The expression pattern of immune-related genes and characterization of tumor immune microenvironment: predicting prognosis and immunotherapeutic effects in cutaneous melanoma

Abstract Background Increasing evidences have revealed the tumor immune microenvironment not only has vital impacts on the origin, progression, and metastasis of tumors significantly but also influences the response to immunotherapy. Nonetheless, to date, the well-rounded expression pattern of immune-related genes in cutaneous melanoma and the comprehensive characterization of tumor immune microenvironment remain not clearly elucidated. Method We comprehensively evaluated the well-rounded expression pattern of immune-related genes of 686 patients with cutaneous melanoma based on immune-related genes with prognostic value and systematically correlated the expression pattern of these genes with the comprehensive characterization of tumor immune microenvironment. The IRGscore was constructed to quantify immunological function of individual using principal component analysis algorithms. Result Three distinct immune subtypes were determined with obvious survival differences. Melanoma patients with high IRGscore was characterized by comprehensive suppression of immune function, showing much poorer prognosis and efficacy for immunotherapy, while the low IRGscore means the robust activation of immune function and the better effect of immunotherapy, which may be responsible for a better prognosis. Besides, the prognostic ability of IRGscore was further validated by the independent dataset of stomach cancers. Furthermore, the predictive effect of immunotherapeutic benefits of IRGscore was demonstrated by the independent dataset of melanoma patients accepting immunotherapy and another predictive model for immunotherapy. Conclusion IRGscore could serve as an independent immunotherapeutic and prognostic predictor, thereby facilitating the identification of appropriate candidates with cutaneous melanoma for immunotherapy and the formulation of individualized therapeutic approaches.