Expression of p-AKT characterizes adenoid cystic carcinomas of head and neck with a higher risk for tumor relapses

Specimen of 29 patients were investigated immunohistochemically with antibodies against p-AKT, TKTL-1 (transketolase-like 1), M2PK (M2 pyruvate kinase), and GLUT-1. Proliferation was investigated by staining with Ki67. The tumors were located at the major or minor salivary glands. Only the typical cribriform subtype was investigated. The initial tumor stage was pT1 or pT2.Expression of p-AKT was significantly (P = 0.036) associated with a higher relapse risk in multivariate analysis. Low expression of M2PK was non-significantly (P = 0.065) predictive for a higher risk. TKTL-1 and GLUT-1 were expressed in the majority of cases, albeit not associated with relapse risk.Adenoid cystic carcinomas positive for p-AKT show a higher relapse risk. However, other parameters of glucose metabolism investigated here or proliferation (Ki67) were not predictive in this entity. Our findings demonstrate a possible background for therapeutic approaches targeting the inhibition of PI3K/AKT pathway.Malignant tumors of salivary glands represent a small subset of all malignancies. Adenoid cystic carcinomas (ACC) are one of the most common types at this anatomic site. They account for 1% of all malignant head and neck tumors, 10% of all salivary gland tumors, and 22% of malignant salivary gland tumors [1,2]. The majority occures at the minor salivary glands (60%) [3]. From the major salivary glands, the parotid is most often involved. Locations like the nasal cavity and the paranasal sinus are also possible. Typically, ACC show an indolent clinical course with a considerable risk for local relapse (60% of patients, mostly <2 years after primary) and late distant metastases (lung or bone), the latter sometimes several years after first diagnosis with fatal outcome. Standard treatment for ACC is surgery, followed by post-operative radiotherapy [4]. Since tumors show a characteristic perineural spread, the surgical key problem is the complete resection. Therefore, the extend of tumor infiltra