Early Detection of Lung Cancer and the Role of Endoscopic Fluorescence Imaging

Abstract

Summary Lung cancer accounts for nearly 30% of all cancer deaths in the developed countries. For advanced (metastatic) stages of this disease there is a lack of effective treatment. For these patients, prognosis is poor, with less than 15% survival 5 years after diagnosis. Recently a number of successful endobronchial therapies including photodynamic therapy have been developed for early stage non-small-cell lung cancer. In small very high risk patient populations, for instance after lobectomy, such early stage bronchial tumors (stage O, IA) may be screened, and thus localised for treatment, with the aid of fluorescence bronchoscopy. To be more effective, one must find and treat these early stage lung cancers in a much larger fraction of the population at risk. This means that one must be concerned with the large medium-high risk population: the heavy smokers with 20–30 or more packyears. Because at most only a few percent of this group may have early stage lung cancer, it would not be cost effective to use bronchoscopy for localisation prior to endobronchial therapy. Consequently the localisation step must be preceded by a means of cheap and effective screening. A major step in this direction has been accomplished for several types of cancer, and for these cancers it has now been shown that the presence of early stage disease can be predicted, with high sensitivity and specificity, from blood serum protein patterns. One may reasonably expect that such a screening step will also be available for early stage lung cancer very soon, so that in the near future fluorescence bronchoscopy, or video fluorescence bronchoscopy, may well play a significant role in lung cancer management. In this context, the present article briefly describes the state of development of autofluorescence bronchoscopy. In particular first results are shown where addition of red backscattered light to the red autofluorescence channel leads to improved imaging.