Imunoexpressão da Ciclooxigenase-2 em neoplasias malignas de glândulas salivares.

Abstract

Salivary gland neoplasms are relatively uncommon, present a wide histological heterogeneity and distinct biological behaviors, corresponding to approximately 3 to 6% of all head and neck tumors. Despite being uncommon, they represent a therapeutic challenge and require thorough clinical monitoring. Cyclooxygenase-2 has been analyzed as a possible biomarker related to the biological behavior of malignant neoplasms, since the expression of inflammatory enzymes contributes to a differential phenotype and unfavorable clinical outcome. In view of the above, the aim of this study was to verify the immunohistochemical expression of cyclooxygenase-2 in malignant salivary gland neoplasms, as well as to observe whether there was an association with the patients' clinicopathological data. Thirty-eight cases of malignant salivary gland neoplasms were selected. Immunoexpression was assessed using the Image J® program. The data collected was analyzed using the Statistical Package for Social Science software. A 5% significance level was adopted for the statistical tests (p<0.05). The patients in the study were mainly female and aged 40 or over; the major salivary glands were the most affected. Most cases were classified as T1-T2, N0 and M0. With regard to COX-2 expression, a higher incidence was found in mucoepidermoid carcinoma (n=11/73.3%) and acinar cell carcinoma (n=7/70%), and this result was statistically significant (p = 0.001). In turn, CME also showed a higher percentage (n=11/73.3%) in the very inflammatory infiltrate category, compared to the other tumors (p = 0.031). When statistically associated, the major salivary glands showed a higher percentage (n=17/63%) in the high COX-2 expression category (p = 0.016). There were no significant associations with clinicopathological parameters. We conclude that higher COX-2 expression and a higher percentage of inflammatory infiltrate are associated with mucoepidermoid carcinoma and acinar cell carcinoma. Larger studies are needed to better understand the role of this enzyme as a biomarker and possible therapeutic target, as well as to be more elucidative when trying to associate patients' clinicopathological data with COX-2 expression.