Early diagnosis of lung cancer.

Early detection and surgical resection is essential for the treatment of lung cancer. Although the introduction of low-dose spiral computed tomography (CT) is considered to be one of the most promising clinical research developments, CT screening is used for detecting small peripheral lesions. Tumors arising in the central airways require other techniques for early detection. Centrally arising squamous cell carcinoma of the airway, especially in heavy smokers, is thought to develop through multiple stages from squamous metaplasia to dysplasia, followed by carcinoma in situ (CIS), progressing to invasive cancer. It would be ideal to be able to detect and treat preinvasive bronchial lesions defined as dysplasia and CIS before progressing to invasive cancer. Great efforts have been made to develop new mucosal imaging techniques. Bronchoscopic imaging techniques capable of detecting preinvasive lesions and currently available in clinical practice include autofluorescence bronchoscopy (AFB), high magnification ronchovideoscope, and narrow band imaging (NBI). For a more precise evaluation of newly detected preinvasive lesions, endobronchial ultrasound (EBUS) and optical coherence tomography (OCT) can be used.