Prognostic value of tumor‐infiltrating immune cells in clinical early‐stage oral squamous cell carcinoma

Background Tumor‐infiltrating immune cells (TIICs) are critical components of tumor immune microenvironment (TIME), which play crucial roles during tumor initiation, development, and progression. However, the prognostic value of TIICs is still not well documented in clinical early‐stage oral squamous cell carcinoma (OSCC). In this study, we aimed to assess the prognostic value of TIICs in clinical early‐stage OSCC and develop a nomogram based on TIICs to predict the prognosis. Methods Eighty patients with clinical early‐stage (cT1,2N0M0) OSCC were enrolled in this study. Immunohistochemical staining was performed to evaluate the infiltration of TIICs, including CD8+ T cells, CD57+ NK cells, CD163+ macrophage, and CD20+ B cells. Overall survival (OS) and disease‐free survival (DFS) curves were plotted by the Kaplan–Meier method. Cox's proportional hazards regression models were performed to assess the prognostic value of TIICs. Finally, a nomogram was established to predict the OS based on TIICs infiltration and assessed by concordance index (C‐index) and calibration curve. Results High infiltrations of CD57+ NK cells and CD20+ B cells indicated a better OS in clinical early‐stage OSCC. Moreover, high infiltration of CD20+ B cells favored a longer DFS. Of note, low infiltrations of CD57+ NK cells and CD20+ B cells were independent prognostic factors for poor OS in clinical early‐stage OSCC. The nomogram that combined CD57+ NK cells with CD20+ B cells could predict the OS in clinical early‐stage OSCC, and the C‐index was 0.801 (95% CI: 0.679–0.924). The calibration plot showed that prediction and observation are well matched. Conclusions High infiltration of CD57+ NK cells and CD20+ B cells indicate a favorable OS in clinical early‐stage OSCC. The nomogram constructed based on TIICs might be used for predicting the prognosis in clinical early‐stage OSCC.