Unsupervised 20-feature immunohistochemical immune profiling identifies exploratory cervical cancer phenotypes with unfavorable survival signals

Objective: To determine whether unsupervised integration of routinely accessible immunohistochemical immune features can identify clinically relevant tumor immune microenvironment phenotypes in cervical cancer. Methods: We performed a retrospective exploratory analysis of surgically treated cervical cancer cases with complete scoring for a 20-feature immunohistochemical immune panel. The features were derived from approximately 11 antibody-defined markers, including separate intratumoral (IT) and stromal (ST) scores where applicable. Hierarchical clustering was performed using standardized feature values, Euclidean distance, and Ward.D2 linkage. The three-cluster solution was the primary unsupervised analysis. The comparison between C2 and combined C1/C3 was an exploratory, outcome-informed contrast generated after inspection of the primary three-cluster survival curves. Cluster-defining features, clinicopathological associations, overall survival, cause-specific Cox models, and competing-risk endpoints were assessed. Results: The source dataset included 226 patients; 177 had pT1b-region disease and 169 had complete data for the 20-feature panel. Three tumor immune microenvironment clusters were identified: C1 (n=50), C2 (n=78), and C3 (n=41). The most discriminatory features were CD8-ST, CD8-IT, CD3-ST, PD-1-ST, PD-1-IT, CD3-IT, CD4-ST, CD68-IT, CD20-ST, and CD57-ST. C2 showed relative depletion of several stromal and intratumoral lymphoid and checkpoint-associated features. In the exploratory C2 versus C1/C3 contrast, C2 was associated with inferior overall survival by Kaplan-Meier analysis (log-rank p=0.012) and univariable Cox regression (HR 2.14, 95% CI 1.16-3.92, p=0.014). After adjustment for age, nodal status, and histology, the association was attenuated and borderline (HR 1.84, 95% CI 0.99-3.42, p=0.055). Fine-Gray analysis showed a similar adverse direction for neoplasm-specific death (SHR 2.37, 95% CI 0.95-5.87, p=0.063). Conclusion: Routine compartment-aware immunohistochemical immune profiling identified exploratory cervical cancer immune phenotypes, including an immune-depleted C2 cluster with unfavorable survival signals. These findings are hypothesis-generating and require independent validation before clinical implementation.