Bone invasion by oral squamous cell carcinoma: essential molecular alterations

Oral squamous cell carcinoma (OSCC) is a globally growing problem with 300,000 new cases each year. The close anatomical relation of the oral mucosa to the jaws often leads to invasion of the bone, implicating extensive resections with major implications on function, aesthetics and quality of life. Planning of bony resections depends on two staging methods: (1) clinical estimation by the surgeon and (2) radiological imaging. Unfortunately both methods have their shortcomings. Most important step in bone invasion is activation of osteoclasts. A better understanding on molecular alterations leading to osteoclastogenesis is of great importance. The presence of teeth and infections in the oral cavity, and hypoxia in the tumour microenvironment could have a key role. We propose that reprogramming energy metabolism and tumour promoting inflammation also play an important role in detecting molecular biomarkers associated with bone invasion by OSCC. Improvement in the understanding of these molecular processes will lead to a better staging protocol and a more tailor-made treatment for the patient. On this topic we did a review of literature and we will propose a hypothesis that might lead to a better understanding of OSCC invading bone.