Correlation between human papillomavirus protein expression and clinicopathological features in oral squamous cell carcinoma.

Objective: Given the implications of concurrent human papilloma viral infection (HPV) in the prognostic course and implications on therapeutic approached of patients with oral squamous cell carcinoma (OSCC), we seek to investigate the implications that P16 expression has on the clinical course and pathological appearance of patients with OSCC and concurrent infection.

Methods: Using S-P immunohistochemistry, we examined the expression of P16 and Ki67 in 460 patients with OSCC. We compared the expression of the protein between the tumor cells and normal epithelial mucosa within the same patient. The clinical and pathological characteristics (including gender, age, histological grade, lymph node metastasis, clinical stage, clinical recurrence, tumor diameter, Ki67 proliferation index) were analyzed by stratification statistically.

Results: In total 460 cases of OSCC were identified and expression of P16 was significantly higher in the OSCC group compared to the normal mucosal epithelial group (X2 = 60.545, p = .000). There also appear to be a gender predilection as the expression was higher in females compared to males (0.218 vs. 0.144, X2 = 3.921, p = .048). Younger age also appears to be a predictive factor as those under 35 years old had higher expression of the protein compared to those over 35 years old (0.294 vs. 0.157, X2 = 4.230, p = .040). P16 positivity showed a significant positive correlation with histologic grade (X2 = 4.114, p = .043). In addition, the positive rate of P16 was higher in patients with ki67 over 85% (0.455 vs. 0.160, X2 = 6.667, p = .023).

Conclusion: OSCC with HPV infection tends to occur more frequently in female patients and those under 35 years of age. HPV infection with expression of the P16 and ki67 protein may promote the proliferation and growth of OSCC at a higher frequency.