The optimal sequence of bronchial brushing and washing for diagnosing peripheral lung cancer using non-guided flexible bronchoscopy

Abstract

The optimum sequence of bronchial brushing and washing for diagnosing peripheral lung cancer, defined as an invisible endobronchial tumour, is not clear and requires further study. We prospectively obtained washing samples after brushing in patients with peripheral lung tumours during non-guided flexible bronchoscopy (FB) to investigate the diagnostic yield of these samples and conducted a retrospective review of the prospectively collected data. The study included 166 patients who met the inclusion criteria. The overall diagnostic yield of bronchial brushing and washing for peripheral lung cancer was 52.4%. The diagnostic yields of brushing and washing were 37.3% and 46.4%, respectively, and that of washing was superior according to McNemar's test (p = 0.017, κ = 0.570). Furthermore, washing was diagnostic, whereas brushing was not, in 15.1% of all cases. Comparison of positive washing cytology (brushing) with the respective pathological diagnosis yielded a concordance rate of 88.3% (90.3%), with κ = 0.769 (0.801) (p < 0.001). Performing washing after brushing during nonguided FB is a very safe, cost-effective procedure that may help improve the diagnostic yield in patients with suspected peripheral lung cancer. Our information will also benefit clinicians performing diagnostic bronchoscopy in patients with suspected peripheral lung cancer when fluoroscopic guidance or advanced bronchoscopy techniques are not available. Flexible bronchoscopy (FB) is an essential step in the diagnosis of lung cancer. Numerous basic diagnostic procedures using FB, including bronchoalveolar lavage or washing, brushing, endobronchial or transbronchial biopsy (TBB), and transbronchial needle aspiration, have been evaluated in various combinations to improve the diagnostic yield of FB in patients with suspected lung cancer 1-3. The diagnostic yield of bronchoscopy for lung cancer depends on whether the tumor is visible within the bronchial tree. The overall sensitivity of FB among many studies of central tumours, defined as visible endobronchial tumours, was 88% (range 67-97%). The sensitivities of endobronchial biopsy, brushing, and washing were 74% (range 48-97%), 61% (23-93%), and 47% (29-78%), respectively. In comparison, the overall sensitivity of FB for peripheral lung cancer, defined as an invisible endobronchial tumour, was 78% (range 36-88%). TBB had the highest sensitivity (57%, range 17-80%), followed by brushing (54%, range 16-84%), and bronchoalveolar lavage or washing (43%, range 12-65%) 3. However, the

Suitability of transbronchial brushing cytology specimens for next‐generation sequencing in peripheral lung cancer

“…Even if the target lesions are quite small, bronchial brushing enables sufficient tumor cells collection. 12 Third, even when fresh frozen samples are required, pathological confirmation is still possible by dividing the same sample into two tubes (Figure 1). A few studies have reported on the feasibility of TBB for NGS analysis.…”

“…In these cases, it is difficult to obtain sufficient tumor cells from small lung nodules by forceps biopsy. Even if the target lesions are quite small, bronchial brushing enables sufficient tumor cells collection 12 . Third, even when fresh frozen samples are required, pathological confirmation is still possible by dividing the same sample into two tubes (Figure 1).…”

“…However, even if we used a virtual bronchoscopic navigation system, it could be difficult to obtain sufficient tissue to confirm malignant pathological diagnosis by forceps biopsy. In these cases, bronchial brushing and washing contributed to the pathological diagnosis in peripheral lung lesions and was able to obtain enough cancer cells 12 …”

“…In these cases, bronchial brushing and washing contributed to the pathological diagnosis in peripheral lung lesions and was able to obtain enough cancer cells. 12 On the other hand, to improve the success rate of NGS analysis, the quantity of nucleic acid is an important issue. Therefore, to investigate the suitability of bronchial brushing cytology specimens obtained by EBUS-GS-TBB, we evaluated the correlation between success rates of NGS and extracted DNA/RNA yields pursuant to biopsy methods.…”

Is flexible bronchoscopy necessary in the preoperative workup of patients with peripheral cT1N0 subsolid lung cancer? —a prospective multi-center cohort study

“…In Jo KW's study, they excluded patients with endobronchial diseases. Recently, Lim and his colleagues showed that bronchial brushing and washing could increase the diagnostic yield for patients with invisible endobronchial tumors (13). Possibly, this procedure may be beneficial for solid tumors.…”