The role of bronchoscopy in the diagnosis of early lung cancer: a review

Abstract

Lung cancer is the leading cause of cancer-related deaths worldwide with an overall 5-year survival rate of 17% after diagnoses. Indeed many patients tend to have a very poor prognosis, due to being diagnosed at an advanced stage. Conversely patients who are diagnosed at an early stage have a 5-year survival >70%, indicating that early detection of lung cancer is crucial to improve survival. Although flexible bronchoscopy is a relatively non-invasive procedure for patients suspected of having lung cancer, only 29% of carcinoma in situ (CIS) and 69% of microinvasive tumors were detectable using white light bronchoscopy (WLB) alone. As a result, in the past two decades, new bronchoscopic techniques have been developed to increase the yield and diagnostic accuracy, such as autofluorescence bronchoscopy (AFB), narrow band imaging (NBI) and high magnification bronchovideoscopy (HMB). However, due to the low specificity and the limitation to detect only proximal bronchial tree, new probe-based technologies have been introduced: radial endobronchial ultrasound (R-EBUS), optical coherence tomography (OCT), confocal laser endomicroscopy (CLE) and laser Raman spectroscopy (LRS). To date, although tissue biopsy remains the gold standard for diagnosing malignant/premalignant airway disease and some techniques are still investigational, bronchoscopic technologies can be considered the safest and most accurate tools to evaluate both central and distal airway mucosa.

Keywords: Bronchoscopy; autofluorescence; endobronchial ultrasound (EBUS); lung cancer; narrow band imaging (NBI).

Figure 1

Squamous cell carcinoma. Bronchoscopic findings of an invasive squamous cell carcinoma of the central airway on autofluorescence imaging (A), white light bronchoscopy (B) and narrow band imaging (C).

Figure 2

Carcinoma in situ. White light bronchoscopy (A) and narrow band imaging (B) of squamous cell carcinoma (carcinoma in situ) of the central airway.

Figure 3

Angiogenic squamous dysplasia. High resolution bronchoscopic findings of biopsy proven angiogenic squamous dysplasia in the central airway on white light (A) and narrow band imaging (B).

Figure 4

Radial probe endobronchial ultrasound. Bronchoscopic evaluation of biopsy proven squamous cell carcinoma of the central airway prior to photodynamic therapy. White light bronchoscopy revealed abnormality at the orifice of the upper division bronchus (A). Central type radial probe endobronchial ultrasound showed no invasion of the tumor into the cartilaginous layer (B).