Real world impact of epidermal growth factor receptor mutation status on treatment patterns in patients with non-small cell lung cancer

Worldwide Prevalence of Epidermal Growth Factor Receptor Mutations in Non-Small Cell Lung Cancer: A Meta-Analysis

Background

Identification of variable epidermal growth factor receptor (EGFR) gene mutations in non-small cell lung cancer (NSCLC) is important for the selection of appropriate targeted therapies. This meta-analysis was conducted to provide a worldwide overview of EGFR mutation and submutation (specifically exon 19 deletions, exon 21 L858R substitutions, and others) prevalence, and identify important covariates that influence EGFR mutation status in patients with advanced NSCLC to address this clinical data gap.

Methods

Embase^® and MEDLINE^® in Ovid were searched for studies published between 2004 and 2019 with cohorts of ≥ 50 adults with EGFR mutations, focusing on stage III/IV NSCLC (≤ 20% of patients with stage I/II NSCLC). Linear mixed-effects models were fitted to EGFR mutation endpoints using logistic transformation (logit), assuming a binomial distribution. The model included terms for an intercept reflecting European studies and further additive terms for other continents. EGFR submutations examined were exon 19 deletions, exon 21 L858R substitutions, and others.

Results

Of 3969 abstracts screened, 57 studies were included in the overall EGFR mutation analysis and 74 were included in the submutation analysis relative to the overall EGFR mutation population (Europe, n = 12; Asia, n = 51; North America, n = 5; Central America, n = 1; South America, n = 1; Oceania, n = 1; Global, n = 3). The final overall EGFR mutations model estimated Asian and European prevalence of 49.1% and 12.8%, respectively, and included an additive covariate for the proportion of male patients in a study. There were no significant covariates in the submutation analyses. Most submutations were actionable: exon 19 deletions (49.2% [Asia]; 48.4% [Europe]); exon 21 L858R substitutions (41.1% [Asia]; 29.9% [Europe]).

Conclusions

Although EGFR mutation prevalence was higher in Asian than Western countries, data support worldwide testing for EGFR overall and submutations to inform appropriate targeted treatment decisions.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40291-021-00563-1.

Utilisation and Determinants of Epidermal Growth Factor Receptor Mutation Testing in Patients with Non-small Cell Lung Cancer in Routine Clinical Practice: A Global Systematic Review

BACKGROUND

Epidermal growth factor receptor (EGFR) mutation testing is recommended for selecting patients with non-squamous non-small cell lung cancer (NSCLC) for EGFR tyrosine kinase inhibitor drug treatment.

OBJECTIVE

The objective of this article was to systematically review available evidence on the utilisation and determinants of EGFR mutation testing of patients with NSCLC in routine clinical practice.

PATIENTS AND METHODS

Searches were made of five electronic databases (Web of Science, MEDLINE [Ovid], Science Direct, EMBASE and Scopus), bibliographies of relevant articles, studies that cited included studies and relevant cancer websites. Studies were included if they: (1) reported the rate of uptake of EGFR testing in patients with NSCLC; (2) were conducted in routine clinical practice settings; (3) were published in English prior to July 2017; and (4) had full text available. Studies were appraised using the STROBE and the National Institutes of Health (National Heart, Lung and Blood Institute) checklists.

RESULTS

Eighteen eligible studies were identified for this systematic review, published between 2011 and 2017, from the USA (n = 7), Canada (n = 2), Republic of Korea (n = 2), Norway (n = 1), Sweden (n = 1), Germany (n = 1), Spain (n = 1), New Zealand (n = 1), China (n = 1) and multiple countries from the Asia-Pacific region (n = 1). Overall, testing for EGFR mutations was undertaken in 16,146 of 52,257 study patients (31%), although testing rates varied widely between different studies (from 7.8% to 78.3%). Single institution retrospective audits reported higher rates of testing (median 65.7%, range 31.3-78.3%) than population-based retrospective cohort analyses (median 23%, range 11-69%) and multi-institutional cross-sectional practitioner surveys (median 19.8%, range 7.8-31.8%). Nine studies reported increasing rates of testing over the study period but maximum testing rates remained less than 75% in most studies. Factors associated with higher testing uptake rates included: female sex; younger age; former/no smoking; advanced stage of lung cancer; adenocarcinoma histology; better mobility; radiation therapy; available tissue specimen; and private insurance. Among 16,146 tested patients, EGFR mutations were detected in 4328 patients (26.8%). However, estimates of mutation prevalence were biased by incomplete and selective testing in many studies.

CONCLUSIONS

The uptake of EGFR mutation testing of patients with NSCLC is suboptimal in many parts of the world. Incomplete uptake of testing is fuelled by selective testing referral practices, sample limitations, and funding constraints.

Value of combining PET/CT and clinicopathological features in predicting EGFR mutation in Lung Adenocarcinoma with Bone Metastasis

Purpose: Epidermal growth factor receptor (EGFR) mutation is the most common target for precision treatment in metastatic lung adenocarcinoma. We investigated the predictive role of ¹⁸F-FDG PET/CT and clinicopathological features for EGFR mutations in lung adenocarcinoma with bone metastasis. Methods: Seventy-five lung adenocarcinoma patients with histologically confirmed bone metastasis were included. They all received EGFR status test and PET/CT before systemic treatment. The differences of maximum standardized uptake value (SUVmax) in primary tumor (pSUVmax), regional lymph node (nSUVmax) and bone metastasis (bmSUVmax) between different EGFR status groups were compared, alongside with common clinicopathological features. Multivariate logistic regression analysis was performed to evaluate predictors of EGFR mutations. Results: EGFR mutations were found in 37 patients (49.3%). EGFR mutations were more common in females, non-smokers, expression of Thyroid Transcription Factor-1 (TTF-1) and NaspinA. Low bmSUVmax was significantly associated with EGFR mutations, while no significant difference was observed in pSUVmax and nSUVmax. Multivariate analysis showed that bmSUVmax ≤7, non-smoking, expression of TTF-1 were predictors of EGFR mutations. The area under the curve (AUC) of receiver operating characteristic (ROC) curve was 0.84 for the combination of the three factors. Conclusion: Low bmSUVmax is more frequently in EGFR mutations, and bmSUVmax is an independent predictor of EGFR mutations. Combining bmSUVmax with other clinicopathological features could forecast the EGFR status in lung adenocarcinoma with unavailable EGFR gene testing.

Treatment Patterns by EGFR Mutation Status in Non-Small Cell Lung Cancer Patients in the USA: A Retrospective Database Analysis

INTRODUCTION

Targeted therapies, including tyrosine kinase inhibitors (TKIs) that target the sensitizing epidermal growth factor receptor (EGFR) gene are recommended for patients with non-small cell lung cancer (NSCLC). Most patients with NSCLC who test positive for the EGFR mutation and receive TKIs develop resistance to these drugs. Questions remain regarding which treatment sequence is optimal for patients with EGFR-mutant NSCLC, and few studies have evaluated patterns of TKI treatment use in NSCLC, irrespective of EGFR mutation status, in a real-world setting. This population-based study aimed to evaluate treatment patterns at a national level in the USA.

METHODS

This retrospective observational study used data from the US Oncology Network's iKnowMed database. Patients with advanced NSCLC who initiated first-line therapy with erlotinib and/or intravenous chemotherapy between January 1, 2012 and June 30, 2015 and met all other study criteria were included. Descriptive analyses assessed demographic and clinical characteristics and treatment patterns among the overall study cohort, as well as for specific erlotinib treatment subgroups, stratified by EGFR status.

RESULTS

Among the 3108 patients identified, 18.5% were EGFR positive, 49.8% were EGFR negative, and 31.7% were EGFR documented unknown. For the overall cohort, 18.4% received first-line erlotinib monotherapy, fewer than 1% received first-line combination therapy (erlotinib plus chemotherapy), 4.7% received second-line erlotinib monotherapy, and 3.3% received second-line combination therapy. First-line erlotinib monotherapy was used in 77.8% of all EGFR positive patients. Almost two-thirds of the overall cohort were not observed to have advanced to second-line therapy.

CONCLUSIONS

As treatment options evolve, this study provides real-world treatment patterns that suggest concordance with NCCN guidelines and confirm the remaining need to understand sequencing of therapies and related outcomes.

FUNDING

Eli Lilly and Company.

EGFR Mutation Testing of non-squamous NSCLC: Impact and Uptake during Implementation of Testing Guidelines in a Population-Based Registry Cohort from Northern New Zealand

BACKGROUND

Since 2013, clinical practice guidelines recommend EGFR mutation testing of non-squamous NSCLC to select advanced-stage patients for first-line treatment using EGFR-TKIs.

OBJECTIVE

We aimed to determine population-based trends in the real-world uptake and impact in routine practice of these recently updated testing guidelines.

PATIENTS AND METHODS

A population-based observational study was conducted of notifications to the New Zealand Cancer Registry of patients eligible for EGFR testing diagnosed in northern New Zealand between January 2010 and April 2014. The main study variable was EGFR mutation testing. Main outcome measures (overall survival and dispensing of EGFR-TKIs) were extracted from prospectively archived electronic databases until October 2015.

RESULTS

The population-based cohort of 1857 patients had an average age of 70 years. Most had adenocarcinoma and metastatic disease at diagnosis. EGFR testing was undertaken in 500 patients (27%) with mutations detected in 109 patients (22%). EGFR testing increased during the period of study from <5% to 67% of patients (P < 0.0001). Full uptake of testing by all eligible patients was limited by a lack of availability of specimens for testing and variable testing referral practices. The proportion of patients treated with EGFR-TKIs decreased during the same time period, both among untested patients (from 12.2% to 2.8% (P < 0.0001)) and in the population as a whole (from 13.7% to 10.6% (P < 0.05)). EGFR testing was associated with prolonged overall survival (Adjusted HR = 0.76 (95% CI, 0.65-0.89) Log-rank P < 0.0001) due at least in part to the much longer overall survival achieved by mutation-positive patients, of whom 79% received EGFR-TKIs. Compared to untested EGFR-TKI-treated patients, mutation-positive EGFR-TKI-treated patients received EGFR-TKIs for longer, and survived longer both from the start of EGFR-TKI treatment and date of their diagnosis.

CONCLUSIONS

In this real world setting, high uptake of EGFR testing was achieved and associated with major changes in EGFR-TKI prescribing and improved health outcomes. Modifiable factors determined testing uptake. Study registration ACTRN12615000998549.

Systemic therapy treatment patterns in patients with advanced non-small cell lung cancer (NSCLC): PIvOTAL study

The aim of this multinational retrospective cohort study, conducted at academic and community oncology centres, was to describe real‐world treatment patterns for patients with a confirmed diagnosis of advanced/metastatic (stage IIIB/IV) non‐small cell lung cancer (NSCLC) who initiated first‐line systemic therapy from January 2011 through June 2014. The study included 1265 patients in Italy, Spain, Germany, Australia, Korea, Taiwan and Brazil. The proportion of patients with squamous versus non‐squamous NSCLC was approximately 20% versus 75%, and associated patient demographic characteristics were similar in all countries, excepting race. Patients with squamous NSCLC were predominantly male and current/ex‐smokers. Biomarker tests were performed for the majority of patients with non‐squamous NSCLC, ranging from 54% (Brazil) to 91% in Taiwan, where, of those tested, 68% with non‐squamous NSCLC had positive epidermal growth factor receptor (EGFR)‐mutation status; in other countries the EGFR‐positive percentages ranged from 17% (Spain/Brazil) to 40% (Korea). Platinum‐based regimens were the most common first‐line therapy in all countries except Taiwan, where gefitinib was the most common first‐line agent. Median overall survival ranged from 9.3 months (Brazil) to 25.5 months (Taiwan). The diagnostic and treatment patterns recorded in this study were heterogeneous but largely in line with NSCLC guidelines during the study period.

Systematic identification of cancer-related long noncoding RNAs and aberrant alternative splicing of quintuple-negative lung adenocarcinoma through RNA-Seq

OBJECTIVES

Lung adenocarcinoma (LUAD) is a common subtype of non-small cell lung cancer prevalent in Asia. There is a dearth of understanding regarding the transcriptome landscape of LUAD without primary known driver mutations. In this study, LUAD samples without well-known driver mutations occurring in EGFR, KRAS, ALK, ROS1 or RET (quintuple-negative) were used for transcriptome study with a focus on long noncoding RNAs (lncRNAs), alternative splicing and gene fusions.

MATERIALS AND METHODS

24 pairs of LUAD and adjacent normal samples and 13 tumor-only samples derived from 37 quintuple-negative patients were used. Differentially expressed lncRNA transcripts were detected by paired t-test and were validated by qPCR. Functions of lncRNAs were predicted by co-expressed mRNAs. Aberrant splicing events in LUAD were identified using MISO. In addition, gene fusions were screened by SOAPfuse.

RESULTS AND CONCLUSION

In total, 90 and 153 up- or down-regulated lncRNA transcripts were detected in LUAD samples in comparison with the adjacent normal samples. The most significantly differentially expressed lncRNA transcript was ENST00000598996.1 (FENDRR) down-regulated in LUAD. By lncRNA-mRNA co-expression analysis, functions of 14 lncRNAs were predicted. The predicted functions included vasculature development, immune response, cell cycle and respiratory gaseous exchange. Furthermore, six co-expressed pairs of lncRNAs and their nearby protein coding genes were identified as associated with lung development. This study also identified two highly recurrent (22 in 24) differential exon skipping events occurring in MYH14 and ESYT2 with exon including isoforms of both genes up-regulated in isoform percentage in LUAD samples. On the other hand, two out of 24 LUAD samples possessed the driver mutation exon 14 skipping of MET. The transcriptional alterations of LUAD samples without well-known driver mutations identified in the study can be used as references for future research. The translational values of these transcriptional changes are also worthy of further investigation.

Rebiopsy for patients with non-small-cell lung cancer after epidermal growth factor receptor-tyrosine kinase inhibitor failure

Although third-generation epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKI) can overcome T790M-mediated resistance in non-small-cell lung cancer (NSCLC), rebiopsy to confirm T790M status is occasionally difficult. We aimed to investigate the current tendency and the limitations of rebiopsy in clinical practice. This study included 139 consecutive NSCLC patients with EGFR mutations, who had experienced progressive disease (PD) after EGFR-TKI treatment. We retrospectively reviewed patient characteristics, tumor progression sites and rebiopsy procedures. Of 120 patients (out of the original 139) who were eligible for clinical trials, 75 (63%) underwent rebiopsy for 30 pleural effusions, 32 thoracic lesions, four bone, two liver, and seven at other sites. Rebiopsy procedures included 30 thoracocentesis, 24 transbronchial biopsies, 13 computed tomography (CT)-guided needle biopsies and 8 other procedures. Of the 75 rebiopsied patients, 71 (95%) were pathologically diagnosed with malignancy; and 34 (45%) had available tissue samples for EGFR analyses. Of the 75 biopsied patients, 61 (81%) were analyzed for EGFR mutation, using tissue or cytology samples; T790M mutations were identified in 20 (33%) of the 61 patients. Of the 120 patients, 45 (38%) did not undergo rebiopsy, because of inaccessible tumor sites (n = 19), patient refusal (n = 6) or decision of physician (n = 10). In conclusion, among patients with EGFR mutations who had PD after EGFR-TKI treatment, 63% underwent rebiopsy. Most rebiopsy samples were diagnosed with malignancy. However, tissue samples were less available and T790M mutations were identified less frequently than in previous studies. Skill and experience with rebiopsy and noninvasive alternative methods will be increasingly important.

EGFR mutation status and first-line treatment in patients with stage III/IV non-small cell lung cancer in Germany: an observational study

INTRODUCTION

EGFR mutations confer sensitivity to EGFR tyrosine kinase inhibitors (TKI) in advanced non-small cell lung cancer (NSCLC). We investigated the clinicopathologic characteristics associated with EGFR mutations and their impact on real-world treatment decisions and outcomes in Caucasian patients with advanced NSCLC.

METHODS

REASON (NCT00997230) was a noninterventional multicenter study in patients (≥18 years) with stage IIIb/IV NSCLC, who were candidates for EGFR mutation testing and first-line systemic treatment, but not eligible for surgery or radiotherapy. Patients were followed up according to normal clinical practice and assessed for primary (correlation of mutation status with baseline characteristics) and secondary endpoints (first-line treatment decision).

RESULTS

Baseline data were obtained for 4,200 patients; 4,196 fulfilled the inclusion criteria; EGFR mutations were detected in 431 patients; no EGFR mutations were detected in 3,590 patients; mutation status was not evaluable in 175 patients. In multivariate analysis, the odds of EGFR mutations were significantly higher (P < 0.0001) in females versus males (odds ratio: 1.85; 95% confidence interval, 1.48-2.32), never-smokers versus smokers (3.64; 2.91-4.56), and patients with adenocarcinoma versus other histologic subtypes (2.94; 2.17-4.08). The most commonly prescribed first-line systemic treatments were: EGFR-TKIs in EGFR mutation-positive NSCLC (56.6%) and combination chemotherapy in EGFR mutation-negative NSCLC (78.5%).

CONCLUSIONS

This represents the largest dataset for EGFR mutations in Caucasian patients and shows EGFR mutations to be most prevalent in females with adenocarcinoma who had never smoked.

IMPACT

These findings add to our understanding of the prognostic and predictive factors of NSCLC, supporting future improved treatment selection.

A phase II trial of gefitinib monotherapy in pretreated patients with advanced non-small cell lung cancer not harboring activating EGFR mutations: implications of sensitive EGFR mutation test

PURPOSE

Efficacy of gefitinib therapy strongly depends on epidermal growth factor receptor (EGFR) mutation status in patients with non-small cell lung cancer (NSCLC). However, cumulative data from many clinical studies demonstrated that some patients with wild-type (WT) EGFR also responded to gefitinib with durable disease control rate (DCR). The aim of this trial was to evaluate the efficacy and toxicity of gefitinib in NSCLC patients with WT EGFR who failed previous chemotherapy.

PATIENTS AND METHODS

Patients with advanced or recurrent NSCLC whose tumors have WT EGFR were eligible. Gefitinib (250 mg/day) was administered until disease progression or unacceptable toxicity occurred. The primary end point was DCR at 8 weeks.

RESULTS

A total of 85 patients (53 men and 32 women; median age, 60 years; range 30-86) were enrolled between October 2010 and May 2013. Seventy-four patients (87.1 %) had adenocarcinoma. Forty-two patients (49.4 %) were treated with gefitinib as second-line chemotherapy. Eleven patients showed partial response, and 21 had stable disease. Thus, objective response rate was 12.9 %, and DCR at 8 weeks was 37.6 %. The median progression-free survival (PFS) and overall survival were 1.9 and 10.9 months, respectively. Skin rash was the most common side effect. It is of note that patients with skin rash of any grade had improved PFS with gefitinib as compared with patients experiencing no skin rash (median PFS: 3.0 vs. 1.7 months, P = 0.004). One patient developed interstitial lung disease (grade 2). Of 11 gefitinib responders, 6 patients were identified as having tumor with activating EGFR mutation by peptide nucleic acid (PNA)-mediated PCR clamping method. Regarding the outcomes of the 79 patients, excluding 6 positive mutations, the response rate was 6.3 %, and DCR at 8 weeks was 31.8 %.

CONCLUSION

Small proportion of NSCLC patients with the WT EGFR benefits with gefitinib. Optimized diagnosis through more sensitive bioassay could have major consequences in terms of the selection of candidate for EGFR TKI in patients with WT EGFR by direct sequencing.