A Case of Heavily Pretreated HER2+ Colorectal Liver Metastases Responsive to Hepatic Arterial Infusion Chemotherapy

• What is Already Known About This Subject?Hepatic arterial infusion (HAI) pumps represent 1 promising treatment strategy for patients presenting with liver only or predominant tumors. HAI therapy is a form of locoregional therapy which administers chemotherapy directly into the hepatic artery, thus limits systemic exposure and spares other organs from toxicity. According to the National Comprehensive Cancer Network Guidelines (NCCN), placement of a HAI pump, in combination with systemic chemotherapy, has a category 2B recommendation for centers with the requisite expertise to perform this procedure. However, the utility of HAI pumps for patients with previously treated relapsed/refractory colorectal cancer (CRC) with colorectal liver metastases (CRLM) remains unclear.

• What are the New Findings?Here, we describe a case of heavily pretreated patient with CRC and CRLM unusually responsive to HAI chemotherapy. Our patient had a progression free survival (PFS) of 20.2 months with HAI therapy, versus a PFS of 3 to 6 months with systemic chemotherapy therapy. Furthermore, in this case, the patient has been able to stay off systemic therapy for over a year by the time of this publication. Based on the patient's response, HAI therapy may slow the rate of disease progression compared to other therapies, as it might “reset the clock” as it did for this patient's very aggressive biology.

• How Might it Impact on Clinical Practice in the Foreseeable Future?We believe this to be the first published case report of a patient with previously treated HER2+ CRC who had progressed on anti-HER2 therapy, who had a substantial response from treatment with FUDR HAI chemotherapy. Our report adds to the dearth of the literature in this patient population, and supports use of HAI chemotherapy as a potential treatment strategy for patients with relapsed, refractory CRLM. This case suggests that HAI chemotherapy with FUDR in combination with systemic therapy has the potential to provide long-term responses even for patients with CRLM refractory to multiple lines of chemotherapy.