Análise da imunoexpressão da ativina A, Ki-67 e Bcl-2 e sua correlação com parâmetros clínico-morfológicos em carcinomas de células escamosas de língua em pacientes jovens e idosos

Abstract

Introduction: Oral squamous cell carcinoma (OSCC) in young individuals has increased in recent years with incidence ranged of 1.4% to 13.0% and the literature has suggested a more aggressive biological behavior that OSCC in older individuals. Immunoexpression of Activin A, Ki-67 and Bcl-2 were studied in various malignant neoplasms, although researches comparing the immunoexpression these markers in OSCC between young and older individuals are scarce. Objectives: To evaluate immunoexpression of activin A, Ki-67 and Bcl-2 in cases of tongue squamous cell carcinoma (TSCC) between young and older patients and verify the association of this immunoexpression with clinicopathological parameters (tumor size, node metastasis, distant metastasis and clinical stage) and histopathological grade of malignancy. Material and methods: The sample was composed for 60 cases of TSCC, diagnosed in two hospitals of reference in oncology in Paraíba state, Brazil. It was considered two groups: 30 cases of young (≤45y) and 30 cases of older (≥60y). Clinical parameters were obtained of medical records. For morphological analysis utilized the histopathological grade of malignancy, proposed by Bryne et al (1992). Immunohistochemical analysis was realized of quali- quantitative manner for polyclonal antibody Activin A and quantitative manner for antibodies Ki-67 and Bcl-2. Statistical analysis utilized Chi-square, Fisher’s exact, Mann Whitney and Spearman’s Correlation (P<0.05). Results: In regarding to clinical and morphological parameters between groups, there was significant difference to tumor size (P=0.024). In older patients, tumor size was associated to T1-T2. Although without significant difference (P>0.05) the older patients were predominantly diagnosed in earlier clinical stage (I/II) and young patients in later clinical stage (III/IV). In both groups, TSCC were classified as high grade of malignancy (P>0.05). The median of Activin A in TSCC was 55 (range, 7.5 to 112.5) in young patients and 65 (range, 40.0 to 90.0) in older patients (P=0.428). Significant difference in the immunoexpression of Activin A was observed in relation to clinical state (III/IV) in older patients (P=0.04). The median of immunoexpression of Ki-67 in TSCC was 46.9 (range, 29.9 to 56.3) in young patients and 34.8 (28.0 to 48.5) in older patients (P=0.085). Significant difference in the immunoexpression of Ki-67 was observed in relation to histological grade of malignancy in both groups, where in young patients was associated to high grade (P=0.039) and olderly patients was associated to low grade (P=0.047). The median of immunoexpression of Bcl-2 in TSCC was 8.85 (range, 3.97 to 16.62) in young patients and 13.3 (range, 7.47 to 25.55) in olderly patients (P=0.049). There was no significant difference was observed in immunoexpression of Bcl-2 in relation to clinical or morphological parameters, in either age groups (P>0.05). In addition, it was observed positive correlation between immunoexpression of Activin A and Bcl-2 in older patients (r=0.370, P=0.044). Conclusions: Based on these results, it is suggested that the difference in biological behavior of TSCC between young and old may be related to different pathogenesis. In young patients, it is suggested that the pathogenesis of TSCC is associated with increased cell proliferation, while in olderly patients, pathogenesis of TSCC is associated evasion of apoptosis, being regulated by activin A.