New approaches to the understanding of the molecular basis of oral cancer

Cancers of the oral cavity, salivary glands, larynx, and pharynx, collectively referred to as squamous cell carcinomas of the head and neck (HNSCC), are the sixth most common cancer among men in the developed world. The prognosis of HNSCC patients is still poor, which reflects the fact that although the risk factors for HNSCC are well-recognized, very little is known about the molecular mechanisms responsible for this malignancy. This review describes some of the current efforts and technological advances that have focused on the creation of a complete information infrastructure for genes expressed during squamous cell carcinogenesis. These include: the recently described HNSCC-specific chromosomal alterations (cCAP); the Head and Neck Cancer Genome Anatomy Project (HN-CGAP), whose goal is the systematic identification and cataloguing of known and novel genes expressed during tumor development; and the use of laser-capture microdissection (LCM), which is pivotal for the comprehensive molecular characterization of normal, pre-cancerous, and malignant cells by means of DNA-array technology. The latter provides the means for the analysis of expression patterns of thousands of genes simultaneously. The use of LCM for proteomics and DNA analysis is also included in this review. These revolutionary approaches are likely to have an unprecedented impact on cancer biology, and provide exciting opportunities to unravel the still-unknown mechanisms involved in squamous cell carcinogenesis. They are also expected to provide a molecular blueprint for HNSCC, thus helping to identify suitable markers for the early detection of pre-neoplastic lesions, as well as novel targets for pharmacological intervention in this disease.