Extended criteria liver resection: Can noncurative intent resection of colorectal liver metastasis improve survival?
Authors: Kalil Jennifer , Krzywon Lucyna , Zlotnik Oran , Chaudhury Prosanto , Lazaris Anthoula , Metrakos Peter 
Published: January 2023

164 Background: From initially believed to be a palliative diagnosis, CRLM management has ranged from nonoperative, resection of only solitary lesions, resection only if 1 cm margin could be obtained, to major hepatectomies with liver regenerative procedures. With a greater understanding of the disease and advances in systemic therapy, clinicians have been able to continuously push the envelope in both resection and local therapies to improve overall survival in patients with CRLM. The constant evolution of management for CRLM raises the question – would patients benefit from a non-curative intent resection by decreasing overall tumor burden? Is there a role for debulking of disease as an extended criterion to improve median survival? Methods: A retrospective study was conducted by identifying patients who consented to participate in the liver disease biobank research program. Consented patients with CRLM evaluated for a two-stage hepatectomy (TSH) between 2012-2020 were identified. Patients were divided into three groups: those that successfully completed TSH, those that underwent the first stage only of the TSH (surgical debulking + best chemotherapy +/- local ablative therapy), and those that were not resected (best chemotherapy +/- local ablative therapy). Patients that underwent successful completion of TSH were excluded from analysis. Kaplan Meier survival curves and log-rank test were performed to assess the median survival between the surgical debulking + best chemotherapy +/- local ablative therapy and best chemotherapy +/- local ablative therapy groups. Results: Of the 114 patients identified, 47 patients underwent successful completion of TSH, 35 patients underwent the first stage only of the TSH, and 32 patients were eventually deemed unresectable. Reasons for unresectability included intraoperative findings (n = 14), progression of disease on best chemotherapy (n = 8), unresectable extrahepatic disease, local recurrence of primary, or unfit for surgery. Patients who underwent first stage of the TSH and those that were not resected both received best chemotherapy with/without local ablative therapies. 32 of the 35 patients in the surgical debulking + best chemotherapy +/- local ablative therapy group and 27 of 32 patients in the best chemotherapy +/- local ablative therapy group presented with synchronous disease. Tumor volume resected ranged from 5% - 95%. Median survial of the surgical debulking + best chemotherapy +/- local ablative therapy group was 31 months vs 20 months in the best chemotherapy +/- local ablative therapy group (p = 0.029). Conclusions: Patients undergoing incomplete resection of CRLM demonstrated a survival benefit compared to patients who did not undergo any surgical resection. This suggests there may be a potential systemic benefit to reducing overall tumor burden. This preliminary study provides the framework to further explore the systemic effects of surgical debulking of CRLM to improve median survival as an extended criterion for non-curative intent liver resection.