recent major oncology meetings, coupled with the personal experience of the authors. For patients with liver metastases that are resectable at presentation, perioperative chemotherapy has become the standard treatment in many institutions, with the recommendation that surgery is performed after a maximum of 6 cycles of systemic therapy. In the case of patients with initially unresectable liver metastases receiving preoperative systemic therapy, patients should be carefully monitored and surgery performed as soon as the metastases become resectable. All patients should, where possible, be treated by a multidisciplinary team. Going forward, it needs to be established whether more intensive treatment (ie, perioperative versus postoperative systemic therapy) is merited for the treatment of patients with initially resectable disease, and what the precise contribution of new therapeutic agents in these settings is, based on new prospective randomized trial data.