Immunologic profiling of adenoid cystic carcinoma (acc)

Background Adenoid cystic carcinoma (ACC) is among the most common malignant salivary gland tumors. Approximately 50% of patients develop distant metastases and up to one third die within 2 years. Chemotherapy provides limited benefit, and is not associated with a survival advantage. Radiotherapy is standard for localized disease, and is also commonly used for palliation of symptomatic metastases. Little is known about endogenous immune responses directed against ACC at baseline, or following conventional treatments. Therefore, we evaluated ACC specimens for infiltrating immune cells and expression of immune checkpoint ligands PD-L1 and PD-L2 and their receptor, PD-1, to guide future investigations of immunotherapy in ACC patients.