Features of expression of oncoprotein p16ІNK4a in squamous cell carcinomas of the oropharynx

Up to 40% of squamous cell carcinoma of the oropharynx (SCCO) are associated with human papillomavirus of a high oncogenic risk, which shows the greatest affinity to the epithelium of the tonsils. One of the indicators of malignant transformation of the multilayered epithelium cells with evidence of HPV lesions is the accumulation of oncoprotein p16INK4a, tumor suppressor from Ink4 family. Presence of excessive amount of p16INK4a in a free state shows its reduced suppressor function and is an indication of the active expression of viral oncogene E7. For multivariate analysis of molecular mechanisms of oncogenic transformation, the obtained data of p16INK4a expression options were distributed according to the clinical and morphological characteristics of squamous cancers. Mixed nuclear-cytoplasmic expression of p16INK4a more than 5% of tumor cells was observed in 73.6% of cases, which confirms the relations of path of carcinogenesis of cancers of this localization with HPV. Statistically significant association between a positive p16INK4a status and decrease of the degree of of SCCO differentiation (p=0,002, r=-0,365) was determined. But with respect to other clinical and morphological characteristics of SCCO and marker p16INK4a statistically significant differences between groups were not found (p>0.05), this denies its prognostic and predictive value in the diagnosis of SCCO.