Imunoexpressão de HLA-DR em carcinomas de células escamosas de língua oral em indivíduos jovens e idosos

Abstract

Oral tongue squamous cell carcinoma (OTSCC) is a malignant neoplasm associated with high recurrence and mortality rates. Although it is usually diagnosed in individuals over 60 years old, recent data indicate an increasing incidence of OTSCC in individuals under 45 years of age. Research has revealed potential differences in the molecular basis and biological behavior of this malignant neoplasm related to patient age, but findings remain conflicting. In the development and progression of various carcinomas, studies have highlighted the importance of the expression of human leukocyte antigen-DR (HLA-DR), a glycoprotein of the major histocompatibility complex (MHC), by neoplastic cells. Despite these findings, information regarding the expression of this protein in OTSCC neoplastic cells is scarce. Therefore, this study analyzed the immunoexpression of HLA-DR in OTSCC from young and elderly individuals and correlated the findings with clinicopathological parameters (tumor size/extent, regional lymph node metastasis, clinical stage, and histopathological malignancy grade). The sample consisted of 34 OTSCC cases (17 diagnosed in young individuals [≤45 years] and 17 in elderly individuals [≥60 years]). Clinical data were collected from medical records, and the histopathological malignancy grade of OTSCC was assessed at the tumor invasion front. For the immunohistochemical study, the percentages of HLA-DR-positive neoplastic cells (cytoplasm/membrane) were evaluated in 10 fields with the highest immunoreactivity (400×) at the tumor invasion front. Data were analyzed using the Mann-Whitney test (p < 0.05). HLA-DR expression was observed in all OTSCC cases, with higher positivity percentages in elderly individuals (median: 29.3%) compared to younger individuals (median: 11.7%) (p = 0.089). Regarding clinicopathological parameters, there was a trend toward higher HLA-DR expression percentages in OTSCC from elderly individuals with intense inflammatory infiltrate (p = 0.051) and intense/extreme nuclear pleomorphism (p = 0.057). In conclusion, the results of this study suggest the involvement of HLA-DR in the pathogenesis of OTSCC in both young and elderly individuals. However, the expression of this glycoprotein in neoplastic cells does not appear to be associated with the progression of this malignant neoplasm. In elderly individuals, HLA-DR expression in OTSCC may be related to the intensity of the inflammatory infiltrate and the degree of nuclear pleomorphism.