XCR1: A promising prognostic marker that pinpoints targeted and immune-based therapy in hepatocellular carcinoma.

ABSTRACT

Objectives: The lymphotactin receptor X-C motif chemokine receptor 1 (XCR1) is an essential member of the chemokine receptor family and is related to tumor development and progression. Nevertheless, further investigation is required to explore its expression patterns, prognostic values, and functions related to target or immune therapies in patients with hepatocellular carcinoma (HCC). Materials and methods: The differential expression patterns of XCR1 and its prognostic influences were performed through The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) databases. Subsequently, immunohistochemistry (IHC) staining and univariate and multivariate Cox regressions were performed to validate the prognostic values in different subgroups. Furthermore, the potential roles of XCR1 in predicting target and immune therapeutic responses were also investigated. Results: Increased expression level of XCR1 was associated with favorable overall survival (OS) and recurrence-free survival (RFS). Subgroup analysis revealed that a high expression level of XCR1 or positive immune cell proportion score (iCPS) were associated with favorable OS in the HCC patients with favorable tumor characteristics. In addition, the enhanced XCR1 expression was associated with the tumor environment scores, immune cell infiltration levels, and the expression levels of immune checkpoint genes. Further analysis revealed that improved expression of XCR1 was linked to better OS and RFS in HCC patients who received sorafenib. Conclusion: This study identified that XCR1 is a valuable prognostic biomarker in the HCC population, especially in those with favorable tumor characteristics. The combination of iCPS status and BCLC status has a synergistic effect on stratifying patients' OS and RFS. Further analyses showed that XCR1 has the potential ability to predict treatment responses to sorafenib and immune-based therapies.