Development of a Research Agenda for the Management of Metastatic Colorectal Cancer: Proceedings from a Multidisciplinary Research Consensus Panel

Abstract

Colorectal cancer (CRC), the second leading cause of cancer death in the United States, occurs in an estimated more than 145,000 patients annually, with almost 50,000 deaths each year. Metastatic liver disease is the cause of death in the majority of them (1,2). Liver-only metastases affect up to one half of patients with CRC (1,2), with approximately 15% (range, 8%–26%) presenting synchronously (3,4) and an additional 15% found metachronously during the next 5 years (3). Colorectal liver metastases (CLMs) are resectable in 20%–25% of patients only; some of the remaining 75%–80% may benefit from “downsizing” therapy, which can result in 10%–20% more patients becoming resectable. Overall survival rates in patients with either primarily or secondarily resectable CLMs can be as high as 58% at 5 years and 15% at 10 years (5,6). Current front-line treatments available to improve downsizing and resectability include systemic therapies (chemotherapy with or without bevacizumab or cetuximab) and pre-operative portal vein embolization (PVE). Other approaches include local ablation therapies, regional intraarterial therapies with embolization (transcatheter arterial chemoembolization, or radio-embolization by selective internal radiation therapy with Yttrium 90-loaded microspheres) or infusion (ie, hepatic arterial infusion [HAI] pump chemotherapy), and external beam radiation therapy (RT). The role of these liver-targeted therapies to promote conversion from unresectable to resectable liver disease remains an evaluation in progress. For the majority of patients with unresectable CRC liver metastases, standard of care is first- and second-line triplet chemotherapy, which is associated with a median survival of 18–24 months (7–10). Multiple single-institution retrospective reports suggest the potential for improvement in survival time by the addition of liver-directed therapies such as chemoembolization, HAI, or radioembolization. This has not been prospectively evaluated in controlled trials, but could potentially represent a major development in Interventional Oncology (IO). The Society of Interventional Radiology (SIR) Foundation has identified the management of metastatic CRC (mCRC) as an emerging inter-ventional radiologic research priority and convened a Research Consensus Panel (RCP) Meeting on October 3, 2011 to establish a prioritized research agenda. This article reports the proceedings from this meeting.