A consensus on liquid biopsy from the 2016 Chinese Lung Cancer Summit expert panel

Detection of plasma EGFR mutations for personalized treatment of lung cancer patients without pathologic diagnosis

INTRODUCTION

Next-generation sequencing (NGS) and digital polymerase chain reaction (PCR) based platforms have been used to detect EGFR mutations in plasma circulating tumor DNA (ctDNA) with high accuracy. Generally, molecular testing is performed after histopathological analysis. However, many patients with suspected advanced nonsmall cell lung cancer are unable to undergo biopsy thus forgoing potential treatment with highly effective tyrosine kinase inhibitors (TKIs) in patients with sensitizing EGFR mutations. We examined the utility of ctDNA testing to detect EGFR mutations in patients' plasma, where tissue biopsy is not feasible.

METHODS

We conducted a single-center, prospective study of 30 Chinese patients with suspected advanced lung cancer, who were unable to undergo a biopsy for initial diagnosis due to comorbidities or poor performance status. Patients with plasma EGFR sensitizing mutations were treated with first-generation EGFR TKIs.

RESULTS

Twenty of 30 patients enrolled had sensitizing EGFR mutations in ctDNA and were started on EGFR TKIs. After a median follow-up of 12 months, median progression-free survival (PFS) was 10 months and median overall survival (OS) was not reached. The median OS for the 10 untreated patients was 3 months.

CONCLUSIONS

In our study, patients with plasma EGFR mutations treated with TKIs showed disease control rate (DCR) and PFS similar to historical controls that were treated based on tissue testing. This is the first prospective study showing that ctDNA genotyping provides a feasible diagnostic approach for frail lung cancer patients who are unable to undergo biopsy, which subsequently leads to EGFR-targeted therapy, and improved outcomes in this subgroup of patients.

Biomarkers in Non-Small Cell Lung Cancers: Indian Consensus Guidelines for Molecular Testing

Novel molecular targets and promising targeted therapies have reshaped diagnostics in patients with advanced non-small cell lung cancer (NSCLC). Despite this progress, the implementation of molecular screening to identify predictive biomarkers in Indian clinical and pathology settings has been challenging due to operational and logistical constraints. This consensus guideline brings together medical oncologists, molecular pathologists and pathologists from India to provide a quick and competent reference for biomarker testing in NSCLC. The guideline summarizes the importance of targetable mutations in NSCLC such as epidermal growth factor receptor (EGFR), rearrangements in anaplastic lymphoma kinase and receptor tyrosine kinase encoded by ROS-1 gene, overexpression of programmed cell death ligand-1 and resistant EGFR mutations. It reaffirms recommendations from international working groups, discusses vulnerable pre-analytical procedures and provides a balanced review on the pros and cons of different diagnostic tests (immunohistochemistry, fluorescence in situ hybridization, polymerase chain reaction-based testing and next-generation sequencing). The document also provides an algorithm to aid diagnostic decision-making and a checklist to assess the quality of testing laboratories that will help the medical oncologists make an informed choice. Overall, these recommendations are based on evidence and clinical experience and will aid policymakers, oncologists, health care practitioners and pathologists who strive to implement molecular strategies and make informed decisions for improved care in NSCLC in India.Funding: AstraZeneca Pharma India Limited.

Established, emerging and elusive molecular targets in the treatment of lung cancer

Although histological subtype still underlies tumour classification and treatment, the recognition that lung cancer is, largely, a genetic disease has prompted a push to reconfigure cancer taxonomies according to molecular criteria. In this review, we discuss established (e.g. EGFR, ALK, ROS1, and programmed cell death 1/programmed death-ligand 1), emerging (e.g. MET, RET, and NTRK) and elusive (e.g. TP53, KRAS, and MYC) molecular targets in the treatment of lung cancer. We synthesize a large and rapidly growing body of literature regarding the discovery and therapeutic inhibition of these targets in lung cancer. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.