Impact of the epithelial dysplasia grading and Ki67 proliferation index in the adjacent non-malignant mucosa on recurrence and survival in head and neck squamous cell carcinoma

This study aimed to evaluate the association between several different aspects of disease in head and neck squamous cell carcinoma (HNSCC): morphological grading, Ki67 proliferation index (PI), invasive front, adjacent non-malignant mucosa (ANMM), recurrence and overall survival of the patients. Sixty-four fully reviewed and followed-up patients with primary HNSCC were matched according to recurrence of the lesion and placed in one of two groups of 32 cases. Chi-square and Fisher's exact tests were used to analyze the clinicopathological parameters between both groups of patients. Association between Ki67 PI and clinicopathological parameters was also analyzed through chi-square and Fisher's exact tests with the binary logistic regression model used as a multivariate analysis. In addition, survival analysis was also performed. Our results showed that high-risk dysplasia in ANMM and high Ki67 PI in ANMM of HNSCC exhibited a higher risk of tumor recurrence. Survival analysis showed that T3/T4 tumor sizes and high Ki67 PI were significantly associated with an increase in the risk of death in multivariate analysis. Our results revealed that high-risk dysplasia and high Ki67 PI of the ANMM are parameters which are indicative of tumor recurrence. Furthermore, T3/T4 tumor sizes and high Ki67 PI in the invasive front appear to be important prognostic tools for HNSCC.