J. Vansteenkiste MD, PhD

Highlights in respiratory oncology

At ASCO 2017, 195 abstracts in the feld of respiratory oncology were presented (169 in 2016): 22 oral presentations (including 4 in a clinical science symposium), 24 poster discussion items, and 149 posters. In this summary, most attention will go to phase III randomized controlled trials (RCTs) and innovative data that are, or may become, relevant for the practicing clinician. As this report is only the “extract of the abstracts”, the reader is referred to the respective abstracts published in J Clin Oncol volume 35 Suppl 15, 2017 (abstracts #8500–8586 and #9000–9107 and available on-line at https://meetinglibrary.asco.org/

Immunotherapy in lung cancer: current approach and clinical application

Since its start in 2009, immunotherapy with immune checkpoint inhibitors has become a hot topic in respiratory oncology. Randomized controlled trials have proven the superiority of immune checkpoint inhibitor therapy versus standard chemotherapy in advanced non-small cell lung cancer (NSCLC). PD-L1 immunohistochemistry (IHC) is so far the most commonly implemented predictive biomarker in the selection of optimal candidates for immunotherapy. Immunotherapy with pembrolizumab is approved in first-line for advanced NSCLC with a PD-L1 expression on >50% of tumor cells, and after at least one prior chemotherapy regimen in case of PD-L1 expression of >1%. Treatment with nivolumab or with atezolizumab is approved for advanced NSCLC after prior chemotherapy, irrespective of the PD-L1 status. Since PD-L1 expression does not always correlate with treatment efficacy, other biomarkers are under investigation. Tumor mutational burden (which correlates clinically with smoking status) and CD8 tumor-infiltrating lymphocytes are associated with increased responsiveness to PD-L1 inhibition, and thus are other promising predictive biomarkers. NSCLC with molecular drivers on the contrary is preferably treated with tyrosine kinase inhibitors (TKIs) rather than immunotherapy due to lower response rates, even in case of high PD-L1 expression. Immunotherapy and other therapeutic modalities (chemotherapy, radiotherapy, TKIs) might work in synergy. The results of the first prospective trials with combination therapy were recently published, and many others are to be expected.

Molecular diagnostics on tissue samples obtained through EBUS-TBNA: review on practice guidelines

Summary

Endobronchial ultrasonography is a minimally invasive endoscopic technique that enables a real time transbronchial needle aspiration. Endobronchial ultrasound guided transbronchial needle aspiration (EBUS-TBNA) specimens have a high diagnostic accuracy in the detection of intrathoracic lymph node metastasis for a variety of malignancies. Predictive biomarker testing is gaining wide importance to tailor the treatment with the largest benefit to the patient. Endobronchial ultrasound guided transbronchial needle aspiration also results in an accurate analysis of molecular alterations (by ImmunoHistoChemistry, Fluorescence In Situ Hybridisation, or gene sequencing) provided that the endoscopist takes sufficient tumour samples and a dedicated cytopathologist is involved in the mastery of the specimens.

Endobronchial ultrasound guided transbronchial needle aspiration samples can be handled in different ways. Liquid-based cytology and smears are mostly used. The choice of the testing method should be based primarily on the nature of the sample to be tested, testing laboratory’s expertise, and available equipment. ImmunoHistoChemistry, Fluorescence In Situ Hybridisation and targeted polymerase chain reaction-based sequencing can be performed on >80% of the endobronchial ultrasound guided transbronchial needle aspiration specimens, as the latter is more sensitive in terms of limit of detection than Sanger sequencing. The next step are the next generation sequencing assays, with only 10–20 ng of DNA sample input per gene mutation, which will minimise rejected samples due to insufficient sample quantity.

(BELG J MED ONCOL 2016;10(1):15–20)