Prognostic Value of Ki‐67 in the Invasive Zone of Oral Squamous Cell Carcinoma

BACKGROUND: The molecular profile of cells within the tumor invasive zone, where tumor cells interact with surrounding non-tumor cells, plays a crucial role in defining tumor malignant characteristics, such as the pattern of invasion (POI). Therefore, evaluating the diagnostic value of the proliferation index molecule, Ki-67, in both tumor cells and adjacent non-tumor cells at the invasive zone with different POIs, holds significant clinical importance for oral squamous cell carcinoma (OSCC). METHODS: This retrospective study included 133 primary OSCC samples, and the spatial pattern of Ki-67 in the tumor invasive zone was analyzed by immunohistochemistry (IHC). The prognostic value of tumor cells and stroma proliferative capacity in different POIs were assessed. RESULTS: Ki-67 was widely expressed in tumor cells and stroma cells within the invasive zone, and cells in high-invasiveness POIs exhibit higher proliferation. Elevated Ki-67 expression in tumor cells was associated with poor overall survival (OS) and disease-free survival (DFS) in patients, which is independent of POIs. In our study, we identified the expression level of Ki-67 in tumor cells across high-invasiveness POIs as an independent risk factor for OS and DFS in OSCC patiens. Additionally, Ki-67 expression in surrounding non-tumor cells did not significantly correlate with patient survival. CONCLUSION: The remarkable proliferation characteristic of tumor cells in high-invasiveness POIs of OSCC tumors plays a crucial role in the prognosis of patients.