[Detection of early hilar lung cancers with fluorescence bronchoscopy]

The development of fluorescence bronchoscopy has made it possible to diagnose locally superficial hilar lung cancers such as carcinoma in situ, and in some cases atypical squamous metaplasia thought to be precancerous lesions. The selection of a treatment modality can be difficult for early hilar lung cancers due to problems associated with multiple lung carcinomas and the large number of heavy smokers afflicted. Many patients also have decreased pulmonary function. If carcinoma in situ and microinvasive carcinomas can be detected early, it may be possible to treat them radically with a less invasive method than surgery, such as endoscopic laser therapy. Centrally arising squamous cell carcinoma of the tracheobronchial tree, especially in heavy smokers, is thought to develop in multiple stages from squamous metaplasia, to atypical squamous metaplasia, followed by carcinoma in situ, and finally invasive cancer. However, it is hoped that preventive medicine for lung cancer will be established whereby patients with localized atypical squamous metaplasia detected by fluorescence bronchoscopy can be carefully monitored and motivated to stop smoking, and also administered chemopreventive agents.