[Soft tissue pathologies of the oral cavity]

The most frequent form of neoplasia in the oral cavity is the squamous cell carcinoma (about 90% of cases) representing the 3-5% of all malignant tumors with about 56% of mortality rate, at 5 years from the diagnosis. In general, the neoplastic disease is now unanimly considered as a multifactorial and multiphasic pathology. Multiphasic since the carcinogenic process consists in the cellular capacity to acquire oncological potentialities through several stages such as: moltiplication (a), transmission (b) of malignity caracteristics to progenic cells, invasivity (c), capacity to give metastasis (d) and also resistance to chemiotherapy. Multifactorial since in the onset of the disease intrinsic and extrinsic factors are certainly involved. In the carcinogenic process of CCS a high percentage has been noticed of loss of heterozygosity (LOH) in the short arm (P) of cromosoms 3 and 9, which contains the tumor-suppressor genes p53 and DDC (Deleted in colon rectal cancer). In the onset of VADS carcinoma and in particular of oral CCS, it has also been formulated the hypothesis of an intrinsic genetic factor (Llewellyn et al., 2001) between patients, also young, who present the neoplasia even trough they have never been exposed to extrinsic risk factors such as smoke and alcohol. Since part of patients with oral CCS do not always refer a common risk factors history as possible extrinsic neoplasia causes, it has been formulated the hypothesis that some viral infections, for their oncogenic capacity, could be the main ethiological factors predisposing to this neoplasia. The HPV are responsible, either in the oral cavity or on the epidermis, for benign proliferations such as: Verruca Vulgaris, Condyloma Acuminatum, Focal Epithelial Hyperplasia, Squamous Cell Papillomas, but also lesions that are potentially or certainly malignant such as CCS and Verrucous Carcinoma. The molecular analysis performed show that proteins produced from E6 and E7 portions of viral genoma (HPV 16-18) interfer and degrade proteins p53 and pRb produced by tumor suppressor genes (TSg). Recently, thanks to new molecular biology techniques, several authors are studying potentially neoplastic lesions, in order to better understand the association with HPV.