CD103 +CD8 +T Cells Combined with Neutrophil-to-lymphocyte Ratio Predict Response to Neoadjuvant Chemoimmunotherapy in Advanced Oral Squamous Cell Carcinoma

Objective: To investigate the relationship between the expression of CD103+CD8+T cells in locally advanced oral squamous cell carcinoma (LA-OSCC), and the response to neoadjuvant chemoimmunotherapy (NACI). Methods: Thirty LA-OSCC patients from the Department of Oral and Maxillofacial Surgery, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, who underwent NACI from June 2020 to December 2022 were analyzed, including 16 responders and 14 non-responders. Using multiple immunofluorescence technique to stain sections of patients to verify the correlation between the expression of CD103+CD8+T cells and the efficacy of NACI. CD103+CD8+T cell density was counted using Inform and HALO software. The Spearman correlation coefficient in rank correlation is used to describe the correlation between CD103+CD8+T cell and neutrophil-to-lymphocyte ratio (NLR), derived neutrophil-to-lymphocyte ratio (dNLR), platelet-lymphocyte ratio (PLR), systemic immune inflammation index (SII) It's effectiveness as a predictive marker to NACI was analyzed by receiver operator characteristic (ROC) curve analysis and decision curve analysis (DCA). Two-tailed t-test or Mann-Whitney U-test was used to compare data between two groups, and one-way ANOVA was used to compare data between multiple groups. SPSS 22.0 and GraphPad prism 9.0 software were used for statistical analysis and plotting of relevant statistical graphs such as histograms. P<0.05 was considered a statistically significant difference. Results: The density of CD103+CD8+T cells has expanded in advanced OSCC patients who are responsive to NACI. The CD103+CD8+T cell densities in the responsive and nonresponsive groups were 118.30(41.92, 197.80) pcs/mm2 and 21.63(4.91, 71.92) pcs/mm2 respectively, with statistically significant differences(U=52.00, P=0.012). CD103+CD8+T cell abundance was negatively correlated with NLR, dNLR, PLR, and SII (P<0.05). ROC curve analysis showed that the AUC for predicting efficacy of NLR, dNLR, PLR, and SII were 0.781 (P=0.009, 95%CI: 0.5715-0.9910), 0.671 (P=0.105, 95%CI: 0.467-0.881), 0.679 (P=0.020 95%CI: 0.549-0.951), 0.750 (P=0.096, 95%CI: 0.461-0.896), respectively. The AUC for CD103+CD8+T cells alone was 0.861 (P=0.013, 95%CI: 0.585-0.950), and the AUC of combining CD103+CD8+T cells with NLR was 0.896 (P=0.025, 95%CI: 0.454-0.938). Conclusions: The density of CD103+CD8+T cells is expanded in advanced OSCC patients who are responsive to NACI. CD103+CD8+T cells positively predict favorable responses as a strong indicator to NACI in advanced OSCC patients. Co-interpretation of CD103+CD8+T cells and NLR value enhances the predictive accuracy of NACI in advanced OSCC patients.