Análise da imunoexpressão da p16 e p53 e sua relação com parâmetros clicicomorfológicos em carcinoma de células escamosas de língua oral em jovens e idosos

Abstract

Oral squamous cell carcinoma is the eighth most prevalent malignant neoplasm in the worldwide, affecting mainly male individuals within their sixth decade of life, exposed to main risk factors, such as tobacco and alcohol consumption, although in the last years it has been observed a change in this profile, with an increase in the incidence of this neoplasm in younger patients. There is no concordance in the literature when comparing the biological behavior of this neoplasm between young and older patients. Objective: To evaluate comparatively the immunoexpression of p16 and p53 in a series of Oral Tongue Squamous Cell Carcinoma (OTSCC) cases in young and elderly individuals, relating to their clinical and morphological parameters. Material and methods: Sample was composed of 80 OTSCC cases, divided in two groups: 40 cases of OTSCC in young individuals (≤45 years old) and 40 cases of OTSCC in elderly individuals (≥60 years old). The clinical data (tumor size, regional node metastasis, distant metastasis and clinical stage) were obtained from the medical records. For morphological analysis, was utilized the system proposed by Bryne et al. (1992). The immunohistochemical analysis (IH) was performed through the positivity index (PI), using the antibodies anti-p16 and anti-p53. The statistical analysis used Chi-square, Fisher‟s exact, Mann Whitney tests and Spearman‟s Correlation. Results: In relation to the clinical-morphological parameters, there were no significance statistical differences between the age groups studied (p>0.05). Although there were no significance differences, the elderly individuals were predominantly diagnosed in initial clinic stages (I/II), 67.5% (27/40), and the younger individuals were in more advanced clinical stages (III/IV), 52.5% (21/40). In both groups, the OTSCC was classified as high degree of malignance (p>0.05). In the IH analysis, observed nuclear immunoexpression of p16 in 77.5% (31/40) of the cases of OTSCC in the young (median 10.80) and 95% (38/40) in the elderly (median 31.65) and a nuclear/cytoplasmic immunoexpression of p16 in 37.5% (15/40) of cases, in both age group studied. There were significant differences the nuclear immunoexpression of p16 in relation to tumor size (T3/T4) (p=0.02) and clinical stage III/IV (p=0.02) in the age group of elderly individuals. It was observed a positive correlation (r=0.395; p=0.012) between nuclear and cytoplasmic immunoexpression of p16 in the age group of young individuals. The nuclear immunoexpression of p53 showed positivity in 77.5% (31/40) of cases in the young (median 18.75) and in 87.5% (35/40) in the elderly (median 19.55) (p> 0.05). Statistical differences immunoexpression of p53 in relation to clinical-morphological parameters were not observed in both groups. Also, there was no correlation between immunoexpression of p16 and p53 in the age groups studied (p>0.05). Conclusions: The p16 and p53 participate of the pathogenesis of OTSCC in young and elderly patients, however, p16 and p53 cannot be utilized as suitable markers to differentiate biological behavior of the OTSCC between two age groups studied. We can also inferred that the p16 is related to tumour progression of OTSCC in elderly patients.