'Biologic endoscopy': optimization of upper aerodigestive tract cancer evaluation

Endoscopy is the first-line examination and most reliable way to get precise bidimensional assessment of the superficial extent of a squamous cell cancer arising within the upper aerodigestive tract (UADT). Its role as the cornerstone at each diagnostic step in the evaluation of head and neck cancer patients, in both treatment and follow-up, cannot be overemphasized. A number of technological improvements have been introduced to enhance conventional white light endoscopy of the UADT, in order to provide deeper insight into the specific biological properties of observed lesions. The purpose of this review is to summarize the most recent trends in 'biologic endoscopy' techniques.

Starting from the use of toluidine blue up to the most recent light-based detection systems such as autofluorescence and narrow band imaging, researchers have devoted substantial efforts to the identification of specific biological properties of neoplastic tissues that can be targeted by new endoscopic tools. These aids attempt to assist the surgeon in achieving a more reliable distinction between normal and neoplastic or precancerous mucosa, within a wide range of inflammatory and iatrogenic modifications.

Even though direct comparison of the efficacy of these techniques is seldom feasible due to their site-specific application, different advantages and disadvantages, economic considerations, and limited diffusion in daily practice, it is nevertheless clear that the future of endoscopy of the UADT will be strongly influenced by these new technologies.