Feasibility of a national expert panel to determine resectability in patients with initially unresectable colorectal cancer liver metastases (CRLM).

Abstract

3562 Background: Decision on optimal treatment strategy for CRLM remains complex because uniform (un)resectability criteria are lacking. We hypothesize that the use of an expert panel can improve the identification of patients with potentially resectable CRLM. The Dutch Colorectal Cancer Group (DCCG) Expert Panel was established in conjunction with the CAIRO5 study (Huiskens J et al. BMC Cancer 2015), a multicenter, randomized, phase-3 trial, investigating optimal systemic induction treatment in patients with initially unresectable CRLM. Here, we present the feasibility of this panel. Methods: The DCCG Expert Panel consists of 13 liver surgeons and 4 radiologists. Consensus was reached on predefined (un)resectability criteria at baseline. An online platform allowed resectability-assessment by 3 surgeons in case of inter-surgeon agreement, and 5 surgeons if they disagreed. CRLM were assessed as 1) resectable 2) potentially resectable, or 3) permanently unresectable. Patients with initially unresectable CRLM were evaluated at baseline and subsequently every 2 months as long as CRLM were considered potentially resectable. Results: Overall, 397 panel evaluations in 183 patients were analyzed. Median time to panel conclusion was 7 days (IQR 5-11 days) and 204 (51%) evaluations showed inter-surgeon disagreement, with major disagreement (resectable versus permanently unresectable) in 24 (14%) and 12 (29%) evaluations after 2 and 4 months of systemic treatment. Ultimately, 84 (79%) patients with resectable CRLM underwent resection and 23 (27%) resections included portal vein embolization or 2-stage procedures. In resectable CRLM with inter-surgeon agreement versus disagreement, R0 resection was achieved in 39 (75%) versus 28 (52%) patients, p = 0.013. Median time to recurrence was similar between resections with panel agreement versus disagreement, 8 versus 6 months, p = 0.447. Conclusions: This study shows the feasibility of a national Liver Expert Panel for prospective resectability assessment of patients with initially unresectable CRLM. High inter-surgeon disagreement supports the use of a panel. We aim to further validate the panel with outcome parameters. Clinical trial information: NCT02162563.