Bronchial Washing Beforeand After Endobronchial Biopsy and Bronchial Brushing

Objective: To identify the optimal position of bronchial washing (BW) in the sequence of bronchoscopic sampling in order to maximize the ability to confirm malignancy for endoscopically visible tumours. Hypothesis to be tested: The investigators hypothesize that the diagnostic yield, with the incorporation of contemporary cytology processing techniques, of combined BW before and after endobronchial biopsy (EBBx) / bronchial brushing (BB) is higher than that of single BW after EBBx / BB. Design and subjects: This is a prospective, randomized controlled study to be conducted in the medical department of a tertiary care hospital in Hong Kong involving patients who will receive bronchoscopy. Patients will be recruited if an endoscopically visible tumour is suspected. Study instruments: Patients will be randomized into two groups. The diagnostic yield of confirming malignancy for endoscopically visible tumours, with the incorporation of contemporary cytology processing techniques, will be compared between obtaining BW before and after EBBx / BB, and obtaining single BW after EBBx / BB. Main outcome measures: Only patients with a definite cytological or histological diagnosis of lung cancer will be included in further analyses. The diagnostic yield of diagnosing lung cancer between the pre \& post-EBBx/BB group and post-EBBx/BB group will be compared by the Chi-square test as an intergroup comparison.