Evaluation of the diagnostic accuracy of bronchial brushing cytology in lung cancer: A meta‐analysis

Abstract

Background Flexible bronchoscopy is commonly used to examine patients suspected to have lung cancer. Bronchial brushing is one of the cytological technologies for lung specimens obtained through a bronchoscope. However, the accuracy of bronchial brushing cytology (BBC) for lung cancer diagnosis is still inconclusive. The aim of this study was to evaluate the diagnostic accuracy of BBC. Methods A literature search was conducted with PubMed, Embase, the Cochrane Library, Web of Science, Biomed Central, Clinical Key, and ClinicalTrials.gov. Studies that assessed the efficacy of BBC in detecting lung cancer were included. Articles that estimated the accuracy on a per‐patient basis were included. Review articles, case reports, and research that provided insufficient data to construct a 2 × 2 table were excluded. Both prospective trials and retrospective studies were included. English language studies were reviewed. Data synthesis was performed with a random‐effects model. Results Seventeen studies with 2538 patients were included in the study. The meta‐analysis for BBC generated a pooled sensitivity of 0.67 (95% confidence interval [CI], 0.65‐0.70) and a pooled specificity of 0.91 (95% CI, 0.89‐0.93). The pooled diagnostic odds ratio for BBC was 24.55 (95% CI, 12.39‐48.66). The subgroup analysis for studies using liquid‐based cytology (LBC) generated a pooled sensitivity of 0.68 and a pooled specificity of 0.92. The pooled diagnostic odds ratio of studies using LBC was 114.18. Conclusions These findings indicate that BBC is a discriminative diagnostic approach with moderate sensitivity and high specificity for diagnosing peripheral pulmonary lesions. BBC using LBC has higher diagnostic performance.

Respiratory cytology in malignant lung disease – The thoracic oncologist’s perspective

“…A pooled analysis where no distinction was made between visible and non-visible lesions demonstrated a sensitivity of 67% and 37% for bronchial brushings and washings respectively. 28 However, a study assessing the diagnostic yield in non-visible parenchymal disease reported a yield of 37.3% and 46.4% for brushings and washings respectively, with a suggestion of improved yields when washings followed bronchial brushings. 29 Liquid-based cytology has gained favour over conventional smears and cytospin preparations, particularly for specimens containing abundant blood and/or mucus.…”

“…The sensitivity of endobronchial brushings and washing for diagnosis of malignancy is influenced by whether the target lesion is visible or not. A pooled analysis where no distinction was made between visible and non‐visible lesions demonstrated a sensitivity of 67% and 37% for bronchial brushings and washings respectively 28 . However, a study assessing the diagnostic yield in non‐visible parenchymal disease reported a yield of 37.3% and 46.4% for brushings and washings respectively, with a suggestion of improved yields when washings followed bronchial brushings 29 …”

Importance of Cytopathologic Diagnosis in Early Cancer Diagnosis in Resource-Constrained Countries

“…Facilities to provide bronchial brushing and washings are few in LMICs, but FNAB either transthoracic or endobronchial ultrasound for lung malignancies seen on a chest X-ray shows sensitivity, specificity, and overall accuracy of 84%-96.29%, 95.45%-100%, and 89.55%-95.91%, respectively. [23][24][25][26][27][28] In a study that reported overall diagnostic characteristics (benign v malignant) of FNAB and CNB, the ranges of sensitivity were 81.3%-90.8% and 85.7%-97.4%; of specificity, 75.4%-100.0% and 88.6%-100.0%; and of accuracy, 79.7%-91.8% and 89.0%-96.9%, respectively. However, for specific diagnostic characteristics of FNAB and CNB (identifying the histologic subtype of malignancies or the specific benign diagnoses), the ranges of sensitivity were 56.3%-86.5% and 56.5%-88.7%; of specificity, 6.7%-57.1% and 52.4%-100.0%; and of accuracy, 40.4%-81.2% and 66.7%-93.2%, respectively.…”

The usefulness of liquid-based cytology of bronchoalveolar lavage fluid combined with bronchial brush specimens in lung cancer diagnosis

“…The diagnostic yield of BB varies widely between studies, with a range of 18% to 87%. 20 Our study group previously mixed BALF and BB samples in a thin-layer prepared bottle to increase the diagnostic yield of BALF and BB. The results were published in a paper that demonstrated that the diagnostic value of LBC of BALF combined with BB was higher than that with BALF alone.…”