Epidermal growth factor receptor mutation analysis in previously unanalyzed histology samples and cytology samples from the phase III Iressa Pan-ASia Study (IPASS)

Inconsistent clinical outcomes following afatinib treatment in NSCLC patients harboring uncommon epidermal growth factor receptor mutation

BACKGROUND

Uncommon epidermal growth factor receptor (EGFR) mutations consist of a heterogeneous population of molecular alterations, and the available clinical data on the outcomes of patients with non-small-cell lung cancer (NSCLC) harboring uncommon EGFR mutations following afatinib treatment are limited. The purpose of this pooled analysis was to investigate the clinicopathological features of patients with uncommon EGFR mutations (um-EGFRms) along with their treatment response and survival outcomes following afatinib treatment.

METHODS

We performed a literature search in the NCBI PubMed database to identify relevant articles and conducted this pooled analysis based on 70 studies. The relationships between patient clinical characteristics, EGFR mutation type and the response to afatinib treatment were analyzed using univariate chi-square analysis, and survival analysis was performed using the Kaplan-Meier method.

RESULTS

Data from a total of 99 patients were included in the pooled analysis. The objective response rate (ORR) to treatment with afatinib was53.5%, with a median progression-free survival (mPFS) of 9.0 months. For patients administered first-line afatinib treatment, the ORR and median PFS were 73.5% and 15.6 months, respectively, which were both superior to those of patients treated with second- or later-line treatments (ORR:37.0%, p < 0.001; mPFS: 6.0months, p = 0.001). Moreover, patients with a single um-EGFRm were more likely to have a favorable response and prognosis benefit after treatment with afatinib than patients with multiple one (ORR: 63.3% vs 38.5%, p=0.017; mPFS: 15.6 months vs 6.0 months,p=0.010). Moreover, single um-EGFRm were independent predictive factors for better treatment response and superior PFS. Subgroup analysis indicated that patients harboring major um-EGFRms (i.e., L861Q, G719X, and S768I) exhibited the best treatment responses and prognoses (ORR: 74.1%, mPFS: 15.6 months), by contrast, patients harboring multiple um-EGFRms comprising 19del/L858R had the worst treatment responses and prognoses (ORR: 23.5%, mPFS: 5.6months).

CONCLUSIONS

Patients with um-EGFRms exhibit favorable but inconsistent responses and survival outcomes following afatinib treatment, which closely related to the mutation pattern and cooccurring partner mutant genes. Administering afatinib for the treatment of patients with um-EGFRm might be considered an effective treatment option in some circumstances, but this recommendation requires further clinical studies for verification.

Insensitivity to T790M mutation? A pooled analysis of outcomes following osimertinib for the treatment of NSCLC patients harboring uncommon epidermal growth factor receptor mutation

Background: In this pooled analysis, the aim was to investigate the clinicopathological characteristics of patients with uncommon epidermal growth factor receptor (EGFR) (ucm-EGFRms) along with their treatment responses and survival following osimertinib treatment.

Methods: Univariate chi-square analysis was conducted to analyze the correlation between clinical characteristics, EGFR mutation type, and treatment response, and the Kaplan-Meier method was applied for survival analysis. Univariate logistic regression model and Cox proportional hazards model were performed to compare the efficacy and prognosis in subgroup analysis.

Results: Seventy-two NSCLC patients in total were included in this pooled analysis. The objective response rate (ORR) for osimertinib treatment was 57.0%, with a median PFS of 7.1 months. Twenty-eight patients received osimertinib as first-line therapy with an ORR of 67.9%, which was higher than that in patients who received osimertinib as second- or later-line therapy, and their response rate was 50%, nevertheless, no statistically significant differences were found (p = 0.139). However, patients who received first-line osimertinib showed a more significant PFS benefit than those who received second- or later-line therapy (mPFS: 16.8 months vs 6.0 months HR: 2.453, 95%CI: 1.285-4.682, p =0.004). Subgroup analysis showed that patients with a single, non-ex20ins, ucm-EGFRm displayed a superior efficacy advantage and favorable survival benefit following osimertinib treatment, with an ORR of 68.8% and an mPFS at 15.1 months. By contrast, patients with a multiple ucm-EGFRm that contain T790M exhibited the worst outcome of osimertinib treatment, with an ORR of 47.6% and an mPFS of only 3.6 months, respectively.

Conclusion: Patients with um-EGFRms exhibit favorable but inconsistent responses and survival outcomes following osimertinib treatment, which is closely related to the mutation pattern and cooccurring partner mutant genes. Administering osimertinib for the treatment of patients with um-EGFRm might be considered an effective treatment option in some circumstances.

Local Therapy Combined With First-Line EGFR Tyrosine Kinase Inhibitor Achieves Favorable Survival in Patients With EGFR-Mutant Metastatic Non-Small Cell Lung Cancer

BACKGROUND

EGFR tyrosine kinase inhibitor (TKI) is recommended as the first-line therapy for patients with EGFR-mutant metastatic non-small cell lung cancer (NSCLC). Yet, resistance often occurs in 1 year after therapy and most progressions occur at the initial sites of disease. Addition of local therapy to the first-line TKI therapy may delay the progression and provide survival benefit to the patients.

METHODS

From 2010 to 2017, metastatic NSCLC patients with EGFR activating mutations who received first-line TKI and relatively radical local therapy (RRLT) were reviewed. RRLT was defined as local curative therapy to the main site or any intensity of local therapy to all sites of disease. The Kaplan-Meier method and log-rank test were used for survival estimation and comparison.

RESULTS

A total of 45 patients were included in this retrospective study with a median follow-up of 48.0 months. The median progression-free survival (PFS) and overall survival (OS) was 17.0 months (95% confidence interval [CI]: 14.6-19.3) and 55.0 months (95% CI: 49.3-60.6), respectively. Univariate analysis indicated that age ⩽ 60 years (P = .019), first-line TKI duration ⩾ 10 months (P = .028), and accumulated TKI duration ⩾ 20 months (P = .016) were significantly associated with favorable OS. Among the 36 patients who progressed during the follow-up, 55.8% of the progressions occurred at the new sites. RRLT combined with TKI did not show any severe toxicity to the patients.

CONCLUSIONS

Combined application of RRLT and first-line TKI may improve the survival and alter the pattern of failure for metastatic NSCLC patients with EGFR activating mutations.

Therapeutic exploration of uncommon EGFR exon 20 insertion mutations in advanced non-small cell lung cancer: breaking through brambles and thorns

BACKGROUND

EGFR exon 20 insertion (EGFR ex20ins) mutations account for about 10-12% of all EGFR-mutated tumors, which are usually associated with primary drug resistance to conventional EGFR-TKI therapy and worse survival outcomes, and are currently a major problem for clinicians in clinical management. In recent years, with the rapid improvement of sequencing technology and careful review of clinical data, investigators have gained a deeper understanding and clearer cognition of the clinicopathological features and molecular mechanisms of these EGFR ex20ins mutations.

PURPOSE

The aim of this study was to systemically review the molecular structure and clinical characteristics of EGFR ex20ins mutations, and focus on summarizing the latest data of emerging therapies (including novel small-molecule EGFR-TKI drugs, specific monoclonal antibodies, novel drugs targeting other mechanisms, and immunotherapy) for those patients.

CONCLUSION

Advances in overcoming these systemic challenges have greatly accelerated the development of new drugs targeting EGFR ex20ins, and are committed to designing more rational combination therapies to overcome or delay the emergence of drug resistance, ultimately improve the prognosis of such uncommon mutant populations.

Bronchial brushing cytology is comparable to bronchial biopsy for epidermal growth factor receptor mutation test in non-small cell lung cancer

Objectives:

Bronchial brushing (BB) is often used to obtain supplementary samples for diagnosing lung cancer. We examined the possibility of epidermal growth factor receptor (EGFR) testing on BB samples and compared them with bronchial biopsy samples.

Material and Methods:

We used 150 BB samples with non-small cell carcinoma submitted to our department within 2 years. Biopsy samples were concurrently submitted for histologic diagnosis. We used the peptide nucleic acid clamping method for EFGR mutation test. Histologic diagnosis identified 137 cases of adenocarcinomas and 13 cases of non-small cell lung carcinoma, not otherwise specified. Each sample was assessed for adequacy and DNA content for EGFR mutation test.

Results:

Among BB samples, 28 had exon 19 deletion, 21 had mutations in exon 21, 99 were wild type, and analysis of two failed. The EGFR mutation rate in BB samples was 33.1% (49/148). Among bronchial biopsy samples, 26 had exon 19 deletion, 20 had mutations in exon 21, 92 were wild type, and analysis of 12 failed. The EGFR mutation rate using biopsy sample was 33.8% (46/136). The mutation detection results were nearly identical in both groups of samples (131/138, 94.9%). However, in two cases, an exon 21 mZutation was detected in biopsy samples but not in BB samples. In five cases, exon 19 deletion (two cases) and exon 21 mutation (three cases) were detected in BB but not in biopsy samples. The median DNA content was 58.83 ng for BB samples and 48.47 ng for biopsy samples. The failure rate for BB samples was lower than for biopsy samples. Overall, the BB samples were comparable to bronchial biopsy samples in terms of DNA quantity and mutation detection results.

Conclusion:

We conclude that in case of inadequate biopsy samples, BB samples can be used as a substitute material for EGFR mutation test.

Establishment and validation of a novel droplet digital PCR assay for ultrasensitive detection and dynamic monitoring of EGFR mutations in peripheral blood samples of non-small-cell lung cancer patients

BACKGROUND

Droplet digital PCR (ddPCR)-based blood detection of EGFR mutations plays significant roles in the individualized therapy of non-small-cell lung cancer (NSCLC) patients. However, a standard assay that is approved by health authorities is still lacking. Additionally, the proper application of this method in clinical settings also needs further investigation.

METHODS

The performance of a newly established ddPCR assay was first evaluated using reference samples and then validated by comparing this method with the amplification refractory mutation system (ARMS) using cell-free DNA (cfDNA) in patients' peripheral blood. Further, the correlation between dynamic quantification of EGFR mutation in the patients and their clinical outcome of tyrosine kinase inhibitors (TKIs) therapy was investigated.

RESULTS

A total of 77 patients were included, with 50 in the test group and 27 in the validation group. According to the results of the reference samples and the blood samples in the test group, the cut-off value for patient detection was proposed as mutation rate ≥ 0.1% (total copy number of cfDNA ≥ 1000) or at least one copy of mutation DNA was detected (total copy number of cfDNA < 1000). With this criterion, superior sensitivity of our assay to that of ARMS was observed (P = 0.002 for Ex19Del & L858R and P < 0.001 for T790M). The dynamic quantification of EGFR mutations during TKI therapy indicated that an increase in mutation abundance was correlated with resistance, while a decline was associated with response. Notably, a rebound in mutation abundance during chemotherapy may indicate a desirable chance for TKI re-treatment.

CONCLUSION

The novel ddPCR assay showed superior sensitivity in the detection of EGFR mutation in blood. The dynamic quantification of EGFR mutations by this assay would greatly facilitate the administration of TKI therapy, including the monitoring of resistance and response, as well as cohort screening for retreatment.

Different efficacy in the non-small cell lung cancer patient with bilateral synchronous lesions treated with neoadjuvant gefitinib therapy: a case report

Gefitinib, the first-generation epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), has become the standard of care for the first-line of therapy for advanced non-small cell lung cancer (NSCLC) with common EGFR mutation. However, the efficacy of preoperative gefitinib therapy in patients with common EGFR mutations remains poorly defined. We describe a NSCLC patient with bilateral synchronous lesions who had a significantly positive response to gefitinib before radical surgical resection. At the time of initial diagnosis, we were unable to confirm whether the two lesions were metastatic or synchronous primary lesions. Accordingly, we performed CT-guided percutaneous left lung biopsy resulting in a diagnosis of lung adenocarcinoma with exon 21 L858R point mutation of EGFR, This diagnosis was followed by preoperative gefitinib therapy for 8 weeks leading to a significant reduction in the lesion in the left lower lobe. Then the left lower lobectomy and mediastinal lymphadenectomy were performed. In addition, 3 months following resection of the left lower lobe tumor the patient underwent a right lower lobe wedge resection. This report indicates that NSCLC patient harboring common EGFR mutation accepting the first-generation EGFR-TKI gefitinib as a neoadjuvant targeted therapy option is safe, feasible, and well-tolerated.

The effect of TKI therapy and chemotherapy treatment delivery sequence on total progression-free survival in patients with advanced EGFR-mutated NSCLC

The present study aimed to evaluate the total progression-free survival (PFS) time of the 1st-line chemotherapy (CHT)/2nd-line tyrosine kinase inhibitor (TKI) and 1st-line TKI/2nd-line CHT therapeutic regimens. Data from patients with non-small-cell lung cancer (NSCLC) harboring sensitizing epidermal growth factor receptor (EGFR) mutations, who had received both TKI and platinum CHT were retrieved from the Shandong Cancer Hospital (Jinan, China) database. A total of 89 patients were included, 50 of whom were treated with the 1st-line CHT/2nd-line TKI regimen and the remaining 39 patients underwent a 1st-line TKI/2nd-line CHT regimen. The differences in total PFS time between the two regimens were analyzed. The median total PFS time was 14.28 months with the 1st-line CHT/2nd-line TKI regimen and 17.77 months with the 1st-line TKI/2nd-line CHT regimen (adjusted hazard ratio, 0.96; 95% confidence interval (CI), 0.56-1.66; P=0.886). A significant difference in PFS time was revealed between the two strategies when comparing only the 1st-line or 2nd-line treatments (all P<0.001). The objective response rate (RR) was 52.0% for those treated with 1st-line CHT/2nd-line TKI and 38.5% for the reverse regimen. After adjusting for associated factors, the odds ratio for the RR was 2.77 (95% CI: 0.77-9.90; P=0.117). The current results revealed that there was no significant difference between the total PFS time of patients with NSCLC undergoing the 1st-line CHT/2nd-line TKI regimen compared with patients with NSCLC undergoing the 1st-line TKI/2nd-line CHT regimen.

Molecular mechanism of acquired drug resistance in the EGFR-TKI resistant cell line HCC827-TR

Background

The first‐line standard treatment of non‐small cell lung cancer (NSCLC) with EGFR mutation is EGFR‐tyrosine kinase inhibitors (TKIs). However, most patients will develop acquired resistance after 9–13 months. This study investigated novel molecular mechanisms of acquired resistance to EGFR‐TKIs to identify a potential new treatment for EGFR‐TKI resistant NSCLC patients.

Methods

We established an EGFR‐TKI resistant cell line (HCC827‐TR) by culturing the HCC827‐P cell line through continuous erlotinib culture. We used Sanger sequencing, RT‐PCR, and western blot to rule out known resistance mechanisms in HCC827‐TR cells, including EGFR‐T790M and MET, PTEN, or EGFR expression changes. Next‐generation sequencing was performed and identified differentially expressed genes between two cell lines and examined the genes with GO and KEGG pathway database analyses. We also examined the molecular alterations in COSMIC and GDSC databases and performed hazard predictions using SIFT, PolyPhen‐2, Mutation Taster, and CADD.

Results

Our results identified FGF2 as a differentially expressed gene with a G101T point mutation in HCC827‐TR cells that showed high mutation frequency and hazard score. HCC827‐TR cells showed elevated FGF2 compared to parental cells. It is noteworthy that treatment with the FGFR inhibitor AZD4547 could restore the sensitivity of HCC872‐TR cells to erlotinib.

Conclusions

An erlotinib‐resistant cell line HCC827‐TR was successfully constructed and we identified the EGFR‐TKI resistance mechanism involving the FGF2 gene mutation. Targeted inhibition of the FGF2/FGFR signaling pathway may effectively restore the sensitivity of the resistant cells to erlotinib. These results suggest a novel treatment strategy for EGFR‐TKI resistant NSCLC patients.

Key points

Significant findings of the study: Identifies a novel molecular mechanism for EGFR‐TKI acquired resistance.

What this study adds: A potential novel strategy for the treatment of EGFR‐TKI resistant NSCLC patients.

[Studies and Progress of EGFR exon 20 Insertion Mutation in Non-small Cell Lung Cancer]

Lung cancer has the highest morbidity and mortality among malignant tumors worldwidely. Targeted therapy related to non-small cell lung cancer (NSCLC) is the research hotspot in recent year. The emergence of epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) has brought a huge change in the treatment of patients with EGFR mutation. The patients with EGFR exon20 insertion are specific cohort in NSCLC. Reviewing the clinical researches to EGFR exon20 insertion mutation positive NSCLC, as well as summarizing character, testing methods and treatment, will provide a help for clinical application, bringing more benefits for patients at the same time.

Development and External Validation of a Nomogram for Predicting Survival in Patients With Stage IA Non-small Cell Lung Cancer ≤2 cm Undergoing Sublobectomy

Background: Postoperative prognosis of early stage non-small cell lung cancer (NSCLC) undergoing sublobectomy is heterogeneous. Therefore, we sought to construct a novel survival prediction model for stage IA NSCLC ≤2 cm undergoing sublobectomy.

Methods: Based on the data from the Surveillance, Epidemiology, and End Results (SEER) program, we successfully determined and incorporated independent prognostic markers to construct the nomogram. Internal validation of the constructed nomogram was conducted through 1,000 bootstrap resamples. The constructed nomogram was further subjected to external validation with an independent cohort of patients from two Chinese institutions. The performance of the survival prediction model was assessed by concordance index, calibration plots, and risk subgroup classification.

Results: A total of 3,238 patients from SEER registries (development cohort), as well as 769 patients from two Chinese institutions (validation cohort) was included. Gender, age, size, histologic type, grade, and examined lymph nodes count were identified as significant prognostic parameters. A novel nomogram was developed and externally validated. Concordance index of constructed nomogram was significantly better than that of the current TNM staging system. Calibration plots demonstrated an optimal consistency between the nomogram predicted and actual observed probability of survival. Survival curves of different risk subgroups within respective TNM stage demonstrated significant distinctions.

Conclusion: We developed and externally validated a survival prediction model for patients with stage IA NSCLC ≤2 cm undergoing sublobectomy. This novel nomogram outperforms the conventional TNM staging system and could help clinicians in postoperative surveillance and future clinical trial design.

[A Review of EGFR-TKIs Therapy of Non-small Cell Lung Cancer with Uncommon EGFR Mutations]

肺癌是目前最常见的癌症，也是导致癌症死亡的首要原因。非小细胞肺癌（non-small cell lung cancer, NSCLC）占85%以上，且高达50%的亚洲NSCLC患者携带表皮生长因子受体（epidermal growth factor receptor, EGFR）基因突变。研究证明，伴有EGFR突变的NSCLC患者接受表皮生长因子受体-酪氨酸激酶抑制剂（epidermal growth factor receptor-tyrosine kinase inhibitors, EGFR-TKIs）治疗能获得更好的生存结果。然而，因为EGFR罕见突变相对治疗效果较差，会对研究结果带来负面影响，所以大部分研究EGFR-TKIs疗效的临床试验都不包含罕见突变患者，另外EGFR罕见突变本身就少见，就导致临床试验中这部分患者数量较少。由于EGFR罕见突变样本量少且具有高度异质性，EGFR-TKIs对EGFR罕见突变患者的疗效仍然不清楚。本文就EGFR罕见突变与EGFR-TKIs的疗效关系进行综述，为携带EGFR罕见突变的NSCLC患者合理选择治疗方式提供指导和建议。

Heterogeneous Responses to Epidermal Growth Factor Receptor (EGFR) Tyrosine Kinase Inhibitors (TKIs) in Patients with Uncommon EGFR Mutations: New Insights and Future Perspectives in this Complex Clinical Scenario

Uncommon Epidermal Growth Factor Receptor (EGFR) mutations represent a distinct and highly heterogeneous subgroup of Non-Small Cell Lung Cancers (NSCLCs), that accounts for approximately 10% of all EGFR-mutated patients. The incidence of uncommon EGFR mutations is growing, due to the wider adoption of next-generation sequencing (NGS) for diagnostic purposes, which enables the identification of rare variants, usually missed with available commercial kits that only detect a limited number of EGFR mutations. However, the sensitivity of uncommon mutations to first- and second-generation EGFR Tyrosine Kinase Inhibitors (TKIs) is widely heterogeneous and less well known, compared with classic mutations (i.e., exon 19 deletions and exon 21 L858R point mutation), since most of the pivotal studies with EGFR TKIs in the first line, with few exceptions, excluded patients with rare and/or complex variants. Recently, the third generation EGFR TKI osimertinib further revolutionized the therapeutic algorithm of EGFR-mutated NSCLC, but its role in patients harboring EGFR mutations besides exon 19 deletions and/or L858R is largely unknown. Therefore, a better knowledge of the sensitivity of uncommon mutations to currently available EGFR TKIs is critical to guiding treatment decisions in clinical practice. The aim of this paper is to provide a comprehensive overview of the treatment of NSCLC patients harboring uncommon EGFR mutations with currently approved therapies and to discuss the emerging therapeutic opportunities in this peculiar subgroup of patients, including chemo-immunotherapy combinations, next-generation EGFR TKIs, and novel targeted agents.

The Roles of Common Variation and Somatic Mutation in Cancer Pharmacogenomics

Cancer pharmacogenomics is the science concerned with understanding genetic alterations and its effects on the pharmacokinetics and pharmacodynamics of anti-cancer drugs, with the aim to provide cancer patients with the precise medication that will achieve a good response and cause low/no incidence of adverse events. Advances in biotechnology and bioinformatics have enabled genomic research to evolve from the evaluation of alterations at the single-gene level to studies on the whole-genome scale using large-scale genotyping and next generation sequencing techniques. International collaborative efforts have resulted in the construction of databases to curate the identified genetic alterations that are clinically significant, and these are currently utilized in clinical sequencing and liquid biopsy screening/monitoring. Furthermore, countless clinical studies have accumulated sufficient evidence to match cancer patients to therapies by utilizing the information of clinical-relevant alterations. In this review we summarize the importance of germline alterations that act as predictive biomarkers for drug-induced toxicity and drug response as well as somatic mutations in cancer cells that function as drug targets. The integration of genomics into the medical field has transformed the era of cancer therapy from one-size-fits-all to cancer precision medicine.

Gefitinib for advanced non-small cell lung cancer

BACKGROUND

The role of gefitinib for the treatment of advanced non-small cell lung cancer (NSCLC) is evolving. We undertook a systematic review to evaluate the available evidence from all randomised trials.

OBJECTIVES

To determine the effectiveness and safety of gefitinib as first-line, second-line or maintenance treatment for advanced NSCLC.

SEARCH METHODS

We performed searches in CENTRAL, MEDLINE and Embase from inception to 17 February 2017. We handsearched relevant conference proceedings, clinical trial registries and references lists of retrieved articles.

SELECTION CRITERIA

We included trials assessing gefitinib, alone or in combination with other treatment, compared to placebo or other treatments in the first- or successive-line treatment of patients with NSCLC, excluding compassionate use.

DATA COLLECTION AND ANALYSIS

We used the standard Cochrane methodology. Two authors independently assessed the search results to select those with sound methodological quality. We carried out all analyses on an intention-to-treat basis. We recorded the following outcome data: overall survival, progression-free survival, toxicity, tumour response and quality of life. We also collected data for the following subgroups: Asian ethnicity and positive epidermal growth factor receptor (EGFR) mutation.

MAIN RESULTS

We included 35 eligible randomised controlled trials (RCTs), which examined 12,089 patients.General populationGefitinib did not statistically improve overall survival when compared with placebo or chemotherapy in either first- or second-line settings. Second-line gefitinib prolonged time to treatment failure (TTF) (hazard ratio (HR) 0.82, 95% confidence interval (CI) 0.75 to 0.90, P < 0.0001) when compared with placebo. Maintenance gefitinib improved progression-free survival (HR 0.70, 95% CI 0.53 to 0.91, P = 0.007) after first-line therapy.Studies in patients of Asian ethnicity or that conducted subgroup analysesSecond-line gefitinib prolonged overall survival over placebo (HR 0.66, 95% CI 0.48 to 0.91, P = 0.01). In the first-line setting, progression-free survival was improved with gefitinib over chemotherapy alone (HR 0.65, 95% CI 0.43 to 0.98, P = 0.04, moderate quality of evidence). Gefitinib given in combination with a chemotherapy regimen improved progression-free survival versus either gefitinib alone or chemotherapy alone (HR 0.69, 95% CI 0.49 to 0.96, P = 0.03; HR 0.69, 95% CI 0.62 to 0.77, P < 0.00001, respectively). In the second-line setting, progression-free survival was superior in patients given gefitinib over placebo or chemotherapy (HR 0.69, 95% CI 0.52 to 0.91, P = 0.009; HR 0.71, 95% CI 0.57 to 0.88, P = 0.002; moderate quality of evidence, respectively). Combining gefitinib with chemotherapy in the second-line setting was superior to gefitinib alone (HR 0.65, 95% CI 0.43 to 0.97, P = 0.04). As maintenance therapy, gefitinib improved progression-free survival when compared with placebo (HR 0.42, 95% CI 0.33 to 0.54, P < 0.00001).Patients with EGFR mutation-positive tumoursStudies in patients with EGFR mutation-positive tumours showed an improvement in progression-free survival in favour of gefitinib over first-line and second-line chemotherapy (HR 0.47, 95% CI 0.36 to 0.61, P < 0.00001; HR 0.24, 95% CI 0.12 to 0.47, P < 0.0001, respectively). Gefitinib as maintenance therapy following chemotherapy improved overall and progression-free survival (HR 0.39, 95% CI 0.15 to 0.98, P = 0.05; HR 0.17, 95% CI 0.07 to 0.41, P < 0.0001, respectively) in one phase III study when compared to placebo.Toxicities from gefitinib included skin rash, diarrhoea and liver transaminase derangements. Toxicities from chemotherapy included anaemia, neutropenia and neurotoxicity.In terms of quality of life, gefitinib improved Functional Assessment of Cancer Therapy-Lung (FACT-L) (standardised mean difference (SMD) 10.50, 95% CI 9.55 to 11.45, P < 0.000001), lung cancer subscale (SMD 3.63, 95% CI 3.08 to 4.19, P < 0.00001) and Trial Outcome Index (SMD 9.87, 95% CI 1.26 to 18.48, P < 0.00001) scores when compared with chemotherapy.

AUTHORS' CONCLUSIONS

This systematic review shows that gefitinib, when compared with standard first- or second-line chemotherapy or maintenance therapy, probably has a beneficial effect on progression-free survival and quality of life in selected patient populations, particularly those with tumours bearing sensitising EGFR mutations.Patients with EGFR mutations lived longer when given maintenance gefitinib than those given placebo.One study conducted subgroup analysis and showed that gefitinib improved overall survival over placebo in the second-line setting in patients of Asian ethnicity. All other studies did not detect any benefit on overall survival. The data analysed in this review were very heterogenous. We were limited in the amount of data that could be pooled, largely due to variations in study design. The risk of bias in most studies was moderate, with some studies not adequately addressing potential selection, attrition and reporting bias. This heterogeneity may have an impact on the applicability of the resultsCombining gefitinib with chemotherapy appears to be superior in improving progression-free survival to either gefitinib or chemotherapy alone, however further data and phase III studies in these settings are required.Gefitinib has a favourable toxicity profile when compared with current chemotherapy regimens. Although there is no improvement in overall survival, gefitinib compares favourably with cytotoxic chemotherapy in patients with EGFR mutations with a prolongation of progression-free survival and a lesser side effect profile.

Quantification of plasma EGFR mutations in patients with lung cancers: Comparison of the performance of ARMS-Plus and droplet digital PCR

OBJECTIVES

EGFR mutation is a key factor to predict EGFR-TKI efficacy. However, a significant number of advanced patients do not have sufficient tumor specimens for molecular testing. Also, there is a lack of quantitative assay to analyze the mutant abundance. This study aims to evaluate the detection efficiency and clinical feasibility of a new platform, namely ARMS-Plus, for the detection and quantification of EGFR mutations in plasma.

MATERIALS AND METHODS

The detection limit of ARMS-Plus was assessed by detecting spiked mutant plasmids which were serially diluted with normal human genomic DNA. The cutoff values were defined by examining the mutant copy numbers presented in 134 healthy controls. Plasma samples from 65 lung cancer patients were collected to evaluate the clinical performance of ARMS-Plus. EGFR mutations were concurrently tested by droplet digital PCR (ddPCR) for the plasma samples and conventional amplification refractory mutation system-PCR (ARMS-PCR) for the matched tumor tissue specimens to serve as a standard for comparison.

RESULTS

In this study, the analytical sensitivity of ARMS-Plus was 0.015%. The cutoff values of EGFR 19Del, L858R, T790M mutations were defined as 2, 5, and 3 copies/mL, respectively. With tumor specimens as the standard, the sensitivity, specificity, and concordance rate of ARMS-Plus and ddPCR were 60.7%, 94.6%, and 80.0%; and 50.0%, 97.3%, and 76.9%, respectively. For quantification, the plasma 19Del and L858R mutant abundance detected by ARMS-Plus and ddPCR were consistent (Spearman R=0.7956 and 0.7710, P<0.0001).

CONCLUSION

ARMS-Plus is a reliable, convenient and cost-effective method for the detection and quantification of plasma EGFR mutations.

Comparison of direct sequencing and amplification refractory mutation system for detecting epidermal growth factor receptor mutation in non-small-cell lung cancer patients: a systematic review and meta-analysis

BACKGROUND

Direct sequencing and amplification refractory mutation system (ARMS) are commonly used to detect epidermal growth factor receptor (EGFR) mutation status in patients with non-small-cell lung cancer to inform the decision-making on tyrosine kinase inhibitors treatment. This study aimed to systematically compare the two methods in terms of the rate of detected mutations and the association of detected mutations with clinical outcomes.

MATERIAL AND METHODS

PubMed, EMBASE, China National Knowledge Infrastructure (in Chinese) and Wanfang database (in Chinese) were searched to identify relevant studies. Meta-analyses of EGFR mutation rates, rate differences, and the associations of EGFR mutations with clinical outcomes of tyrosine kinase inhibitors treatment were conducted.

RESULTS

Eight hundred and sixty-six records were retrieved and 26 studies with 3282 patients were included. The pooled rate of mutations detected by ARMS (41%, 95% confidence interval (CI) 35% to 47%) was significantly higher than that by direct sequencing (28%, 95%CI 22% to 34%), with a weighted rate difference of 11% (95%CI 8% to 13%). There was a consistent trend that the associations between ARMS-detected mutations and clinical outcomes were stronger than those between direct-sequencing-detected mutations and clinical outcomes (pooled risk ratio for objective response: 5.18 vs. 2.25; hazard ratio for progression-free survival: 0.30 vs. 0.42; hazard ratio for overall survival: 0.46 vs. 0.54).

CONCLUSIONS

More patients with EGFR mutations can be identified by ARMS than by direct sequencing, and those identified by ARMS seems to be able to benefit more from tyrosine kinase inhibitors than those identified by direct sequencing.

Outcomes of research biopsies in clinical trials of EGFR mutation-positive non-small cell lung cancer patients pretreated with EGFR-tyrosine kinase inhibitors

BACKGROUND/PURPOSE

Research biopsies (RBs) are crucial for developing novel molecular targeted agents. However, the safety and diagnostic yields of RBs have not been investigated in EGFR mutation-positive non-small cell lung cancer (NSCLC) patients pretreated with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs).

METHODS

We searched the medical records of NSCLC patients who participated in lung cancer clinical trials and underwent mandatory RBs between 2012 and 2014 at our institution. Only patients with EGFR mutation-positive NSCLC pretreated with at least 1 EGFR-TKI were enrolled.

RESULTS

Of 140 enrolled patients, 73 (52.1%) and 59 (42.1%) had exon 19 deletions and exon 21 L858R mutation, respectively. Before RBs, 108 (77.1%), 83 (59.3%), and 36 (25.7%) patients had been treated with gefitinib, erlotinib, and afatinib, respectively. Computed tomography-guided percutaneous core needle biopsy was the most frequently used modality among 181 RBs performed (50.8%), followed by ultrasonography-guided (32.0%) and endoscopic RBs (16.0%). The most common RB sites were the lung (69.6%), pleura (8.8%), and liver (6.1%). Pathologic examinations revealed malignant cells in most RB specimens (72.9%). Complications due to RBs included pneumothorax (11.6%), bleeding (6.1%), and infection (1.1%). Only 1 patient required chest tube placement for pneumothorax, and 2 patients underwent endotracheal intubation because of bleeding.

CONCLUSION

RBs in this patient population were generally safe. Pneumothorax was the most frequent complication; bleeding, while infrequent, increased the risk of severe events. The diagnostic yields and complications of any particular modality should therefore be discussed with prospective clinical trial participants.

Racial and Ethnic Differences in the Epidemiology and Genomics of Lung Cancer

BACKGROUND

Lung cancer is the most common cancer in the world. In addition to the geographical and sex-specific differences in the incidence, mortality, and survival rates of lung cancer, growing evidence suggests that racial and ethnic differences exist.

METHODS

We reviewed published data related to racial and ethnic differences in lung cancer.

RESULTS

Current knowledge and substantive findings related to racial and ethnic differences in lung cancer were summarized, focusing on incidence, mortality, survival, cigarette smoking, prevention and early detection, and genomics. Systems-level and health care professional-related issues likely to contribute to specific racial and ethnic health disparities were also reviewed to provide possible suggestions for future strategies to reduce the disproportionate burden of lung cancer.

CONCLUSIONS

Although lung carcinogenesis is a multifactorial process driven by exogenous exposures, genetic variations, and an accumulation of somatic genetic events, it appears to have racial and ethnic differences that in turn impact the observed epidemiological differences in rates of incidence, mortality, and survival.

A Survival Scoring System for Non-Small Cell Lung Cancer Patients with De Novo Bone Metastases

In the pre-tyrosine kinase inhibitors (TKIs) era, non-small cell lung cancer (NSCLC) patients with de novo bone metastases had a worse prognosis than those without. However, whether epidermal growth factor receptor (EGFR)-TKIs affect the outcomes of EGFR mutant NSCLC patients with de novo bone metastases has not been well studied thus far. We retrospectively studied the effect of EGFR mutation status and first-line EGFR-TKIs on patient outcomes and created a survival scoring system for NSCLC patients with de novo bone metastases. This retrospective study evaluated 1510 NSCLC patients diagnosed between November 2010 and March 2014. Among these patients, 234 patients had de novo bone metastases. We found that 121 of these 234 patients (51.7%) had positive EGFR mutation tests, and a positive EGFR mutation test significantly affected overall survival (OS) (EGFR mutant: 15.2 months, EGFR wild type: 6.5 months; p < 0.001). Other prognostic factors significant in the multivariable analysis for NSCLC with de novo bone metastases included Eastern Cooperative Oncology Group performance status (PS) (OS; PS 0–2: 11.2 months, PS 3–4: 4.9 months; p = 0.002), presence of extraosseous metastases (OS; with extraosseous metastases: 8.8 months, without extraosseous metastases: 14.0 months; p = 0.008), blood lymphocyte-to-monocyte ratio (LMR) (OS; LMR > 3.1: 17.1months, LMR ≤ 3.1: 6.9months; p < 0.001). A positive EGFR mutation status reversed the poor outcomes of NSCLC patients with de novo bone metastases. A simple and useful survival scoring system including the above clinical parameters was thus created for NSCLC patients with de novo bone metastases.

Correlation between status of epidermal growth factor receptor mutation and distant metastases of lung adenocarcinoma upon initial diagnosis based on 1063 patients in China

The study aimed to explore the correlations between status of epidermal growth factor receptor (EGFR) mutations and distant metastases. A total of 1063 patients with lung adenocarcinoma indentified with status of EGFR mutations from August 2010 to May 2015 at Shanxi Cancer Hospital were enrolled. 456 patients were confirmed with EGFR mutations. The associations among EGFR mutations, clinical factors, and distant metastases at initial diagnosis were evaluated. Patients harboring EGFR mutation were more likely to be female (P < 0.001), with no smoking history (P < 0.001), brain metastases (P = 0.029), and higher ECOG performance scores (P = 0.025). The correlation between EGFR mutation status and distant metastases showed statistical significance both in univariate (P = 0.022) and in multivariate analysis (OR 1.573, 95 % CI 1.202-2.059, P = 0.001) especially in brain metastases (OR 1.675, 95 % CI 1.132-2.479, P = 0.010) and lung metastases (OR 1.571, 59 % CI 1.101-2.243 P = 0.013). Furthermore, the 19del mutations showed associations with brain metastases (OR 1.586, 95 % CI 1.028-2.447, P = 0.037), and lung metastases (OR 1.587, 95 % CI 1.065-2.346, P = 0.023). The exon 21 point mutations showed statistically significant differences in liver metastases (OR 1.987, 95 % CI 1.094-3.067, P = 0.024). In conclusion, the EGFR mutations in lung adenocarcinoma patients were independently correlated with distant metastases. Subgroup analyses showed that patients harboring 19del mutations presented different distant metastases compared with those harboring 21 point mutaions.

Relationship between miR-7 expression and treatment outcomes with gefitinib in non-small cell lung cancer

The aim of the present study was to assess the effects of gefitinib chemotherapy on the serum levels of miR-7 in patients with non-small cell lung cancer (NSCLC). A total of 126 patients were enrolled in the present study (stage I-II, n=54 and stage III-IV, n=72). Patients with stage I-II NSCLC underwent surgery in combination with gefitinib chemotherapy, whereas only gefitinib chemotherapy was administered to patients with stage III-IV disease. Serum levels of miR-7 before and after treatment were measured with quantitative polymerase chain reaction using fluorogenic probes, and miR-7 positivity and scoring in resected specimens were determined by immunohistochemistry. The number of miR-7-positive cases and the number of cases with higher miR-7 scores were significantly lower among patients with stage I-II NSCLC than those with stage III-IV disease. Additionally, serum levels of miR-7 before and after intervention were lower in stage I-II than in stage III-IV NSCLC cases. Serum levels of miR-7 after treatment were significantly lower than those before intervention in the two groups. The treatment success rate was significantly higher in miR-7-negative patients than in miR-7-positive patients in the two patient groups. Adverse event rates in miR-7-negative and -positive patients were comparable between the groups. Among those with stage III-IV NSCLC, the survival rate of miR-7-positive patients was significantly lower than that of miR-7-negative patients. Conversely, among those with I-II NSCLC, the progression-free survival and median survival time of miR-7-positive patients were significantly lower than those of miR-7-negative patients. Our findings suggest that serum and expression levels of miR-7 in the tissue were closely associated with tumor staging and the therapeutic effects of gefitinib in NSCLC.

MassARRAY, pyrosequencing, and PNA clamping for EGFR mutation detection in lung cancer tissue and cytological samples: a multicenter study

BACKGROUND

Testing for epidermal growth factor receptor (EGFR) mutation is an important process in the therapeutic plan of patients with lung cancer. Recently, MassARRAY, based on matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, has been shown to be a useful method for somatic mutation analysis with pyrosequencing and peptide nucleic acid clamping (PNAc).

METHODS

A total of 107 tissues and 67 cytological samples, which were confirmed to have lung adenocarcinoma at nine hospitals in Korea, were collected. Among the MassARRAY, pyrosequencing, and PNAc, the concordance rates and sensitivity of EGFR mutation detection were analyzed and validated in comparative tissue and cytological specimens.

RESULTS

The concordance rate between pyrosequencing and PNAc was higher than that between MassARRAY and either of the pyrosequencing and PNAc in both tissue and cytological samples. In a comparison of diagnostic performance, MassARRAY (sensitivity: 85.7 %) was higher than pyrosequencing (74.3 %) and PNAc (70 %) in tissue, although pyrosequencing (80.5 %) was more highly sensitive, compared to MassARRAY (70.7 %) and PNAc (70.7 %) in terms of cytology. Unexpectedly, use of MassARRAY resulted in a significantly different EGFR mutation detection rate between tissue and cytological samples.

CONCLUSIONS

When used for the detection of EGFR mutations, MassARRAY was more sensitive than pyrosequencing or PNA clamping in tissue, but not in cytological samples. In EGFR mutation detection between tissues and cytology, PNAc showed relatively higher concordance than MassARRAY or pyrosequencing.

Comparison of EGFR mutation detection between the tissue and cytology using direct sequencing, pyrosequencing and peptide nucleic acid clamping in lung adenocarcinoma: Korean multicentre study

BACKGROUND

The importance of sensitive methods for the detection of epidermal growth factor receptor (EGFR) mutation is emphasized. The aim of this study is to perform comparative and concordance analyses of direct sequencing, pyrosequencing and peptide nucleic acid (PNA) clamping for detecting EGFR gene mutations using archived tissue and cytology specimens.

METHODS

Samples from a total of 112 cases, which were diagnosed with adenocarcinoma of the lung at nine hospitals in Korea were collected. Using the above three methods, the concordance rates of EGFR mutations in exons 18, 19, 20 and 21 were analysed and validated in comparative tissue and cytology specimens.

RESULTS

Comparison of EGFR mutation detection between the tissue and cytology had a high concordance rate. The diagnostic performance of pyrosequencing and PNA clamping in tissue was higher than that of direct sequencing as well as cytology. Additionally, among some of the patients who had EGFR wild type by single method, EGFR mutations were detected by other methods. Cytology specimens had a diagnostic performance for the detection of EGFR mutations.

CONCLUSIONS

Cytology specimens had a diagnostic performance for the detection of EGFR mutations that was comparable to that of tissues. For detecting EGFR mutations, pyrosequencing or PNA clamping was more sensitive than direct sequencing. In EGFR mutation negative patients who are difficult to obtain tissue, repeating test using pyrosequencing or PNA clamping is recommended to improve the detection rate of EGFR mutation than only one, especially in cytology.

Frequency of EGFR mutations in lung adenocarcinoma with malignant pleural effusion: Implication of cancer biological behaviour regulated by EGFR mutation

OBJECTIVE

A retrospective single-centre study to compare the clinical features of patients with lung adenocarcinoma with and without epidermal growth factor receptor (EGFR) mutations.

METHODS

Pretreatment medical records of patients with lung adenocarcinoma were reviewed. DNA was extracted from paraffin wax-embedded tumour tissue for analysis of EGFR mutations. Malignant pleural effusion (MPE) was diagnosed by cytopathological testing of pleural fluid.

RESULTS

EGFR mutations (19-Del and L858R) were recorded in 81/283 patients (28.6%). MPE was found in 42/283 patients (14.8%). In patients with stage IV disease, the frequency of EGFR mutations was higher in those with MPE than in those without MPE. EGFR mutations were independently associated with female sex, no history of smoking and presence of MPE.

CONCLUSIONS

There was a positive association between EGFR mutation and the presence of MPE. EGFR mutations may play an important role in the formation of MPE.

Preanalytic parameters in epidermal growth factor receptor mutation testing for non-small cell lung carcinoma: A review of cytologic series

The results from molecular assays can be affected significantly by the preanalytic condition of cytologic samples. The authors review current knowledge on the use of cytologic samples for epidermal growth factor receptor (EGFR) mutation testing in non–small cell lung cancer with a focus on preanalytic parameters. A systematic electronic search of the MEDLINE database was performed to identify original articles that reported the use of cytologic samples for EGFR molecular analysis and included a minimum of 100 samples. The information collected included author(s), journal, and year of publication; number of patients and samples; sampling method; type of preparation; type of fixative; staining techniques; mutation analysis techniques; tumor cellularity; the percentage of tumor cells; data on DNA quantity, quality, and concentration; failed assays; and the mutation rate. EGFR mutation analysis was conducted on 4999 cytologic samples from 22 studies that fulfilled the inclusion criteria. Fine‐needle aspirates and pleural effusions were the most common types of specimens used. DNA was mainly extracted from cell blocks and smears, and the most commonly reported fixatives included formalin, ethanol, and CytoLyt. Cellularity assessments and DNA yields were available from 5 studies each. The average success rate for the assays that used cytologic specimens was 95.87% (range, 85.2%‐100%). The mutation rate ranged from 6% to 50.46%, and a higher mutation detection rate and lower numbers of insufficient cases were reported for pleural effusions and lymph node samples from endobronchial ultrasound‐guided transbronchial needle aspiration compared with histologic specimens. Low cellularity and a low percentage of tumor cells were associated with higher test failure rates. Future guidelines should consider the current data for specific recommendations regarding cytologic samples. Cancer (Cancer Cytopathol) 2015;123:633–643. © 2015 American Cancer Society.

Preanalytic parameters for epidermal growth factor receptor mutation testing are reviewed in non–small cell lung cancer using 4999 cytologic samples from 22 studies. A higher mutation detection rate and lower numbers of insufficient cases are observed for pleural effusions and lymph node samples obtained using endobronchial ultrasound‐guided transbronchial needle aspiration compared with histologic specimens, and low cellularity and a lower percentage of tumor cells are associated with higher test failure rates. Future guidelines should consider the current data for specific recommendations regarding cytologic samples.

Gefitinib: a review of its use in adults with advanced non-small cell lung cancer

Gefitinib (Iressa®) is a selective small-molecule epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (EGFR TKI) indicated for the treatment of adults with locally advanced or metastatic non-small cell lung cancer (NSCLC) with activating mutations of EGFR tyrosine kinase. Large phase III or IV clinical trials in patients with locally advanced or metastatic NSCLC showed that gefitinib as first- or subsequent-line treatment significantly prolonged progression-free survival (PFS) and improved objective response rates and/or health-related quality of life parameters in patients with activating EGFR mutations and in clinically selected patients (e.g., Asian patients or never-smokers) who are more likely to harbour these mutations. Overall survival did not increase significantly with gefitinib, although post-study treatments may have had a confounding effect on this outcome. Gefitinib was generally well tolerated in these studies, with mild or moderate skin reactions, gastrointestinal disturbances and elevations in liver enzymes among the most common adverse reactions in gefitinib recipients; interstitial lung disease has also been reported in <6 % of gefitinib recipients. Compared with chemotherapy, gefitinib as first- or subsequent-line therapy provided similar or greater PFS benefit and was generally associated with fewer haematological adverse events, neurotoxicity, asthenic disorders, as well as grade ≥3 adverse events. Although the position of gefitinib with respect to other EGFR TKIs is not definitively established, current evidence indicates that gefitinib monotherapy is an effective and generally well-tolerated first- or subsequent-line treatment option for patients with NSCLC and activating EGFR mutations who have not received an EGFR TKI previously.

Suitability of surgical tumor tissues, biopsy, or cytology samples for epidermal growth factor receptor mutation testing in non-small cell lung carcinoma based on chinese population

BACKGROUND

Epidermal growth factor receptor (EGFR) mutation status is crucial in treatment selection for non-small cell lung cancer (NSCLC) patients; however, the detection materials' availability remains challenging in clinical practice. In this study, we collected surgical resection tissues, lymph node biopsy, and cytological samples for EGFR mutation testing and investigated the associations between gene mutation and clinical characteristics.

METHODS

Two hundred and seventy-six NSCLC adenocarcinoma specimens were collected, and highly sensitive amplification refractory mutation system method was implemented for EGFR mutation detection, with clinicopathologic characteristics involved in the final analysis.

RESULTS

In the total of 276 samples, 96% (265/276) of tumors obtained evaluable EGFR mutation status, the frequency of mutation was 55.8% (148/265) in all specimens, and three different type samples shared a comparable successful testing rate: 97.4% (38/39) in surgical tumor tissues, 100% (108/108) in lymph node biopsy samples, and 92.2% (119/129) in cytological samples. EGFR mutation was significantly associated with sex, smoking history, lymph node metastasis status (N stage), primary tumor size, testing tissues origin, and sample type (P < .05). Multivariate analysis reconfirmed that smoking history and primary tumor size shared significant correlation with EGFR mutation after adjustment.

CONCLUSIONS

Both lymph node biopsy and cytological samples were suitable surrogates for EGFR mutation detection in NSCLC compared with tumor tissues, gene status should be detected widely considering the high EGFR mutation rate, and nonsmoking history together with smaller primary tumor size was an independent indicator of EGFR mutation status.

How Molecular Understanding Affects to Prescribing Patterns and Clinical Outcome of Gefitinib in Non-small Cell Lung Cancer? 10 Year Experience of Single Institution

Purpose

Gefitinib was introduced in 2002 for treatment of non-small cell lung cancer (NSCLC); however, it is not clear whether its use in daily practice has changed the outcome of patients. The purpose of this study is to evaluate the question of how molecular understanding regarding gefitinib and epidermal growth factor receptor (EGFR) mutation affect the prescribing patterns and clinical outcomes of treatment with gefitinib in NSCLC, in a real practical field.

Materials and Methods

We conducted a retrospective analysis of the consecutive database of NSCLC patients who were treated with gefitinib at Seoul National University Hospital between January 2002 and December 2011. Prescribing patterns and clinical outcomes were analyzed by year.

Results

A total of 1,115 NSCLC patients, who received gefitinib at recurred or metastatic setting, were included in this study. Proportion of patients receiving gefitinib, for the first line, showed a gradual increase, from 5.2% in 2002-2003 to 30.6% in 2010-2011. Proportion of patients who underwent EGFR mutation testing showed a rapid increase, from 0.6% in 2004-2005 to 73.5% in 2010-2011. The response rate also showed a gradual increase, from 17.2% in 2002-2003 to 57.1% in 2010-2011 (p<0.001). The median progression-free survival of gefitinib was increased with statistical significance from 2.8 months in 2002-2003 to 9.1 months in 2010-2011 (p<0.001).

Conclusion

We demonstrated that molecular understanding and practical use of EGFR mutation testing have resulted in a change in the prescription patterns of gefitinib. Use of an enrichment strategy can lead to improvement in the efficacy of gefitinib in real practice.

Treatment of Non-small Cell Lung Carcinoma after Failure of Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor

Since the first description of non-small cell lung cancer (NSCLC) with activating epidermal growth factor receptor (EGFR) mutation as a distinct clinical entity, studies have proved EGFR tyrosine kinase inhibitors (TKIs) as a first choice of treatment. The median response duration of TKIs as a first-line treatment for EGFR mutant tumors ranges from 11 to 14 months. However, acquired resistance to EGFR-TKIs is inevitable due to various mechanisms, such as T790M, c-Met amplification, activation of alternative pathways (IGF-1, HGF, PI3CA, AXL), transformation to mesenchymal cell or small cell features, and tumor heterogeneity. Until development of a successful treatment strategy to overcome such acquired resistance, few options are currently available. Here we provide a summary of the therapeutic options after failure of first line EGFR-TKI treatment for NSCLC.

Present status and problems on molecular targeted therapy of cancer

Numerous clinical trials of molecular targeted drugs for cancer have been conducted, with remarkable results for certain drugs and accumulation of "negative data" causing a hitch in the development plan for some other compounds. Five recent issues and problems of molecular targeted therapies were discussed critically. Drug discovery and effects against driver mutations (activating mutations) and problems: possibility for circumventing inherent and acquired resistance with the aim of achieving radical cure. Synthetic lethality: reasonable patient selection in individualized treatment strategy. Response rate and progression-free survival improvement with or without overall survival benefit and enhancement of toxicity in bevacizumab therapy: best endpoints for the evaluation of effect of antiangiogenic therapy. Negative data on small-molecule targeted therapy, primarily vascular endothelial growth factor tyrosine kinase inhibitors: loose GO or NO-GO decision criteria for further development of new compounds in early clinical trials. Effect of immunotherapy: difficulty to verify by proof of principle study. We are faced to many questions for the development of efficient personalized therapy. Accumulation of scientific global preclinical and clinical evidences is essential to use these new therapeutic modalities for the improvement of oncologic health care.

The role of stereotactic ablative radiotherapy for early-stage and oligometastatic non-small cell lung cancer: evidence for changing paradigms

A compelling body of non-randomized evidence has established stereotactic ablative lung radiotherapy (SABR) as a standard of care for medically inoperable patients with peripheral early-stage non-small cell lung cancer (NSCLC). This convenient outpatient therapy, which is typically delivered in 3-8 fractions, is also well tolerated by elderly and frail patients, makes efficient use of resources and is feasible using standard commercial equipment. The introduction of lung SABR into large populations has led to an increased utilization of radiotherapy, a reduction in the proportion of untreated patients and an increase in overall survival. In selected patients, the same ablative technology can now achieve durable local control of NSCLC metastases in a variety of common locations including the adrenal glands, bone, brain, and liver. At the same time as this, advances in prognostic molecular markers and targeted systemic therapies mean that there is now a subgroup of patients with stage IV NSCLC and a median survival of around 2 years. This creates opportunities for new trials that incorporate SABR and patient-specific systemic strategies. This selective mini-review focuses on the emerging role of SABR in patients with early-stage and oligometastatic NSCLC.