Introduction: We attempted to assess the correlation between the Doppler mode image patterns during endobronchial ultrasound-guided (EBUS) transbronchial needle aspiration and the expression of angiogenesis-related molecules within lymph nodes in patients with non-small-cell lung cancer.
Methods: Thirty-eight archived EBUS- transbronchial needle aspiration samples of lymph nodes (27 metastatic and 11 nonmetastatic) in patients with non-small-cell lung cancer with Doppler mode ultrasound image were analyzed. The Doppler mode image of the vasculature of the targeted lymph node was categorized into the following groups: normal blood flow, low blood flow (LBF), and high blood flow (HBF). Vascular index ratio (vascular area/lymph node area) of each metastatic lymph node was calculated. Total RNA and protein was extracted and analyzed for expression of HIF-1α, VEGF-A, and VEGF-C by quantitative RT-PCR and enzyme-linked immunosorbent assay.
Results: Within the 27 metastatic lymph nodes, eight were categorized into the LBF group and 19 into the HBF group. Vascular index ratio was significantly higher in HBF than LBF (p = 0.0003). mRNA expression of HIF-1α and VEGF-A was significantly higher in metastatic lymph nodes than in benign lymph nodes (p < 0.0001). Compared with LBF and HBF, HIF-1α mRNA expression was significantly higher in LBF (p = 0.01) and VEGF-C mRNA expression was significantly higher in HBF (p = 0.0315). There was no significant difference in protein expression by enzyme-linked immunosorbent assay analysis.
Conclusions: The vascularity of metastatic lymph nodes observed by EBUS correlates with the mRNA expression of HIF-1α and VEGF-C (not VEGF-A). This correlation is a clinical utility that needs to be evaluated further.