Prognostic Significance of Lymphocyte-to-Monocyte Ratio in Patients With Unresectable Biliary Tract Cancer Undergoing Systemic Chemotherapy.

Background/aim: The incidence of biliary tract cancers (BTC), including cholangiocarcinoma and gallbladder cancer, has been increasing worldwide. Approximately 70% of BTC patients have advanced disease at diagnosis, leading to a poor survival rate. Recent clinical trials have demonstrated that the addition of immune checkpoint inhibitors, such as durvalumab or pembrolizumab, to gemcitabine plus cisplatin chemotherapy significantly improves survival rates, making triple therapy the current standard for first-line treatment of BTC. Few models with predictive value exist for BTC. Lymphocyte-to-monocyte ratio (LMR) is a relatively new inflammation-related score and translational biomarker and has prognostic value for survival of patients with other cancers. This study assessed the prognostic value of LMR in patients with advanced BTC and analyzed the risk factors associated with overall survival (OS).

Patients and methods: This prospective study enrolled 75 patients with advanced BTC who were treated with gemcitabine-based chemotherapies at Aso Iizuka Hospital, Japan. The cutoff value of LMR for predicting 6-month survival was 3.27.

Results: OS was longer for patients with high LMR compared with low LMR (median 32.4 months and 8.6 months, respectively; p=0.0069). Multivariate analysis identified LMR >3.27 [hazard ratio (HR)=0.427, p=0.0339] and objective response rate (HR=0.210, p=0.0116) as independent factors associated with OS.

Conclusion: Despite some limitations, such as the single-center design and small sample size, the results of this study suggest a potential role for LMR in predicting survival outcomes for BTC patients treated with gemcitabine-based chemotherapies.