ASO Author Reflections: Neutrophil-to-Lymphocyte Ratio Predicts Recurrence Pattern in Patients with Resectable Colorectal Liver Metastases

The vast improvement in colorectal cancer (CRC) outcomes has necessitated prognosis assessment tools beyond conventional staging systems in patients with colorectal liver metastases (CRLM).1 To address this, several tumor-focused scoring systems were established but presented major setbacks, including high cost, overcomplexity, and being retrospective in nature.2 It has since emerged that the immune system plays a significant role in cancer progression through systemic inflammatory processes,3 and therefore can supply simple, rapid, and cost-effective means to prospectively predict the natural history of disease. High neutrophil-to-lymphocyte ratio (NLR) was found to be an effective prognostic biomarker in various types of solid tumors.4 The pro-malignant environment created by a high neutrophil count combined with an inadequate response to the tumor due to relative lymphocytopenia reflects a systemic inflammatory condition that can promote aggressive disease behavior, resulting in poor outcomes.3 To date, few studies have been conducted regarding NLR in CRLM patients, and these studies have yielded conflicting results, with no specific mechanism or disease course, which may explain the poor outcomes.4 It has been hypothesized that a high preoperative NLR is associated with poor survival through a more aggressive recurrence pattern.5 …