Epidermal growth factor receptor tyrosine kinase inhibitors in elderly or poor performance status patients with advanced non-small cell lung cancer

Elderly and poor performance status advanced non-small cell lung cancer (NSCLC) patients often tolerate chemotherapy poorly. Special approaches are needed for these patient populations. Tyrosine kinase inhibitors (TKIs) of the epidermal growth factor receptor (EGFR), erlotinib and gefitinib, are active agents in the treatment of advanced NSCLC. Several phase II trials have been conducted utilizing EGFR TKIs in elderly or poor performance status patients with advanced NSCLC. This review will summarize the results of erlotinib or gefitinib in these subsets of patients with advanced NSCLC.     

“Who Should Receive Epidermal Growth Factor Receptor Inhibitors for Non-Small Cell Lung Cancer and When?”

Opinion statement Inhibition of the epidermal growth factor receptor (EGFR) pathway in non-small cell lung cancer (NSCLC) is an exciting and rapidly evolving field. Erlotinib and gefitinib, two tyrosine kinase inhibitors (TKIs) of EGFR, have demonstrated activity in advanced NSCLC in the second- and third-line settings. Subset analyses of phase II and phase III clinical trials lead to the recognition that these two agents had more activity in certain subsets of NSCLC patients including never smokers, people of Asian descent and patients with EGFR FISH-positive or mutation-positive tumors. In particular, never smokers had statistically significant improvements in survival with either erlotinib or gefitinib therapy. Patients with EGFR FISH- or mutation-positive tumors had improved response rates to TKI therapy while those with KRAS mutant tumors did not derive any benefit. In the BR.21 trial treatment with erlotinib resulted in statistically significant improvements in overall survival and quality of life. Thus, while the question of who should receive EGFR TKI therapy is still not completely answered, all patients should be considered for erlotinib therapy in the second- or third-line setting. In daily clinical practice, there is currently no data to support the use of EGFR mutation or FISH status in this decision making process. Prospective trials are ongoing to determine which patient and tumor characteristics are predictive of a clinical benefit from TKI therapy.     

Genotype-driven therapies for non-small cell lung cancer: focus on EGFR, KRAS and ALK gene abnormalities

Non-small cell lung cancers (NSCLCs) are heterogeneous cancers. In 2004, the identification of epidermal growth factor receptor (EGFR) somatic mutations provided the first glimpse of a clinically relevant NSCLC oncogene. Approximately 70% of NSCLCs with EGFR mutations (exon 19 deletions or the exon 21 L858R) attain responses to EGFR tyrosine kinase inhibitors (TKIs) gefitinib and erlotinib, with improved response rate (RR), progression-free survival (PFS) and in some reports overall survival (OS) when compared with EGFR wildtype (WT) cases. Three randomized trials of gefitinib versus chemotherapy (IPASS, WJTOG3405, NEJ002) in stage IV NSCLC have consistently demonstrated better RR and PFS (hazard ratios of 0.48 [IPASS], 0.49 [WJTOG3405] and 0.30 [NEJ002]) for EGFR-mutated NSCLCs treated with gefitinib. Novel irreversible EGFR TKIs (afatinib, XL647, PF00299804) show similar activity in EGFR-mutated patients. A translocation involving the anaplastic lymphoma kinase (ALK) gene with EML4, identified in 2007, is the most recent oncogene found in NSCLC. Crizotinib (PF02341066), an ALK TKI, has shown impressive activity against ALK translocated NSCLC in an expanded cohort of a phase I trial (NCT00585195). Over 80 patients have been treated and the RR is ～60% with the 6-month PFS rate exceeding 70%. A registration phase III trial of crizotinib versus second-line chemotherapy (pemetrexed/docetaxel) is underway (PROFILE 1007, NCT00932893). KRAS, EGFR mutations and ALK translocations are mutually exclusive and few EGFR WT NSCLCs respond to EGFR TKIs. The promising results of EGFR and ALK TKIs in molecular subgroups of NSCLCs herald a new age of drug and clinical trial development for patients with NSCLC.     

Gefitinib in Advanced Non‐Small Cell Lung Cancer: Does It Deserve a Second Chance?

There has been intense investigation into the epidermal growth factor receptor (EGFR) as a therapeutic target in the treatment of non-small cell lung cancer (NSCLC). Currently there are two EGFR tyrosine kinase inhibitors, erlotinib and gefitinib, approved for the treatment of advanced NSCLC. In a phase III trial (BR.21), treatment with erlotinib resulted in a statistically significant improvement in overall survival in patients who had experienced progression after one or two previous chemotherapy treatments in comparison with best supportive care (BSC). In contrast, in the Iressa Survival Evaluation in Lung Cancer (ISEL) trial, treatment with gefitinib did not result in a statistically significant improvement in overall survival time in comparison with BSC in patients who had received one or two previous chemotherapy treatments and were refractory to or intolerant of the previous chemotherapy. After the results of the ISEL trial, the U.S. Food and Drug Administration restricted the use of gefitinib, and gefitinib was effectively removed from routine clinical practice within the U.S. However, gefitinib was approved in other countries and clinical trials investigating gefitinib continued. Recently the Iressa Non-small cell lung cancer Trial Evaluating REsponse and Survival against Taxotere (INTEREST) trial met the primary endpoint of demonstrating noninferiority in terms of overall survival for gefitinib (250 mg daily) in comparison with docetaxel (75 mg/m(2) every 3 weeks). Patients treated with gefitinib experienced a lower rate of treatment-related toxicity and higher rate of improvement in quality of life. Results of recent gefitinib trials have been provocative, and suggest a role for gefitinib in the treatment of advanced NSCLC.     

Afatinib in the treatment of EGFR mutation-positive NSCLC – A network meta-analysis

Objectives

Epidermal growth factor receptor (EGFR) mutation-positive non-small cell lung cancer (NSCLC) is a specific lung cancer subtype characterized by sensitivity to treatment with EGFR tyrosine kinase inhibitors (TKIs). Two reversible EGFR TKIs (gefitinib, erlotinib) and the irreversible ErbB family blocker afatinib are currently approved for treatment of EGFR mutation-positive NSCLC, but no head-to-head trials have been reported to date. We aimed to assess the relative efficacy of the three drugs by conducting a network meta-analysis (NMA).

Materials and methods

A systematic literature review was conducted to identify all the available evidence. Outcomes of interest were progression-free survival (PFS) and overall survival. For PFS, results by investigator review were considered as not all trials assessed PFS independently. Results were analyzed using Bayesian methods.

Results

The literature search identified 246 articles that were assessed for eligibility, of which 21 studies were included in the NMA, including eight trials performed in an EGFR mutation-positive population. The estimated PFS HR (95% credible interval, CrI) for afatinib compared with gefitinib was 0.70 (0.40–1.16) and compared with erlotinib was 0.86 (0.50–1.50) in the total population. The estimated probability of being best for afatinib over all other treatments for PFS was 70% versus 27% for erlotinib and 3% for gefitinib; the estimated probability of chemotherapy being the best treatment was 0%. Estimated HR (95% CrI) in patients with common mutations was 0.73 (0.42–1.24) for afatinib compared with erlotinib and 0.60 (0.34–0.99) for afatinib compared with gefitinib. OS findings were not significantly different between treatments.

Conclusions

In the absence of direct head-to-head trial data comparing efficacy between the three EGFR TKIs, our analysis suggests that afatinib is a viable treatment alternative to erlotinib or gefitinib in terms of PFS. A direct trial-based comparison of the efficacy of these agents is warranted to clarify their relative benefits.     

Efficacy of EGFR tyrosine kinase inhibitors in patients with EGFR-mutated non-small-cell lung cancer: a meta-analysis of 13 randomized trials

Advanced non-small-cell lung cancer (NSCLC) harboring activating mutations of epidermal growth factor receptor (EGFR) are particularly sensitive to tyrosine kinase inhibitors (TKIs), namely erlotinib and gefitinib. The purpose of this meta-analysis was to evaluate the benefit of EGFR TKIs in EGFR-mutated NSCLCs. Eligible studies included published randomized controlled trials in which erlotinib or gefitinib (alone or with chemotherapy) were compared with standard therapy in 1260 patients with EGFR-mutated NSCLCs who were included in 13 trials. The mutational status was obtained through a retrospective or prospective analysis. Relative risk (RR) was calculated for response rate, and hazard ratios (HRs) were calculated for progression-free and overall survival. EGFR TKIs increase the chance of obtaining an objective response almost 2-fold when compared with chemotherapy (RR, 2.06; 2p < .00001). The response rate was 70% vs. 33.2% in first-line trials. In 3 second-line trials, response rates were 47.4% vs. 28.5%, with a benefit similar to first-line trials (RR, 1.79; 2p = .04). EGFR TKIs reduced the hazard of progression by 70% in all trials (HR, 0.30; 2p < .00001) and by 65% in first-line trials only (HR, 0.35; 2p < .00001). Overall, however, they do not improve survival (HR, 0.96; 2p = .71). NSCLCs harboring EGFR mutations derive greater benefit from erlotinib or gefitinib than from chemotherapy. All patients affected by NSCLC with an EGFR-positive mutation test result must be offered the opportunity to be treated with an EGFR TKI upfront or during the natural course of the disease if not previously exposed.     

Gefitinib and Erlotinib in Metastatic Non‐Small Cell Lung Cancer: A Meta‐Analysis of Toxicity and Efficacy of Randomized Clinical Trials

Background.

Tyrosine kinase inhibitors (TKIs) targeting the epidermal growth factor receptor (EGFR) have been evaluated in patients with metastatic and advanced non-small cell lung cancer (NSCLC). The U.S. Food and Drug Administration initially granted accelerated approval to gefitinib but subsequently rescinded the authorization. Erlotinib and afatinib are similar compounds approved for the treatment of metastatic NSCLC. The objective of this study was to compare the efficacy and toxicity of erlotinib, gefitinib, and afatinib in NSCLC.

Methods.

We tabulated efficacy variables including overall response rate (ORR), progression-free survival (PFS), and overall survival (OS) and quantitated toxicities and rates of dose reductions and discontinuation. Summary odds ratios were calculated using random and fixed-effects models. An odds ratio was the summary measure used for pooling of studies.

Results.

We examined 28 studies including three randomized trials with afatinib. Clinical toxicities, including pruritus, rash, anorexia, diarrhea, nausea, fatigue, mucositis, paronychia, and anemia, were similar between erlotinib and gefitinib, although some statistical differences were observed. Afatinib treatment resulted in more diarrhea, rash, and paronychia compared with erlotinib and gefitinib. Regarding efficacy, similar outcomes were recorded for ORR, PFS, or OS in the total population and in specific subgroups of patients between erlotinib and gefitinib. All three TKIs demonstrated higher ORRs in first line in tumors harboring EGFR mutations.

Conclusion.

Gefitinib has similar activity and toxicity compared with erlotinib and offers a valuable alternative to patients with NSCLC. Afatinib has similar efficacy compared with erlotinib and gefitinib in first-line treatment of tumors harboring EGFR mutations but may be associated with more toxicity, although further studies are needed. Gefitinib deserves consideration for U.S. marketing as a primary treatment for EGFR-mutant NSCLC.     

Epidermal growth factor receptor tyrosine kinase inhibitors in lung cancer: impact of primary or secondary mutations

The discovery of mutations in the tyrosine kinase (TK) domain of the epidermal growth factor receptor (EGFR) and the positive results of the National Cancer Institute of Canada Clinical Trials Group BR.21 phase III, randomized, placebo-controlled trial of erlotinib in patients with advanced-stage non-small-cell lung cancer that had failed to respond to first- or second-line chemotherapy provides new treatment options for patients with lung cancer and new insights into the pathophysiology of this malignancy. The similarity in patient characteristics significantly associated with EGFR mutations and in those who responded to therapy in BR.21 led to the hypothesis that EGFR mutation status can be used as a predictive marker for response and survival benefit in patients treated with the EGFR TK inhibitors erlotinib and gefitinib. This review summarizes the available data to date on the frequency and type of EGFR TK domain mutations and their association with clinical features, response, and survival outcome of patients treated with erlotinib and gefitinib.     

Efficacy of EGFR tyrosine kinase inhibitors for non-adenocarcinoma NSCLC patients with EGFR mutation

Purpose

The epidermal growth factor receptor tyrosine kinase inhibitors (EGFR TKIs) gefitinib and erlotinib have shown dramatic response rate (RR) and significant prolongation of progression-free survival (PFS) in non-small-cell lung cancer (NSCLC) patients with EGFR mutation. Since only a few patients with non-adenocarcinoma histology have been enrolled in clinical trials, the efficacy of EGFR TKIs in non-adenocarcinoma NSCLC patients with EGFR mutation has not yet been fully determined.

Methods

We retrospectively analyzed clinical outcomes, including RR, PFS, and OS, in patients who were treated with the EGFR TKIs gefitinib or erlotinib and compared the results with those of adenocarcinoma patients with EGFR mutation and non-adenocarcinoma patients with wild-type EGFR.

Results

Among 250 patients with non-adenocarcinoma of the lung who underwent EGFR mutation genotyping, 21 were found to have an EGFR mutation (8.4?%). Twelve of the 21 patients were treated with the EGFR TKIs gefitinib (n?=?6) or erlotinib (n?=?6). The most common mutation was exon 19 deletion (n?=?7). The RR and disease control rate for 12 patients receiving EGFR TKIs were 50 and 75?%, respectively. The median PFS was 3.67?months (95?% CI: 1.34?C5.99), which was significantly lower than that of 269 adenocarcinoma patients with EGFR mutation (13.53?months) but better than that of 32 non-adenocarcinoma patients with wild-type EGFR (1.83?months) who were treated with EGFR TKIs.

Conclusions

The results of this study show that the EGFR mutation rate in Korean patients with non-adenocarcinoma of the lung is relatively high and that the clinical outcomes of EGFR TKIs are modest.     

The LUX-Lung clinical trial program of afatinib for non-small-cell lung cancer

Epidermal growth factor receptor (EGFR)-mutant non-small-cell lung cancer (NSCLC) represents a distinct disease entity whose molecular phenotype predicts exquisite sensitivity to the reversible EGFR-tyrosine kinase inhibitors (TKIs) gefitinib or erlotinib. However, primary or acquired resistance to these agents remains a major clinical problem. Afatinib is a novel dual irreversible EGFR/HER2 TKI that has been shown in preclinical studies to potentially prevent, delay or overcome resistance to reversible EGFR-TKIs. On this basis, the LUX-Lung clinical trial program has been recently launched for testing this molecule in advanced NSCLC patients. Notably, early results from the randomized LUX-Lung 1 trial indicate that afatinib significantly prolongs progression-free survival compared with placebo in pretreated patients with clinically acquired resistance to gefitinib or erlotinib. On the other hand, the LUX-Lung 2 trial shows that afatinib is highly active in the EGFR-mutant subgroup of patients. While these preliminary data open a new exciting scenario for the future development of anti-EGFR therapies in NSCLC, ongoing afatinib trials will definitively establish a role for this molecule in the treatment of advanced NSCLC.     

Tyrosine Kinase Inhibitors for the Treatment of EGFR Mutation-Positive Non–Small-Cell Lung Cancer: A Clash of the Generations

The availability of 3 generations of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) with different pharmacologic characteristics and clinical profiles has provided oncologists with a potentially confusing choice for the treatment of EGFR mutation-positive non–small-cell lung cancer. Although recent head-to-head clinical trials have demonstrated improved efficacy with second-generation (ie, afatinib, dacomitinib) and third-generation (ie, osimertinib) TKIs compared with the first-generation TKIs (eg, erlotinib, gefitinib), acquired resistance has been inevitable, regardless of which agent has been chosen as first-line therapy. Thus, the potential availability of subsequent treatment options is an important consideration. Recent data have demonstrated that osimertinib confers an overall survival benefit compared with first-generation EGFR TKIs, and dacomitinib has shown an overall survival benefit compared with gefitinib in an exploratory analysis. However, the relative benefits of different sequential EGFR-TKI regimens, especially those involving second- and third-generation agents, have remained uncertain and require prospective evaluation. Few such data currently exist to inform treatment choices. In the present review, we examined the pharmacologic characteristics and current clinical data for EGFR TKIs, including emerging information on the molecular mechanisms of resistance across the different generations of TKIs. Given the uncertainties regarding the optimal treatment choice, we have focused on the factors that might help determine the treatment decisions, such as efficacy and safety in patient subgroups. We also discussed the emerging real-world data, which have provided some insights into the benefits of sequential regimens in everyday clinical practice.     

Overcoming molecular mechanisms of resistance to first-generation epidermal growth factor receptor tyrosine kinase inhibitors

The epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) gefitinib and erlotinib have provided substantial benefits to patients with advanced non-small cell lung cancer (NSCLC). However resistance to these agents has emerged as a significant clinical issue; most patients who initially respond to treatment eventually experience relapse. The mechanisms underlying gefitinib and erlotinib resistance are multifactorial and several have been described. Clearly there is a need for novel and more effective therapies that can overcome resistance to the currently available TKIs. Several agents are in clinical development, including irreversible EGFR TKIs, inhibitors of the MET pathway, and others. In this review we discuss the various underlying mechanisms of gefitinib and erlotinib resistance and highlight the agents currently in clinical development that may have potential for overcoming this resistance.     

Epidermal growth factor receptor mutations, small-molecule kinase inhibitors, and non-small-cell lung cancer: current knowledge and future directions.

PURPOSE: Gefitinib and erlotinib are small molecules that selectively inhibit epidermal growth factor receptor (EGFR) tyrosine kinase activity. When these drugs were introduced into the clinic, the specific targets affected in human tumors were unknown. In April 2004, two groups reported that mutations in the tyrosine kinase domain of EGFR are strongly associated with gefitinib sensitivity in patients with non-small-cell lung cancer (NSCLC). We subsequently extended these findings and showed that such mutations are also associated with sensitivity to erlotinib. Here, we present current knowledge about EGFR mutations in the context of clinical trials involving gefitinib and erlotinib in NSCLC. DESIGN: This article reviews the rationale for targeting EGFR, the development of gefitinib and erlotinib, the discovery of EGFR mutations, and subsequent studies to define the incidence, spectrum, and functions of EGFR mutations. RESULTS: The discovery of EGFR mutations promises to alter the ways in which we consider and treat NSCLC. CONCLUSION: This information can guide practitioners and help them inform their patients about EGFR mutations and their impact on the treatment of NSCLC.     

Non-small-cell lung cancer harbouring mutations in the EGFR kinase domain

Key “driver” mutations have been discovered in specific subgroups of non-small-cell lung cancer (NSCLC) patients. Activating mutations in the form of deletions in exon 19 (del 19) or the missense mutation L858R in the tyrosine kinase domain of the epidermal growth factor receptor (EGFR) predict outcome to EGFR tyrosine kinase inhibitors (TKIs) such as gefitinib and erlotinib. Pooled data from several phase II studies show that gefitinib and erlotinib induce responses in over 70% of NSCLC patients harbouring EGFR mutations, with progression-free survival (PFS) ranging from 9 to 13 months and median survival of around 23 months. Two studies in Caucasian and Asian patients have confirmed that these subgroups of patients attain response rates of 70% with erlotinib and gefitinib, including complete responses, PFS up to 14 months and median survival up to 27 months. These landmark outcomes have been accompanied by new challenges: the additional role of chemotherapy and the management of tumours with the secondary T790M mutation that confers resistance to EGFR TKIs. Mechanisms of resistance to reversible EGFR TKIs should be further clarified and could be related to modifications in DNA repair. The presence of double mutations (T790M plus either L858R or del 19) at the time of diagnosis could be much more frequent than originally thought. The sensitivity to EGFR TKIs could be greatly influenced by the expression of genes involved in the repair of DNA double-strand breaks by homologous recombination and non-homologous end joining.     

Integration of EGFR inhibitors and conventional chemotherapy in the treatment of non-small-cell lung cancer

Introduction/Background

Given the limited gains of traditional chemotherapy in improving outcomes in patients with advanced non–small-cell lung cancer (NSCLC), recent research efforts have investigated the integration of targeted agents into the treatment algorithm.

Materials and Methods

Searches of PubMed and of recent results from key oncology congresses were performed to identify relevant articles and abstracts. Initial phase III trials combining the reversible epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) gefitinib and erlotinib with platinum-based doublets as first-line therapy failed to demonstrate an overall survival advantage in unselected patients with NSCLC. However, in recent years, there has been substantial progress in understanding the determinants of response to EGFR TKI therapy, including the presence of activating EGFR mutations, which has been reflected in clinical trials specifically evaluating these patient populations. In addition, evidence suggesting potential mechanistic interference between concurrent EGFR TKIs and chemotherapy has also been observed, fueling interest in sequential or intermittent dosing. EGFR-targeted agents such as the multitargeted TKI vandetanib and the next-generation EGFR TKIs afatinib (BIBW 2992) and PF00299804 are also under clinical investigation for the treatment of NSCLC, both alone and in combination with chemotherapy.

Conclusions

Trials evaluating various regimens of EGFR-targeted agents and chemotherapy are planned and/or underway and will hopefully define the role of integrated therapy in NSCLC.     

Nationwide Real-world Cohort Study of First-line Tyrosine Kinase Inhibitor Treatment in Epidermal Growth Factor Receptor-mutated Non–small-cell Lung Cancer

BackgroundOnly a few randomized trials directly compared the relative efficacy of tyrosine kinase inhibitors (TKIs) in patients with advanced epidermal growth factor receptor (EGFR)-mutated non–small-cell lung cancer (NSCLC), and most trials comprised selected series from Asian populations. Therefore, the aim of this study was to assess the overall survival (OS) of advanced EGFR-mutated NSCLC in a large white population and to evaluate variation between different TKIs and identify predictors of survival.Patients and MethodsInformation about clinical characteristics, treatment, and survival for 873 patients with stage IV EGFR + NSCLC, diagnosed from 2015 through 2017, was derived from the Netherlands Cancer Registry. OS was evaluated by actuarial analysis and multivariable Cox regression. Prognostic factors are reported as hazard ratios and 95% confidence intervals.ResultsA total of 596 (68%) patients received first-line treatment with regular TKIs, providing a median survival of 20.2 months. Forty-five percent of patients were 70 years and older, and 54% of patients had distant metastasis in multiple organs. In the multivariate analysis, survival was significantly worse for men, and patients with higher age, poorer performance, and ≥ 3 organs with metastasis. Compared with erlotinib, OS was worse for gefitinib users (adjusted hazard ratio, 1.30; 95% confidence interval, 1.02-1.64), predominantly in patients with brain metastasis.ConclusionDutch patients with EGFR-mutated NSCLC who received first-line treatment with regular TKIs have a median OS of 20.2 months in a nationwide real-world cohort. In patients with brain metastasis, erlotinib showed superior results compared with gefitinib and was similar to afatinib.     

EGFR tyrosine kinase inhibitors for the treatment of NSCLC in East Asia: present and future

Treatment with one of the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) gefitinib or erlotinib has become an additional option for patients with non-small cell lung cancer (NSCLC). Further investigation clearly demonstrated that a subset of patients show a better response to these agents than the overall patient population: individuals with adenocarcinoma histology, females, never-smokers and those of East Asian origin. The ISEL and BR21 studies showed that East Asian patients had significantly longer survival compared with the total study population after EGFR-TKI treatment. The increased response to EGFR-TKIs observed in East Asian patients can likely be attributed to the higher prevalence of activating EGFR mutations found in these individuals. Data from several studies in Japan, Korea, Taiwan and China support this, showing a high occurrence of activating mutations. Furthermore, in prospective studies of gefitinib in these populations, sensitive activating mutations (deletions in exon 19 or L858R) are associated with high overall response and disease control rates. Within East Asian patients, predictors of response to gefitinib include female sex, adenocarcinoma histology, no smoking history and receiving gefitinib first-line, although there may be an interaction between these factors. All patients eventually develop acquired resistance to the currently available EGFR TKIs. In addition, the presence of EGFR mutations is a useful tool to determine NSCLC patients' prognosis; some studies suggested that this may apply if patients are receiving first-line chemotherapy, not only if they are receiving EGFR-TKIs.     

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

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

The role of irreversible HER family inhibition in the treatment of patients with non-small cell lung cancer

Small-molecule tyrosine kinase inhibitors (TKIs) of the human epidermal growth factor receptor (HER) include the reversible epidermal growth factor receptor (EGFR/HER-1) inhibitors gefitinib and erlotinib. EGFR TKIs have demonstrated activity in the treatment of patients with non-small cell lung cancer (NSCLC) harboring activating EGFR mutations; however, multiple mechanisms of resistance limit the benefit of these drugs. Although resistance to EGFR TKIs can be intrinsic and correlated with molecular lesions such as in Kirsten rat sarcoma viral oncogene homolog (KRAS; generally observed in a wild-type EGFR background), acquired resistance to EGFR TKIs can evolve in the setting of activating EGFR mutations, such as in the case of EGFR T790M mutations. Several irreversible inhibitors that target multiple members of the HER family simultaneously are currently in clinical development for NSCLC and may have a role in the treatment of TKI-sensitive and TKI-resistant disease. These include PF00299804, an inhibitor of EGFR/HER-1, HER-2, and HER-4, and afatinib (BIBW 2992), an inhibitor of EGFR/HER-1, HER-2, and HER-4. Results of large, randomized trials of these agents may help to determine their potential for the treatment of NSCLC.     

Thyroid carcinoma after treatment for malignancies in childhood and adolescence: from diagnosis through follow-up

Non-small cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) mutations derive greater benefits from first- and second-generation tyrosine kinase inhibitors (TKIs) than from chemotherapy, especially in the first-line setting. Thus, main treatment guidelines indicate to test all patients with lung adenocarcinoma for these genetic abnormalities and recommend the employment of TKIs in these patients. However, many unanswered questions about the optimal use of TKIs in lung cancer remain; in particular, an open question is which of the currently available TKIs (gefitinib, erlotinib and afatinib) might be the best choice in untreated NSCLC patients. In the current review, we will analyze the state of EGFR-TKIs therapy in untreated EGFR-mutated NSCLC patients with a focus on both efficacy and toxicity.