135O_PR: Plasma genotyping for predicting benefit from osimertinib in patients (pts) with advanced NSCLC

Noncoding RNAs and Liquid Biopsy in Lung Cancer: A Literature Review

Lung cancer represents a genetically heterogeneous disease with low survival rates. Recent data have evidenced key roles of noncoding RNAs in lung cancer initiation and progression. These functional RNA molecules that can act as both oncogenes and tumor suppressors may become future biomarkers and more efficient therapeutic targets. In the precision medicine era, circulating nucleic acids have the potential to reshape the management and prognosis of cancer patients. Detecting genomic alterations and level variations of circulating nucleic acids in liquid biopsy samples represents a noninvasive method for portraying tumor burden. Research is currently trying to validate the potential role of liquid biopsy in lung cancer screening, prognosis, monitoring of disease progression, and treatment response. However, this method requires complex detection assays, and implementation of plasma genotyping in clinical practice continues to be hindered by discrepancies that arise when compared to tissue genotyping. Understanding the genomic landscape of lung cancer is essential in order to provide useful and innovative research in the age of patient-tailored therapy. In this landscape, the noncoding RNAs play a crucial role due to their target genes that dramatically influence the tumor microenvironment and the response to therapy. This article addresses present and future possible roles of liquid biopsy in lung cancer. It also discusses how the complex role of noncoding RNAs in lung tumorigenesis could influence the management of this pathology.

First-Line Treatment in EGFR Mutant Non-Small Cell Lung Cancer: Is There a Best Option?

First generation or second generation EGFR tyrosine kinase inhibitors are currently the standard of care for the first-line management of non-small cell lung cancer (NSCLC) patients with activating mutations within the kinase domain of the epidermal growth factor receptor gene (1, 2). Resistance to targeted therapy can develop after 9–11 months (3–8). Third generation inhibitors were developed to target the EGFR T790M clone, which is the most common dominant second site resistance mutation after first or second generation inhibitors. Osimertinib received full FDA approval for the second-line treatment of advanced NSCLC based on a phase III study comparing the compound to chemotherapy. Recent data demonstrates an important impact for osimertinib in the front-line space based on results comparing the compound to first-generation erlotinib or gefitinib therapy.

Liquid biopsy genotyping in lung cancer: ready for clinical utility?

Liquid biopsy is a blood test that detects evidence of cancer cells or tumor DNA in the circulation. Despite complicated collection methods and the requirement for technique-dependent platforms, it has generated substantial interest due, in part, to its potential to detect driver oncogenes such as epidermal growth factor receptor (EGFR) mutants in lung cancer. This technology is advancing rapidly and is being incorporated into numerous EGFR tyrosine kinase inhibitor (EGFR-TKI) development programs. It appears ready for integration into clinical care. Recent studies have demonstrated that biological fluids such as saliva and urine can also be used for detecting EGFR mutant DNA through application other user-friendly techniques. This review focuses on the clinical application of liquid biopsies to lung cancer genotyping, including EGFR and other targets of genotype-directed therapy and compares multiple platforms used for liquid biopsy.

The Importance of Biopsy in the Era of Molecular Medicine

Recent advances in the molecular characterization of cancers have triggered interest in developing a new taxonomy of disease in oncology with the goal of using the molecular profile of a patient's tumor to predict response to treatment. Image-guided needle biopsy is central to this "precision medicine" effort. In this review, we first discuss the current role of biopsy in relation to clinical examples of molecular medicine. We then outline important bottlenecks to the advancement of precision medicine and highlight the potential role of image-guided biopsy to address these challenges.

Next-Generation EGFR Tyrosine Kinase Inhibitors for Treating EGFR-Mutant Lung Cancer beyond First Line

Tyrosine kinase inhibitors (TKIs) against the human epidermal growth factor receptor (EGFR) are now standard treatment in the clinic for patients with advanced EGFR mutant non-small-cell lung cancer (NSCLC). First-generation EGFR TKIs, binding competitively and reversibly to the ATP-binding site of the EGFR tyrosine kinase domain, have resulted in a significant improvement in outcome for NSCLC patients with activating EGFR mutations (L858R and Del19). However, after a median duration of response of ~12 months, all patients develop tumor resistance, and in over half of these patients this is due to the emergence of the EGFR T790M resistance mutation. The second-generation EGFR/HER TKIs were developed to treat resistant disease, targeting not only T790M but EGFR-activating mutations and wild-type EGFR. Although they exhibited promising anti-T790M activity in the laboratory, their clinical activity among T790M+ NSCLC was poor mainly because of dose-limiting toxicity due to simultaneous inhibition of wild-type EGFR. The third-generation EGFR TKIs selectively and irreversibly target EGFR T790M and activating EGFR mutations, showing promising efficacy in NSCLC resistant to the first- and second-generation EGFR TKIs. They also appear to have lower incidences of toxicity due to the limited inhibitory effect on wild-type EGFR. Currently, the first-generation gefitinib and erlotinib and second-generation afatinib have been approved for first-line treatment of metastatic NSCLC with activating EGFR mutations. Among the third-generation EGFR TKIs, osimertinib is today the only drug approved by the Food and Drug Administration and the European Medicines Agency to treat metastatic EGFR T790M NSCLC patients who have progressed on or after EGFR TKI therapy. In this review, we summarize the available post-progression therapies including third-generation EGFR inhibitors and combination treatment strategies for treating patients with NSCLC harboring EGFR mutations and address the known mechanisms of resistance.

Precision Oncology: Who, How, What, When, and When Not?

Precision oncology, defined as molecular profiling of tumors to identify targetable alterations, is rapidly developing and has entered the mainstream of clinical practice. Genomic testing involves many stakeholders working in a coordinated fashion to deliver high-quality tissue samples to high-quality laboratories, where appropriate next-generation sequencing (NGS) molecular analysis leads to actionable results. Clinicians should be familiar with the types of genomic variants reported by the laboratory and the technology used to determine the results, including limitations of current testing methodologies and reports. Interpretation of genomic results is best undertaken with multidisciplinary input to reduce uncertainty in clinical recommendations relating to a documented variant. Non-small cell lung cancer has emerged as a prototype disease where genomic data from at least several well-documented alterations with approved targeted agents are essential for optimal treatment from diagnosis of advanced disease. Due to the development of resistance to targeted therapies, resampling and retesting of tumors, including using liquid biopsy technology after clinical progression, may be important in making treatment decisions. The value of molecular profiling depends on avoiding both underutilization for well-documented variant target-drug pairs and overutilization of variant-drug therapy without proven benefit. As techniques evolve and become more cost effective, the use of molecular testing may prove to add more specificity and improve outcomes for a larger number of patients.