Applying Fong's CRS Liver Score in Patients with Colorectal Liver Metastases Treated by Cryotherapy

BackgroundA significant proportion of patients with liver metastases from colorectal cancer have unresectable disease and we have used cytoablative treatment such as cryotherapy in some of these patients. We retrospectively reviewed patients who underwent hepatic cryotherapy for colorectal metastases and studied the effect of the clinical risk score (CRS) reported by Fong et al, which can predict survival following liver resection.MethodsA retrospective study was performed on patients who underwent hepatic cryotherapy between 1990 and 2000 in St George Hospital. There were 61 patients in this study and they were stratified into prognostic groups based on five preoperative CRS parameters: primary node positive, disease-free interval from primary to metastases < 12 months, number of hepatic tumours > 1, largest hepatic tumour > 5 cm and carcinoembryonic antigen level > 200 ng/mL. The median follow-up was 25 months.ResultsThe median survival was 26 months and the 3-year survival rate was 37%. Median survivals for patients with CRS scores 1 (13%), 2 (25%), 3 (53%), 4 (6%) and 5 (4%) were 37, 25, 30, 21 and 15 months, respectively (R2 = 0.81).ConclusionThe CRS score can be used to predict outcome of hepatic cryotherapy, but the difference in survival between CRS 2, 3 and 4 is modest.