Preoperative Aspartate Aminotransferase-to-Platelet Ratio Index Predicts Perioperative Liver-Related Complications Following Liver Resection for Colorectal Cancer Metastases

Background and Aims: There are limited data on the potential role of preoperative non-invasive markers, specifically the aspartate-to-alanine aminotransferase ratio and the aspartate aminotransferase-to-platelet ratio index, in predicting perioperative liver-related complications after hepatectomy for colorectal cancer metastases. Methods: Patients undergoing liver resection for colorectal cancer metastases in a European institution during 2003-2010 were retrospectively enrolled. Relevant data, such as neoadjuvant chemotherapy, preoperative liver function tests, and perioperative complications, were collected from medical records. The nontumorous liver parenchyma in the surgical specimens of 31 patients was re-evaluated. Results: Overall, 215 patients were included. In total, 40% underwent neoadjuvant chemotherapy and 47% major resection, while 47% had perioperative complications (6% liver-related). In multivariate regression analysis, the aspartate aminotransferase-to-platelet ratio index was independently associated with liver-related complications (odds ratio: 1.149, p=0.003) and perioperative liver failure (odds ratio: 1.155, p=0.012). The latter was also true in the subcohort of patients with neoadjuvant chemotherapy (odds ratio: 1.157, p=0.004) but not in those without such therapy (p=0.062). The aspartate-to-alanine aminotransferase ratio was not related to liver-related complications (p=0.929). The area under the receiver operating characteristics curve for the aspartate aminotransferase-to-platelet ratio index as a predictor of liver-related complications was 0.857 (p=0.008) in patients with neoadjuvant chemotherapy. Increasing aspartate aminotransferase-to-platelet ratio index was observed with an increase in degrees of sinusoidal obstruction syndrome (p=0.01) but not for fibrosis (p=0.175) or steatosis (p=0.173) in the nontumorous liver in surgical specimens. Conclusion: The preoperative aspartate aminotransferase-to-platelet ratio index, but not the aspartate-to-alanine aminotransferase ratio, predicts perioperative liver-related complications following hepatectomy due to colorectal cancer metastases, in particular after neoadjuvant chemotherapy. The aspartate aminotransferase-to-platelet ratio index is related to sinusoidal obstruction syndrome in the nontumorous liver.