Androgen receptor overexpression by immunohistochemistry in malignant salivary gland tumors in Tanzania.

BACKGROUND

Malignant salivary gland tumors (SGTs) present diagnostic challenges and limited treatment options. This study aims to determine the proportion of malignant SGTs overexpressing the androgen receptor (AR) by immunohistochemistry (IHC) and its association to age, sex, anatomical site, histopathological subtype and grade which may inform customized treatment approaches.

METHODOLOGY

This was a retrospective cross-sectional analytical study of archived paraffin embedded tissue blocks of malignant SGTs diagnosed at MNH Central Pathology Laboratory (CPL) from January 2019 to December 2022. IHC staining using a monoclonal Rabbit Anti-Human AR and interpretation was done using Allred score. The AR overexpression was assessed and compared by age, sex anatomical site, histological subtype and histological grade of the tumor.

RESULTS

Out of 158 (60%) malignant SGTs, 115 cases underwent AR IHC where, mean age was 49.7 ± 17.9, females were 61(53%). Major salivary gland involvement was (67)58.1%, predominantly parotid gland 35(52.2%), Adenoid cystic carcinoma and Mucoepidermoid carcinoma were the most common tumors accounting for 38(33%) and 22 (19%) respectively. High grade tumors were prevalent accounting for 53(46.1%). Androgen receptor overexpression was observed in 49(42.6%). A significant association was observed between AR and parotid gland anatomical location (aOR = 3.45, 95% CI = 1.1-10, p = 0.027) and high-grade tumors (aOR = 5.1, 95% CI = 1.4-19, p = 0.014). No significant association between AR overexpression and age (p-value 0.253), sex (p-value 0.708) and histological subtype (p-value 0.557), although highest proportion were seen in salivary duct carcinoma (71.4%).

CONCLUSION

High-grade malignant SGTs and parotid gland location are associated with AR overexpression. This suggests that androgen deprivation therapy (ADT) has the potential to play a role in the management of advanced SGTs. However, large-scale studies that will include comprehensive molecular investigations and efficacy exploration of ADT are recommended to clarify our current findings and inform therapeutic options for patient with high grade and recurrent tumors.