A Nationwide Study on the Impact of Routine Testing for EGFR Mutations in Advanced NSCLC Reveals Distinct Survival Patterns Based on EGFR Mutation Subclasses

Regional differences in predictive biomarker testing rates for patients with metastatic NSCLC in the Netherlands

BACKGROUND

Predictive biomarker testing has a key role in the treatment decision-making for patients with non-small cell lung cancer (NSCLC) and is mandated by (inter)national guidelines. The aim of this study was to establish guideline-adherent biomarker testing rates in the Netherlands in 2019 and to examine associations of demographical, clinical, and environmental factors with guideline-adherent testing.

METHODS

This study involved the integration of clinical data of the Netherlands Cancer Registry with pathology reports of the Dutch Nationwide Pathology Databank. Data extracted from these reports included sample type, diagnosis, and molecular testing status of predictive biomarkers. The study population comprised all patients diagnosed with metastatic non-squamous NSCLC in the Netherlands in 2019.

RESULTS

In the cohort of 3877 patients with metastatic non-squamous NSCLC under investigation, overall molecular testing rates for non-fusion predictive biomarkers (EGFR, KRAS, BRAF, ERBB2, MET) ranged from 73.9 to 89.0 %, while molecular testing for fusion-drivers (ALK, ROS1, RET, NTRK) ranged from 12.6 % to 63.9 %. Guideline-adherent testing of EGFR, KRAS, and ALK was performed in 85.2 % of patients, with regional rates spanning from 76.0 % to 90.8 %. Demographical and clinical factors associated with guideline-adherent biomarker testing included lower age (OR = 1.05 per one year decrease; p < 0.001), female sex (OR = 1.36; p = 0.002), diagnosis of adenocarcinoma (OR = 2.48; p < 0.001), availability of histological tumor material (OR = 2.46; p < 0.001), and clinical stage of metastatic disease (p = 0.002). Other factors associated with guideline-adherent biomarker testing included diagnosis at academic center (OR = 1.87; p = 0.002) and patient's region of residence (p < 0∙001).

CONCLUSION

Optimization of the chain-of-care of predictive biomarker testing in patients with NSCLC in the Netherlands is needed to provide adequate care for these patients.

Developments in predictive biomarker testing and targeted therapy in advanced stage non-small cell lung cancer and their application across European countries

In the past two decades, the treatment of metastatic non-small cell lung cancer (NSCLC), has undergone significant changes due to the introduction of targeted therapies and immunotherapy. These advancements have led to the need for predictive molecular tests to identify patients eligible for targeted therapy. This review provides an overview of the development and current application of targeted therapies and predictive biomarker testing in European patients with advanced stage NSCLC. Using data from eleven European countries, we conclude that recommendations for predictive testing are incorporated in national guidelines across Europe, although there are differences in their comprehensiveness. Moreover, the availability of recently EMA-approved targeted therapies varies between European countries. Unfortunately, routine assessment of national/regional molecular testing rates is limited. As a result, it remains uncertain which proportion of patients with metastatic NSCLC in Europe receive adequate predictive biomarker testing. Lastly, Molecular Tumor Boards (MTBs) for discussion of molecular test results are widely implemented, but national guidelines for their composition and functioning are lacking. The establishment of MTB guidelines can provide a framework for interpreting rare or complex mutations, facilitating appropriate treatment decision-making, and ensuring quality control.

Real-world EGFR testing practices for non-small-cell lung cancer by thoracic pathology laboratories across Europe

BACKGROUND

Testing for epidermal growth factor receptor (EGFR) mutations is an essential recommendation in guidelines for metastatic non-squamous non-small-cell lung cancer, and is considered mandatory in European countries. However, in practice, challenges are often faced when carrying out routine biomarker testing, including access to testing, inadequate tissue samples and long turnaround times (TATs).

MATERIALS AND METHODS

To evaluate the real-world EGFR testing practices of European pathology laboratories, an online survey was set up and validated by the Pulmonary Pathology Working Group of the European Society of Pathology and distributed to 64 expert testing laboratories. The retrospective survey focussed on laboratory organisation and daily EGFR testing practice of pathologists and molecular biologists between 2018 and 2021.

RESULTS

TATs varied greatly both between and within countries. These discrepancies may be partly due to reflex testing practices, as 20.8% of laboratories carried out EGFR testing only at the request of the clinician. Many laboratories across Europe still favour single-test sequencing as a primary method of EGFR mutation identification; 32.7% indicated that they only used targeted techniques and 45.1% used single-gene testing followed by next-generation sequencing (NGS), depending on the case. Reported testing rates were consistent over time with no significant decrease in the number of EGFR tests carried out in 2020, despite the increased pressure faced by testing facilities during the COVID-19 pandemic. ISO 15189 accreditation was reported by 42.0% of molecular biology laboratories for single-test sequencing, and by 42.3% for NGS. 92.5% of laboratories indicated they regularly participate in an external quality assessment scheme.

CONCLUSIONS

These results highlight the strong heterogeneity of EGFR testing that still occurs within thoracic pathology and molecular biology laboratories across Europe. Even among expert testing facilities there is variability in testing capabilities, TAT, reflex testing practice and laboratory accreditation, stressing the need to harmonise reimbursement technologies and decision-making algorithms in Europe.

Prevalence, clinical and molecular characteristics of early stage EGFR-mutated lung cancer in a real-life West-European cohort: Implications for adjuvant therapy

OBJECTIVES

The landmark ADAURA study recently demonstrated a significant disease-free survival benefit of adjuvant osimertinib in patients with resected EGFR-mutated lung adenocarcinoma. However, data on prevalence rates and stage distribution of EGFR mutations in non-small cell lung cancer in Western populations are limited since upfront EGFR testing in early stage lung adenocarcinoma is not common practice. Here, we present a unique, real-world, unselected cohort of lung adenocarcinoma to aid in providing a rationale for routine testing of early stage lung cancers for EGFR mutations in the West-European population.

MATERIAL AND METHODS

We performed routine unbiased testing of all cases, regardless of TNM stage, with targeted next-generation sequencing on 486 lung adenocarcinoma cases between 01- January 2014 and 01 February 2020. Clinical and pathological data, including co-mutations and morphology, were collected. EGFR-mutated cases were compared to KRAS-mutated cases to investigate EGFR-specific characteristics.

RESULTS

In total, 53 of 486 lung adenocarcinomas (11%) harboured an EGFR mutation. In early stages (stage 0-IIIA), the prevalence was 13%, versus 9% in stage IIIB-IV. Nine out of 130 (7%) stage IB-IIIA patients fit the ADAURA criteria. Early stage cases harboured more L858R mutations (p = 0.02), fewer exon 20 insertions (p = 0.048), fewer TP53 co-mutations (p = 0.007), and were more frequently never smokers (p = 0.04) compared to late stage cases with EGFR mutations. The KRAS-mutated cases were distributed more evenly across TNM stages compared to the EGFR-mutated cases.

CONCLUSION

As (neo-)adjuvant targeted therapy regimes enter the field of lung cancer treatment, molecular analysis of early stage non-small cell lung cancer becomes relevant. Testing for EGFR mutations in early stage lung adenocarcinoma holds a substantial yield in our population, as our number needed to test ratio for adjuvant osimertinib was 14.4. The observed differences between early and late stage disease warrant further analysis to work towards better prognostic stratification and more personalised treatment.

Frequency, underdiagnosis, and heterogeneity of epidermal growth factor receptor exon 20 insertion mutations using real-world genomic datasets

Epidermal growth factor receptor (EGFR) exon 20 insertion mutations (ex20ins) account for ≤ 12% of all EGFR-mutant nonsmall cell lung cancers. We analysed real-world datasets to determine the frequency of ex20ins variants, and the ability of polymerase chain reaction (PCR) and next-generation sequencing (NGS) to identify them. Three real-world United States NGS databases were used: GENIE, FoundationInsights, and GuardantINFORM. Mutation profiles consistent with in-frame EGFR ex20ins were summarized. GENIE, FoundationInsights, and GuardantINFORM datasets identified 180, 627, and 627 patients with EGFR ex20ins respectively. The most frequent insertion region of exon 20 was the near loop (~ 70%), followed by the far loop (~ 30%) and the helical (~ 3-6%) regions. GENIE, FoundationInsights, and GuardantINFORM datasets identified 41, 102, and 96 unique variants respectively. An analysis of variants projected that ~ 50% of EGFR ex20ins identified by NGS would have been missed by PCR-based assays. Given the breadth of EGFR ex20ins identified in the real-world US datasets, the ability of PCR to identify these mutations is limited. NGS platforms are more appropriate to identify patients likely to benefit from EGFR ex20ins-targeted therapies.

The Presence of EGFR T790M in TKI-Naïve Lung Cancer Samples of Patients Who Developed a T790M-Positive Relapse on First or Second Generation TKI Is Rare

EGFR-mutated non-small cell lung cancer (NSCLC) patients can be effectively treated with tyrosine kinase inhibitors (TKI) but frequently present with an EGFR T790M resistance mutation at relapse. We aimed to screen for T790M in pre-treatment formalin-fixed and paraffin-embedded (FFPE) tissue samples of patients with a confirmed T790M mutation at progression. We analyzed 33 pre-treatment DNA samples of NSCLC patients who progressed upon TKI between 2013 to 2019. To establish storage-time dependent formalin fixation-induced background levels for C>T mutations, we analyzed DNA isolated from archival (stored >1 year, n = 22) and recently generated (stored <1 month, n = 11) FFPE samples and included DNA isolated from white blood cells (WBC) (n = 24) as controls. DNA samples were analyzed by droplet digital (dd)PCR, and positivity was defined by outlier detection according to Grubb’s criterion. The T790M background allele frequency levels were 0.160% in DNA isolated from archival-FFPE, 0.100% in fresh FFPE, and 0.035% in WBC. Progression-free survival (PFS) time of the single T790M positive patient was 9 months, while T790M negative patients had a median PFS of 10 months (range 2−27). Proper storage time matched FFPE control samples are essential for reliable detection of T790M mutation at low VAF. The presence of EGFR T790M mutations in pre-TKI samples is rare, even in patients who progressed with EGFR T790M mutations.

Case Report: Afatinib Sensitivity in Rare EGFR E746_L747delinsIP Mutated LUAD With Peritoneal Metastases

Patients with non-small cell lung cancer harboring the epidermal growth factor receptor (EGFR)-sensitive mutations are known to benefit significantly from EGFR tyrosine kinase inhibitors (TKIs), such as erlotinib, gefitinib, icotinib, or afatinib. However, the efficacy of EGFR-TKIs against rare mutations has not yet been well investigated. Here, we report a female patient with advanced lung adenocarcinoma (LUAD), carrying a rare mutation of EGFR Exon19 E746_L747delinsIP, who was administered first-generation EGFR-TKIs as the first-line treatment. The patient continued to progress slowly until peritoneal metastases have occurred. Subsequently, the patient was treated with anlotinib for 5 months until disease progression. Given the finding of the same EGFR rare mutation in peritoneal effusion without other EGFR-TKI resistance mutations, the patient received afatinib with a tremendous response. Our results may be of clinical relevance for patients with LUAD carrying this rare mutation, and these findings warrant further investigation.

A Real-World Systematic Analysis of Driver Mutations' Prevalence in Early- and Advanced-Stage NSCLC: Implications for Targeted Therapies in the Adjuvant Setting

Simple Summary

The development of oncogene-targeted drugs has radically changed the course of non small cell lung carcinoma (NSCLC) in the advanced stage. Recently, the ADAURA trial demonstrated the efficacy of Osimertinib also in the adjuvant setting of EGFR-mutated NSCLC. This raises the question regarding whether the same paradigm applies also to currently approved drugs directed against non-EGFR NSCLC drivers. Herein we compared actionable genomic alterations in early- and advanced-stage NSCLC in 1961 unselected single-institution cases analyzed by routine molecular diagnostics procedures. Our data add significantly to the currently limited real-world data on actionable mutations in surgically resectable NSCLC. Our finding that distinct NSCLC genomic drivers are mutated at similar frequencies in early- and advanced-stage tumors implies that the relative biological potency of currently actionable NSCLC genomic drivers is conserved throughout clinical evolution and supports the hypothesis that genotype-matched therapies are likely to provide significant benefit in an adjuvant setting

Abstract

The approval of osimertinib for adjuvant treatment of stage I–II–III EGFR-mutated NSCLC (early stage) represents a paradigm shift, raising the question of whether other genotype-matched therapeutics approved for advanced-stage NSCLC can also provide clinical benefit in the adjuvant setting. However, there is a paucity of real-world data on the prevalence of actionable genomic alterations (GAs) in early-stage NSCLC. We used next-generation sequencing, complemented by immunohistochemistry and fluorescence in situ hybridization, to screen our single-institution cohort of 1961 NSCLC consecutive cases for actionable molecular targets. The prevalence of actionable GAs was comparable in early versus advanced-stage NSCLC, the only exception being KRAS mutations (more frequent in early-stage cases). Consistent with advanced-stage tumors being more aggressive, co-occurrence of TP53 and EGFR GAs as well as copy number gains were less frequent in early-stage tumors. EGFR mutations and high expression of PD-L1 were inversely associated, whereas KRAS mutations and high PD-L1 reactivity showed positive association. Recapitulating advanced-stage tumors, early-stage NSCLC had the highest share of EGFR mutations in lepidic and acinar subtypes. Resected lepidic tumors contained the highest proportion of the KRAS G12C actionable variant. These results, obtained with routine diagnostic technologies in an unselected clinical setting, provide a significant addition of real-world data in early-stage NSCLC.

Impact of time-to-treatment on survival for advanced non-small cell lung cancer patients in the Netherlands: a nationwide observational cohort study

BACKGROUND

The assumption that more rapid treatment improves survival of advanced non-small cell lung cancer (NSCLC) has not yet been proven. We studied the relation between time-to-treatment and survival in advanced stage NSCLC patients in a large multicentric nationwide retrospective cohort. Additionally, we identified factors associated with delay.

METHOD

We selected 10 306 patients, diagnosed and treated between 2014 and 2019 for clinical stage III and IV NSCLC, from the Netherlands Cancer Registry that includes nationwide data from 109 Dutch hospitals. Associations between survival and time-to-treatment were tested with Cox proportional hazard regression analyses. Time-to-treatment was adjusted for multiple covariates including diagnostic procedures and type of therapy. Factors associated with delay were identified by multilevel logistic regression.

RESULTS

Risk of death significantly decreased with longer time-to-treatment for stage III patients receiving only radiotherapy (adjusted HR, aHR >21 days: 0.59 (95% CI 0.48 to 0.73)) or any type of systemic therapy (aHR >49 days: 0.72 (95% CI 0.56 to 0.91)) and stage IV patients receiving chemotherapy and/or immunotherapy (aHR >21 days: 0.81 (95% CI 0.73 to 0.88)). No significant association was found for stage III patients treated with chemoradiotherapy and stage IV patients treated with targeted therapy. More complex diagnostic procedures often delay treatment.

CONCLUSION

Although in general it is important to start treatment as early as possible, our study finds no evidence that a more rapid start of treatment improves outcomes in advanced stage NSCLC patients. The benefit of urgent treatment is probably confounded by unmeasured patient and tumour characteristics and, clinical urgency dictating timelines of treatment. Time-to-treatment and its impact should be continuously evaluated as therapeutic strategies continue to evolve and improve.