Head and Neck Squamous Cell Carcinoma (HNSCC), particularly Oropharyngeal Squamous Cell Carcinoma (OPSCC), is a major global health challenge due to its increasing incidence and high mortality rate. This study investigates the role of aldo-keto reductase 1C2 (AKR1C2) in OPSCC, focusing on its expression, correlation with Human Papillomavirus (HPV) status, oxidative stress status, and clinical outcomes, with an emphasis on sex-specific differences. We analyzed AKR1C2 expression using immunohistochemistry in formalin-fixed, paraffin-embedded tissue samples from 51 OPSCC patients. Additionally, we performed RT-qPCR in cultured HPV16-E6*I and HPV16-E6 overexpressing HEK293 cell lines (p53^WT). Statistical analyses were performed to assess the correlation between AKR1C2 expression and patient data. Our results indicate a significant association between increased AKR1C2 expression and higher AJCC classification (p = 0.009) as well as positive HPV status (p = 0.008). Prognostic implications of AKR1C2 varied by sex, whereby female patients with high AKR1C2 expression had better overall survival, whereas male patients exhibited poorer outcomes. Additionally, AKR1C2 expression was linked to HPV status, suggesting a potential HPV-specific regulatory mechanism. These findings underscore the complex interplay among AKR1C2, HPV, and patient sex, highlighting the need for personalized treatment strategies for OPSCC. Targeted inhibition of AKR1C2, considering sex-specific differences, may enhance therapeutic outcomes. Future research should investigate these mechanisms to enhance treatment efficacy.

Human papillomavirus-mediated recurrent respiratory papillomatosis (RRP) is a premalignant neoplasia of the upper airway characterized by significant dysphonia and respiratory obstruction. Immune checkpoint blockade has emerged as a potential alternative to repeated surgical interventions in RRP. Here, we investigated the intralesional T-cell composition and expression of the immune checkpoints programmed death-ligand 1 (PD-L1) and cytotoxic T-lymphocyte antigen 4 (CTLA-4) in RRP. We analyzed tissue samples from 30 patients treated at a tertiary care center between 2009 and 2021, including paired samples from individual patients collected at different time points. Immunohistochemical staining was performed for CD4, CD8, CTLA-4, FoxP3, and PD-L1 and correlated with disease severity and previous adjuvant therapies. Overall disease burden and intervention-free survival were not associated with the abundance of CD4⁺, CD8⁺, or FoxP3⁺ T cells, nor with immune checkpoint expression. However, patients with aggressive disease exhibited a higher intralesional FoxP3/CD4 T-cell ratio. Prior intralesional cidofovir treatment was associated with reduced CD4⁺ T-cell infiltration. These findings suggest that a locally immunosuppressive microenvironment, reflected by an elevated FoxP3/CD4 ratio, contributes to disease severity in RRP. Consistent CTLA-4 expression across all evaluated samples supports further investigation of anti-CTLA-4 therapy, either alone or in combination with other checkpoint inhibitors.