Prognostic significance of cytotoxic-T-lymphocytes to immunosuppressive lymphocytes ratio (CIL) in laryngeal squamous cell carcinoma

Immunoscore (IS), based on CD3/CD8, has been proposed to characterize the immune landscape of the tumor immune microenvironment and has demonstrated an association with the prognosis of laryngeal squamous cell carcinoma (LSCC). However, traditional IS does not include immunosuppressive cells. The purpose of this study is to evaluate the prognostic performance of cytotoxic-T-lymphocytes to immunosuppressive cells ratio (CIL) in laryngeal squamous cell carcinoma (LSCC) patients. Two cohorts were included in this study: The training cohort (N = 75) consisted of tumor tissue microarrays from LSCC patients in our department, and the validation cohort (N = 116) utilized bulk RNA-seq data from the TCGA database. Patients with high IS or CIL showed significantly prolonged overall survival and disease-free survival in both cohorts. Upon analyzing the relative contribution of each parameter, it was found that CIL exhibited the highest significance among the factors examined. It emerged as the strongest predictor of overall survival, emphasizing its crucial influence in determining the outcomes. The prognostic ability of IS-TCGA was similar to the original IS. Additionally, high CILM2-TCGA was associated with prolonged survival of patients with LSCC in the TCGA dataset. CIL, which is easier to construct than IS, proves to be reliable in predicting survival outcomes for patients with LSCC.