Immunohistochemical Expression of Baculoviral Inhibitor of Apoptotic Proteins Repeat-Containing Protein in Tumors of Salivary Gland Origin.

Background: Salivary gland tumors (SGTs) include benign and malignant tumors, such as pleomorphic adenoma (PA), mucoepidermoid carcinoma (MEC), and adenoid cystic carcinoma (ACC). Baculoviral inhibitors of apoptotic proteins (BIAPs) repeat-containing protein 6 (BIRC6), is an anti-apoptotic protein that plays an important role in cancers.

Purpose: We aimed to evaluate the expression of BIRC6 in SGTs and its correlation with the clinicopathological features.

Materials and method: In this cross-sectional study, 56 SGT tissue samples, including 15 cases of MEC, 20 cases of ACC, and 21 cases of PA, as well as nine cases of normal salivary gland tissues, were investigated for BIRC6 expression by immunohistochemical analysis.

Results: BIRC6 was found in 2.50%, 63%, 88%, and 63% of normal tissue, MEC, ACC, and PA, respectively. The mean total score of BIRC6 expression was 9.13; for ACC, MEC, PA, and normal tissue of the salivary gland were 10.25, 9.13, 9.00, and 3.00, respectively. The high expression of BIRC6 was detected in 29 cases of malignant and 15 cases of benign SGTs. The frequency of high or low expression was not different between the male and female patients (p= 0.833), patients aged below or above 65 years (p= 0.950), patients with different tumor sizes (p= 0.734), and metastasis status (p= 0.977).

Conclusion: The higher expression intensity and percentage of BIRC6 in malignant and benign SGTs suggests it as a potential marker to be used in future targeted therapy for SGTs.