The Global Immune–Nutrition–Inflammation Index (GINI) as a Candidate Prognostic Marker in Patients with Cutaneous Squamous Cell Carcinoma Treated with Cemiplimab

Background/Objectives: Cutaneous squamous cell carcinoma (cSCC) is a highly prevalent malignancy. While Cemiplimab has transformed the treatment landscape across various disease stages, reliable pretreatment biomarkers for risk stratification remain lacking.. The Global Immune–Nutrition–Inflammation Index (GINI) is a composite biomarker integrating systemic inflammation and nutritional status into a single score. This study aimed to evaluate the prognostic value of the pretreatment GINI in patients with cSCC receiving Cemiplimab across all treatment settings. Methods: This retrospective cohort study evaluated 73 patients with unresectable, locally advanced, or metastatic cSCC treated with Cemiplimab between 2020 and 2023. Pretreatment laboratory parameters were extracted to calculate the GINI score. Receiver operating characteristic (ROC) curve analysis determined the optimal GINI cutoff to stratify patients into low- and high-GINI groups. Survival outcomes, including overall survival (OS) and progression-free survival (PFS), were analyzed using Kaplan–Meier curves and multivariable Cox proportional hazards models. Results: An optimal GINI cutoff of 74.4 divided the cohort into low-GINI (38%) and high-GINI (62%) groups. In the multivariable Cox regression models, a high pretreatment GINI remained independently associated with both inferior OS (adjusted HR 2.51, 95% CI 1.05–6.01, p = 0.039) and inferior PFS (adjusted HR 3.22, 95% CI 1.45–7.14, p = 0.004). When compared against five established inflammatory biomarkers (NLR, PLR, LMR, PNI, and CAR), the GINI consistently demonstrated comparable prognostic performance across multiple statistical approaches. Conclusions: The pretreatment GINI is a candidate prognostic marker for patients with cSCC undergoing Cemiplimab therapy. Given its cost-effectiveness and ready availability from routine clinical laboratory workups, the GINI score may improve prognostic risk stratification and could potentially inform risk assessment and clinical monitoring in real-world oncological practice.