Difference in the yields of bronchial washing cytology before and after forceps biopsy for lung cancer diagnosis

Objectives: Fiberoptic bronchoscopy (FOB) has been one of the essential procedures used in the diagnosis of lung cancer. Diagnostic yields of FOB related procedures such as bronchial washing (BW), bronchial brushing (BB), bronchial biopsy (BBx), and transbronchial biopsy (TBBx) depend on the location and extent of the tumors. The yields of BW vary among different studies (39-79%). Some reported that the yield might increase in post-bronchoscopic sputum. Since samples from BW are obtained directly from the respiratory tract, we hypothesized that post bronchoscopic forceps biopsy BW might further increase the yield as well. The objective of this study was to compare the diagnostic yields of bronchial washing before and after forceps biopsy for lung cancer. Material and Method: 114 patients, 70 with endobronchial lesions (42 exophytic lesions, 28 submucosal lesions) and 44 with non-endobronchial lesions, suspected to have lung cancers were evaluated at Siriraj Hospital between March and October 2000. All the patients underwent FOB with initial BW then forceps biopsy (BBx or TBBx) of the lesions followed by re-BW. The cytological specimens were blinded to the cytopathologists. Positive cytologic results of each procedural specimen were compared to final malignancy diagnosis (by positive specimens from FOB, transthoracic needle aspiration, surgery, clinical and radiological follow-up) to determine the sensitivity of each test. Statistical analysis: Chi-square test comparing sensitivity of each test. Results: 82 /114 patients (39 patients had exophytic lesions, 24 patients had submucosal lesions, and 19 patients had peripheral lung lesions) had a final diagnosis of malignancy. The sensitivity of initial BW before forceps biopsy was 37.8% (31/82), re-BW after forceps biopsy was 37.8% (31/82), both initial BW and re-BW was 46.3% (38/82), and forceps biopsy alone was 79.3% (65/82). There was no statistically significant difference (p>0.05) in the sensitivity of initial BW, re-BW and combined initial BW and re-BW. No major complications such as massive hemorrhage, respiratory failure, or death occurred. Conclusion: The diagnostic yields of BW before and after forceps biopsy for malignancy were not different in our study. However, the yield seemed to be higher when combined pre and post-forceps biopsy BW was used.