Metabolic response to preoperative chemotherapy predicts prognosis for patients undergoing surgical resection of colorectal cancer metastatic to the liver.

BACKGROUND: Biological characteristics of colorectal cancer liver metastases (CRCLM) are increasingly recognized as major determinants of patient outcome. The purpose of this study was to evaluate the prognostic value of metabolic response to preoperative chemotherapy as quantified by (18)F-FDG positron emission tomography (PET) for patients undergoing liver resection of CRCLM. METHODS: All patients (n = 80) who had staging PET before liver resection for CRCLM at Austin Health in Melbourne between 2004 and 2011 were included. Thirty-seven patients had PET and CT imaging before and after preoperative chemotherapy. Semiquantitative PET parameters-maximum standardized uptake variable (SUVmax), metabolic tumour volume (MTV), and total glycolytic volume (TGV)-were derived. Metabolic response was determined by the proportional change in PET parameters (∆SUVmax, ∆MTV, ∆TGV). Prognostic scores, CT RECIST response, and tumour regression grading (TRG) were also assessed. Correlation to recurrence-free (RFS) and overall survival (OS) was assessed using Kaplan-Meier survival and multivariate analysis. RESULTS: Semiquantitative parameters on staging PET before chemotherapy were not predictive of prognosis, whereas all parameters after chemotherapy were prognostic for RFS and OS. Only ∆SUVmax was predictive of RFS and OS on multivariate analysis. Patients with metabolically responsive tumours had an OS of 86 % at 3 years vs. 38 % with nonresponsive or progressive tumours (p = 0.003). RECIST and TRG did not predict outcome. CONCLUSIONS: Tumour metabolic response to preoperative chemotherapy as quantified by PET is predictive of prognosis in patients undergoing resection of CRCLM. Assessing metabolic response uniquely characterizes tumour biology, which may allow future optimization of patient and treatment selection.

Outcomes after Liver Transplantation with Steatotic Grafts: Redefining Acceptable Cutoffs for Steatotic Grafts.

Background: Graft macrosteatosis can predispose to a higher risk of graft loss so we sought to redefine acceptable cutoffs for graft steatosis. Methods: Data of 26,103 donors who underwent liver transplantation (LT) between January 2004 and December 2018 from the UNOS-STAR database were utilized. A high-risk steatotic (HRS) graft and a low-risk steatotic (LRS) graft were defined as ≥20% and <20% macrosteatosis, respectively. High-risk steatotic grafts were further classified as grafts with 20-29% (G1S grafts), 30-39% (G2S grafts), and ≥40% steatosis (G3S grafts). Outcomes between groups were compared. Results: LRS grafts had excellent graft (93.3 and 87.7%) and overall survival (95.4 and 90.5%) at 90 days and 1 year. Compared to LRS grafts, G1S, G2S, and G3S grafts had worse graft and overall survival at 90 days and 1-year (p <0.001). There was no difference in graft or overall survival of G1S or G3S grafts compared to G2S grafts until after adjustment in which G3S grafts were found to be associated with an increased risk of graft loss-aHR 1.27 (1.03-1.57), p = 0.02. Discussion: Liver grafts can be categorized into three categories: (1) <20% or "very low risk", (2) 20-39% or "low-to-moderate risk", and usually acceptable, and (3) ≥40% steatosis or "moderate-to-high risk". How to cite this article: Da BL, Satiya J, Heda RP, et al. Outcomes after Liver Transplantation with Steatotic Grafts: Redefining Acceptable Cutoffs for Steatotic Grafts. Euroasian J Hepato-Gastroenterol 2022;12(Suppl 1):S5-S14.

Metabolic response evaluation for colorectal liver metastases and correlation to pathologic response and tumour markers.

BACKGROUND: Tumour metabolic response to chemotherapy is increasingly recognized as a prognostic indicator for colorectal cancer liver metastases (CRCLM). However, its clinical role and the underlying biological mechanism of its prognostic ability are unclear. This study compares metabolic to pathologic response for CRCLM, and correlates metabolic response to tumour expression of six key biomarkers. METHODS: Thirty-seven patients who had positron emission tomography imaging before and after pre-operative chemotherapy prior to liver resection for CRCLM were included. Metabolic response was assessed according to the positron emission tomography response criteria in solid tumours (PERCIST) and correlated to recurrence-free and overall survival. PERCIST was compared to tumour regression grading, computed tomography (CT) response, tumour necrosis and mucin and immunohistochemical expression of Ki-67, hypoxia inducible factor 1α, vascular endothelial growth factor, p53, p16 and vimentin. Area under the receiver operating characteristic curve (AUC), Kaplan-Meier survival, Spearman's correlation (rs ) and multivariate Cox regression analyses were used. RESULTS: PERCIST correlated significantly to 2-year mortality (AUC = 0.162, P < 0.01) and 2-year recurrence (AUC = 0.284, P = 0.03). Metabolically responsive tumours conferred a better overall survival (P = 0.01) and recurrence-free survival (P = 0.03). Tumour regression grading did not stratify for outcome. Metabolic response was significantly correlated to Ki-67 and p16 expression (rs = 0.559 and rs = -0.549, respectively). Multivariate analysis revealed only PERCIST to be correlated to death and recurrence. CONCLUSION: Pre-operative PERCIST assessment of CRCLM was more prognostic than pathologic and CT response assessment. Metabolic non-response correlated with tumour proliferation and loss of tumour suppression.