Prospective evaluation of EBUS-TBNA specimens for programmed death-ligand 1 expression in non-small cell lung cancer patients: a pilot study

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA): revolutionizing the landscape of lung disease diagnostics

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) has emerged as a revolutionary diagnostic tool for lung diseases, including lung cancer, sarcoidosis, and lymphoproliferative diseases. This minimally invasive procedure offers a superior diagnostic yield while ensuring maximum patient safety when compared to traditional invasive techniques such as mediastinoscopy and thoracoscopy. By enabling real-time imaging and sampling of mediastinal and hilar lymph nodes and masses directly from the bronchoscope, EBUS-TBNA has redefined the precision of diagnostic bronchoscopy. This comprehensive review explores the origins, development, and current status of EBUS-TBNA, highlighting its successes and identifying potential areas for improvement. Technological advancements have continuously enhanced the reliability and efficacy of EBUS-TBNA over time. The mechanisms underlying the superior diagnostic yield of EBUS-TBNA are thoroughly discussed, further solidifying its position as the gold standard for lung cancer staging and diagnosis. Furthermore, this review delves into the crucial role of EBUS-TBNA in lung cancer diagnosis, supported by studies comparing its accuracy, safety, and cost-effectiveness to other diagnostic tools. Looking ahead, ongoing research aims to expand the applications of EBUS-TBNA and improve its diagnostic performance. Notable advancements in needle design and sampling techniques hold promise for further enhancing its efficacy. Maximizing its potential through comprehensive training and continuous technological developments will enable broader clinical applications, ultimately leading to improved patient outcomes. As EBUS-TBNA continues to evolve, its diagnostic impact is expected to increase, solidifying its position as an indispensable tool in the diagnosis and management of lung diseases.

Diagnostic Performance and Cell Count of EBUS-TBNA Needle Gauges: A Prospective Trial

BACKGROUND

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a well-established diagnostic procedure for evaluating hilar and mediastinal lymphadenopathies and is the gold standard for lung cancer diagnosis and staging. Recent studies assessed the effectiveness of the 19-G flex needle in obtaining larger EBUS-TBNA samples, and prospective small series gave similar results in terms of diagnostic yield when testing different gauge needles. The lack of homogeneity between series and the small sample size of some prospective cohorts poses a limit to the validity of those results. This prospective controlled study compared the 19-G flex and 22-G needles in terms of diagnostic yield. An objective laboratory method was used to count cells and compare the two needles' cytologic yields.

MATERIAL

A prospective controlled study was conducted on 90 patients undergoing EBUS-TBNA for the diagnosis of hilar and mediastinal lymphadenopathies. The institutional ethic committee (IEO573) approved the study, and informed consent was obtained from all patients.

RESULTS

A total of 90 patients were enrolled in this study, 84.4% of whom were diagnosed with malignancy and 15.6% with non-neoplastic disease. Sensitivity for malignancy was 93.4% (CI: 87.4-97.1%) for the 19-G needle and 92.6% (CI: 86.3-96.5%) for the 22-G needle (p = 0.80). The percentage of malignant cells in the cell block was 63.9% and 61.5% for the 22-G and 19-G needles, respectively. The cell count assessed by flow cytometry was 2071 cells/µL (IQR: 600,2265) with the 22-G needle and 2761 cells/µL (IQR: 505,3250) with the 19-G needle (p = 0.79). The malignant cell count was 0.05 × 10³ cells/µL with the 22-G and 0.08 × 10³ cells/µL with the 19-G needle (p = 0.70). There was no difference in the presence of tissue cores in the samples, and rapid on-site evaluation (ROSE) cellularity was comparable between the two needles.

CONCLUSIONS

The 19-G flex EBUS-TBNA needle is comparable to the 22-G needle in terms of diagnostic yield for cyto-histological evaluation of hilar and mediastinal lymphadenopathies. There is no difference between the 19-G and 22-G needle cell counts evaluated by flow cytometry.

Effector Memory T Cells and CD45RO+ Regulatory T Cells in Metastatic vs. Non-Metastatic Lymph Nodes in Lung Cancer Patients

Lymphocytes play a leading role in regulation of the immune system in lung cancer patients. The recognition of T cells profile may help in prediction of effectiveness of anticancer immunotherapy. The aim of the study was to determine the dominant subpopulation of CD4+ and CD8+ lymphocytes in metastatic and non-metastatic lymph nodes (LNs) of lung cancer patients. LNs aspirates were obtained during EBUS/TBNA procedure and cells were analyzed by flow cytometry. We showed a higher percentage of CD4+ and CD8+ effector memory T cells in the metastatic than in the non-metastatic LNs (28.6 vs. 15.3% and 28.6 vs. 14.0%, p< 0.05). The proportion of CD45RO+ T regulatory cells (CD45RO+ Tregs) was higher in the metastatic LNs than in the non-metastatic ones (65.6 vs. 31%, p< 0.05). We reported the significant differences in T cell subsets depending on the lung cancer metastatic process. We observed that the effector memory T cells were predominant subpopulations in metastatic LNs. Lymphocyte profile in LNs is easy to evaluate by flow cytometry of EBUS/TBNA samples and may reflect the immune status in lung cancer.

Endoscopic Applications of Near-Infrared Photoimmunotherapy (NIR-PIT) in Cancers of the Digestive and Respiratory Tracts

Near-infrared photoimmunotherapy (NIR-PIT) is a newly developed and promising therapy that specifically destroys target cells by irradiating antibody-photo-absorber conjugates (APCs) with NIR light. APCs bind to target molecules on the cell surface, and when exposed to NIR light, cause disruption of the cell membrane due to the ligand release reaction and dye aggregation. This leads to rapid cell swelling, blebbing, and rupture, which leads to immunogenic cell death (ICD). ICD activates host antitumor immunity, which assists in killing still viable cancer cells in the treated lesion but is also capable of producing responses in untreated lesions. In September 2020, an APC and laser system were conditionally approved for clinical use in unresectable advanced head and neck cancer in Japan, and are now routine in appropriate patients. However, most tumors have been relatively accessible in the oral cavity or neck. Endoscopes offer the opportunity to deliver light deeper within hollow organs of the body. In recent years, the application of endoscopic therapy as an alternative to surgery for the treatment of cancer has expanded, providing significant benefits to inoperable patients. In this review, we will discuss the potential applications of endoscopic NIR-PIT, especially in thoracic and gastrointestinal cancers.