Multicentre prospective phase II trial of gefitinib for advanced non-small cell lung cancer with epidermal growth factor receptor mutations: results of the West Japan Thoracic Oncology Group trial (WJTOG0403)

Relationship between driver gene mutations and clinical pathological characteristics in older lung adenocarcinoma

Objectives

Lung adenocarcinoma (LUAD) is the most common newly diagnosed malignant tumor in older people. As older patients age, organ function decreases, leading to increased adverse reactions to treatment. The epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase tyrosine (ALK) tyrosine kinase inhibitors (TKIs) therapy are more effective and well-tolerated than chemotherapy, while the rate of genetic testing and subsequent targeted treatment among older patients remains relatively low, the clinical benefit limitation for those patients. This study aims to investigate the mutation characteristics of LUAD diver gene and its relationship with clinicopathological features in older LUAD.

Materials and methods

A total of 275 patients were diagnosed as LUAD and were over sixty years old. We utilized next-generation sequencing technology to detect and analyze gene mutations in postoperative tissue specimens, including EGFR, KRAS, ALK, ROS1, RET, MET, BRAF, HER2, PIK3CA and NRAS.

Results

A total of 90.18% (248/275) of older LUAD patients experienced genetic mutations. The EGFR (192, 69.82%) had the highest mutation rate among ten genes, followed by KRAS (21, 7.64%), MET (21, 7.64%), ERBB2 (15, 5.45%), RET (9, 3.27%), ALK (8, 2.91%), ROS1 (8, 2.91%), PIK3CA (6, 2.18%), BRAF (5, 1.82%) and NRAS (1, 0.36%). We also found thirty patients (15.63%) with EGFR mutations also having other gene mutations. The L858R mutation and exon19 deletion were the predominant EGFR mutations, accounting for 84.90% of EGFR-mutated patients. In addition, fifty-one kinds of EGFR mutations were detected, distributed in the protein tyrosine kinase catalytic domain (43, 84.31%), cysteine enriched domain (4, 7.84%), receptor binding domain (3, 5.88%), and EGFR transmembrane domain (1,1.96%). Ten cases of gene fusion mutation were detected. Two rare partner genes, PKHD1 (P60:R34) and STK39 (R33:S11), were detected by ROS1 gene fusion. RET gene fusion revealed a rare companion gene KCND2 (R11:K2). The EGFR mutations were more prevalent in female, non-smoking patients (p < 0.05), and the KRAS mutations were more common in male and smoking patients (p < 0.01). In addition, the BRAF mutations were more likely to occur in the right lung (p < 0.05).

Conclusion

Older LUAD populations exhibit diverse genetic mutations, which may also exist simultaneously. Simultaneous detection of multiple genes by NGS can accelerate and enhance targeted treatment benefits for older LUAD patients, ultimately improving their quality of life.

A prospective phase 2 study of expeditious EGFR genotyping and immediate therapeutic initiation through extracellular vesicles (EV)-based bronchoalveolar lavage fluid (BALF) liquid biopsy in advanced NSCLC patients

Background

In our previous study, epidermal growth factor receptor (EGFR) genotyping using extracellular vesicles (EV)-derived DNA isolated from bronchoalveolar lavage fluid (BALF) was proven to be highly concordant with conventional tissue-based genotyping and its turn-around-time (TAT) was only 1-2 days. On this background, we prospectively validated the performance of EV-based BALF liquid biopsy for EGFR genotyping in the real practice of advanced non-small cell lung cancer (NSCLC) patients.

Methods

After screening 120 newly diagnosed stage III-IV NSCLC patients, 51 cases were detected as EGFR-mutated by EV-based BALF EGFR genotyping and 40 patients were enrolled for gefitinib treatment. BALF EV were isolated by ultracentrifuge method and EGFR genotyping was performed with PCR-based PNA-clamping assisted fluorescence melting curve analysis. The objective response rate, progression-free survival (PFS), TAT, time to treatment initiation (TTI), and concordance rate were analyzed with clinical parameters.

Results

There was only one false positive case among the 120 screened patients and the overall concordance rate between tissue biopsy and EV-based BALF liquid biopsy was 99.2% including the subtype of EGFR mutations. TAT for EV-based BALF EGFR genotyping was 1.9±1.1 days, while tissue-based TAT was 12.1±7.2 days (P<0.001). EGFR genotyping was determined even before obtaining histopathologic report in most cases. TTI in BALF EGFR genotyping was faster than tissue genotyping (7.8±6.5 vs. 13.8±12.9 days). Therapeutic outcomes of response rate and PFS were almost similar to tissue-based results.

Conclusions

We demonstrated, for the first time, that EV-based BALF liquid biopsy should be an excellent platform for expeditious EGFR genotyping and rapid therapeutic intervention even before obtaining the result of histopathology in advanced NSCLC patients.

Pharmacogenetics of Anticancer Drugs: Clinical Response and Toxicity

Cancer is the most challenging disease for medical professionals to treat. The factors underlying the complicated situation include anticancer drug-associated toxicity, non-specific response, low therapeutic window, variable treatment outcomes, development of drug resistance, treatment complications, and cancer recurrence. The remarkable advancement in biomedical sciences and genetics, over the past few decades, however, is changing the dire situation. The discovery of gene polymorphism, gene expression, biomarkers, particular molecular targets and pathways, and drug-metabolizing enzymes have paved the way for the development and provision of targeted and individualized anticancer treatment. Pharmacogenetics is the study of genetic factors having the potential to affect clinical responses and pharmacokinetic and pharmacodynamic behaviors of drugs. This chapter emphasizes pharmacogenetics of anticancer drugs and its applications in improving treatment outcomes, selectivity, toxicity of the drugs, and discovering and developing personalized anticancer drugs and genetic methods for prediction of drug response and toxicity.

Third-generation EGFR and ALK inhibitors: mechanisms of resistance and management

The discoveries of EGFR mutations and ALK rearrangements as actionable oncogenic drivers in non-small-cell lung cancer (NSCLC) has propelled a biomarker-directed treatment paradigm for patients with advanced-stage disease. Numerous EGFR and ALK tyrosine kinase inhibitors (TKIs) with demonstrated efficacy in patients with EGFR-mutant and ALK-rearranged NSCLCs have been developed, culminating in the availability of the highly effective third-generation TKIs osimertinib and lorlatinib, respectively. Despite their marked efficacy, resistance to these agents remains an unsolved fundamental challenge. Both 'on-target' mechanisms (largely mediated by acquired resistance mutations in the kinase domains of EGFR or ALK) and 'off-target' mechanisms of resistance (mediated by non-target kinase alterations such as bypass signalling activation or phenotypic transformation) have been identified in patients with disease progression on osimertinib or lorlatinib. A growing understanding of the biology and spectrum of these mechanisms of resistance has already begun to inform the development of more effective therapeutic strategies. In this Review, we discuss the development of third-generation EGFR and ALK inhibitors, predominant mechanisms of resistance, and approaches to tackling resistance in the clinic, ranging from novel fourth-generation TKIs to combination regimens and other investigational therapies.

A network meta-analysis for efficacies and toxicities of different concurrent chemoradiotherapy regimens in the treatment of locally advanced non-small cell lung cancer

BACKGROUND

Concurrent chemoradiotherapy (CCRT) has become the cornerstone of treatment for patients with locally advanced non-small cell lung cancer (LA-NSCLC). The aim of this study was to compare the efficacies and toxicities of different CCRT regimens in the treatment of LA-NSCLC by adopting a network meta-analysis (NMA).

METHODS

An exhaustive search of PubMed, EMBASE, Web of Science, and the Cochrane Central Register of Controlled Trials (CENTRAL) was conducted to identify relevant studies from inception to October 1, 2020. Direct and indirect evidence was combined to calculate the odds radios (ORs) and 95% confidence intervals (CIs), as well as to plot the surface under the cumulative ranking (SUCRA) curves. Cluster analyses were adopted to compare the efficacies and toxicities of different CCRT regimens according to the similarity of 2 variables. Publication bias was detected by comparison-adjusted funnel plots.

RESULTS

Twenty-two studies were enrolled in this NMA, including 18 regimens: CCRT (cisplatin + etoposide), CCRT (carboplatin + paclitaxel), CCRT (pemetrexed + carboplatin), CCRT (pemetrexed + cisplatin), CCRT (docetaxel + cisplatin), CCRT (S-1 + cisplatin), CCRT (mitomycin + vindesine + cisplatin), CCRT (cisplatin + vinorelbine), CCRT (cisplatin), CCRT (etoposide + cisplatin + amifostine), RT, CCRT (5-FU), CCRT (paclitaxel + cisplatin), CCRT (irinotecan + carboplatin), CCRT (nedaplatin), CCRT (carboplatin + etoposide), CCRT (paclitaxel), and CCRT (carboplatin). The results indicated that the regimens with CCRT (cisplatin + etoposide), CCRT (carboplatin + paclitaxel), CCRT (pemetrexed + cisplatin), CCRT (S-1 + cisplatin), and CCRT (cisplatin + vinorelbine) had relatively better efficacies compared with other regimens. As for toxicities of different CCRT regimens, the CCRT (carboplatin + paclitaxel), CCRT (pemetrexed + cisplatin), and CCRT (docetaxel + cisplatin) were relatively lower.

CONCLUSIONS

Our study demonstrated that CCRT (pemetrexed + cisplatin) and CCRT (carboplatin + paclitaxel) might be the best options for the treatment of LA-NSCLC, and CCRT (pemetrexed + cisplatin) had the highest 3-year overall survival (OS) rate.

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.

Nephrotoxicity as a Complication of Chemotherapy and Immunotherapy in the Treatment of Colorectal Cancer, Melanoma and Non-Small Cell Lung Cancer

Acute kidney injury is a common complication of many medical procedures, including those used in cancer treatment. Both chemotherapy and immunotherapy may result in deterioration of kidney function, which may lead to an increase in mortality among patients with cancer. Antineoplastic agents can affect any element of the nephron, leading to the appearance of clinical symptoms such as proteinuria, hypertension, electrolyte disorders, glomerulonephritis, acute and chronic interstitial nephritis and acute kidney injury. The medical literature describing renal complications occurring during chemotherapeutic and immunotherapeutic treatment in neoplasms, such as colorectal cancer, non-small cell lung cancer and melanoma, was analysed. The immune system plays an important role in controlling the development of neoplasms and fighting them. Oncological treatment algorithms include immunotherapy as monotherapy, combined with chemotherapy or chemotherapy as monotherapy. In the treatment of the above-mentioned neoplasms immunotherapeutics are used, such as checkpoint inhibitors (CPI) (i.e., ipilimumab, pembrolizumab, nivolumab, atezolizumab), vascular endothelial growth factor (VEGF) inhibitors (i.e., bevacizumab, ramucirumab) and a variety of chemotherapeutic agents (irinotecan, capecitabine, oxaliplatin, gefitinib, erlotinib, gemcitabine, cisplatin, paclitaxel, carboplatin, doclitaxel, vinorelbine, topotecan, etoposide). In our article, we focused on the number and type of renal complications as well as on the time of their manifestation when using specific treatment regimens. Our analysis also includes case reports. We discussed treatment of immunological complications and adjustments of the dose of chemotherapeutic agents depending on the creatinine clearance. Analysing the data from the literature, when two immunotherapeutic agents are used together, the number of recorded renal complications increases. Bevacizumab and ramucirumab are the cause of the largest number of renal complications among the immunotherapeutic agents described above. Cisplatin is the best-described substance with the greatest nephrotoxic potential among the chemotherapeutic agents. Crucial for renal complications are also cancer stage, previous chemotherapy and other risk factors of AKI such as age, comorbidities and medications used. Due to the described complications during oncological treatment, including kidney damage, it seems necessary to elaborate standards of cooperation between oncologists and nephrologists both during and after treatment of a patient with cancer. Therefore, it is necessary to conduct further research and develop algorithms for management of a cancer patient, especially during such an intensive progress in oncology.

EGFR variant allele frequency predicts EGFR-TKI efficacy in lung adenocarcinoma: a multicenter study

Background

Although lung adenocarcinoma (LADC) with sensitizing mutations of the epidermal growth factor receptor (EGFR) is highly sensitive to EGFR tyrosine kinase inhibitors (EGFR-TKIs), in most cases disease progression inevitably occurs. Our aim was to investigate the predictive and prognostic significance of adjusted tumoral EGFR variant allele frequency (EGFR-aVAF) in the above setting.

Methods

Eighty-nine Caucasian advanced-stage LADC patients with known exon-specific EGFR mutations undergoing EGFR-TKI treatment were included. The correlations of EGFR-aVAF with clinicopathological variables including progression-free and overall survival (PFS and OS, respectively) were retrospectively analyzed.

Results

Of 89 EGFR-mutant LADC patients, 46 (51.7%) had exon 19 deletion, while 41 (46.1%) and 2 (2.2%) patients had exon 21- and exon 18-point mutations, respectively. Tumoral EGFR-aVAF was significantly higher in patients harboring EGFR exon 19 mutations than in those with exon 21-mutant tumors (P<0.001). Notably, patients with EGFR exon 19 mutant tumors demonstrated significantly improved PFS (P=0.003) and OS (P=0.02) compared to patients with exon 21 mutations. Irrespective of specific exon mutations, a statistically significant positive linear correlation was found between EGFR-aVAF of tumoral tissue and PFS (r=0.319; P=0.002). High (≥70%) EGFR-aVAF was an independent predictor of longer PFS [vs. low (<70%) EGFR-aVAF; median PFSs were 52 vs. 26 weeks, respectively; P<0.001]. Additionally, patients with high EGFR-aVAF also had significantly improved OS than those with low EGFR-aVAF (P=0.011).

Conclusions

Our study suggests that high (≥70%) EGFR-aVAF of tumoral tissue predicts benefit from EGFR-TKI treatment in advanced LADC and, moreover, that exon 19 EGFR mutation is associated with high EGFR-aVAF and improved survival outcomes.

Effects of hyperinsulinemia on acquired resistance to epidermal growth factor receptor-tyrosine kinase inhibitor via the PI3K/AKT pathway in non-small cell lung cancer cells in vitro

Patients with lung cancer harboring activating epidermal growth factor (EGFR) mutations and pre-existing diabetes have been demonstrated to exhibit poor responses to first-line EGFR-tyrosine kinase inhibitor (TKI) therapy. Strategies for the management of acquired resistance to EGFR-TKIs in patients with advanced non-small cell lung cancer (NSCLC) are urgently required. Only a limited number of studies have been published to date on the effects of insulin on EGFR-TKI resistance in NSCLC. Hence, the aim of the present study was to investigate the roles of hyperinsulinemia and hyperglycemia in mediating gefitinib resistance in NSCLC cells with activating EGFR mutations. In the present study, the HCC4006 cell line, which harbors EGFR mutations, was co-treated with gefitinib and long-acting insulin glargine. Whether hyperinsulinemia is able to mediate EGFR-TKI resistance in the NSCLC cell line harboring activating EGFR mutations was also investigated, and the possible underlying mechanisms responsible for these actions were explored. The inhibition of cell proliferation, and the potential mechanism of gefitinib resistance, were examined using an MTS proliferation assay and western blot analysis, and through the transfection of siRNAs. Whether the inhibition of AKT is able to overcome EGFR-TKI resistance induced by long-acting insulin was also investigated. The results obtained suggested that hyperinsulinemia induced by glargine upregulated NSCLC cell proliferation and survival, and induced gefitinib resistance. By contrast, the morphology and proliferation of the cells in a medium containing a 2-fold concentration of glucose were not significantly affected. Gefitinib resistance induced by hyperinsulinemia may have been mediated via the phosphoinositide 3-kinase (PI3K)/AKT pathway rather than the mitogen-activated protein kinase extracellular signal regulated kinase (MAPK/ERK) pathway. AKT serine/threonine kinase 1 knockdown by siRNA rescued the gefitinib resistance that was induced by hyperinsulinemia. In conclusion, hyperinsulinemia, but not hyperglycemia, was identified to cause the development of gefitinib resistance in NSCLC cells with activating EGFR mutations. However, additional studies are required to investigate strategies, such as co targeting hyperinsulinemia and the PI3K/AKT pathway, for overcoming EGFR-TKI resistance in patients with NSCLC.

Specific Gene Co-variation Acts Better Than Number of Concomitant Altered Genes in Predicting EGFR-TKI Efficacy in Non-small-cell Lung Cancer

BACKGROUND

There occurs huge heterogeneity in clinical outcomes for patients with epidermal growth factor receptor (EGFR)-mutated non-small-cell lung cancer (NSCLC) treated with EGFR tyrosine kinase inhibitors (EGFR-TKIs). The purpose of this study was to indicate genetic biomarkers predicting primary resistance of EGFR-TKIs in these patients.

PATIENTS AND METHODS

Using a next-generation sequencing panel with 168 cancer-related genes, matched tumor biopsy and plasma samples before treatments from patients with NSCLC were analyzed. Patients taking EGFR-TKIs were followed-up with imaging examination. Correlation of co-alterative genes with progression-free survival (PFS) was analyzed.

RESULTS

Of the 48 patients treated with EGFR-TKIs, 46 (95.83%) had at least 1 genetic co-variant beyond EGFR mutation. Multivariate analysis indicated that RB1, PIK3CA, and ERBB2 co-alterations, rather than number of co-alterative genes, were independently associated with poorer PFS. Grouping patients by specific gene status showed best likelihood ratio χ², Akaike information criterion, and Harrell concordance index. The median PFS for patients in group A (less genetic co-variations and wild specific genes), group B (more genetic co-variations and wild specific genes), group C (less genetic co-variations and altered specific genes), and group D (more genetic co-variations and altered specific genes) were 10.4, 9.13 (vs. group A; P = .3112), 6.33 (vs. group B; P = .0465), and 3.90 (vs. group C; P = .0309) months, respectively.

CONCLUSIONS

This study revealed a high concomitant genetic alteration rate in patients with EGFR-mutated NSCLC. Specific gene variants were more important than number of altered genes in predicting poor PFS, and may help select patients needing new treatment strategies.

Inhibition of lncRNA PART1 Chemosensitizes Wild Type but Not KRAS Mutant NSCLC Cells

Background

Lung cancer has the highest incidence among solid tumors in men and is the third most common cancer in women. Despite improved understanding of genomic and mutational landscape in non-small cell lung cancer (NSCLC), the five-year survival in these patients has remained stagnant at a dismal 15%. The first line of treatment commonly adapted for NSCLC patients with somatic mutation in EGFR is tyrosine kinase inhibitor gefitinib or erlotinib. EGFR mutant cells seem to be intrinsically sensitive to tyrosine kinase inhibitors; however, the remaining 20-30% patients are resistant to tyrosine kinase inhibitor.

Materials and Methods

Here we show, using in vitro normal and NSCLS cell lines, that the lncRNA Prostate androgen-regulated transcript 1 (PART1) is expressed at higher levels in NSCLC cells compared to normal lung epithelial cell line, corroborating two earlier studies.

Results

We additionally show that these cells are resistant to erlotinib which is reversed in some, but not all, cell lines following suppression of PART1 expression. The differential response to erlotinib following siRNA-mediated knockdown of PART1 was found to be related to the mutational status of KRAS. Only in cells with wild-type KRAS suppression of PART1 sensitized them to erlotinib. Knockdown of mutant KRAS did not sensitize those cell lines to erlotinib. But knockdown of mutant KRAS along with suppression of PART1 sensitized the cells to treatment with erlotinib. The results from the study reveal a yet undefined and important role of lncRNA PART1 in defining sensitivity to erlotinib. This action is mediated by mutation status of KRAS.

Conclusion

Even though preliminary, our results indicate PART1 might be a potential candidate for targeted therapy or used as a predictor of chemosensitivity in patients with NSCLC.

Clinical significance of EGFR mutation types in lung adenocarcinoma: A multi-centre Korean study

Adenocarcinoma is the most common type of non-small cell lung cancer. Some causative genomic alterations in epidermal growth factor receptor (EGFR), including deletions in exon 19 (E19 dels) and a point mutation in E21, are known to have favourable prognoses due to sensitivity to tyrosine kinase inhibitors; however, the prognoses of other uncommon mutations are unclear. This study analysed the clinical significance of EGFR mutation types in lung adenocarcinoma. We retrospectively reviewed 1,020 subjects (mean age: 66.8 years, female: 41.7%) who were diagnosed with advanced lung adenocarcinoma, had EGFR mutation data, and did not undergo surgery from five medical institutes between 2010 and 2016. Subjects were classified according to EGFR mutation status, particularly for exon-specific mutations. EGFR positivity was defined as the presence of mutation and EGFR negativity was defined as wild-type EGFR. EGFR positivity was 38.0%, with the incidence of mutations in E18, E19, E20, and E21 was 3.6%, 51.0%, 3.4%, and 42.0%, respectively. The EGFR positive group survived significantly longer than the negative group (p<0.001), and there was a significant difference in survival among the four EGFR mutation sites (p = 0.003); E19 dels were the only significant factor that lowered mortality (HR: 0.678, p = 0.002), while an E21 mutation was the prognostic factor associated with the most increased mortality (HR: 1.365, p = 0.015). Amongst EGFR positive subjects, the proportion of E19 dels in TKI-responders was significantly higher and that of E21 mutations significantly lower, compared with non-responders. In TKI treatment, mutations in E18 and E20 were not worse factors than the E21 L858R mutation. In conclusion, the presence of EGFR mutations in advanced lung adenocarcinoma can predict a good prognosis; E19 dels prospect to have a better prognosis than other mutations, while an E21 mutation is expected to increase mortality.

Clinicopathological features and diagnostic methods of ALK fusion‑positive non‑small cell lung cancer in Korea

Lung cancer is one of the most common malignancies and the leading cause of cancer-associated mortality in Korea. A significant amount of effort has been put into the development of new and more effective treatments and biological markers for the prediction of therapeutic responses, which has led to the identification of various genetic changes in cancer, that are the so-called ‘growth drivers’ of carcinogenesis. Certain genetic alterations have become new treatment targets, and it has been suggested that different mutations are associated with different clinicopathological characteristics and prognosis. The present study aimed to evaluate the status of the key ‘driver’ mutation anaplastic lymphoma kinase (ALK) fusion in Korean patients with non-small cell lung cancer (NSCLC) and its association with clinicopathological characteristics, including the presence of other genetic mutations. The present study also compared different methods for ALK fusion detection, including fluorescence in situ hybridization (FISH), immunohistochemistry (IHC) and next-generation sequencing (NGS) to evaluate which method is the most effective. A total of 482 patients with NSCLC who underwent ALK FISH analysis were evaluated for clinicopathological features, such as age, sex, smoking history, tumor stage, histological subtype, immunohistochemical profile, including ALK and EGFR mutation statuses, and survival. Some ALK FISH-positive and -negative cancers were newly submitted to NGS analysis for DNA and RNA alterations. The ALK fusion-positive tumors were associated with a younger age, female patients, frequent nodal metastases, advanced stage and shorter survival. Comparing the results of ALK FISH, IHC and NGS analyses, it was concluded that in practice, ALK testing should better be diversified concerning FISH and IHC, and NGS analysis would be a good alternative to FISH, with an additional advantage of being able to concurrently detect different mutations.

Epidermal growth factor receptor first generation tyrosine-kinase inhibitors

The epidermal growth factor receptor (EGFR) oncogene was positioned as an attractive target for drug development in non-small cell lung cancer (NSCLC). Gefitinib and erlotinib were the first two reversible inhibitors of the EGFR kinase. The discovery of EGFR kinase domain-activating mutations that significantly correlated with a high likelihood of response to EGFR tyrosine-kinase inhibitors (TKIs) allowed to design studies to test these drugs as potential first-line therapies. In the same way, the feasibility of personalized medicine was established in patients with advanced NSCLC. Currently in the field of NSCLC with EGFR mutation have developed second and even third generation TKIs that would be gaining the positioning in the treatment of this subset population of NSCLC. In spite of this, without the knowledge that EGFR first generation TKIs have provided, we would not have gotten so far. We will review step by step how it was forged the exciting history of the subpopulation of lung cancer with EGFR mutated, through the various clinical trials performed with first generation TKIs that changed the focus, the future of NSCLC as well as survival of these patients.

Circulating miR-30b and miR-30c predict erlotinib response in EGFR-mutated non-small cell lung cancer patients

OBJECTIVES

MiR-30b, miR-30c, miR-221 and miR-222 are known to induce gefitinib resistance in lung cancer cell lines with activation of mutations in the epidermal growth factor receptor (EGFR). However, the role of these four microRNAs in tyrosine kinase inhibitor (TKI)-resistance in non-small cell lung cancer (NSCLC) patients is unknown. Thus, the aim of this study was to investigate the predictive value of miR-30b, miR-30c, miR-221 and miR-222 in plasma from EGFR-mutated lung cancer patients receiving erlotinib.

MATERIALS AND METHODS

The cohort consisted of 29 EGFR-mutated lung cancer patients receiving erlotinib. Plasma levels of miR-30b, miR-30c, miR-221 and miR-222 were analyzed by qPCR from blood samples collected before treatment start. Plasma concentration of each microRNA was correlated to clinical outcome.

RESULTS

Plasma concentrations of miR-30b and miR-30c could be determined in all 29 patients. Low plasma concentrations of miR-30b and miR-30c showed significant correlation with superior progression-free survival (PFS) (miR-30b: HR = 0.303 [0.123-0.747], p < 0.05; miR-30c: HR = 0.264 [0.103-0.674], p < 0.05). Low plasma concentrations of miR-30c were also significantly correlated with superior overall survival (OS) (HR = 0.30 [0.094-0.954], p < 0.041).

CONCLUSION

High plasma concentrations of miR-30b and miR-30c predicted shorter PFS and OS. This implies that miR-30b and miR-30c could have clinical potential as biomarkers in EGFR-mutated lung cancer patients.

Incense burning smoke sensitizes lung cancer cells to EGFR TKI by inducing AREG expression

Incense burning is common in Asian countries due to the religious beliefs. Environmental exposure to incense burning smoke is a potential risk factor for tumor development and progression of non-small cell lung cancer (NSCLC). Eastern Asia ethnic origin is strongly associated the clinical benefits of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in NSCLC patients. However, the impact of the oriental custom of incense burning on the cancer progression and the EGFR TKI-sensitivity of NSCLC remains unclear. Our results showed that long-term exposure to incense burning extract (IBE) increases the cellular proliferation with S phase accumulation and the motility activity of NSCLCs. Interestingly, IBE enhances EGFR signaling activity without affecting its genetic status, and increases the cellular sensitivity of NSCLC cell lines to EGFR TKIs. Auramine, a yellow dye for making incense sticks, was identified as a residual composition in the burning incense smoke, and showed similar EGFR TKI-sensitizing effects. Furthermore, IBE or auramine transcriptionally induce EGFR ligand amphiregulin (AREG) expression for the enhancement of EGFR activity. Neutralization of AREG reduced the viability of IBE-treated cells. These results indicated that exposure to incent smoke may enhance NSCLC progression and their sensitivity to EGFR TKIs through increasing their oncogenic addiction to AREG-induced EGFR signaling.

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.

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.

A novel RFLP-ARMS TaqMan PCR-based method for detecting the BRAF V600E mutation in melanoma

To enable the rapid and sensitive screening of the BRAF V600E mutation in clinical samples, a novel method combining restriction fragment length polymorphism (RFLP) analysis with the popular amplification refractory mutation system (ARMS) TaqMan quantitative (qPCR) genotyping method in a single reaction tube was developed. A total of 2 primer pairs were designed to enrich for and genotype the BRAF mutational hotspot (RFLP primers and ARMS primers) and a restriction enzyme was used to remove the wild-type alleles. The analysis revealed that this method detected mutant alleles in mixed samples containing >0.1% mutant sequences. In a survey of 53 melanoma samples, this method detected 21 mutation-positive samples. This novel RFLP-ARMS TaqMan qPCR protocol may prove useful for detecting mutations in clinical samples containing only a small proportion of mutant alleles.

Current outcomes of postrecurrence survival in patients after resection of non-small cell lung cancer

Background

Despite complete resection, patients with resectable non-small cell lung cancer (NSCLC) sometimes experience recurrence in various sites, generally with an unfavorable prognosis. Receptor tyrosine kinase inhibitors (TKIs) have produced a dramatic response in patients with advanced NSCLC harboring sensitive mutations.

Methods

We retrospectively investigated 281 patients with recurrence who underwent complete resection of their NSCLC between January 2005 and December 2013 with tumors in which the status of epidermal growth factor receptor (EGFR) mutation, KRAS mutation, and anaplastic lymphoma kinase (ALK) rearrangement was confirmed. Clinicopathological factors, including mode of recurrence, oncogenic status, and postrecurrence survival (PRS), were reviewed. We aimed to investigate the prognostic factors of PRS by univariate and multivariate analyses.

Results

Among the 281 patients, 135 patients (48.0%) with EGFR mutation, 33 (11.7%) with KRAS mutation, 13 (4.7%) with ALK rearrangement, and 100 (35.6%) with triple negative (TN) mutation were identified. Median survival time after recurrence was 26.1 months. In multivariate analysis, the presence of EGFR mutation, pStage I, the presence of both local and systemic therapies for recurrence, and longer time to recurrence (TTR) were significant favorable factors for PRS. With regard to the initial site of recurrence, the presence of pleural and/or bone recurrence reduced PRS significantly. The presence of pulmonary recurrence increased PRS, especially in patients with EGFR- or ALK-mutated tumors.

Conclusions

This study documented the current outcomes of PRS. EGFR mutated status, pStage I, longer TTR and presence of multimodal therapy for recurrence were favorable factors for PRS.

Anlotinib as a third-line therapy in patients with refractory advanced non-small-cell lung cancer: a multicentre, randomised phase II trial (ALTER0302)

BACKGROUND

Anlotinib (AL3818) is a novel multitarget tyrosine kinase inhibitor, inhibiting tumour angiogenesis and proliferative signalling. The objective of this study was to assess the safety and efficacy of third-line anlotinib for patients with refractory advanced non-small-cell lung cancer (RA-NSCLC).

METHODS

Eligible patients were randomised 1 : 1 to receive anlotinib (12 mg per day, per os; days 1-14; 21 days per cycle) or a placebo. The primary end point was progression-free survival (PFS).

RESULTS

A total of 117 eligible patients enrolled from 13 clinical centres in China were analysed in the full analysis set. No patients received immune check-point inhibitors and epidermal growth factor receptor status was unknown in 60.7% of the population. PFS was better with anlotinib compared with the placebo (4.8 vs 1.2 months; hazard ratio (HR)=0.32; 95% confidence interval (CI), 0.20-0.51; P<0.0001), as well as overall response rate (ORR) (10.0%; 95% CI, 2.4-17.6% vs 0%; 95% CI, 0-6.27%; P=0.028). The median overall survival (OS) was 9.3 months (95% CI, 6.8-15.1) for the anlotinib group and 6.3 months (95% CI, 4.3-10.5) for the placebo group (HR=0.78; 95% CI, 0.51-1.18; P=0.2316). Adverse events were more frequent in the anlotinib than the placebo group. The percentage of grade 3-4 treatment-related adverse events was 21.67% in the anlotinib group.

CONCLUSIONS

Anlotinib as a third-line treatment provided significant PFS benefits to patients with RA-NSCLC when compared with the placebo, and the toxicity profiles showed good tolerance.

Real world treatment and outcomes in EGFR mutation-positive non-small cell lung cancer: Long-term follow-up of a large patient cohort

OBJECTIVES

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) have been shown to be effective for the treatment of EGFR mutation-positive non-small cell lung cancer (NSCLC) in clinical trials. However, there is a lack of data from routine clinical practice. This study determined treatment and outcomes in patients with EGFR mutation-positive NSCLC treated in a real world setting.

MATERIALS AND METHODS

Clinical characteristics, information about NSCLC treatment regimens and survival outcomes data were obtained retrospectively from 17 medical centers across Japan. In addition to overall survival (OS), subgroup analyses were conducted based on first- and second-line treatments and combinations, and for patients who had survived >5 years from initiation of first-line treatment.

RESULTS

The full analysis set comprised 1656 patients (mean 67 years, 80.6% with performance status 0 or 1). Median follow-up was 29.5 months and median OS was 29.7 months; 3- and 5-year survival rates were 41.2% and 21.5%, respectively. Significant predictors of OS were younger age, no smoking history, histological diagnosis of adenocarcinoma, less advanced clinical stage, good performance status and major EGFR-activating mutation. Despite some imbalances in baseline characteristics, patients who received first-line chemotherapy had numerically higher 5-year survival rates than those who received first-line EGFR-TKIs.

CONCLUSIONS

This large, long-term analysis of EGFR mutation-positive NSCLC patients provides useful information about treatment outcomes in clinical practice. Updated analyses are required to determine real world outcomes for NSCLC patients treated with the latest available agents, including immunotherapies.

The impact of intermittent versus continuous exposure to EGFR tyrosine kinase inhibitor on selection of EGFR T790M-mutant drug-resistant clones in a lung cancer cell line carrying activating EGFR mutation

Drug-resistant cell lines are essential tools for investigating the mechanisms of resistance to molecular-targeted anti-cancer drugs. However, little is known about how to establish clinically relevant drug-resistant cell lines. Our study examined the impact of a drug-free period on the establishment of a cell line with clinically relevant resistance to molecular-targeted drugs. We used PC9 cells, a lung cancer cell line carrying EGFR mutation, because this is a validated target for EGFR tyrosine kinase inhibitors (TKI). PC9 cells were intermittently or continuously exposed to increasing concentrations of gefitinib (0.01 μM to 1.0 μM) and the emergence of the most common acquired resistance mutation in EGFR, T790M, was determined. T790M was detected at a 25-fold lower drug concentration in cells continuously exposed to gefitinib (PC9/GRc) than in cells intermittently exposed to gefitinib (PC9/GRi) (0.04 μM vs 1.0 μM, respectively). The mutation frequencies at those drug concentrations were 19.8% and 8.0% in PC9/GRc and PC9/GRi cells, respectively. After drug-free culture for 8 weeks, resistance to gefitinib decreased in the PC9/GRi cells but not in the PC9/GRc cells. In the PC9/GRc cells, the frequency of the T790M mutation was consistently about 20% from 0.04 μM to 1.0 μM of gefitinib. In the PC9/GRc cells, the T790M mutation was detected in all single-cell clones, at frequencies ranging from 7.0% to 37.0%, with a median of 19.5% (95% confidence interval, 17.3%–20.9%). In conclusion, compared with intermittent drug exposure, continuous exposure might select better minor drug-resistant clones when creating cell lines resistant to molecular-targeted drugs.

Postoperative survival of EGFR-TKI-targeted therapy in non-small cell lung cancer patients with EGFR 19 or 21 mutations: a retrospective study

Background

The aim of this retrospective study is to identify epidermal growth factor receptor (EGFR) mutations in non-small cell lung cancer patients and to compare the long-term postoperative outcomes in different EGFR-TKI-targeted therapy effects between the different EGFR mutation groups.

Methods

A total of 2094 postoperative non-small cell lung cancer (NSCLC) patients with EGFR gene detection were collected in the Department of Pathology in the Cancer Hospital Chinese Academy of Medical Sciences from January 2003 to January 2014. Three hundred sixty-three patients were treated with EGFR tyrosine kinase inhibitor (TKI) after surgery: 184 harbored the exon 19 deletion mutation and 179 cases carried the exon 21 L858R point mutation. The end points included progression-free survival (PFS), overall survival (OS), and the response rate.

Results

OS was increased in the EGFR exon 19 deletion group compared with the exon 21 L858R point mutation group (92 vs. 65 months; P < 0.001). But the median PFS did not differ between two groups (12 vs 14 months). The objective response rate (ORR) in 19 deletion group was increased compared with L858R mutation patients (28.35 vs. 22.73%). The disease control rate (DCR) of patients with 19 deletion benefited more from targeted therapy, compared with L858R group (93.71 vs. 84.31%, P = 0.014). In 19 deletion group, a high ORR and DCR were noted in patients treated with icotinib, 16 out of 18 achieved stable disease (SD), and the DCR in this population was 100%.

Conclusions

EGFR subtypes could influence the postoperative survival of NSCLC patients with TKI-targeted therapy.

Sensitive genotyping of mutations in the EGFR gene from NSCLC patients using PCR-GoldMag lateral flow device

Epidermal growth factor receptor (EGFR) mutations predict better outcomes with EGFR tyrosine kinase inhibitors in patients with non-small cell lung cancer (NSCLC). Most common activating mutations include in-frame deletion in exon 19 and L858R substitution in exon 21, which account for >90% of all EGFR mutations in NSCLC. In this study, a PCR-GoldMag lateral flow assay (PCR-GoldMag LFA) was developed for the visual detection of delE746-A750 and L858R of EGFR mutations. Forty formalin-fixed paraffin-embedded (FFPE) tissue samples of NSCLC patients were analyzed using PCR-GoldMag LFA system and verified by direct sequencing and TaqMan-PCR detection methods. Results showed that EGFR mutations were detected in 34 cases among the 40 samples (85%) by PCR-GoldMag LFA method. Among the 34 cases, 5 cases were simultaneously detected with delE746-A750 in exon 19 and L858R mutation in exon 21. Compared with sequencing, only 4 samples were detected as delE746-A750, which revealed higher sensitivity of PCR-GoldMag LFA detection method than direct sequencing. TaqMan-PCR method verified the L858R mutation and was in 100% agreement with our method. These results indicated that our method has obvious advantages to analyze clinical samples and offers a more sensitive alternative to direct sequencing for the detection of EGFR mutations.

Efficacy of epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) in targeted therapy of lung squamous cell carcinoma patients with EGFR mutation: a pooled analysis

PURPOSE

This pooled analysis aims to evaluate the efficacy of epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) in lung squamous cell carcinoma with EGFR mutation.

METHODS

Advanced stage (IIIB/IV) lung squamous cell carcinoma patients with EGFR mutations treated with EGFR-TKIs were extracted from the publications searched from the databases of EMBASE, Medline (Ovid SP), Web of Science, Cochrane library, PubMed Publisher, ASCO meeting abstract and Google Scholar before August 2016, or identified from the database of Shanghai Chest Hospital from July 2014 to August 2016. Pooled objective response rate, disease control rate and median progression-free survival were accessed directly or by Kaplan-Meier method and combined in different studies by Comprehensive Meta Analysis software via one-group dichotomous or continuous analysis functions.

RESULTS

The combined objective response rate, disease control rate and median progression-free survival were 31.6% (95%CI, 24.1%∼40.2%), 72.0% (95% CI, 63.5%∼79.2%) and 3.08 months (95% CI, 2.31-3.84 months) in lung squamous cell carcinoma patients with EGFR mutation.

CONCLUSION

The EGFR-TKIs had a modest response for EGFR mutated lung squamous cell carcinoma patients and might be a selective option for those patients.

Efficacy of epidermal growth factor receptor-tyrosine kinase inhibitors for lung squamous carcinomas harboring EGFR mutation: A multicenter study and pooled analysis of published reports

Epidermal growth factor receptor (EGFR) mutations are common in lung adenocarcinoma (ADC) but rare in squamous cell carcinoma (SQC). The efficacy of EGFR-tyrosine kinase inhibitors (EGFR-TKIs) for SQC with EGFR mutations is unclear. The aim of this study was to evaluate the efficacy of EGFR-TKIs for these patients. We performed a retrospective matched-pair case-control study from 3 cancer centers, including 44 SQC and 44 ADC patients with EGFR mutation who were treated with EGFR-TKI. Subsequently, we performed a pooled analysis on the efficacy of EGFR-TKIs for EGFR-mutant SQC in 115 patients, including 71 patients selected from 25 published reports. In our multicenter study, EGFR-mutant SQC and ADC patients had similar objective response rate (ORR) (43.2% vs. 54.5%, p = 0.290), but SQC patients had lower disease control rate (DCR) (71.3% vs. 100%, p = 0.001), significant shorter median progression free survival (PFS) (5.1 vs. 13.0 months, p = 0.000) and median overall survival (OS) (17.2 vs. 23.6 months, p = 0.027). In pooled analysis, the ORR, DCR, PFS and OS of SQC patients were 39.1%, 71.3%, 5.6 months and 15.0 months, respectively. Performance status was the only independent predictor of PFS and erlotinib treatment was associated with a better survival. In conclusion, EGFR-TKI was less effective in EGFR-mutant SQC than in ADC but still has clinical benefit for SQC patients. Further study is need to evaluate the using of EGFR-TKIs in these SQC patients.

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.

Incorporating Erlotinib or Irinotecan Plus Cisplatin into Chemoradiotherapy for Stage III Non-small Cell Lung Cancer According to EGFR Mutation Status

Purpose

Concurrent chemoradiotherapy (CCRT) is the standard care for stage III non-small cell lung cancer (NSCLC) patients; however, a more effective regimen is needed to improve the outcome by better controlling occult metastases. We conducted two parallel randomized phase II studies to incorporate erlotinib or irinotecan-cisplatin (IP) into CCRT for stage III NSCLC depending on epidermal growth factor receptor (EGFR) mutation status.

Materials and Methods

Patients with EGFR-mutant tumors were randomized to receive three cycles of erlotinib first and then either CCRT with erlotinib followed by erlotinib (arm A) or CCRT with IP only (arm B). Patients with EGFR unknown or wild-type tumors were randomized to receive either three cycles of IP before (arm C) or after CCRT with IP (arm D).

Results

Seventy-three patients were screened and the study was closed early because of slow accrual after 59 patients were randomized. Overall, there were seven patients in arm A, five in arm B, 22 in arm C, and 25 in arm D. The response rate was 71.4% and 80.0% for arm A and B, and 70.0% and 73.9% for arm C and D. The median overall survival (OS) was 39.3 months versus 31.2 months for arm A and B (p=0.442), and 16.3 months versus 25.3 months for arm C and D (p=0.050). Patients with sensitive EGFR mutations had significantly longer OS than EGFR-wild patients (74.8 months vs. 25.3 months, p=0.034). There were no unexpected toxicities.

Conclusion

Combined-modality treatment by molecular diagnostics is feasible in stage III NSCLC. EGFR-mutant patients appear to be a distinct subset with longer survival.

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.

Correlation between epidermal growth factor receptor tyrosine kinase inhibitor efficacy and circulating tumor cell levels in patients with advanced non-small cell lung cancer

Objective

The aim of this study was to investigate the correlation between the efficacy of epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) and circulating tumor cell (CTC) levels in patients with advanced non-small cell lung cancer (NSCLC). The efficacy of EGFR-TKIs in reducing CTC counts in patients with advanced NSCLC was studied.

Patients and methods

A total of 66 patients with advanced NSCLC were enrolled and divided into two groups (those with high CTC counts and those with low CTC counts) based on the patients’ median CTC counts. All the patients were treated with an EGFR-TKI, and the treatment efficacy and prognoses were compared.

Results

The treatment efficacies were 53.3% (16/30) and 27.8% (10/36) for the low CTC group and high CTC group, respectively, and this difference was statistically significant (P<0.05). The median overall survival was 22.8 months (95% confidence interval [CI]: 18.9–26.8 months) for the low CTC group and 18.3 months (95% CI: 2.9–8.2 months) for the high CTC group. The median progression-free survival was 11.5 months (95% CI: 8.1–15 months) and 5.6 months (95% CI: 2.9–8.2 months) for the low and high CTC groups, respectively, and the difference was statistically significant (P<0.05).

Conclusion

The CTC count can be used as an index for predicting the EGFR-TKI effect on patients with advanced NSCLC. Efficacy and prognosis of EGFR-TKI treatment and CTC count were considered important, and the CTC count could be used to predict the efficacy of EGFR-TKI treatment and prognosis of advanced NSCLC. The change in CTC expression levels can be used as an index for evaluating the prognosis of patients with advanced NSCLC.

Knockdown of OCT4 may sensitize NSCLC cells to cisplatin

PURPOSE

Cisplatin is commonly used in non-small-cell lung cancer (NSCLC) chemotherapy; however, chemoresistance to cisplatin remains a great clinical challenge. Octamer-binding protein 4 (OCT4) has been reported to be overexpressed in NSCLC. In this study, we aimed to investigate the potential role of OCT4 in NSCLC with chemoresistance to cisplatin.

METHODS

Expressions of OCT4 was detected in NSCLC tissues and cell lines. We utilized siRNA to knock down OCT4 expression in human NSCLC cells and analyzed their phenotypic changes.

RESULTS

We found that the difference of OCT4 expression between NSCLC and the adjacent non-tumourous tissues was statistically significant. Knockdown of OCT4 in NSCLC cells could decrease cell proliferation, and potentiate apoptosis induced by cisplatin, suggesting OCT4 may contribute to cisplatin resistance in NSCLC.

CONCLUSION

Our findings indicate that targeting OCT4 could improve cisplatin effect in NSCLC, confirming their role in modulating cisplatin sensitivity.

Different EGFR Gene Mutations in Exon 18, 19 and 21 as Prognostic and Predictive Markers in NSCLC: A Single Institution Analysis

BACKGROUND

Mutations of epidermal growth factor receptor (EGFR) in non-small cell lung cancer (NSCLC) predict longer overall survival (OS) and response to EGFR tyrosine kinase inhibitors (TKIs). The clinical relevance of different mutations in terms of response to TKIs and prognosis is still unclear.

OBJECTIVES

The aims of the present study were to assess the relationship between mutations in exon 18, 19 and 21 in patients treated with TKIs and their clinical outcomes, and evaluate the role of specific point mutations.

METHODS

We included in this analysis 55 patients with metastatic NSCLC and mutations in exon 18, 19 and 21, treated in our center between 2004 and 2014. All patients received treatment with TKIs in first and/or subsequent lines. Endpoints analyzed were OS (primary) and time to progression (TTP) (secondary), according to exon mutations and specific point mutations.

RESULTS

A strong negative prognostic association for OS (p = 0.02) and TTP (p = 0.03) was found for exon 18 mutations compared with exon 19 deletions . A trend toward a longer median OS was observed in exon 19 deletions versus exon 21 point mutations (+6.6 months), although more exon 19-mutated patients had brain metastases at diagnosis. Comparing each mutation, p.E746_A750del and p.E746_T751del of exon 19 and p.L858R mutation of exon 21, a trend toward improved OS in p.E746_A750del was found.

CONCLUSION

In this analysis, exon 19 deletions were associated with better outcomes, despite a higher percentage of brain metastases in this group. The prognostic relevance of p.E746_A750del requires further studies.

Gefitinib in the treatment of nonsmall cell lung cancer with activating epidermal growth factor receptor mutation

Lung cancer is still the main cause of cancer-related deaths worldwide, with most patients present with advanced disease and poor long-term prognosis. The aim of lung cancer treatment is to slow down the progression of the disease, to relieve the patients from the lung cancer symptoms and whenever possible, to increase the overall survival. The discovery of small molecule targeting tyrosine kinase of epidermal growth factor receptor opens a new way in the management of advanced nonsmall cell lung cancer (NSCLC). This review will discuss several Phase II and III trials evaluated the clinical efficacy of gefitinib as monotherapy in pretreated patients with advanced NSCLC, as well as both monotherapy and combined with chemotherapy in chemotherapy-naive patients.

Detected EGFR mutation in cerebrospinal fluid of lung adenocarcinoma patients with meningeal metastasis

Objective

To discuss the application of ARMS method to detect EGFR gene mutation in cerebrospinal fluid of lung adenocarcinoma patients with meningeal metastasis.

Methods

5 cases of lung adenocarcinoma were identified with meningeal metastasis that were cleared EGFR gene mutation by gene sequencing method. From each patient 5ml cerebrospinal fluid was obtained by lumbar puncture. ARMS method was used to detect EGFR mutations in cerebrospinal fluid.

Results

5 samples of cerebrospinal fluid were successfully detected by ARMS method, 3 samples found that EGFR gene mutations, the mutations in line with direct sequencing method.

Conclusion

ARMS method can be used to detect EGFR gene mutations of cerebrospinal fluid samples in lung adenocarcinoma with meningeal metastasis. But cerebrospinal fluid specimens from histological specimens, blood samples need to be confirmed by further comparative study whether there is advantage.

Pulmonary Toxicities of Gefitinib in Patients With Advanced Non-Small-Cell Lung Cancer: A Meta-Analysis of Randomized Controlled Trials

Gefitinib is a selective tyrosine kinase inhibitor of the epidermal growth factor receptor (EGFR) used to treat adults with EGFR mutation-positive non-small-cell lung cancer (NSCLC). Clinical benefits of gefitinib administration in NSCLC patients have been observed in clinical practice, but the extent of the pulmonary toxicity of gefitinib in patients with advanced NSCLC remains unclear. The aim of this systematic review was to evaluate the overall incidence and risk of gefitinib-related pulmonary toxicity in advanced NSCLC patients. Relevant trials were identified from the databases of Pubmed, Embase, Cochrane Library, and the clinicaltrials.gov of the U.S. National Institutes of Health. The outcomes included the overall incidence, odds ratios (ORs), and 95% confidence intervals (CIs). Fixed-effects models were used in the statistical analyses according to the heterogeneity of the included studies. According to the data from the included trials, the overall incidence of high-grade hemoptysis, pneumonia, pneumonitis, and interstitial lung disease (ILD) was 0.49% (95% CI: 0.24%-0.99%), 2.33% (95% CI: 1.47%-3.66%), 2.24% (95% CI: 1.34%-3.72%), and 1.43% (95% CI: 0.98%-2.09%), respectively. The pooled ORs of high-grade hemoptysis, pneumonia, pneumonitis, and ILD were 1.73 (95% CI: 0.46-6.52; P = 0.42), 0.99 (95% CI: 0.66-1.49; P = 0.95), 4.70 (95% CI: 1.48-14.95; P = 0.0087), and 2.64 (95% CI: 1.22-5.69; P = 0.01), respectively. Gefitinib was associated with a significantly increased risk of high-grade/fatal ILD and pneumonitis compared with the controls, whereas the risk of other high-grade pulmonary events (pneumonia and hemoptysis) was not significant. Careful surveillance of gefitinib-related pulmonary toxicity is critical for the safe use of this drug.

[Research progress of lung cancer with leptomeningeal metastasis]

脑膜转移是肺癌最严重的并发症之一，患者预后极差。脑膜转移患者临床表现缺乏特异性，主要表现为脑、脑神经、脊神经受累症状。目前诊断主要依据肿瘤病史、临床症状、增强核磁共振（magnetic resnance image, MRI）扫描和脑脊液细胞学检查。近年来新的检测方式在临床上不断涌现，明显提高了脑膜转移的早期发现率，但肺癌脑膜转移的综合治疗疗效仍不令人满意。本文就肺癌脑膜转移的病理生理、临床表现、诊断方法及治疗疗效的研究进展做一综述。

TAE226, a Bis-Anilino Pyrimidine Compound, Inhibits the EGFR-Mutant Kinase Including T790M Mutant to Show Anti-Tumor Effect on EGFR-Mutant Non-Small Cell Lung Cancer Cells

TAE226, a bis-anilino pyrimidine compound, has been developed as an inhibitor of focal adhesion kinase (FAK) and insulin-like growth factor-I receptor (IGF-IR). In this study, we investigated the effect of TAE226 on non-small-cell lung cancer (NSCLC), especially focusing on the EGFR mutational status. TAE226 was more effective against cells with mutant EGFR, including the T790M mutant, than against cells with wild-type one. TAE226 preferentially inhibited phospho-EGFR and its downstream signaling mediators in the cells with mutant EGFR than in those with wild-type one. Phosphorylation of FAK and IGF-IR was not inhibited at the concentration at which the proliferation of EGFR-mutant cells was inhibited. Results of the in vitro binding assay indicated significant differences in the affinity for TAE226 between the wild-type and L858R (or delE746_A750) mutant, and the reduced affinity of ATP to the L858R (or delE746_A750) mutant resulted in good responsiveness of the L858R (or delE746_A750) mutant cells to TAE226. Of interest, the L858R/T790M or delE746_A750/T790M mutant enhanced the binding affinity for TAE226 compared with the L858R or delE746_A750 mutant, resulting in the effectiveness of TAE226 against T790M mutant cells despite the T790M mutation restoring the ATP affinity for the mutant EGFR close to that for the wild-type. TAE226 also showed higher affinity of about 15-fold for the L858R/T790M mutant than for the wild-type one by kinetic interaction analysis. The anti-tumor effect against EGFR-mutant tumors including T790M mutation was confirmed in mouse models without any significant toxicity. In summary, we showed that TAE226 inhibited the activation of mutant EGFR and exhibited anti-proliferative activity against NSCLCs carrying EGFR mutations, including T790M mutation.

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.

Posttranslational modifications of FOXO1 regulate epidermal growth factor receptor tyrosine kinase inhibitor resistance for non-small cell lung cancer cells

Epidermal growth factor receptor tyrosine kinase inhibitors (TKIs) are effective clinical therapies for advanced non-small cell lung cancer (NSCLC) patients, while resistance to TKIs remains a serious problem in clinical practice. Recently, it has been proposed that targeting mTOR could overcome TKI resistance in NSCLC cells. Forkhead box class O1 (FOXO1) has emerged as an important rheostat that modulates the activity of Akt and mTOR signaling pathway. However, the role of FOXO1 and related regulatory mechanism in TKI resistance in NSCLC remain largely unknown. Here, we find that mTOR-AKT-FOXO1 signaling cascade is deregulated in TKI-resistant NSCLC cells and that FOXO1 was highly phosphorylated and lowly acetylated upon erlotinib treatment. Combination of mTOR or PI3K inhibitor and erlotinib overcomes TKI resistance to inhibit cell growth and induce apoptosis in TKI-resistant NSCLC cells. Furthermore, the phosphorylation and acetylation of FOXO1 are reversely modulated by mTORC2-AKT signaling pathway. FOXO1 mutation analyses reveal that FOXO1 acetylation inhibits cell proliferation and promotes NSCLC cell apoptosis, while the phosphorylation of FOXO1 plays opposite roles in NSCLC cells. Importantly, increasing FOXO1 acetylation by a HDAC inhibitor, depsipeptide, overcomes TKI resistance to effectively induce TKI-resistant NSCLC cell apoptosis. Together, FOXO1 plays dual roles in TKI resistance through posttranslational modifications in NSCLC and this study provides a possible strategy for treatment of TKI-resistant NSCLC patients.

Fuzheng Kang'ai decoction combined with gefitinib in advanced non-small cell lung cancer patients with epidermal growth factor receptor mutations: study protocol for a randomized controlled trial

Background

Patients with advanced non-small cell lung cancer (NSCLC) harboring mutations of the epidermal growth factor receptor (EGFR) gene respond well to the EGFR tyrosine kinase inhibitor (TKI) gefitinib. Chinese herbal medicine (CHM) has been used as a complementary therapy for cancer for decades in China. CHM was proved to be effective in improving the quality of life (QOL) and reducing the toxicity associated with chemotherapy in patients with NSCLC. The purpose of the present trial is to determine whether CHM (Fuzheng Kang’ai decoction (FZKA), a CHM formula) combined with gefitinib results in longer progression-free survival with less toxicity than gefitinib alone.

Methods/Design

This is a randomized, placebo-controlled, double-blind trial. This trial is designed to determine if CHM (FZKA) combined with gefitinib results in longer progression-free survival with less toxicity than gefitinib alone. A total of 70 NSCLC patients with EGFR mutations will be randomly assigned to treatment group (gefitinib plus FZKA granules) or control group (gefitinib plus placebo). The primary endpoint is progression-free survival. Secondary endpoints are: (1) overall survival; (2) disease control rate; (3) QOL, measured with the questionnaire of Functional Assessment of Cancer Therapy-lung (FACT-L 4.0) and Lung Cancer Symptom Scale and (4) safety.

Discussion

In previous clinical practice, we found that CHM (FZKA) could improve the therapeutic efficacy of gefitinib. This study will provide objective evidence to evaluate the efficiency of CHM combined with gefitinib in NSCLC patients with EGFR mutations, and may provide a novel regimen for patients with NSCLC.

Trial registration

Chinese Clinical Trial Registry (www.chictr.org): ChiCTR-IOR-14005679, registered 17 December 2014.

Pretreatment levels of the serum biomarkers CEA, CYFRA 21-1, SCC and the soluble EGFR and its ligands EGF, TGF-alpha, HB-EGF in the prediction of outcome in erlotinib treated non-small-cell lung cancer patients

The aim of this study has been to investigate the potential of serum biomarkers used in clinical practice (CEA, CYFRA 21-1, SCC) together with the serum epidermal growth factor receptor (EGFR) and its associated ligands (EGF, TGF-α, HB-EGF) as outcome predictors of non-small cell lung cancer (NSCLC) patients treated with the TKI erlotinib. The pretreatment levels of these markers were evaluated through immunoassays carried out in 58 patients. The progression-free survival (PFS) and overall survival (OS) were assessed by the Kaplan-Meier method and differences between groups were compared by means of the Log-Rank test. Association of risk factors with survival was evaluated using the univariate and multivariate Cox modelling procedures. Higher CEA (>5 ng/mL) and sEGFR (>56.87 ng/mL) concentrations associated significantly with a higher overall survival. The pre-treatment sEGFR serum levels constituted an independent prognostic factor. The EGFR gene mutational status and the sEGFR level combination was the single to associate significantly with longer progression-free survival periods, in circumstances in which the EGFR gene was mutated and increased protein serum levels were detected. The overall survival as assessed through a Cox analysis revealed similar death hazards with respect to low sEGFR levels combined both with non-mutated EGFR genotypes and low CEA serum levels. Our results suggest that the pre-treatment CEA and sEGFR serum levels may provide a comparable source of information to that supplied by the EGFR gene mutational status with respect to the prognosis of erlotinib treated NSCLC patients. A combined sEGFR and CEA level appraisal could be of considerable value to select patients to undergo EGFR-TKI treatments.

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.

Incidence and risk of xerosis with targeted anticancer therapies

BACKGROUND

Many targeted therapies used in the treatment of cancer can lead to the development of xerosis, but the incidence and relative risk of xerosis have not been ascertained.

OBJECTIVE

We conducted a systematic review and metaanalysis of clinical trials, to ascertain the incidence and risk of developing xerosis after taking anticancer drugs.

METHODS

The PubMed (1966-October 2013), Web of Science (January 1998-October 2013), and American Society of Clinical Oncology abstracts (2004-2013) databases were searched for clinical trials of 58 targeted agents. Results were calculated using random or fixed effects models.

RESULTS

The incidences of all- and high-grade xerosis were 17.9% (95% confidence interval [CI]: 15.6-20.4%) and 1.0% (95% CI: 0.9-1.5%), respectively. The risk of developing all-grade xerosis was 2.99 (95% CI: 2.0-4.3), and it varied across different drugs (P < .001).

LIMITATIONS

The reporting of xerosis may vary among clinicians and institutions, and the incidence may be affected by age, concomitant medications, comorbidities, and underlying malignancies or skin conditions.

CONCLUSION

Patients receiving targeted therapies have a significant risk of developing xerosis. Patients should be counseled and treated early for this symptom to prevent suboptimal dosing and quality of life impairment.

Quantum dots immunofluorescence histochemical detection of EGFR gene mutations in the non-small cell lung cancers using mutation-specific antibodies

BACKGROUND

Epidermal growth factor receptor (EGFR) mutation status plays an important role in therapeutic decision making for non-small cell lung cancer (NSCLC) patients. Since EGFR mutation-specific antibodies (E746-A750del and L858R) have been developed, EGFR mutation detection by immunohistochemistry (IHC) is a suitable screening test. On this basis, we want to establish a new screening test, quantum dots immunofluorescence histochemistry (QDs-IHC), to assess EGFR gene mutation in NSCLC tissues, and we compared it to traditional IHC and amplification refractory mutation system (ARMS).

MATERIALS AND METHODS

EGFR gene mutations were detected by QDs-IHC, IHC, and ADx-ARMS in 65 cases of NSCLC composed of 55 formalin-fixed, paraffin-embedded specimens and ten pleural effusion cell blocks, including 13 squamous cell carcinomas, two adenosquamous carcinomas, and 50 adenocarcinomas.

RESULTS

Positive rates of EGFR gene mutations detected by QDs-IHC, IHC, and ADx-ARMS were 40.0%, 36.9%, and 46.2%, respectively, in 65 cases of NSCLC patients. The sensitivity of QDs-IHC when detecting EGFR mutations, as compared to ADx-ARMS, was 86.7% (26/30); the specificity for both antibodies was 100.0% (26/26). IHC sensitivity was 80.0% (24/30) and the specificity was 92.31% (24/26). When detecting EGFR mutations, QDs-IHC and ADx-ARMS had perfect consistency (κ  =0.882; P<0.01). Excellent agreement was observed between IHC and ADx-ARMS when detecting EGFR mutations (κ  =0.826; P<0.01).

CONCLUSION

QDs-IHC is a simple and standardized method to detect EGFR mutations with its high sensitivity and specificity, as compared with real-time polymerase chain reaction. In addition, the development of specific antibodies against EGFR mutation proteins might be useful for the diagnosis and treatment of lung cancer.

High specificity but low sensitivity of mutation-specific antibodies against EGFR mutations in non-small-cell lung cancer

Determination of epidermal growth factor receptor (EGFR) mutations has a pivotal impact on treatment of non-small-cell lung cancer (NSCLC). A standardized test has not yet been approved. So far, Sanger DNA sequencing has been widely used. Its rather low sensitivity has led to the development of more sensitive methods including real-time PCR (RT-PCR). Immunohistochemistry with mutation-specific antibodies might be a promising detection method. We evaluated 210 samples with NSCLC from an unselected Caucasian population. Extracted DNA was analyzed for EGFR mutations by RT-PCR (Therascreen EGFR PCR kit, Qiagen, UK; reference method). For immunohistochemistry, antibodies against exon19 deletions (clone 6B6), exon21 mutations (clone 43B2) from Cell Signaling Technology (Boston, USA) and EGFR variantIII (clone 218C9) from Dako (Copenhagen, DK) were applied. Protein expression was evaluated, and staining score (multipum of intensity (graded 0-3) and percentages (0-100%) of stained tumor cells) was calculated. Positivity was defined as staining score >0. Specificity of exon19 antibody was 98.8% (95% confidence interval=95.9-99.9%) and of exon21 antibody 97.8% (95% confidence interval=94.4-99.4%). Sensitivity of exon19 antibody was 63.2% (95% confidence interval=38.4-83.7%) and of exon21 antibody was 80.0% (95% confidence interval=44.4-97.5%). Seven exon19 and four exon21 mutations were false negatives (immunohistochemistry negative, RT-PCR positive). Two exon19 and three exon21 mutations were false positive (immunohistochemistry positive, RT-PCR negative). One false positive exon21 mutation had staining score 300. The EGFR variantIII antibody showed no correlation to EGFR mutation status determined by RT-PCR or to EGFR immunohistochemistry. High specificity of the mutation-specific antibodies was demonstrated. However, sensitivity was low, especially for exon19 deletions, and thus these antibodies cannot yet be used as screening method for EGFR mutations in NSCLC. Refinement of sensitivity for the mutation-specific antibodies is warranted to improve molecular diagnosis using EGFR immunohistochemistry.