Management of EGFR-mutated non-small-cell lung cancer: practical implications from a clinical and pathology perspective

Sequential chemotherapy and icotinib as first-line treatment for advanced epidermal growth factor receptor-mutated non-small cell lung cancer

BACKGROUND

Icotinib could have potential effect and tolerability when used sequentially with chemotherapy for advanced epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC).

AIM

To evaluate the efficacy and safety of chemotherapy followed by icotinib maintenance therapy as first-line treatment for advanced EGFR-mutated NSCLC.

METHODS

This multicenter, open-label, pilot randomized controlled trial enrolled 68 EGFR-mutated stage IIIB/IV NSCLC patients randomized 2:3 to the icotinib alone and chemotherapy + icotinib groups.

RESULTS

The median progression-free survival in the icotinib alone and chemotherapy + icotinib groups was 8.0 mo (95%CI: 3.84-11.63) and 13.4 mo (95%CI: 10.18-16.33), respectively (P = 0.0249). No significant differences were found in the curative effect when considering different cycles of chemotherapy or chemotherapy regimen (all P > 0.05).

CONCLUSION

A sequential combination of chemotherapy and EGFR-tyrosine kinase inhibitor is feasible for stage IV EGFR-mutated NSCLC patients.

The Effect of Adding Biological Factors to the Decision-Making Process for Spinal Metastasis of Non-Small Cell Lung Cancer

Molecular target therapies have markedly improved the survival of non-small cell lung cancer (NSCLC) patients, especially those with epidermal growth factor receptor (EGFR) mutations. A positive EGFR mutation is even more critical when the chronicity of spinal metastasis is considered. However, most prognostic models that estimate the life expectancy of spinal metastasis patients do not include these biological factors. We retrospectively reviewed 85 consecutive NSCLC patients who underwent palliative surgical treatment for spinal metastases to evaluate the following: (1) the prognostic value of positive EGFR mutation and the chronicity of spinal metastasis, and (2) the clinical significance of adding these two factors to an existing prognostic model, namely the New England Spinal Metastasis Score (NESMS). Among 85 patients, 38 (44.7%) were EGFR mutation-positive. Spinal metastasis presented as the initial manifestation of malignancy in 58 (68.2%) patients. The multivariate Cox proportional hazard model showed that the chronicity of spinal metastasis (hazard ratio (HR) = 1.88, p = 0.015) and EGFR mutation positivity (HR = 2.10, p = 0.002) were significantly associated with postoperative survival. The Uno’s C-index and time-dependent AUC 6 months following surgery significantly increased when these factors were added to NESMS (p = 0.004 and p = 0.022, respectively). In conclusion, biological factors provide an additional prognostic value for NSCLC patients with spinal metastasis.

The cost-effectiveness of dacomitinib in first-line treatment of advanced/metastatic epidermal growth factor receptor mutation-positive non-small-cell lung cancer (EGFRm NSCLC) in Sweden

AIMS

Although the benefit of first-line epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) over chemotherapy in EGFR mutation-positive (EGFRm) non-small-cell lung cancer (NSCLC) has been demonstrated in clinical trials, the optimal treatment sequence remains unclear. The objective of our study was to evaluate the cost-effectiveness of dacomitinib in Sweden vs afatinib and osimertinib in first-line treatment of EGFRm NSCLC.

MATERIALS AND METHODS

A partitioned survival model was developed with three health states: progression-free, post-progression, and death. Progression-free and overall survival curves were used to inform movements between states. Clinical data were taken from randomized trials, compared via a network meta-analysis (NMA). Utility data were taken from published studies and costs from national Swedish sources. The model used a 15-year time horizon and a Swedish healthcare payer perspective. Sensitivity and scenario analyses were performed.

RESULTS

The base-case analysis showed that dacomitinib accrued a total of 2.10 quality-adjusted life-years (QALYs) at a total cost of Swedish krona (SEK) 874,615. The incremental cost-effectiveness ratio (ICER) for dacomitinib vs afatinib was SEK 461,556 per QALY gained. The ICER of osimertinib vs dacomitinib, where the small QALY gains of the former came at a high additional cost, was SEK 11,444,709. Deterministic and probabilistic sensitivity analyses confirmed the robustness of these results; changes to drug and medical resource use costs and overall survival had the greatest impact on ICER estimates.

LIMITATIONS

This model is subject to uncertainty associated with extrapolating long-term treatment effects from shorter trial follow-up periods, although this would also be a limitation when using direct comparison or time-dependent hazard ratios. The NMA was limited by the use of indirect comparison, although sensitivity analyses supported the robustness of our findings.

CONCLUSIONS

Our model demonstrated that dacomitinib is cost-effective for first-line EGFRm NSCLC treatment in Sweden vs afatinib and osimertinib.

Indirect analysis of first-line therapy for advanced non-small-cell lung cancer with activating mutations in a Japanese population

Background: Five EGFR-tyrosine kinase inhibitors (EGFR TKIs) are currently available in the first-line setting for non-small-cell lung cancer (NSCLC) in Japan. The aim here was to compare the relative efficacy of EGFR TKIs in the Japanese population. Materials & methods: A systematic review identified randomized controlled trials examining the efficacy of first-line EGFR TKIs. A Bayesian network meta-analysis was used to assess these EGFR TKI comparisons for progression-free survival (PFS). Results: A total of seven randomized controlled trials were identified and considered for network meta-analysis. Dacomitinib showed a trend toward improved PFS versus all comparators. Conclusion: Dacomitinib demonstrated a trend toward improved PFS and therefore, should be considered one of the standard first-line therapies for Japanese patients diagnosed with EGFR+ non-small-cell lung cancer.

Clinical implication and usefulness of de novo EGFR T790M mutation in lung adenocarcinoma with EGFR-tyrosine kinase inhibitor sensitizing mutation

In total, 102 cases diagnosed as lung adenocarcinoma with EGFR-tyrosine kinase inhibitor (TKI) sensitizing mutations (mEGFR) and had been treated with 1^st ~ 2^nd generation EGFR-TKI alone were enrolled for this study. De novo T790 M status was tested using the tissues at the initial diagnosis and positivity was defined as the ratio of T790 M/wild-type copies over 0.00294 by ddPCR.

Seventy patients (68.6%) harbored the de novo T790 M. De novo T790 M was more frequently detected in cases with EGFR L858 R mutation than those with EGFR exon 19 deletion (E19d) mutations (P = 0.024). Forty-three patients underwent rebiopsy due to disease progression. The cases who experienced progression due to acquired T790 M were more likely to have E19d at initial diagnosis and the presence of de novo T790 M and the ratio of T790 M/wild-type copies did not relate to the emergence of acquired T790 M. On the other hand, the cases with a longer duration of disease-control by EGFR-TKI had higher change to get acquired T790 M mutation (P-value = 0.040).

The presence of de novo T790 M has limitation in predicting disease progression by acquired T790 M, suggesting that identifying de novo T790 M through the ultrasensitive methods may not be necessary identifying patients who would be beneficial by 3rd-generation EGFR-TKI as the 1st line treatment.

Molecularly targeted therapies in non-small cell lung cancer: The evolving role of tyrosine kinase inhibitors

Non-small cell lung cancer (NSCLC) is a major subtype of lung cancer. Patients with NSCLC are diagnosed at a locally advanced or metastatic stage where prognosis with palliative chemotherapy is poor. The discovery of epidermal growth factor receptor (EGFR) mutations has revolutionized cancer treatment for NSCLC by promoting the development of molecularly targeted therapies like tyrosine kinase inhibitors (TKIs). This review summarizes the clinical efficacy and tolerability of EGFR-TKIs, including osimertinib, in EGFR-mutated advanced NSCLC. EGFR-TKIs have demonstrated superior response and overall survival rates compared with chemotherapy in EGFR-mutated NSCLC. However, despite the initial rapid and durable clinical responses, acquired resistance to first- and second-generation TKIs eventually develops in most cases, with disease progression observed mostly within 12 months of treatment initiation. Osimertinib, a potent third-generation TKI, irreversibly inhibits mutated EGFR alleles, including T790M. In addition to longer survival and higher response rate, osimertinib has a favorable safety profile with a lower incidence of grade ≥3 treatment-related adverse events compared with other TKIs. Based on the efficacy and safety results, recently the National Comprehensive Cancer Network (NCCN) has included osimertinib as the "preferred first-line of treatment" in patients with metastatic EGFR mutationpositive NSCLC. Thus, osimertinib as first-line therapy for EGFRpositive patients irrespective of the T790M mutation status could be an ideal choice in the Indian setting where only 50% of patients opt for any second-line therapy after first-line failure.

TUSC7 suppression of Notch activation through sponging MiR-146 recapitulated the asymmetric cell division in lung adenocarcinoma stem cells

AIMS

Lung adenocarcinoma consists of multiple therapeutic targets, however, patients will inevitably progress to later stage diagnosis with Tyrosine Kinase Inhibitor treatment resistance. We aim to investigate the roles of non-coding TUSC7 in ordering the cell division tendency, helping to sensitize the resistance in a miRNA incorporating way.

MATERIALS AND METHODS

Online study of bioinformatics analysis, molecular experiments of luciferase test, immunofluorescence staining and qRT-PCR were applied to dig out the mechanistic regulations.

KEY FINDINGS

TUSC-7 inhibited the renewal ability of adenocarcinoma stem cells, yielding to asymmetric cell splitting. Informatics analysis and the luciferase testing confirmed the 3'UTR binding site, and revealed the post-transcriptional regulation of NUMB referring to miR-146. TUSC-7 sponged miR-146 and abolished its degradation toward to NUMB, and this integrated cascade made several genes become tangled to full functionality.

SIGNIFICANCE

TUSC-7 was proved to be one strong suppressive lnc-RNA in lung adenocarcinoma stem cells, functioning through inactivating NOTCH signaling, and the turbulence on division modes precisely pointed to the key mechanisms of stem cells' renewal. The decreasing of tumor suppressive miR-146 was necessary in TUSC-7 conducted renewal repression, despite it alone could also reduce the renewal efficiency, indicating that more complicated non-coding genes may be involved in its regulation.

Impact of smoking on frequency and spectrum of K-RAS and EGFR mutations in treatment naive Indonesian lung cancer patients

Background: Indonesia has the highest cigarette consumption in the world. We explored the clinical impact of smoking on the prevalence of EGFR and K-RAS mutations and survival in this prospective study.

Methods: 143 treatment naive lung cancer patients were recruited from Persahabatan Hospital, a national tertiary hospital. DNA from cytological specimens had been extracted and genotyped for both EGFR and K-RAS mutations using a combination of PCR high resolution melting, restriction fragment length polymorphism (RFLP) and direct DNA sequencing.

Results:EGFR mutation frequency in never smokers (NS) and ever smokers (ES) were 75% and 56% (p = 0.0401), respectively. In this cohort, the overall K-RAS mutation rate was 7%. Neither gender nor smoking history were associated with K-RAS mutation significantly. However, K-RAS transversion mutations were more common in male ES than transition mutations. Smoking history did not affect EGFR and K-RAS mutation frequencies in women. Concurrent EGFR/K-RAS mutation rate was 2.8% (4 of 143 patients). Four out of 91 EGFR mutation positive patients (4.4%) had simultaneous K-RAS mutation.

Conclusions: In region where cigarette consumption is prevalent, smoking history affected frequencies of EGFR and K-RAS mutations, mainly in males.

Utilization of Archived Plasma to Detect Epidermal Growth Factor Receptor Mutation in Non-Small Cell Lung Cancer Patients

Precision medicine has received increased attention as an effective approach for the treatment of cancer patients. Because of challenges associated with the availability of archived tissue, liquid biopsies are often performed to detect cancer-specific mutations. One of the major advantages of the liquid biopsy is that the treatment can be monitored longitudinally, even after the tumor tissue is no longer available. In a clinical setting, one component of precision medicine is the detection of cancer-specific mutations using archived samples. In this study, we evaluated the epidermal growth factor receptor (EGFR) mutation status of samples of lung cancer patients stored before introduction of the plasma EGFR test at our institution. The aim of this study was to validate the utility of archived plasma samples for detection of the EGFR mutation in nonsmall cell lung cancer (NSCLC) patients. The Cobas^® EGFR Mutation Test v2 was the first liquid biopsy test approved as a companion diagnostic test for patients with NSCLC treated with tyrosine kinase inhibitors. We tested for the EGFR mutation in 116 plasma samples archived in the biobank, and the results were compared with those obtained in the tissue or cytology EGFR mutation test. The EGFR mutation-positive rate from archived plasma was lower than that determined from tissue or cytology at 19.0% and 53.4%, respectively, and the concordance rate between the two tests was 58.6%. Of interest, five (4.3%) samples showed the T790M mutation in the plasma test, whereas this mutation was only detected in two (1.7%) tissue/cytology samples. Five (4.3%) samples were additionally positive in the plasma test. Overall, these results indicate that archived plasma samples can serve as an alternative source for the plasma EGFR mutation test when tissue samples are not available, and can improve precision medicine and long-term follow-up in a noninvasive manner.

Axl is a novel target of celastrol that inhibits cell proliferation and migration, and increases the cytotoxicity of gefitinib in EGFR mutant non‑small cell lung cancer cells

Gefitinib, an epidermal growth factor receptor tyrosine kinase inhibitor (EGFR‑TKI) is an excellent therapeutic agent to treat EGFR mutation‑positive non‑small cell lung cancer (NSCLC). However, the initial response decreases as chemoresistance develops. In the present study, gefitinib‑resistant EGFR mutant NSCLC PC‑9/GR cells were established to examine the characteristics and mechanisms associated with chemoresistance. Axl expression in PC‑9/GR cells was transcriptionally upregulated, since Axl protein and mRNA expression levels were identified to be increased according to western blot analysis and reverse transcription polymerase chain reaction results. The inhibitory effect of celastrol on Axl protein expression level, cell viability and clonogenicity were identified in parental and gefitinib‑resistant PC‑9 cells. In addition, treatment of PC‑9/GR cells with celastrol and gefitinib in combination was demonstrated to synergistically suppress Axl protein expression level, cell proliferation and migration. Taken together, upregulation of Axl expression seems to be associated with chemoresistance of PC‑9/GR cells. Furthermore, celastrol targets Axl to exert its anticancer effects in order to increase the susceptibility of PC‑9/GR cells to gefitinib and overcome chemoresistance.

FGFR4 increases EGFR oncogenic signaling in lung adenocarcinoma, and their combined inhibition is highly effective

OBJECTIVES

Lung adenocarcinoma accounts for approximately half of lung cancer cases. Twenty to 50% of tumors of this type harbor mutations affecting epidermal growth factor receptor (EGFR) expression or activity, which can be therapeutically targeted. EGFR inhibitors in this context exhibit high efficacy and are currently used in the clinical setting. However, not all adenocarcinomas harboring EGFR mutations respond to therapy, so predictive biomarkers of therapeutic outcomes, as well as novel therapies sensitizing these tumors to EGFR inhibition, are needed.

MATERIALS AND METHODS

We performed in vitro gene overexpression/silencing and tumorigenic surrogate assays, as well as in vitro and in vivo combination treatments with Fibroblast Growth Factor Receptor (FGFR)/EGFR inhibitors. At the clinical level, we determined FGFR4 expression levels in tumors from patients treated with EGFR inhibitors and correlated these with treatment response.

RESULTS

We describe a cooperative interaction between EGFR and FGFR4, which results in their reciprocal activation with pro-oncogenic consequences in vitro and in vivo. This cooperation is independent of EGFR activating mutations and increases resistance to different EGFR inhibitors. At the therapeutic level, we provide evidence of the synergistic effects of the combination of EGFR and FGFR inhibitors in high FGFR4-expressing, EGFR-activated tumors in vitro and in vivo. Correlated with these results, we found that patients treated with EGFR inhibitors relapse earlier when their tumors exhibit high FGFR4 expression.

CONCLUSIONS

We propose a novel predictive biomarker for EGFR-targeted therapy, and a highly efficacious combinatory therapeutic strategy to treat EGFR-dependent; this may may extend the use of appropriate inhibitors beyond EGFR-mutated adenocarcinoma patients.

Short-Term Responders of Non-Small Cell Lung Cancer Patients to EGFR Tyrosine Kinase Inhibitors Display High Prevalence of TP53 Mutations and Primary Resistance Mechanisms

Non-small cell lung cancer (NSCLC) with activating EGFR mutations in exon 19 and 21 typically responds to EGFR tyrosine kinase inhibitors (TKI); however, for some patients, responses last only a few months. The underlying mechanisms of such short responses have not been fully elucidated. Here, we sequenced the genomes of 16 short-term responders (SR) that had progression-free survival (PFS) of less than 6 months on the first-generation EGFR TKI and compared them to 12 long-term responders (LR) that had more than 24 months of PFS. All patients were diagnosed with advanced lung adenocarcinoma and harbored EGFR 19del or L858R mutations before treatment. Paired tumor samples collected before treatment and after relapse (or at the last follow-up) were subjected to targeted next-generation sequencing of 416 cancer-related genes. SR patients were significantly younger than LR patients (P < .001). Collectively, 88% of SR patients had TP53 variations compared to 13% of LR patients (P < .001). Additionally, 37.5% of SR patients carried EGFR amplifications compared to 8% of LR patients. Other potential primary resistance factors were also identified in the pretreatment samples of 12 SR patients (75%), including PTEN loss; BIM deletion polymorphism; and amplifications of EGFR, ERBB2, MET, HRAS, and AKT2. Comparatively, only three LR patients (25%) were detected with EGFR or AKT1 amplifications that could possibly exert resistance. The diverse preexisting resistance mechanisms in SR patients revealed the complexity of defining treatment strategies even for EGFR-sensitive mutations.

Circulating tumour DNA in EGFR-mutant non-small-cell lung cancer

The advent of targeted therapy in non-small-cell lung cancer (nsclc) has made the routine molecular diagnosis of EGFR mutations crucial for optimal patient management. Obtaining tumour tissue for biomarker testing, especially in the setting of re-biopsy, can present many challenges. A potential alternative source of tumour dna is circulating cell-free tumour-derived dna (ctdna). Although ctdna is present in low quantities in plasma, the convenience of sample acquisition and the increasing reliability of detection methods make this approach a promising one. The various performance characteristics of both digital and nondigital platforms are still variable, and a standardized approach is needed that will make those platforms reliable clinical tools for the detection of EGFR sensitizing mutations and resistance mutations, including the T790M resistance mutation. Information derived from ctdna can be used to assess tumour burden, to identify genomic-based resistance mechanisms, and to track dynamic changes during therapy.

Characteristics of progression to tyrosine kinase inhibitors predict overall survival in patients with advanced non-small cell lung cancer harboring an EGFR mutation

Background

Non-small cell lung cancer (NSCLC) harboring EGFR-sensitizing mutations has a distinct biology and heterogeneous clinical behavior. We evaluated the characteristics to progression such as clinical patterns of progression (dramatic, gradual, and local) with the prognosis of NSCLC patients treated with tyrosine kinase inhibitors (TKIs).

Methods

We reviewed 123 advanced-NSCLC patients with an EGFR-sensitizing mutation treated with TKIs (gefitinib, erlotinib and afatinib). We assessed patients according to clinical factors and progression pattern to TKIs at three centers.

Results

For all patients, 58.5%, 31.7% and 9.8% harbored exon19 deletion, exon21 L858R mutation and other-sensitivity mutations, respectively. Median progression-free survival (PFS) was 8.8 months (95% CI: 7.9-9.7). Sixty percent of patients were asymptomatic. Dramatic-progression was the most frequent pattern (50.4%), followed by gradual-progression (32.5%), and local-progression (17.1%). Median overall survival (OS) was 23.1 months (95% CI: 17.4-28.9). In the univariate analysis, factors associated to a longer OS included pattern [gradual-progression (32.1), dramatic (19.5) and local (18.8 months), P=0.008], and the time to progression to TKI [>12 months (38.5), 6-12 months (19.1), <6 months (9.6), P<0.001]. Multivariate analysis showed that only time to progression to TKI was independently associated to OS and PFS.

Conclusions

Factors at TKI progression associated to a longer OS can define a subset of patients who may benefit from continued TKI therapy, as well as from local-ablative therapy in progression sites, especially in patients without T790M or who lack access to third-generation TKI.

The liquid biopsy: a tool for a combined diagnostic and theranostic approach for care of a patient with late-stage lung carcinoma presenting with bilateral ocular metastases

INTRODUCTION

Liquid biopsies (LB) are used routinely in clinical practice in two situations for late stage non-small-cell lung cancer (NSCLC) patients, (i) at the initial diagnosis when looking for activating mutations in EGFR in the absence of analyzable tissue DNA and, (ii) during tumor progression on a tyrosine kinase inhibitor treatment to look for the resistance mutation T790M in EGFR. LB is not presently recommended in daily practice for the diagnosis of NSCLC. Areas covered: We report the diagnosis of a NSCLC in a patient with bilateral ocular metastases after detection of a deletion in exon 19 of EGFR when using plasma DNA. Without histological analysis, the origin of the primary ocular metastasis was uncertain. In this context, a LB showing an activating mutation in EGFR and circulating tumor cells positive for TTF1 led to the diagnosis of NSCLC and targeted therapy. Expert commentary: When no tumor tissue sample is available a LB can be used to diagnose for metastatic NSCLC, when a mutation in EGFR is identified. While a tissue biopsy is the gold standard approach for the diagnosis of a NSCLC and for identification of activating mutations, LB can exceptionally provide both a diagnosis of the primitive tumor and indicate appropriate therapy based on a molecular analysis.