Gefitinib for non-small-cell lung cancer patients with epidermal growth factor receptor gene mutations screened by peptide nucleic acid-locked nucleic acid PCR clamp

QT-Interval Prolongation, Torsades de Pointes, and Heart Failure With EGFR Tyrosine Kinase Inhibitors in Non-Small Cell Lung Cancer: Systematic Review

A systematic literature review was conducted to determine the incidence and mortality of QT-interval prolongation (QTp), torsades de pointes (TdP), and heart failure (HF) in patients with non-small cell lung cancer (NSCLC) who received epidermal growth factor receptor (EGFR) TKIs. Of 296 identified publications, 95 met eligibility criteria and were abstracted for QTp/TdP and HF outcomes (QTp/TdP: 83 publications, including 5 case study publications; HF: 79 publications, including 6 case study publications [involving 8 patients]). QTp incidence ranged from 0% to 27.8% in observational studies and from 0% to 11% in clinical trials, with no deaths due to QTp. There were no TdP events or deaths due to TdP. The incidence of HF ranged from 0% to 8%, and HF mortality rates ranged from 0% to 4%. Patients receiving treatment with EGFR TKIs should be monitored for signs of QTp, TdP, and HF per prescribing information. Standardized definitions and methods to improve monitoring of QTp, TdP, and HF-related events are needed in patients with NSCLC.

Clinical utility of the Oncomine Dx Target Test multi-CDx system and the possibility of utilizing those original sequence data

BACKGROUND

Companion diagnostic tests play a crucial role in guiding treatment decisions for patients with non-small cell lung cancer (NSCLC). The Oncomine Dx Target Test (ODxTT) Multi-CDx System has emerged as a prominent companion diagnostic method. However, its efficacy in detecting driver gene mutations, particularly rare mutations, warrants investigation.

AIMS

This study aimed to assess the performance of the ODxTT in detecting driver gene mutations in NSCLC patients. Specifically, we aimed to evaluate its sensitivity in detecting epidermal growth factor receptor (EGFR) mutations, a key determinant of treatment selection in NSCLC.

MATERIALS AND METHODS

We conducted a retrospective analysis of NSCLC patients who underwent testing with the ODxTT at Keio University Hospital between May 2020 and March 2022. Patient samples were subjected to both DNA and RNA tests. Driver gene mutation status was assessed, and instances of missed mutations were meticulously examined.

RESULTS

Of the 90 patients, five had nucleic acid quality problems, while 85 underwent both DNA and RNA tests. Driver gene mutations were detected in 56/90 (62.2%) patients. Of the 34 patient specimens, driver mutations were not detected using the ODxTT; however, epidermal growth factor receptor (EGFR) mutations were detected using polymerase chain reaction-based testing in two patients, and a KRAS mutation was detected by careful examination of the sequence data obtained using the ODxTT in one patient. For the above three cases, carefully examining the gene sequence information obtained using the ODxTT could identify driver mutations that were not mentioned in the returned test results. Additionally, we confirmed comparable instances of overlook results for EGFR mutations in the dataset from South Korea, implying that this type of oversight could occur in other countries using the ODxTT. EGFR mutation was missed in ODxTT in Japan (6.3%, 2/32), South Korea (2.0%, 1/49), and overall (3.7%, 3/81).

CONCLUSION

Even if sufficient tumor samples are obtained, rare EGFR mutations (which are excluded from the ODxTT's genetic mutation list) might not be detected using the current ODxTT system due to the program used for sequence analysis. However, such rare EGFR mutations can still be accurately detected on ODxTT's sequence data using next-generation sequencing.

Locked nucleic acid (LNA): A modern approach to cancer diagnosis and treatment

Cancer is responsible for about one in six deaths in the world. Conventional cancer treatments like chemotherapy, radiotherapy, and surgery are associated with drug poisoning and poor prognosis. Thanks to advances in RNA delivery and target selection, new cancer medicines are now conceivable to improve the quality of life and extend the lives of cancer patients. Antisense oligonucleotides (ASOs) and siRNAs are the most important tools in RNA therapies. Locked Nucleic Acids (LNAs) are one of the newest RNA analogs, exhibiting more affinity to binding, sequence specificity, thermal stability, and nuclease resistance due to their unique properties. Assays using LNA are also used in molecular diagnostic methods and provide accurate and rapid mutation detection that improves specificity and sensitivity. This study aims to review the special properties of LNA oligonucleotides that make them safe and effective antisense drugs for cancer treatment by controlling gene expression. Following that, we go over all of the molecular detection methods and cancer treatment antisense tactics that are possible with LNA technology.

Epidermal Growth Factor Receptor Expression and Resistance Patterns to Targeted Therapy in Non-Small Cell Lung Cancer: A Review

Globally, lung cancer is the leading cause of cancer-related death. The majority of non-small cell lung cancer (NSCLC) tumours express epidermal growth factor receptor (EGFR), which allows for precise and targeted therapy in these patients. The dysregulation of EGFR in solid epithelial cancers has two distinct mechanisms: either a kinase-activating mutation in EGFR (EGFR-mutant) and/or an overexpression of wild-type EGFR (wt-EGFR). The underlying mechanism of EGFR dysregulation influences the efficacy of anti-EGFR therapy as well as the nature of resistance patterns and secondary mutations. This review will critically analyse the mechanisms of EGFR expression in NSCLC, its relevance to currently approved targeted treatment options, and the complex nature of secondary mutations and intrinsic and acquired resistance patterns in NSCLC.

Simultaneous Detection of the T790M and L858R Mutations in the EGFR Gene by Oligoribonucleotide Interference-PCR

A de novo single-nucleotide mutation in the EGFR gene can cause the development of lung cancer. EGFR tyrosine kinase inhibitors (EGFR-TKIs) are used for clinical treatment of such lung cancers, but acquired resistance often mitigates their efficacy. Accordingly, monitoring of de novo and acquired nucleotide mutations is essential for clinical treatment of lung cancers with EGFR-TKIs. Previously, we reported that oligoribonucleotide interference-PCR (ORNi-PCR) can accurately and cost-effectively detect single-nucleotide mutations. In this study, we applied ORNi-PCR to simultaneous detection of the de novo L858R and acquired T790M mutations in the EGFR gene in lung cancer cells. First, we established optimal experimental conditions for ORNi-PCR to simultaneously detect the two single-nucleotide mutations in genomic DNA from lung cancer cells. The conditions we established could also be used for ORNi-PCR using complementary DNA reverse-transcribed from extracted RNA. We found that ORNi-PCR could detect lung cancer cells possessing both single-nucleotide mutations among a large number of cells harboring wild-type sequences, even when the cancer cells constituted less than ~0.2% of all cells. Our findings demonstrate that ORNi-PCR can simultaneously detect multiple single-nucleotide mutations in a gene of interest and might therefore be useful for simultaneous detection of EGFR mutations in clinical examinations.

Plasma ctDNA monitoring during epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor treatment in patients with EGFR-mutant non-small cell lung cancer (JP-CLEAR trial)

BACKGROUND

Osimertinib, a third generation epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI), is active against EGFR-mutant non-small cell lung cancer (NSCLC) resistant to first-/second-generation EGFR-TKIs with the T790M mutation. T790M monitoring in plasma circulating tumor DNA (ctDNA) in patients receiving EGFR-TKIs is less invasive than re-biopsy and could provide valuable clinical information.

METHODS

Patients with advanced or postoperative recurrent NSCLC with sensitizing EGFR mutations who were planned to receive or were receiving first-/second-generation EGFR-TKI treatment without disease progression were eligible for enrollment. Plasma samples at baseline and every 1-2 months thereafter were analyzed for EGFR mutation status using the cobas®EGFR Mutation Test v2.

RESULTS

Between September 2016 and March 2017, 122 patients at 15 Japanese institutions were enrolled. In August 2018, 1291 plasma samples from 121 patients were analyzed for EGFR mutation status. At baseline, a sensitizing EGFR mutation was detected in 29 (23.9%) of 121 patients and T790M mutation was detected in three (2.5%). At follow-up, 66 (54.5%) patients experienced disease progression and 64 (52.9%) discontinued first-line EGFR-TKI treatment. Twenty-two (18.2%) patients showed T790M in plasma ctDNA, of which 15(68.2%) received osimertinib. Although 31 patients received re-biopsy to examine EGFR status at disease progression, T790M was detected in only nine (22.0%) patients, of which 7 (77.8%) received osimertinib.

CONCLUSIONS

ctDNA monitoring during EGFR-TKI treatment is useful for detecting T790M mutation. The efficacy of osimertinib treatment based on T790M status in plasma ctDNA remains to be established, warranting further research.

Different subtypes of EGFR exon19 mutation can affect prognosis of patients with non-small cell lung adenocarcinoma

Aims

In this study, we determined whether different subtypes of epidermal growth factor receptor (EGFR) exon19 mutation are associated with the therapeutic effect of EGFR-tyrosine kinase inhibitors (TKIs) on advanced non-small cell lung adenocarcinoma.

Methods

A total of 122 patients with stage III or IV non-small cell lung adenocarcinoma were retrospectively reviewed. Clinical characteristics of these patients, including progression-free survival (PFS) outcome for EGFR-TKI treatment, were analyzed.

Results

According to the mutation pattern, we classified the in-frame deletions detected on EGFR Exon19 into three different types: codon deletion (CD), with a deletion of one or more original codons; codon substitution and skipping (CSS), with a deletion of one or two nucleotides but the residues could be translated into a new amino acid without changing following amino acid sequence; CD or CSS plus single nucleotide variant (SNV) (CD/CSS+SNV), exclude CD or CSS, there’s another SNV nearby the deletion region. The clinical characteristics of three groups were analyzed and as a result, no significant difference was found. By comparing the average number of missing bases and amino acids of the three mutation subtypes, it could be discovered that the number of missing bases and amino acids of the three mutation subtypes is diverse, and group CSS> group CD> group CD/CSS+SNV. Finally, survival analysis was performed between three groups of patients. The median PFS of group CD, group CSS and group CD/CSS+SNV was 11 months, 9 months and 14 months respectively. There was a distinct difference in the PFS between group CSS and group CD/CSS+SNV (P = 0.035<0.05), and the PFS of group CD/CSS+SNV was longer.

Conclusions

Different mutation subtypes of EGFR exon19 can predict the therapeutic effect of EGFR-TKIs on advanced non-small cell lung adenocarcinoma.

Targeting oncogenic drivers in lung cancer: Recent progress, current challenges and future opportunities

Targeted therapies have changed the landscape of treatments for non-small cell lung cancer (NSCLC). Specific targeted therapies have been approved for NSCLC patients harboring genetic alterations in four oncogenes, and agents targeting additional oncogenic drivers are under investigation. Standard first-line chemotherapy has been supplanted by these targeted therapies due to superior efficacy and lower toxicity. Despite excellent response rates and durable responses in some cases, most patients experience relapse within a few years due to the development of acquired drug resistance. Next generation targeted therapies are being developed to overcome drug resistance and extend the duration of therapy. In this review, we summarize the current treatment strategies for the major targetable oncogenic mutations/alterations in NSCLC and discuss the mechanisms leading to acquired drug resistance.

Pneumonitis in advanced non-small-cell lung cancer patients treated with EGFR tyrosine kinase inhibitor: Meta-analysis of 153 cohorts with 15,713 patients: Meta-analysis of incidence and risk factors of EGFR-TKI pneumonitis in NSCLC

PURPOSE

Pneumonitis is a significant toxicity of EGFR tyrosine kinase inhibitors (EGFR-TKI) in non-small-cell lung cancer (NSCLC) patients. We studied the incidence of pneumonitis in clinical trials of EGFR-TKI published in 2003-2017, and performed subgroups analyses to identity predisposing factors.

METHODS

Ovid-MEDLINE and EMBASE search up to 4/17/17 using the keywords, "erlotinib", "gefitinib", "afatinib", "osimertinib", and "lung cancer", resulted in a total of 153 eligible trial cohorts with 15,713 advanced NSCLC patients treated with EGFR-TKI. The pooled incidence of all-grade, high-grade, and grade 5 pneumonitis was obtained. Subgroup analyses were performed with meta-regression using study-level covariates.

RESULTS

Among the patients without prior exposure to EGFR-TKI, the overall incidence was 1.12% (95% CI:0.79-1.58%) for all-grade, 0.61% (95% CI:0.40-0.93%) for high-grade, and 0.20% (95% CI:0.11-0.38%) for grade 5 pneumonitis. The incidence was significantly higher in Japanese studies compared to studies of non-Japan origin, for all-grade (4.77% vs. 0.55%, p < 0.001), high grade (2.49% vs. 0.37%, p < 0.001), and grade 5 pneumonitis (1.00% vs. 0.18%, p < 0.001). Multivariate analyses demonstrated higher odds of pneumonitis in Japanese studies for all-grade (odds ratio [OR]: 5.04; 95% CI:3.14-8.11, p < 0.001), high-grade (OR: 4.45; 95% CI:2.50-7.93, p < 0.001), and grade 5 pneumonitis (OR: 4.55; 95% CI:2.20-9.44, p < 0.001) compared to others, after adjusting for types of EGFR-TKI and lines of therapy. In patients with EGFR retreatment analyzed separately, the pooled incidence was 1.13% (95% CI:0.40-3.15%) for all-grade, 0.49% (95% CI:0.21-1.11%) for high-grade, and 0.16% (95% CI:0.04-0.65%) for grade 5 pneumonitis.

CONCLUSIONS

The overall incidence of EGFR-TKI pneumonitis was 1.12% in patients without prior exposure to EGFR-TKI, and 1.13% in EGFR-TKI retreatment group. The cohorts from Japan had significantly higher incidence of pneumonitis, providing insights for further mechanistic studies.

Droplet digital polymerase chain reaction assay and peptide nucleic acid-locked nucleic acid clamp method for RHOA mutation detection in angioimmunoblastic T-cell lymphoma

Angioimmunoblastic T‐cell lymphoma (AITL) is a subtype of nodal peripheral T‐cell lymphoma (PTCL). Somatic RHOA mutations, most frequently found at the hotspot site c.50G > T, p.Gly17Val (G17V RHOA mutation) are a genetic hallmark of AITL. Detection of the G17V RHOA mutations assists prompt and appropriate diagnosis of AITL. However, an optimal detection method for the G17V RHOA mutation remains to be elucidated. We compared the sensitivity and concordance of next‐generation sequencing (NGS), droplet digital PCR (ddPCR) and peptide nucleic acid‐locked nucleic acid (PNA‐LNA) clamp method for detecting the G17V RHOA mutation. G17V RHOA mutations were identified in 27 of 67 (40.3%) PTCL samples using NGS. ddPCR and PNA‐LNA clamp method both detected G17V mutations in 4 samples in addition to those detected with NGS (31 of 67, 46.3%). Additionally, variant allele frequencies with ddPCR and those with NGS showed high concordance (P < .001). Three other RHOA mutations involving the p.Gly17 position (c.[49G > T;50G > T], p.Gly17Leu in PTCL198; c.[50G > T;51A > C], p.Gly17Val in PTCL216; and c.50G > A, p.Gly17Glu in PTCL223) were detected using NGS. These sequence changes could not appropriately be detected using the ddPCR assay and the PNA‐LNA clamp method although both indicated that the samples might have mutations. In total, 34 out of 67 PTCL samples (50.7%) had RHOA mutations at the p.Gly17 position. In conclusion, our results suggested that a combination of ddPCR/PNA‐LNA clamp methods and NGS are best method to assist the diagnosis of AITL by detecting RHOA mutations at the p.Gly17 position.

A novel ARMS-based assay for the quantification of EGFR mutations in patients with lung adenocarcinoma

Quantification of epidermal growth factor receptor (EGFR) mutations is important for the prediction of tyrosine kinase inhibitor (TKI) efficacy in patients with non-small cell lung cancer (NSCLC). However, clinicians lack a sensitive and convenient method to quantify EGFR mutant abundance. The present study introduces a novel method, namely amplification refractory mutation system (ARMS)-Plus, for the quantitative analysis of EGFR exon 19 deletion (19Del), L858R and T790M mutations. Formalin-fixed paraffin-embedded tumor samples were collected from 77 patients with lung adenocarcinoma. DNA was extracted and analyzed for EGFR mutations using ARMS-Plus. The performance of ARMS-Plus was then compared with that of conventional ARMS-polymerase chain reaction (ARMS-PCR) and droplet digital PCR (ddPCR). The results demonstrated that the concordance rate of EGFR mutation testing between ARMS-Plus and ddPCR was 98.7% (76/77, Kappa=0.9739). 19Del and L858R mutations were detected in 23 and 12 patients, respectively. There was a significant difference between ARMS-Plus and ddPCR in the evaluation of 19Del mutant abundance (P=0.0002); however, not in that of L858R mutant abundance (P=0.7334). The ARMS-Plus results in L858R mutant abundance were concordant with that of ddPCR (R2=0.8081). These results indicated that the sensitivity and specificity of ARMS-Plus in identifying EGFR mutations were similar to that of ddPCR. For quantitative analysis, the results of ARMS-Plus in evaluating L858R mutant abundance revealed a positive correlation with the ddPCR results. Thus, ARMS-Plus provides an alternative method, which is reliable and cost-effective, to quantify EGFR mutations and thereby, aid treatment decisions in patients with lung adenocarcinoma.

The clinical features of squamous cell lung carcinoma with sensitive EGFR mutations

BACKGROUND

The process of selecting patients on the basis of epidermal growth factor receptor (EGFR) mutations would likely result in a patient population with greater sensitivity to EGFR tyrosine kinase inhibitors (EGFR-TKIs). However, EGFR mutation status is not routinely examined in patients with squamous cell lung cancer (Sq) because of the low incidence of EGFR mutations and the poor clinical response to EGFR-TKIs.

METHODS

We retrospectively reviewed the clinical features of patients at our hospital with Sq who carried EGFR-TKI-sensitive EGFR mutations and assessed their responses to EGFR-TKIs.

RESULTS

EGFR mutation status was tested in 23 of 441 patients with Sq (5.2%) admitted to our hospital during the study period. An EGFR mutation (exon 19 deletion 3, L858R 2) was identified in five of the 23 patients (21.7%), all of whom were female never-smokers. Of these five patients, four (4/9; 44.4%) were in the normal lung group, one (1/12; 8.3%) was in the emphysematous lung group, and none (0/2; 0%) in the fibrotic lung group. Two of these five patients with the EGFR mutation received gefitinib and two received afatinib. Although the two patients who were treated with gefitinib did not respond well to treatment (stable disease, 1 patient; progressive disease, 1 patient), the two patients who were treated with afatinib showed a good response (partial response, 2 patients).

CONCLUSION

The administration of afatinib to Sq patients after selecting patients using the EGFR mutation test based on their underlying pulmonary disease and smoking status would likely result in a population with a greater sensitivity to afatinib.

Exploitation of Gene Expression and Cancer Biomarkers in Paving the Path to Era of Personalized Medicine

Cancer therapy agents have been used extensively as cytotoxic drugs against tissue or organ of a specific type of cancer. With the better understanding of molecular mechanisms underlying carcinogenesis and cellular events during cancer progression and metastasis, it is now possible to use targeted therapy for these molecular events. Targeted therapy is able to identify cancer patients with dissimilar genetic defects at cellular level for the same cancer type and consequently requires individualized approach for treatment. Cancer therapy begins to shift steadily from the traditional approach of “one regimen for all patients” to a more individualized approach, through which each patient will be treated specifically according to their specific genetic defects. Personalized medicine accordingly requires identification of indicators or markers that guide in the decision making of such therapy to the chosen patients for more effective therapy. Cancer biomarkers are frequently used in clinical practice for diagnosis and prognosis, as well as identification of responsive patients and prediction of treatment response of cancer patient. The rapid breakthrough and development of microarray and sequencing technologies is probably the main tool for paving the way toward “individualized biomarker-driven cancer therapy” or “personalized medicine”. In this review, we aim to provide an updated knowledge and overview of the current landscape of cancer biomarkers and their role in personalized medicine, emphasizing the impact of genomics on the implementation of new potential targeted therapies and development of novel cancer biomarkers in improving the outcome of cancer therapy.

Second-Line Treatment of NSCLC-The Pan-ErbB Inhibitor Afatinib in Times of Shifting Paradigms

In contrast to the established role of epidermal growth factor receptor (EGFR) inhibitors for the first-line treatment of patients with non-small cell lung cancer (NSCLC) harboring activating EGFR mutations, the role of EGFR blockade and of EGFR molecular testing in the second-line treatment remains less clear. The irreversible pan-ErbB family inhibitor afatinib (Gi(l)otrif^®) was recently FDA- and EMA-approved for the second-line treatment of NSCLC with squamous cell histology irrespective of the EGFR mutational status (LUX-Lung 8). Contrariwise, results from the TAILOR and DELTA trials among retrospective biomarker analyses show the predictive value of the EGFR mutational status for efficacy of reversible EGFR inhibitors also as a second-line therapy. This mini review critically summarizes the current role of EGFR-targeting strategies in the second-line treatment of NSCLC with special respect to afatinib in light of emerging T790M-specific EGFR and immune check point inhibitors. The review also emphasizes the urgent need for reliable biomarkers to guide therapeutic decision-making and outlines prospective changes to the second-line landscape with some of the current second-line treatment concepts likely to be moved to the first-line.

An Analysis of EGFR Mutations among 1506 Cases of Non-Small Cell Lung Cancer Patients in Guangxi, China

An association between epidermal growth factor receptor (EGFR) and clinical characteristics of non-small cell lung cancer (NSCLC) was reported ten years ago. In addition, a different type of relationship was seen in different ethic races. However, the relationship between these factors is not well understood in the Guangxi province. Up to now, there are only very limited data on the association of TTF1/EGFR protein positivity and EGFR mutation status in NSCLC. This study aims to investigate the role of EGFR gene mutation status on the clinical characteristics and the relationship with TTF-1/EGFR protein positivity of patients with NSCLC in Guangxi, China. 1506 samples from different patients with NSCLC were detected by amplification refractory mutation system for 29 hotspot mutations. Analysis of the relationship between clinical characteristics and EGFR mutation status was performed by using the crosstabs Chi-square and SPSS 21.0 software. Of 1506 samples, 537 (35.7%) revealed tyrosine kinase inhibitor (TKI) sensitive EGFR mutations with 27 (1.8%) cases harboring TKI resistant EGFR mutations or union co-existing EGFR-TKIs sensitive mutations. EGFR-TKIs sensitive mutations were not significantly associated with age and TNM-M stage (P = 0.863; P = 0.572, respectively). However, they were significantly associated with p-stage, TNM-T stage and TNM-N stage (P = 0.011, P < 0.001, P = 0.036, respectively). Immunohistochemical studies revealed that TTF-1 and EGFR protein expression level were all associated with EGFR mutation status (P < 0.001, P = 0.002, respectively). Of the 537 EGFR-TKIs sensitive mutation cases, the rates of exon 19-del, 18 G719X point, exon 21 L858R and L861Q points were 54.6, 0.9, 42.3 and 0.9%, respectively. EGFR TKI-sensitive mutations commonly occur in female, non-smoking and adenocarcinoma patients. The p-stage, TNM-T stage, TNM-N stage, EGFR and TTF-1 protein expression levels have close relationships with EGFR mutation status.

A decade of EGFR inhibition in EGFR-mutated non small cell lung cancer (NSCLC): Old successes and future perspectives

The discovery of Epidermal Growth Factor Receptor (EGFR) mutations in Non Small Cell Lung Cancer (NSCLC) launched the era of personalized medicine in advanced NSCLC, leading to a dramatic shift in the therapeutic landscape of this disease. After ten years from the individuation of activating mutations in the tyrosine kinase domain of the EGFR in NSCLC patients responding to the EGFR tyrosine kinase inhibitor (TKI) Gefitinib, several progresses have been done and first line treatment with EGFR TKIs is a firmly established option in advanced EGFR-mutated NSCLC patients. During the last decade, different EGFR TKIs have been developed and three inhibitors have been approved so far in these selected patients. However, despite great breakthroughs have been made, treatment of these molecularly selected patients poses novel therapeutic challenges, such as emerging of acquired resistance, brain metastases development or the need to translate these treatments in earlier clinical settings, such as adjuvant therapy.

The aim of this paper is to provide a comprehensive review of the major progresses reported so far in the EGFR inhibition in this molecularly-selected subgroup of NSCLC patients, from the early successes with first generation EGFR TKIs, Erlotinib and Gefitinib, to the novel irreversible and mutant-selective inhibitors and ultimately the emerging challenges that we, in the next future, are called to deal with.

[Association between the epidermal growth receptor status and the efficacy of first-line chemotherapy in patients with advanced non-small cell lung cancer]

背景与目的

表皮生长因子受体（epidermal growth factor receptor, EGFR）基因状态是表皮生长因子受体酪氨酸激酶抑制剂（epidermal growth factor receptor tyrosine kinase inhibitor, EGFR-TKI）疗效的预测因素，但其对化疗疗效的预测作用尚不明确。本研究旨在探讨对晚期非小细胞肺癌（non-small cell lung cancer, NSCLC）患者一线化疗疗效的预测意义。

方法

收集首都医科大学附属北京胸科医院自2006年1月10日-2013年12月20日经组织病理学证实的181例Ⅲb期/Ⅳ期的NSCLC患者。分析EGFR基因状态、临床特征与化疗疗效及无疾病进展生存期（progression-free survival, PFS）之间的关系。

结果

181例患者均进行了EGFR基因检测，EGFR突变患者75例（41.4%），野生型为106例（58.6%）。全部患者均接受一线化疗，客观缓解率（objective response rate, ORR）为26.0%，疾病控制率（disease control rate, DCR）为70.2%。EGFR突变患者的DCR显著高于EGFR野生型患者高（84.0% vs 60.4%, P=0.001）。亚组分析显示，19外显子缺失突变患者化疗的ORR、DCR均高于EGFR野生型患者（P值分别为0.049，0.002）。21外显子L858R突变患者的DCR高于EGFR野生型患者（P=0.010）。全部患者中，168例患者可评价PFS，中位PFS为4.3个月，其中腺癌患者PFS较鳞癌患者延长（4.7个月 vs 3.0个月，P=0.036）；突变患者PFS长于野生型患者（6.3个月 vs 3.0个月，P=0.002）；体力状况评分（performance status, PS）0-1分组患者PFS较评分为2分延长（4.4个月 vs 0.7个月，P=0.016）。Cox多因素分析显示，EGFR突变是影响PFS的独立因素（HR=0.654, 95%CI: 0.470-0.909, P=0.012）。

结论

EGFR突变是晚期NSCLC患者一线化疗PFS的预测因素。

The Emergent Landscape of Detecting EGFR Mutations Using Circulating Tumor DNA in Lung Cancer

The advances in targeted therapies for lung cancer are based on the evaluation of specific gene mutations especially the epidermal growth factor receptor (EGFR). The assays largely depend on the acquisition of tumor tissue via biopsy before the initiation of therapy or after the onset of acquired resistance. However, the limitations of tissue biopsy including tumor heterogeneity and insufficient tissues for molecular testing are impotent clinical obstacles for mutation analysis and lung cancer treatment. Due to the invasive procedure of tissue biopsy and the progressive development of drug-resistant EGFR mutations, the effective initial detection and continuous monitoring of EGFR mutations are still unmet requirements. Circulating tumor DNA (ctDNA) detection is a promising biomarker for noninvasive assessment of cancer burden. Recent advancement of sensitive techniques in detecting EGFR mutations using ctDNA enables a broad range of clinical applications, including early detection of disease, prediction of treatment responses, and disease progression. This review not only introduces the biology and clinical implementations of ctDNA but also includes the updating information of recent advancement of techniques for detecting EGFR mutation using ctDNA in lung cancer.

Increased survival with the combination of stereotactic radiosurgery and gefitinib for non-small cell lung cancer brain metastasis patients: a nationwide study in Taiwan

PURPOSE

Whole brain irradiation (WBRT) either with or without resection has historically been the treatment for brain metastases from non-small cell lung cancer (NSCLC). The effect of gamma knife (GK) radiosurgery, chemotherapy, or the combination remains incompletely defined. In this study, we assessed the outcome of brain metastases from non-small cell lung cancer treated by WBRT followed by GK, gefitinib, or the combination of GK and gefitinib.

MATERIAL AND METHODS

We retrieved the records of NSCLC patients with brain metastases from the National Health Insurance Research Database (NHIRD) of Taiwan from 2004 to 2010. WBRT either with or without resection was the first line treatment for nearly all patients. The decision to add GK and/or gefitinib treatment was at the discretion of the treating physician and based upon a patient's medical records and imaging data. These patients were classified into four groups including WBRT, WBRT + gefitinib, WBRT + GK, WBRT + gefitinib + GK. These data was evaluated for difference in survival and factors that portended an extended survival from the time of brain metastasis diagnosis.

RESULTS

Of the 60194 patients with newly diagnosed NSCLC, 23874 (39.6 %) developed brain metastases. The distribution of patients for the groups was WBRT for 20241, WBRT + gefitinib for 3379, WBRT + GK for 155, and WBRT+ gefitinib + GK for 99 patients. The median survival for the time of brain metastasis diagnosis for WBRT, WBRT+ gefitinib, WBRT+ GK, WBRT+ gefitinib + GK groups was 0.53, 1.01, 1.46, and 2.25 years, respectively (p < 0.0001). The hazard ratio (95 % CI) for survival was 1, 0.56, 0.43, and 0.40, respectively (p < 0.001). The adjusted hazard ratio (95 % CI) by age, sex and Charlson comorbidity index (CCI) was 1, 0.73, 0.49, and 0.42, respectively (p < 0.001).

CONCLUSION

Patients with brain metastases from NSCLC receiving GK or gefitinib demonstrated extended survival. The improved survival seen with GK and gefitinib suggests a survival benefit in selected patients receiving the combined treatment. Further Phase II study should be conducted to assessment these influence.

Is the current diagnostic algorithm reliable for selecting cases for EGFR- and KRAS-mutation analysis in lung cancer?

OBJECTIVES

Adenocarcinoma (ADC) of the lung may harbor EGFR- or KRAS-mutations, which are relevant for treatment decisions. There is no consensus on the percentages of EGFR- and KRAS-mutations that are allowed to be missed by a diagnostic algorithm, although a percentage of less than 1% for EGFR-mutations has been suggested. The current guidelines do not advise to perform EGFR-mutation analysis in unequivocal squamous cell carcinoma (SqCC). For KRAS-mutations no threshold for missing cases is suggested yet. To improve segregation between ADC and SqCC in small samples, the classification of lung cancer was updated in 2011, adding immunohistochemistry (IHC) for p63 and TTF-1 to the diagnostic algorithm. In this study we examined how many cases with an EGFR- or KRAS-mutation in our database would have been missed, if the current guideline for selecting cases for mutation analysis would have been applied.

MATERIALS AND METHODS

From an institutional lung cancer database of specimens analyzed for EGFR- and KRAS-mutations (n=816), cases harboring a mutation without being treated prior with an EGFR-TKI were selected (n=336). Corresponding original histological diagnoses and IHC for TTF-1, p63 and PAS-D were collected. Cases with SqCC on HE or with an IHC pattern favoring SqCC were reassessed according to the criteria of the 2011-classification.

RESULTS

From the 336 cases 70% had a KRAS-mutation and 30% an EGFR-mutation. The number of cases with SqCC on HE and/or an IHC-profile favoring SqCC was 12. After the reassessment six specimens (1.8%) would not have been tested for EGFR-/KRAS-mutations, if the current diagnostic algorithm had been used: 2.0% of EGFR-mutations and 1.7% KRAS-mutations. All six cases were NSCLC with an IHC-profile favoring SqCC.

CONCLUSION

Most NSCLC-cases with EGFR- and KRAS-mutations are selected by the current diagnostic algorithm. As a small but relevant fraction is missed, there is room for improvement.

Pooled safety analysis of EGFR-TKI treatment for EGFR mutation-positive non-small cell lung cancer

OBJECTIVES

Three epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) - afatinib, erlotinib, and gefitinib - are available for the treatment of patients with EGFR mutation-positive non-small cell lung cancer (NSCLC). Given the long-term exposure of such patients to EGFR-TKIs, the toxicological properties of these agents in these individuals may differ from those observed in unselected patients. We compared the frequencies of severe adverse events (AEs) among EGFR mutation-positive NSCLC patients treated with these three EGFR-TKIs.

MATERIALS AND METHODS

We performed a pooled analysis of severe AEs according to the type of EGFR-TKI administered with the use of data extracted from prospective clinical trials that evaluated the clinical efficacy of gefitinib, erlotinib, or afatinib in NSCLC patients with EGFR mutations.

RESULTS

Twenty-one trials published between 2006 and 2014 and including 1468 patients were eligible for analysis. Patients in 13 trials (n=457) received gefitinib, those in 5 trials (n=513) received erlotinib, and those in 3 trials (n=498) received afatinib. Rash and diarrhea of grade ≥3 were significantly more frequent with afatinib therapy than with erlotinib or gefitinib therapy. The frequency of interstitial lung disease (ILD) of grade ≥3 was low (0.6-2.2%) with all three EGFR-TKIs and did not differ significantly among them. Gefitinib was associated with a significantly higher frequency of hepatotoxicity of grade ≥3 compared with erlotinib or afatinib. The overall frequency of AEs leading to treatment withdrawal was 6.1% (83 of 1354 evaluable patients), with such AEs occurring significantly more often with afatinib or gefitinib than with erlotinib. The most common withdrawal AEs were skin toxicity, ILD, and hepatotoxicity.

CONCLUSION

Such information on AEs should facilitate selection of the most appropriate EGFR-TKI for EGFR mutation-positive NSCLC patients with regard to mitigation of the risk for certain types of toxicity.

Pragmatic issues in biomarker evaluation for targeted therapies in cancer

Predictive biomarkers are becoming increasingly important tools in drug development and clinical research. The importance of using both guidelines for specimen acquisition and analytical methods for biomarker measurements that are standardized has become recognized widely as an important issue, which must be addressed in order to provide high-quality, validated assays. Herein, we review the major challenges in biomarker validation processes, including pre-analytical (sample-related), analytical, and post-analytical (data-related) aspects of assay development. Recommendations for improving biomarker assay development and method validation are proposed to facilitate the use of predictive biomarkers in clinical trials and the practice of oncology.

Targeted treatment of mutated EGFR-expressing non-small-cell lung cancer: focus on erlotinib with companion diagnostics

Deeper understanding of the pathobiology of non-small-cell lung cancer (NSCLC) has led to the development of small molecules that target genetic mutations known to play critical roles in the progression to metastatic disease. The discovery of epidermal growth factor receptor (EGFR) mutations in 15%–20% of lung adenocarcinomas and the associated response to EGFR tyrosine kinase inhibitors have provided a successful avenue of attack in late-stage adenocarcinomas. Use of the EGFR tyrosine kinase inhibitors gefitinib, erlotinib, and afatinib is limited to patients who have adenocarcinomas with known activating EGFR mutations. However, the EGFR mutation testing landscape is varied and includes many screening and targeted methods, each with its own benefits and limitations. These tests can simplify the drug discovery process, make clinical trials more efficient and informative, and individualize cancer therapy. In practice, the choice of method should be determined by the nature of the sample to be tested, the testing laboratory’s expertise and access to equipment, and whether the detection of only known activating EGFR mutations, or of all possible mutations, is required. Development of companion diagnostic tests for this identification is advancing; nevertheless, the use of such tests merits greater attention.

Different efficacy of EGFR tyrosine kinase inhibitors and prognosis in patients with subtypes of EGFR-mutated advanced non-small cell lung cancer: a meta-analysis

BACKGROUND

Nearly 85 % of lung-cancer-specific epidermal growth factor receptor (EGFR) sensitive mutations comprise a substitution at position 858 (21L858R) and deletion mutants in exon 19 (19del). The aim of this study was to assess the role of EGFR mutation subtypes in predicting the efficacy of EGFR tyrosine kinase inhibitors (EGFR TKIs) and the prognosis of patients with advanced non-small cell lung cancer (NSCLC).

METHOD

We systematically searched for eligible articles investigating the association between EGFR mutation subtypes and the efficacy of EGFR TKIs and the prognosis of patients with NSCLC. The summary risk ratio (RR) and mean difference (MD) were calculated using meta-analysis. In addition, we used variance analysis for the progression-free survival data (PFS) and used the rank sum test for the overall survival data.

RESULTS

We identified 22 eligible trials involving 1,082 patients. The objective response rate of the 19del mutation group was significantly higher than the 21L858R mutation group (RR 1.23; 95 % CI 1.12-1.36; P < 0.0001). The PFS (MD 3.55; 95 % CI 0.90-6.20; P = 0.009; MD 2.57; 95 % CI 0.51-4.62; P = 0.01) and overall survival (OS) (MD 10.52; 95 % CI 5.10-15.93; P = 0.0001) of the 19del mutation group were significantly longer than the 21L858R mutation group; the same results were observed in the variance analysis and rank sum test.

CONCLUSION

The 19del mutation may be a more efficient clinical marker for predicting the response of patients with NSCLC to EGFR TKIs. Furthermore, patients with the 19del mutation have both a longer PFS and OS. The 19del mutation is also the prognostic factor for patients with NSCLC.

Epidermal growth factor receptor tyrosine kinase inhibitors for non-small cell lung cancer

First-generation epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), including gefitinib and erlotinib, have proven to be highly effective agents for advanced non-small cell lung cancer (NSCLC) in patients harboring an activating EGFR mutation such as the exon 19 deletion mutation and L858R. Although those reversible small molecular targeted agents provide a significant response and survival benefit, all responders eventually acquire resistance. Second-generation EGFR-targeting agents, such as irreversible EGFR/HER2 tyrosine kinase inhibitors and pan-HER TKIs, may improve survival further and be useful for patients who acquired resistance to first-generation EGFR-TKIs. This review discusses novel therapeutic strategies for EGFR-mutated advanced NSCLC using first- and second-generation EGFR-TKIs.

Pooled analysis of clinical outcome for EGFR TKI-treated patients with EGFR mutation-positive NSCLC

Patients with non-small-cell lung cancer (NSCLC) appear to gain particular benefit from treatment with epidermal growth factor receptor (EGFR) tyrosine-kinase inhibitors (TKI) if their disease tests positive for EGFR activating mutations. Recently, several large, controlled, phase III studies have been published in NSCLC patients with EGFR mutation-positive tumours. Given the increased patient dataset now available, a comprehensive literature search for EGFR TKIs or chemotherapy in EGFR mutation-positive NSCLC was undertaken to update the results of a previously published pooled analysis. Pooling eligible progression-free survival (PFS) data from 27 erlotinib studies (n = 731), 54 gefitinib studies (n = 1802) and 20 chemotherapy studies (n = 984) provided median PFS values for each treatment. The pooled median PFS was: 12.4 months (95% accuracy intervals [AI] 11.6-13.4) for erlotinib-treated patients; 9.4 months (95% AI 9.0-9.8) for gefitinib-treated patients; and 5.6 months (95% AI 5.3-6.0) for chemotherapy. Both erlotinib and gefitinib resulted in significantly longer PFS than chemotherapy (permutation testing; P = 0.000 and P = 0.000, respectively). Data on more recent TKIs (afatinib, dacomitinib and icotinib) were insufficient at this time-point to carry out a pooled PFS analysis on these compounds. The results of this updated pooled analysis suggest a substantial clear PFS benefit of treating patients with EGFR mutation-positive NSCLC with erlotinib or gefitinib compared with chemotherapy.

A new receptor tyrosine kinase inhibitor, icotinib, for patients with lung adenocarcinoma cancer without indication for chemotherapy

Epidermal growth factor receptor (EGFR) is an important therapeutic target in lung cancer. Gefitinib and erlotinib, two reversible EGFR receptor tyrosine kinases inhibitors (TKIs), have been approved for the treatment of patients with metastatic non small-cell lung cancer. Icotinib, which is a selective EGFR-TKI, provides a similar efficacy to gefitinib. The present study aimed to investigate the survival and safety of icotinib in patients with lung adenocarcinoma with a poor performance status (PS). A total of 42 cases of lung adenocarcinoma, including 35 females and 7 males, were enrolled. Icotinib was used as the first-line of treatment due to poor PS of the patient or a more advanced age. Icotinib (125 mg) was orally administered three times per day. The overall response rate and disease control rates were 33.3 and 85.7%, respectively. The median survival time was 13.0 months (95% CI, 5.6–20.4), The median progression-free survival time was 7.0 months, and the 1-year survival rate was 71.4%. A total of 79% of patients had an improved PS following icotinib treatment. Grade 1 to 2 rashes and diarrhea were the most frequent side effects. One patient succumbed during the study due to interstitial pneumonia. In conclusion, this is the first study indicating that patients with lung adenocarcinoma and poor PS may benefit from first-line icotinib therapy, but should be cautious of the occurrence of interstitial lung disease.

Correlation between EGFR mutation status and response to first-line platinum-based chemotherapy in patients with advanced non-small cell lung cancer

Background

The purpose of this research was to investigate the relationship between epidermal growth factor receptor (EGFR) mutations and the response to first-line chemotherapy in patients with advanced non-small cell lung cancer (NSCLC).

Methods

A total of 266 patients with stage IIIB or IV NSCLC who received platinum-based doublet therapies as first-line chemotherapy were investigated retrospectively, and their clinical data were assessed according to EGFR mutation.

Results

EGFR mutations were identified in 45.5% of patients. There was no significant difference in response rate between EGFR mutation carriers and EGFR wild-type carriers (P=0.484). Among the patients with Kirsten rat sarcoma viral oncogene homolog (KRAS) wild-type, however, those with EGFR mutations responded better to treatment than EGFR wild-type patients (46.2% versus 20.8%, P=0.043). The disease control rate associated with pemetrexed-based treatments was higher than for vinorelbine-based therapies in EGFR mutation patients (P=0.001). EGFR mutation was found in patients with longer progression-free survival and median survival time, and improved 1-year and 2-year overall survival when compared with EGFR wild-type patients (6.1 versus 5.0 months, P=0.004; 18.9 versus 13.8 months, P=0.001; 81.0% versus 63.4%, P=0.002; and 33.9% versus 22.8% P=0.044, respectively). Patients with the EGFR exon 19 mutation had longer progression-free survival than those with EGFR exon 21 mutation (P=0.007). Multivariate analysis showed that the response to first-line chemotherapy and the presence of EGFR mutations were independent prognostic factors in patients with advanced NSCLC.

Conclusion

Our data showed that the presence of EGFR mutations meant longer survival times for patients with advanced NSCLC who received platinum-based doublet first-line chemotherapy, especially in those with the exon 19 deletion mutation. Among KRAS wild-type patients, those with EGFR mutation responded better to first-line chemotherapy than EGFR wild-type patients.

Brain metastasis effectively treated with erlotinib following the acquisition of resistance to gefitinib: a case report

Introduction

Non-small-cell lung cancer harboring an activated epidermal growth factor receptor mutation exhibits a good response to epidermal growth factor receptor-tyrosine kinase inhibitors; however, clinicians often experience treatment failure following the development of resistance to epidermal growth factor receptor-tyrosine kinase inhibitor.

Case presentation

We here report a case of a 56-year-old Japanese woman with non-small-cell lung carcinoma with a secondary T790M mutation associated with resistance to epidermal growth factor receptor-tyrosine kinase inhibitor that maintained sensitivity of brain metastases to epidermal growth factor receptor-tyrosine kinase inhibitor. An autopsy showed that the primary focus had a T790M mutation; however, no mutations of T790M were found in the brain metastases.

Conclusion

This case demonstrates the detection of T790M was associated with the clinical responsiveness to epidermal growth factor receptor-tyrosine kinase inhibitor.

Gefitinib: re-emerging from the shadows

SUMMARY In the past decade, the identification of mutations in the EGFR gene and the sensitivity of activating mutations to EGF receptor–tyrosine kinase inhibitors has improved survival in a subset of non-small-cell lung cancer patients. Over 70% of patients with EGFR mutations have a response to gefitinib therapy. Gefitinib, a first-generation EGF receptor–tyrosine kinase inhibitor, is well tolerated and continues to be widely used. However, eventually most patients develop resistance to gefitinib. This article reviews the pharmacology of gefitinib and summarizes the clinical trials that have resulted in its current day indications.

Coadministration of erlotinib and curcumin augmentatively reduces cell viability in lung cancer cells

Resistance to erlotinib in lung cancer cases includes T790M mutant epidermal growth factor receptor and c-Met gene amplification, but other unknown mechanisms account for about 30% of the resistance. Activation of the nuclear factor kappa B (NFkappaB)-related pathways in association with the reduction in ikappaB level may be one of such potential mechanisms. It is known that curcumin inhibits the inducible activation of NFkappaB at least in part by sustaining ikappaB expression level. Therefore, we evaluated the effects of coadministration of erlotinib and curcumin on lung cancer cells. We found that erlotinib and curcumin augmentatively reduced cell viability. Studies in PC9 cells showed that induction of apoptosis was involved. Expression of ikappaB was elevated in PC9 cells by curcumin administration, and pretreatment with siRNAs for ikappaB significantly attenuated the reduction in cell viability after coadministration of erlotinib and curcumin. Furthermore, coadministration of erlotinib and/or curcumin augmentatively attenuated the growth of PC9 tumors in mice. These results suggested the existence of an augmentative tumor growth inhibitory effect between erlotinib and curcumin, and this effect was at least in part mediated by the increase in the expression of ikappaB induced by curcumin.

Molecular testing guideline for selection of lung cancer patients for EGFR and ALK tyrosine kinase inhibitors: guideline from the College of American Pathologists, International Association for the Study of Lung Cancer, and Association for Molecular Pathology

OBJECTIVE

To establish evidence-based recommendations for the molecular analysis of lung cancers that are required to guide EGFR- and ALK-directed therapies, addressing which patients and samples should be tested, and when and how testing should be performed.

PARTICIPANTS

Three cochairs without conflicts of interest were selected, one from each of the 3 sponsoring professional societies: College of American Pathologists, International Association for the Study of Lung Cancer, and Association for Molecular Pathology. Writing and advisory panels were constituted from additional experts from these societies.

EVIDENCE

Three unbiased literature searches of electronic databases were performed to capture published articles from January 2004 through February 2012, yielding 1533 articles whose abstracts were screened to identify 521 pertinent articles that were then reviewed in detail for their relevance to the recommendations. EVIDENCE was formally graded for each recommendation.

CONSENSUS PROCESS

Initial recommendations were formulated by the cochairs and panel members at a public meeting. Each guideline section was assigned to at least 2 panelists. Drafts were circulated to the writing panel (version 1), advisory panel (version 2), and the public (version 3) before submission (version 4).

CONCLUSIONS

The 37 guideline items address 14 subjects, including 15 recommendations (evidence grade A/B). The major recommendations are to use testing for EGFR mutations and ALK fusions to guide patient selection for therapy with an epidermal growth factor receptor (EGFR) or anaplastic lymphoma kinase (ALK) inhibitor, respectively, in all patients with advanced-stage adenocarcinoma, regardless of sex, race, smoking history, or other clinical risk factors, and to prioritize EGFR and ALK testing over other molecular predictive tests. As scientific discoveries and clinical practice outpace the completion of randomized clinical trials, evidence-based guidelines developed by expert practitioners are vital for communicating emerging clinical standards. Already, new treatments targeting genetic alterations in other, less common driver oncogenes are being evaluated in lung cancer, and testing for these may be addressed in future versions of these guidelines.

Molecular testing guideline for selection of lung cancer patients for EGFR and ALK tyrosine kinase inhibitors: guideline from the College of American Pathologists, International Association for the Study of Lung Cancer, and Association for Molecular Pathology

OBJECTIVE

To establish evidence-based recommendations for the molecular analysis of lung cancers that are that are required to guide EGFR- and ALK-directed therapies, addressing which patients and samples should be tested, and when and how testing should be performed.

PARTICIPANTS

Three cochairs without conflicts of interest were selected, one from each of the 3 sponsoring professional societies: College of American Pathologists, International Association for the Study of Lung Cancer, and Association for Molecular Pathology. Writing and advisory panels were constituted from additional experts from these societies.

EVIDENCE

Three unbiased literature searches of electronic databases were performed to capture articles published published from January 2004 through February 2012, yielding 1533 articles whose abstracts were screened to identify 521 pertinent articles that were then reviewed in detail for their relevance to the recommendations. Evidence was formally graded for each recommendation.

CONSENSUS PROCESS

Initial recommendations were formulated by the cochairs and panel members at a public meeting. Each guideline section was assigned to at least 2 panelists. Drafts were circulated to the writing panel (version 1), advisory panel (version 2), and the public (version 3) before submission (version 4).

CONCLUSIONS

The 37 guideline items address 14 subjects, including 15 recommendations (evidence grade A/B). The major recommendations are to use testing for EGFR mutations and ALK fusions to guide patient selection for therapy with an epidermal growth factor receptor (EGFR) or anaplastic lymphoma kinase (ALK) inhibitor, respectively, in all patients with advanced-stage adenocarcinoma, regardless of sex, race, smoking history, or other clinical risk factors, and to prioritize EGFR and ALK testing over other molecular predictive tests. As scientific discoveries and clinical practice outpace the completion of randomized clinical trials, evidence-based guidelines developed by expert practitioners are vital for communicating emerging clinical standards. Already, new treatments targeting genetic alterations in other, less common driver oncogenes are being evaluated in lung cancer, and testing for these may be addressed in future versions of these guidelines.

Epidermal growth factor receptor tyrosine kinase inhibitors as initial therapy for non-small cell lung cancer: focus on epidermal growth factor receptor mutation testing and mutation-positive patients

Activation of the epidermal growth factor receptor (EGFR) pathway has been implicated in tumorigenesis in non-small cell lung cancer (NSCLC), the most common type of lung cancer. As a result, EGFR has become a key focus for the development of personalized therapy, with several molecular biomarkers having been investigated as potential predictors of response with EGFR tyrosine kinase inhibitors (TKIs) in NSCLC (e.g., EGFR expression, EGFR gene copy gain, and EGFR mutations). Of these, activating mutations in EGFR have thus far given the most consistent results based on the available evidence from preclinical studies and clinical trials. In an attempt to identify patients who are most likely to benefit from treatment with EGFR TKIs, EGFR mutation testing is being increasingly utilized in clinical practice. Currently in the United States, no EGFR TKI or accompanying mutational test is approved for the identification and first-line treatment of patients with advanced NSCLC. However, the first-generation EGFR TKIs, erlotinib and gefitinib, as well as investigational ErbB family TKIs and EGFR mutation testing methods are being evaluated in this setting. This review will discuss EGFR mutation testing as a biomarker of response to EGFR TKIs and the evolution of EGFR mutational analysis in NSCLC. Completed and ongoing clinical trials evaluating currently available or investigational EGFR TKIs as first-line therapy in molecularly and clinically selected patients with NSCLC, with a focus on trials in patients whose tumors have EGFR mutations, will also be reviewed.

Molecularly targeted approaches herald a new era of non-small-cell lung cancer treatment

The discovery of activating mutations in the epidermal growth-factor receptor (EGFR) gene in 2004 opened a new era of personalized treatment for non-small-cell lung cancer (NSCLC). EGFR mutations are associated with a high sensitivity to EGFR tyrosine kinase inhibitors, such as gefitinib and erlotinib. Treatment with these agents in EGFR-mutant NSCLC patients results in dramatically high response rates and prolonged progression-free survival compared with conventional standard chemotherapy. Subsequently, echinoderm microtubule-associated protein-like 4 (EML4)–anaplastic lymphoma kinase (ALK), a novel driver oncogene, has been found in 2007. Crizotinib, the first clinically available ALK tyrosine kinase inhibitor, appeared more effective compared with standard chemotherapy in NSCLC patients harboring EML4-ALK. The identification of EGFR mutations and ALK rearrangement in NSCLC has further accelerated the shift to personalized treatment based on the appropriate patient selection according to detailed molecular genetic characterization. This review summarizes these genetic biomarker-based approaches to NSCLC, which allow the instigation of individualized therapy to provide the desired clinical outcome.

Molecular testing guideline for selection of lung cancer patients for EGFR and ALK tyrosine kinase inhibitors: guideline from the College of American Pathologists, International Association for the Study of Lung Cancer, and Association for Molecular Pathology

OBJECTIVE

To establish evidence-based recommendations for the molecular analysis of lung cancers that are required to guide EGFR- and ALK-directed therapies, addressing which patients and samples should be tested, and when and how testing should be performed.

PARTICIPANTS

Three cochairs without conflicts of interest were selected, one from each of the 3 sponsoring professional societies: College of American Pathologists, International Association for the Study of Lung Cancer, and Association for Molecular Pathology. Writing and advisory panels were constituted from additional experts from these societies.

EVIDENCE

Three unbiased literature searches of electronic databases were performed to capture articles published from January 2004 through February 2012, yielding 1533 articles whose abstracts were screened to identify 521 pertinent articles that were then reviewed in detail for their relevance to the recommendations. Evidence was formally graded for each recommendation.

CONSENSUS PROCESS

Initial recommendations were formulated by the cochairs and panel members at a public meeting. Each guideline section was assigned to at least 2 panelists. Drafts were circulated to the writing panel (version 1), advisory panel (version 2), and the public (version 3) before submission (version 4).

CONCLUSIONS

The 37 guideline items address 14 subjects, including 15 recommendations (evidence grade A/B). The major recommendations are to use testing for EGFR mutations and ALK fusions to guide patient selection for therapy with an epidermal growth factor receptor (EGFR) or anaplastic lymphoma kinase (ALK) inhibitor, respectively, in all patients with advanced-stage adenocarcinoma, regardless of sex, race, smoking history, or other clinical risk factors, and to prioritize EGFR and ALK testing over other molecular predictive tests. As scientific discoveries and clinical practice outpace the completion of randomized clinical trials, evidence-based guidelines developed by expert practitioners are vital for communicating emerging clinical standards. Already, new treatments targeting genetic alterations in other, less common driver oncogenes are being evaluated in lung cancer, and testing for these may be addressed in future versions of these guidelines.

IDH1 mutations in oligodendroglial tumors: comparative analysis of direct sequencing, pyrosequencing, immunohistochemistry, nested PCR and PNA-mediated clamping PCR

Mutations in isocitrate dehydrogenase 1 (IDH1) are found in a high proportion of glial tumors and have a significant prognostic impact. Although direct sequencing has been considered to be the gold-standard method to detect this mutation, the sensitivity of this technique has been questioned especially because specimens from glial tumors may contain large numbers of non-tumor cells. We screened 141 cases of oligodendroglial tumors for IDH1 mutations using peptide nucleic acid (PNA)-mediated clamping polymerase chain reaction (PCR) and compared the results with the results of direct sequencing, pyrosequencing, and immunohistochemistry (IHC). Nested PCR was only performed in cases having mutant IDH1 only discovered by clamping PCR. Using dilution experiments mixing IDH1 wild-type and mutant DNA samples, clamping PCR detected mutations in samples with a 1% tumor DNA composition. Using PNA clamping PCR, we detected 138 of 141 (97.9%) cases with mutant IDH1 in our series, which is significantly higher (P = 0.016; PNA clamping vs. direct sequencing) than those of direct sequencing (74.5%), pyrosequencing (75.2%) and IHC (75.9%). From our results, almost all oligodendroglial tumors have IDH1 mutations, and this suggests that IDH1 mutation is an early and common event especially in the development of oligodendroglial tumors.

Fool's gold, lost treasures, and the randomized clinical trial

Background

Randomized controlled trials with a survival endpoint are the gold standard for clinical research, but have failed to achieve cures for most advanced malignancies. The high costs of randomized clinical trials slow progress (thereby causing avoidable loss of life) and increase health care costs.

Discussion

A malignancy may be caused by several different mutations. Therapies effective vs one mutation may be discarded due to lack of statistical significance across the entire population. Conversely, expensive large randomized trials may have sufficient statistical power to demonstrate benefit despite the therapy only working in subgroups. Non-cost-effective therapy is then applied to all patients (including subgroups it cannot help). Randomized trials comparing therapies with different mechanisms of action are misleading since they may conclude the therapies are “equivalent” despite benefitting different subpopulations, or may erroneously conclude that one therapy is superior simply because it targets a larger subpopulation. Furthermore, minor variances in patient selection may determine study outcome, a therapy may be discarded as ineffective despite substantial benefit in one subpopulation if harmful in another, randomized trials may more effectively detect therapies with minor benefit in most patients vs marked benefit in subpopulations, and randomized trials in unselected patients may erroneously conclude that “shot-gun” combinations are superior to single agents when sequential administration of personalized single agents might work better and spare patients treatment with drugs that cannot help them. We must identify predictive biomarkers early by comparing responding to progressing patients in phase I-II trials. Enriching randomized trials for biomarker-positive patients can markedly reduce required patient numbers and costs despite expensive screening for biomarker-positive patients. Available data support approval of new drugs without randomized trials if they yield single-agent sustained responses in patients refractory to standard therapies. Conversely, new approaches are needed to guide development of drug combinations since both standard phase II approaches and phase II-III randomized trials have a high risk of misleading.

Summary

Traditional randomized clinical trials approaches are often inefficient, wasteful, and unreliable. New clinical research paradigms are needed. The primary outcome of clinical research should be “Who (if anyone) benefits?” rather than “Does the overall group benefit?”

Treating Patients With EGFR-Sensitizing Mutations: First Line or Second Line—Is There a Difference?

First-line epidermal growth factor receptor tyrosine kinase inhibitor (EGFR TKI) is a standard treatment for patients with activating EGFR mutations. Six randomized studies have demonstrated consistent improvement in tumor response rate and progression-free survival over platinum-based combination chemotherapy. The only reason to consider EGFR TKI as second-line therapy is that none of the six comparative studies has shown improvement in overall survival, which can be explained by the high proportion of patients from the chemotherapy arm crossing over to the EGFR TKI arm on progression. It is true that patients with EGFR mutations may benefit from second-line EGFR TKI therapy, but we cannot conclude that the benefit is either equal to or inferior to first-line EGFR TKI therapy. To date, there are no direct comparative data between first- and second-line EGFR TKI in patients with activating EGFR mutations. Tumor response rates to second-line EGFR TKI have been inconsistent, which could potentially be explained by the impact of first-line chemotherapy on the abundance of tumor cells with activating EGFR mutations. However, numerous arguments, including assurance on drug exposure, improvement in quality of life, better tolerance by patients with poor performance status, and deferral of whole-brain radiation therapy for patients with brain metastasis, support the general application of first-line EGFR TKI.

Epidermal growth factor receptor (EGFR) mutation and personalized therapy in advanced nonsmall cell lung cancer (NSCLC)

Before 2009, nonsmall cell lung cancer (NSCLC) was one disease entity treated by cytotoxic chemotherapy that provided a response rate of 20-35 % and a median survival time (MST) of 10-12 months. In 2004, it was found that activated mutations of the epidermal growth factor receptor (EGFR) gene were present in a subset of NSCLC and that tumors with EGFR mutations were highly sensitive to EGFR tyrosine kinase inhibitors (TKI). Four phase III studies (North East Japan (NEJ) 002, West Japan Thoracic Oncology Group (WJTOG) 3405, OPTIMAL, and EUROTAC) prospectively compared TKI (gefitinib or erlotinib) with cytotoxic chemotherapy as first-line therapy in EGFR-mutated NSCLC. These studies confirmed that progression-free survival (PFS) with TKIs (as the primary endpoint) was significantly longer than that with standard chemotherapy (hazard ratio [HR] = 0.16-0.49) from 2009 to 2011. Although the NEJ 002 study showed identical overall survival (OS) between the arms (HR = 0.89), quality of life (QoL) was maintained much longer in patients treated with gefitinib. In conclusion, TKI should be considered as the standard first-line therapy in advanced EGFR-mutated NSCLC. Since 2009, a new step has been introduced in the treatment algorithm for advanced NSCLC.

Association of integrin beta1 and c-MET in mediating EGFR TKI gefitinib resistance in non-small cell lung cancer

Although some patients are initially sensitive to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR TKIs), resistance invariably develops. Therefore, it’s very important to study the molecular mechanism of this resistance. In our previous study we found that integrin beta1 can induce EGFR TKIs resistance in non-small cell lung cancer (NSCLC) cells. Here we analyzed the association of integrin beta1 and c-MET that is a recognized mechanism of EGFR TKIs resistance in NSCLC to demonstrate the mechanism of integrin beta1 related EGFR TKIs resistance. We found that the ligands of integrin beta1 and c-MET could synergistically promote cell proliferation and their inhibitors could synergistically improve the sensitivity to gfitinib, increase apoptosis, and inhibit the downstream signal transduction: focal adhesion kinase (FAK) and AKT. On the other hand, ligand-dependent activation of integrin beta1 could induce EGFR TKIs resistance through activating c-MET and its downstream signals. Thus, it can be concluded that there is crosstalk between integrin beta1 and c-MET and integrin beta1 mediates EGFR TKI resistance associating with c-MET signaling pathway in non-small cell lung cancer.

Personalized medicine for targeted and platinum-based chemotherapy of lung and bladder cancer

The personalized medicine revolution is occurring for cancer chemotherapy. Biomarkers are increasingly capable of distinguishing genotypic or phenotypic traits of individual tumors, and are being linked to the selection of treatment protocols. This review covers the molecular basis for biomarkers of response to targeted and cytotoxic lung and bladder cancer treatment with an emphasis on platinum-based chemotherapy. Platinum derivatives are a class of drugs commonly employed against solid tumors that kill cells by covalent attachment to DNA. Platinum-DNA adduct levels in patient tissues have been correlated to response and survival. The sensitivity and precision of adduct detection has increased to the point of enabling subtherapeutic dosing for diagnostics applications, termed diagnostic microdosing, prior to the initiation of full-dose therapy. The clinical status of this unique phenotypic marker for lung and bladder cancer applications is detailed along with discussion of future applications.

Importance of the cytological samples for the epidermal growth factor receptor gene mutation test for non-small cell lung cancer

Mutations in the epidermal growth factor receptor (EGFR) gene confer it with cancer driver gene functions in non-small cell lung cancer (NSCLC). Epidermal growth factor receptor -tyrosine kinase inhibitors are effective agents against NSCLC with a mutated EGFR gene. Accordingly, many guidelines recommend the use of an EGFR mutation test in NSCLC. However, not all patients are tested in most countries where tissue samples are mainly used for the test. As of 2011, most of the patients with advanced NSCLC are tested in Japan, and the use of cytological samples has significantly contributed to this success. A portion of samples used to determine a definite diagnosis of NSCLC, either tissue samples or cytological samples, is ensured to contain cancer cells, and is then investigated by an EGFR mutation test that is applicable to both tissue samples and cytological samples. Cytological samples now account for one-third of all the samples investigated. EGFR mutation is detected in cytological samples at a similar rate with tissue samples. The criterion ensuring an EGFR mutation test to have satisfactory sensitivity and specificity for use in both tissue and cytological samples is presented. Cytological samples are valuable clinical sources being collected less invasively than tissue samples, and should therefore be extensively used in EGFR mutation testing.

First-line gefitinib in patients aged 75 or older with advanced non-small cell lung cancer harboring epidermal growth factor receptor mutations: NEJ 003 study

INTRODUCTION

Recent studies have demonstrated that first-line treatment with gefitinib, an epidermal growth factor receptor (EFGR)-targeted tyrosine kinase inhibitor, is significantly superior to standard chemotherapy for advanced non-small-cell lung cancer (NSCLC) harboring EGFR sensitive mutations. Meanwhile, the efficacy of gefitinib therapy among elderly populations diagnosed with EGFR-mutated NSCLC has not yet been elucidated. The purpose of this study was to investigate the efficacy and feasibility of gefitinib for chemotherapy-naive patients aged 75 or older with NSCLC harboring EGFR mutations; generally, these patients have no indication for treatment with platinum doublets.

METHODS

Chemotherapy-naive patients aged 75 years or older with performance status 0 to 1 and advanced NSCLC harboring EGFR mutations, as determined by the peptide nucleic acid-locked nucleic acid polymerase chain reaction clamp method, were enrolled. The enrolled patients received 250 mg/day of gefitinib orally.

RESULTS

Between January 2008 and May 2009, 31 patients were enrolled, all of whom were eligible. The median age was 80 (range, 75-87) years. Twenty-five patients (81%) were women, and 30 patients (97%) had adenocarcinoma. The overall response rate was 74% (95% confidence interval, 58%-91%), and the disease control rate was 90%. The median progression-free survival was 12.3 months. The common adverse events were rash, diarrhea, and liver dysfunction. One treatment-related death because of interstitial lung disease occurred.

CONCLUSIONS

This is the first study that verified safety and efficacy of first-line treatment with gefitinib in elderly patients having advanced NSCLC with EGFR mutation. Considering its strong antitumor activity and mild toxicity, first-line gefitinib may be preferable to standard chemotherapy for this population.

Updated overall survival results from a randomized phase III trial comparing gefitinib with carboplatin-paclitaxel for chemo-naïve non-small cell lung cancer with sensitive EGFR gene mutations (NEJ002)

BACKGROUND

NEJ002 study, comparing gefitinib with carboplatin (CBDCA) and paclitaxel (PTX; Taxol) as the first-line treatment for advanced non-small cell lung cancer (NSCLC) harboring an epidermal growth factor receptor (EGFR) mutation, previously reported superiority of gefitinib over CBDCA/PTX on progression-free survival (PFS). Subsequent analysis was carried out mainly regarding overall survival (OS).

MATERIALS AND METHODS

For all 228 patients in NEJ002, survival data were updated in December, 2010. Detailed information regarding subsequent chemotherapy after the protocol treatment was also assessed retrospectively and the impact of some key drugs on OS was evaluated.

RESULTS

The median survival time (MST) was 27.7 months for the gefitinib group, and was 26.6 months for the CBDCA/PTX group (HR, 0.887; P=0.483). The OS of patients who received platinum throughout their treatment (n=186) was not statistically different from that of patients who never received platinum (n=40). The MST of patients treated with gefitinib, platinum, and pemetrexed (PEM) or docetaxel (DOC, Taxotere; n=76) was around 3 years.

CONCLUSIONS

No significant difference in OS was observed between gefitinib and CBDCA/PTX in the NEJ002 study, probably due to a high crossover use of gefitinib in the CBDCA/PTX group. Considering the many benefits and the risk of missing an opportunity to use the most effective agent for EGFR-mutated NSCLC, the first-line gefitinib is strongly recommended.