Endobronchial ultrasound-guided transbronchial needle biopsy for the diagnosis of intrathoracic lymph node metastases from extrathoracic malignancies: a meta-analysis and systematic review.

Intrathoracic lymph node metastases in patients with extrathoracic malignancies are a common clinical manifestation. Several studies evaluating intrathoracic lymph node metastases in patients with extrathoracic malignancy by using the endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) have been reported. The objective of this meta-analysis is to investigate the diagnostic value of EBUS-TBNA for diagnosing intrathoracic lymph node metastases in patients with extrathoracic malignancies. We systematically searched Cochrane Library, Medline and Embase for relevant studies published prior to May 2013. Studies specifically designed to evaluate the diagnostic accuracy of EBUS-TBNA for intrathoracic lymph node metastases in patients with an extrathoracic malignancy were selected. Diagnostic accuracy meta-analysis was conducted by pooling estimates of sensitivity, specificity, negative likelihood ratio (NLR), positive likelihood ratio (PLR) and diagnostic odds ratios (DOR) derived from a summary receiver operating characteristic (SROC) analysis of the original studies. Six studies were included, which provided a dataset of 533 patients. EBUS-TBNA pooled estimates had 0.85 sensitivity (95% confidence interval (CI): 0.80-0.89), 0.99 specificity (95% CI: 0.95-1.00), PLR 28.63 (95% CI: 11.51-71.22) and NLR 0.16 (95% CI: 0.12-0.21). The overall DOR was 179.77 (95% CI: 66.29-487.50). The area under the SROC curve and the diagnostic accuracy were 0.9247 and 0.8588, respectively. Evidence gathered from studies of moderate quality reveals a high degree of diagnostic accuracy of EBUS-TBNA for diagnosing intrathoracic lymph node metastases in patients with extrathoracic malignancies.