INTRODUCTION
head and neck malignancies, head and neck cancer, tumor
ADENOID CYSTIC CARCINOMA, TUMOR, HEAD AND NECK CANCER
Adenoid cystic carcinoma (ACC) is a rare subtype of head and neck cancer mostly occurred at salivary glands accounting for 1% of head and neck malignancies.All‐trans retinoic acid (ATRA), a major metabolic derivative of vitamin A, is a critical lipid signaling molecule in regulating embryonic and postnatal development. As an inducer of tumor cell differentiation,As an indolent tumor, ACCs were characterized by an immune‐excluded microenvironment, the presence of M2‐polarized macrophages and myeloid‐derived suppressor cells (MDSC), and very low mutational load are the key drivers of resistance to antiangiogenic therapies.Less efficacy of monotherapy ATRA and poor tolerance of monotherapy apatinib limited their usage in clinical practice, and the combination of ATRA and Low‐dose apatinib may be a promising new approach. As we know, the two positive feedback loops mediated by MYB and VEGF in ACC, and in mechanism, combination of ATRA and apatinib could block these two loops at same time (Figure The potential mechanism of action of ATRA/Apatinib combination.