KEY WORDSColorectal metastases, liver metastases, unresectable metastases, adjuvant chemotherapy, intraarterial chemotherapy, hepatic arterial infusion pump chemotherapy
BACKGROUNDOver the past several years, important progress has been made in the treatment of patients with metastatic colorectal cancer. Median overall survival in these patients now extends beyond 2 years with a combination of modern systemic therapies [1][2][3][4][5][6][7][8] . Approximately 60% of patients present with liver-only or liver-predominant metastases, and if complete surgical resection is achieved in those patients, 5-year overall survival approaches 50% 9-11 . In patients with initially unresectable colorectal liver metastases (crlms), systemic therapy can, in up to 30% of patients, produce a tumour response sufficient to allow for resection and the possibility of long-term survival or cure 12,13 . An important goal of aggressive therapy in patients with initially unresectable crlms is therefore conversion to resectability.Although the response rate to systemic therapy is good in untreated patients, response rates to chemotherapy in the second-line setting remain disappointing. The most encouraging results are obtained with the addition of biologic agents to chemotherapy, achieving response rates of up to 20%-35% and a corresponding median survival of up to 1 year in the second-line setting [14][15][16][17][18] . Given the limited efficacy of systemic therapy beyond the first-line setting, patients could benefit from other treatments that would increase response and resectability rates.Hepatic arterial infusion pump (haip) chemotherapy has been extensively studied in patients with crlms. The rationale for arterial delivery of ABSTRACT Despite significant improvements in systemic therapy for patients with colorectal liver metastases (crlms), response rates in the first-line setting are not optimal, and response rates in the second-line setting remain disappointing. Hepatic arterial infusion pump (haip) chemotherapy has been extensively studied in patients with crlms, but it remains infrequently used.We convened an expert panel to discuss the role of haip in the contemporary management of patients with crlm. Using a consensus process, we developed these statements:• haip chemotherapy should be given in combination with systemic chemotherapy.• haip chemotherapy should be offered in the context of a multidisciplinary program that includes expertise in hepatobiliary surgery, medical oncology, interventional radiology, nursing, and nuclear medicine.• haip chemotherapy in combination with systemic therapy should be considered in patients with unresectable crlms who have progressed on first-line systemic treatment. In addition, haip chemotherapy is acceptable as first-line treatment in patients with unresectable colorectal liver metastases.• haip chemotherapy is not recommended in the setting of extrahepatic disease outside the context of a clinical trial.• haip chemotherapy in combination with systemic therapy is an option for select pati...