Frequency Of Epidermal Growth Factor Receptor Mutations Research Articles

Determination of EGFR and KRAS mutational status in Greek non-small-cell lung cancer patients.

It has been reported that certain patients with non-small-cell lung cancer (NSCLC) that harbor activating somatic mutations within the tyrosine kinase domain of the epidermal growth factor receptor (EGFR) gene may be effectively treated using targeted therapy. The use of EGFR inhibitors in patient therapy has been demonstrated to improve response and survival rates; therefore, it was suggested that clinical screening for EGFR mutations should be performed for all patients. Numerous clinicopathological factors have been associated with EGFR and Kirsten-rat sarcoma oncogene homolog (KRAS) mutational status including gender, smoking history and histology. In addition, it was reported that EGFR mutation frequency in NSCLC patients was ethnicity-dependent, with an incidence rate of ~30% in Asian populations and ~15% in Caucasian populations. However, limited data has been reported on intra-ethnic differences throughout Europe. The present study aimed to investigate the frequency and spectrum of EGFR mutations in 1,472 Greek NSCLC patients. In addition, KRAS mutation analysis was performed in patients with known smoking history in order to determine the correlation of type and mutation frequency with smoking. High-resolution melting curve (HRM) analysis followed by Sanger sequencing was used to identify mutations in exons 18–21 of the EGFR gene and in exon 2 of the KRAS gene. A sensitive next-generation sequencing (NGS) technology was also employed to classify samples with equivocal results. The use of sensitive mutation detection techniques in a large study population of Greek NSCLC patients in routine diagnostic practice revealed an overall EGFR mutation frequency of 15.83%. This mutation frequency was comparable to that previously reported in other European populations. Of note, there was a 99.8% concordance between the HRM method and Sanger sequencing. NGS was found to be the most sensitive method. In addition, female non-smokers demonstrated a high prevalence of EGFR mutations. Furthermore, KRAS mutation analysis in patients with a known smoking history revealed no difference in mutation frequency according to smoking status; however, a different mutation spectrum was observed.

Frequency of EGFR Mutation and EML4-ALK fusion gene in Arab Patients with Adenocarcinoma of the Lung

Abstract Introduction: Improvement in the clinical outcome of lung cancer is likely to be achieved by identification of the molecular events that underlie its pathogenesis. The frequency of epidermal growth factor receptor (EGFR) mutations is ethnicity-dependent, with a higher proportion in Asian populations than in whites, while the incidence of EML4-ALK (echinoderm microtubule-associated-protein like 4-anaplastic lymphoma kinase) fusion gene ranged from 1.6% to 16.4% in patients with NSCLC and these individuals were distinct from those harbouring mutations in the epidermal growth factor receptor gene. This study was conducted to determine the frequency of EGFR mutation and EML4-ALK fusion gene in our population and to determine the effect of different clinicopathological features on the expression of those mutations in patients with lung adenocarcinoma. Results: EGFR mutations were detected in approximately 33% of our patients in this series; the most frequently detected mutation was exon 19 deletion. EML4-ALK fusion gene was detected in 7.3% of patients. Conclusion: Our population exhibited the incidence of EGFR mutation approximately similar to that reported in East Asia and Japanese patients, higher than that recorded in USA, and Australia. However, more studies with larger patients’ numbers are needed to verify this finding.

Updated Frequency of EGFR and KRAS Mutations in NonSmall-Cell Lung Cancer in Latin America: The Latin-American Consortium for the Investigation of Lung Cancer (CLICaP)

Previously, we reported the frequency of epidermal growth factor receptor (EGFR) and KRAS mutations in nonsmall-cell lung cancer (NSCLC) patients in Latin America. The EGFR mutation frequency was found between Asian (40%) and Caucasian (15%) populations. Here, we report the updated distribution of NSCLC mutations. A total of 5738 samples from NSCLC patients from Argentina (1713), Mexico (1417), Colombia (1939), Peru (393), Panama (174), and Costa Rica (102) were genotyped for EGFR and KRAS. The median patient age was 62.2 ± 12.3 years; 53.5% were women, 46.7% had a history of smoking, and 95.2% had adenocarcinoma histology. The frequency of EGFR mutations was 26.0% (95% confidence interval [CI], 24.9-27.1; Argentina, 14.4% [12.8-15.6]; México, 34.3% [31.9-36.7]; Colombia, 24.7% [22.8-26.6]; Peru, 51.1% [46.2-55.9]; Panamá, 27.3 [20.7-33.9]; and Costa Rica, 31.4% [22.4-40.4]). The frequency of KRAS mutations was 14.0% (9.1-18.9). In patients with adenocarcinoma, EGFR mutations were independently associated with gender (30.7% females vs. 18.4% males; p < 0.001), nonsmoker status (27.4% vs. 17.1%, p < 0.001), ethnicity (mestizo/indigenous, 35.3% vs. Caucasian, 13.7%, p < 0.001), and the absence of KRAS mutation (38.1% vs. 4.7%; p < 0.001). The overall response rate to EGFR tyrosine kinase inhibitors was 60.6% (95% CI, 52-69), with a median progression-free survival and overall survival of 15.9 (95% CI, 12.420.6) and 32 months (95% CI, 26.5-37.6), respectively. Our findings support the genetic heterogeneity of NSCLC in Latin America, confirming that the frequency of EGFR mutations is intermediate between that observed in the Asian and Caucasian populations.

Increase EGFR Mutations Detection Rate in Lung Adenocarcinoma by Real-Time PCR Screening Followed by Direct Sequencing.

Recently, a number of small-molecule tyrosine kinase inhibitors (TKIs) have been developed to target the ATP-binding cleft of the epidermal growth factor receptor (EGFR). The presence of EGFR mutations in non-small cell lung cancer (NSCLC) correlates with the responsiveness to TKIs. Therefore, the identification of EGFR mutations before the administration of TKIs of NSCLC has become important. The aim of the present study was to investigate the occurrence of EGFR mutations in the southern Taiwanese population with NSCLC using a combination of real-time polymerase chain reaction (PCR) kit and direct sequencing. In the present study, DNAs were extracted from 249 cases of formalin-fixed, paraffin-embedded NSCLC samples for clinical EGFR mutational analysis by real-time PCR kit and direct sequencing. The results showed that the frequency of EGFR mutations is 63% in the southern Taiwanese population. Most of the EGFR mutations are located at exons 19 and 21. In addition, we indicated that a combination of real-time PCR kit and direct sequencing increases the rate of mutation by 4%. Direct sequencing revealed 9 EGFR mutations including 6 reported EGFR mutations and 3 novel EGFR mutations. In the present study, we have demonstrated that a combination of real-time PCR kit and direct sequencing increases the detection rate of EGFR mutations. Therefore, our proposed EGFR mutation detection strategy could be applied in clinical settings. In addition, our results indicated the prevalence of EGFR mutational status in the southern Taiwanese population.

Clinical analysis of 50 Eastern Asian patients with primary pulmonary large-cell neuroendocrine carcinoma.

BackgroundTo understand the clinicopathological features of patients with primary pulmonary large-cell neuroendocrine carcinoma (LCNEC), including the frequency of epidermal growth factor receptor (EGFR) mutation, and to explore prognostic factors.MethodsWe investigated a cohort of 50 individuals from our center database who were diagnosed with operable pulmonary LCNEC and treated in Sun Yat-sen University Cancer Center. Serum albumin (ALB) and neuron-specific enolase (NSE) were also collected. Survival curves were obtained with the Kaplan–Meier method, and the differences between groups in survival were tested by the log-rank test.ResultsThe median age was 59 years (range, 40–80 years). Fourteen patients underwent mutational analysis of EGFR; of these, 12 had wild-type EGFR and the remaining two had EGFR mutations in exons. The median disease-free survival (DFS) of pulmonary LCNEC was 49.3 months and that of overall survival (OS) was not reached. DFS and OS were shorter for patients with decreased serum ALB than for patients with normal serum ALB (P=0.003 and P=0.004, respectively). Meanwhile, a high level of NSE was also significantly associated with short DFS and OS (P=0.005 and P=0.000, respectively). Multivariate analysis showed that decrease in serum ALB was an independent prognostic factor for OS (P=0.046).ConclusionThe frequency of EGFR mutation in LCNEC patients is low. Serum ALB and NSE levels are valuable prognostic factors for LCNEC patients.

PD-L1 is highly expressed in lung lymphoepithelioma-like carcinoma: A potential rationale for immunotherapy.

Programmed cell death-ligand 1 (PD-L1) and driver mutations are found in non-small cell lung cancers (NSCLCs) and may be suitable targets for specific therapies, but their roles in lymphoepithelioma-like carcinoma (LELC) of the lung are unclear. Sixty-six patients with pulmonary LELCs were investigated. Paraffin-embedded tumor sections were stained with PD-L1 antibody. Tumors with moderate-to-strong membrane staining in ≥5% of tumor cells were positive for PD-L1 overexpression. The presence of driver mutations in the genes for epidermal growth factor receptor (EGFR), KRAS, and BRAF were examined by direct sequencing. Anaplastic lymphoma kinase (ALK) and ROS1 levels were determined by immunohistochemistry. Correlations of PD-L1 expression and driver mutations with clinicopathologic parameters were analyzed. The overall frequency of PD-L1 overexpression and EGFR mutation was 75.8% and 12.1%, respectively. No KRAS, BRAF, ALK or ROS1 aberrations could be detected. PD-L1 expression was not associated with driver mutations. Multivariate analysis revealed that smoking and advanced stage were independent risk factors for poor overall survival, whereas PD-L1 positivity was not significantly associated with patient outcome. There are high PD-L1 expression and infrequent driver mutations in LELCs compared with conventional NSCLCs. The high expression of PD-L1 in EBV and inflammation associated LELC may provide a rationale for immunotherapy in this subtype of lung cancer.

Frequency of EGFR mutations in non-small cell lung cancer patients: screening data from West Siberia.

Incorporation of molecular analysis of the epidermal growth factor receptor (EGFR) gene into routine clinical practice has shown great promise to provide personalized therapy of the non-small cell lung cancer (NSCLC) in the developed world. However, the genetic testing of EGFR mutations has not yet become routine clinical practice in territories remote from the central regions of Russia. Therefore, we aimed to study the frequency of major types of activating mutations of the EGFR gene in NSCLC patients residing in West Siberia. We examined EGFR mutations in exons 19 and 21 in 147 NSCLC patients (excluding squamous cell lung carcinomas) by real time polymerase chain reaction. EGFR mutations were detected in 28 of the 147 (19%) patients. There were 19 (13%) cases with mutations in exon 19 and 9 cases (6%) in exon 21. Mutations were more frequently observed in women (42%, p=0.000) than in men (1%). A significantly higher incidence of EGFR mutations was observed in bronchioloalveolar carcinomas (28%, p=0.019) and in adenocarcinomas (21%, p=0.024) than in large cell carcinomas, mixed adenocarcinomas, and NOS (4%). The EGFR mutation rate was much higher in never-smokers than in smokers: 38% vs. 3% (p=0.000). The frequency of EGFR mutations in the Kemerovo and Tomsk regions was 19%. The incorporation of molecular analysis of the EGFR gene into routine clinical practice will allow clinicians to provide personalised therapy, resulting in a significant increase in survival rates and improvement in life quality of advanced NSCLC patients.

O2. Frequency of EGFR gene mutations in patients with NSCLC in Czech Republic

Background: Worldwide, lung cancer is the most common cause of cancer-related death, and was responsible for 1.56 million deaths annually, as of 2012. The situation in the Czech Republic is identical, lung cancer is the leading cause of mortality due to malignant tumours, with 5,572 cancer related deaths in 2010. The detection of epidermal growth factor receptor (EGFR) gene mutations can guide targeted therapies for non-small cell lung cancer (NSCLC), because most of these mutations are strongly associated with clinical response to EGFR tyrosine kinase inhibitors. The aim of this study was to verify the frequency of EGFR mutations in a large group of Caucasians patients with advanced stage non-squamous NSCLC. Methods: Analysed data were collected in the period from November 15, 2011 to June 30, 2013 in three pneumo-oncological centres. Totally, 486 patients diagnosed with adenocarcinoma (459 cases) or NSCLC-NOS (27 cases) were tested for EGFR mutations, consisting of 284 males and 202 females, with median age of 66.5 years. Results: EGFR mutations were detected in 74 patients (15.2%). Mutations were shown in 25 (8.8%) men vs. 49 (24.3%) women (P<0.001), in 12 (6.7%) smokers vs. 20 (11.2%) ex-smokers vs. 38 (37.3%) non-smokers (P<0.001), and in 32 (15.7%) patients under 65 years of age vs. 42 (14.9%) patients over 65 years of age (P=0.898). Conclusions: The authors showed that the overall frequency of EGFR mutations in patients with non-squamous NSCLC was 15.2%, most commonly in female patients and non-smokers. The study results are in concordance with recent studies in which the frequency of EGFR mutations varies between 8-23% in Caucasian population. This information can help us to estimate number of patients who will need EGFR tyrosine kinase inhibitors in the first line of treatment.

Molecular epidemiology of lung cancer and geographic variations with special reference to EGFR mutations.

Lung cancer is a leading cause of cancer-related mortality in many countries. Although recent advances in targeted therapy against driver oncogenes have significantly improved patient outcome, cure of this disease is still exceptional. Although tobacco is a known cause of lung cancer, not all smokers develop lung cancer, and conversely many patients, especially Asian female patients with lung cancer, are lifetime never-smokers. Therefore, efforts to understand the basis for different susceptibilities to lung cancer among individuals with different genetic, biologic, ethnic, and social backgrounds are important to help develop effective preventive measures. Lung cancer in never-smokers has many different characteristics to lung cancer in smokers, such as adenocarcinoma predominance and high frequency of epidermal growth factor receptor (EGFR) mutation yet low number of genetic changes. Epidemiologic studies suggest that East Asians are more susceptible to smoking-unrelated lung cancer but less susceptible to smoking-related lung cancer compared with Caucasians. Mutations in the EGFR gene are more common in Asian females and never-smokers. Our case-control study suggests that EGFR mutation occurs independent of smoking, and that the apparent low frequency of EGFR mutations in smokers may be the result of dilution by smoking-related lung cancer. The frequencies of three EGFR gene polymorphisms associated with increased protein expression are significantly different between East Asians and Caucasians, favoring lower protein expression in East Asians. Although these may be associated with preferred expression of the EGFR mutant allele, it is difficult to explain the frequent EGFR mutation in Asian patients. Genome wide association studies (GWAS) revealed several loci related to lung cancer susceptibility. In the future, GWAS may identify loci that are specifically related to EGFR-targeted carcinogenesis, leading to identification of carcinogens that induce EGFR mutations and effective prevention measures.

The efficacy of EGFR gene mutation testing in various samples from non-small cell lung cancer patients: a multicenter retrospective study.

Introduction Testing for the epidermal growth factor receptor (EGFR) gene mutations requires considerable multidisciplinary experience of clinicians (for appropriate patient selection), pathologists (for selection of appropriate cytological or histological material) and geneticists (for performing and reporting reliable molecular tests). We present our experience on the efficacy of routine EGFR testing in various types of tumor samples and the frequency of EGFR mutations in a large series of Polish non-small cell lung cancer (NSCLC) patients. MethodsDeletions in exon 19 and substitution L858R in exon 21 of EGFR gene were assessed using real-time PCR techniques in 1,138 small biopsies or cytological specimens and in 1,312 surgical samples. ResultsOut of 2,450 diagnostic samples (containing >10 % of tumor cells), the occurrence of EGFR gene mutations was 9 %; more frequently in women (13.9 %) and adenocarcinoma patients (10 %), particularly with accompanying expression of TTF1 (13.0 %). The frequency of EGFR gene mutations was similar in cytological and histological specimens, and in primary and metastatic lesions, and did not depend on the percentage of tumor cells and quality of isolated DNA. Cytological or small biopsy, compared to surgical specimens showed lower percentage of tumor cells, with no impact on the quality of real-time PCR assay.ConclusionCytological and small biopsy samples with low (10–20 %) content of tumor cells and specimens from metastatic lesions are a sufficient source for EGFR mutation testing in NSCLC patients. The incidence of EGFR gene mutations in examined population was similar to those reported in other Caucasian populations.

Epidermal Growth Factor Receptor Mutations in 510 Finnish Non–Small-Cell Lung Cancer Patients

Among the driver gene mutations in non-small-cell lung cancer, mutations in epidermal growth factor receptor (EGFR) are the most important because of their predictive role in selecting patients eligible for targeted therapy. Our aim was to study EGFR mutations in a Finnish non-small-cell lung cancer cohort of 528 patients. Mutation testing was conducted on DNA extracted from paraffin-embedded, formalin-fixed tumor material using the following real-time polymerase chain reaction-based kits: Therascreen EGFR PCR Kit and cobas EGFR Mutation Test. EGFR mutation frequency was 11.4% and all positive cases were adenocarcinomas, of which a majority had an acinar predominant pattern. Mutations were seen significantly more often in females and never-smokers than in males and smokers. The most frequent mutations were L858R in exon 21 and deletions in exon 19. Overall survival of the patients, not treated with EGFR inhibitor, did not differ between EGFR mutation-positive and EGFR mutation-negative patients. EGFR mutation profile in this Finnish non-small-cell lung cancer cohort resembles in many respect with that of other Western European cohorts, even though the overall frequency of mutations is slightly higher. We show the occurrence of EGFR mutations in patients with occupational asbestos exposure and also in those diagnosed with chronic obstructive pulmonary disease who have not been often investigated before.

Correlation of survival and EGFR mutation with predominant histologic subtype according to the new lung adenocarcinoma classification in stage IB patients.

BackgroundA new lung adenocarcinoma classification proposed by the International Association for the Study of Lung Cancer, American Thoracic Society, and European Respiratory Society (IASLC/ATS/ERS) has recently been published. This study aimed to investigate the utility of the new histological classification for identifying the prognostic subtypes of adenocarcinomas in stage IB patients.Correlations between the classification and the presence of epidermal growth factor receptor (EGFR) mutation status was also studied.MethodsOne hundred and thirty-six patients with stage IB lung adenocarcinoma operated on in Zhejiang Cancer Hospital were identified between 2002 and 2011. Patients overall survival and disease-free survival were calculated using Kaplan-Meier and Cox regression analyses. EGFR mutations were detected using the amplification refractory mutation system.ResultsA total of 136 cases were included in current study, of which 38 were papillary predominant, 39 were acinar predominant, 22 were micropapillary predominant, 21 were lepidic predominant subtypes, 14 were solid predominant, and 2 were variants of invasive adenocarcinoma. Patients with micropapillary- and solid-predominant tumors had the lowest five-year disease-free survival (28.4 and 36.7%, respectively). Univariate and multivariate analysis showed that the micropapillary-predominant subtype was an independent predictor of disease-free survival (P = 0.0041 and 0.048, respectively), but not overall survival (P = 0.175 and 0.214, respectively). EGFR mutations were significantly associated with the micropapillary-predominant subtype patients (P = 0.0026). The EGFR mutation frequency is lower in the solid-predominant subtype than other subtypes (P = 0.0508).ConclusionsThe predominant subtype in the primary tumor was associated with prognosis in resected stage IB lung adenocarcinoma. The EGFR mutation frequency of micropapillary-predominant subtype is higher than other subtypes.

Detecting the spectrum of multigene mutations in non-small cell lung cancer by Snapshot assay.

As molecular targets continue to be identified and more targeted inhibitors are developed for personalized treatment of non-small cell lung cancer (NSCLC), multigene mutation determination will be needed for routine oncology practice and for clinical trials. In this study, we evaluated the sensitivity and specificity of multigene mutation testing by using the Snapshot assay in NSCLC. We retrospectively reviewed a cohort of 110 consecutive NSCLC specimens for which epidermal growth factor receptor (EGFR) mutation testing was performed between November 2011 and December 2011 using Sanger sequencing. Using the Snapshot assay, mutation statuses were detected for EGFR, Kirsten rate sarcoma viral oncogene homolog (KRAS), phosphoinositide-3-kinase catalytic alpha polypeptide (PIK3CA), v-Raf murine sarcoma viral oncogene homolog B1 (BRAF), v-ras neuroblastoma viral oncogene homolog (NRAS), dual specificity mitogen activated protein kinase kinase 1 (MEK1), phosphatase and tensin homolog (PTEN), and human epidermal growth factor receptor 2 (HER2) in patient specimens and cell line DNA. Snapshot data were compared to Sanger sequencing data. Of the 110 samples, 51 (46.4%) harbored at least one mutation. The mutation frequency in adenocarcinoma specimens was 55.6%, and the frequencies of EGFR, KRAS, PIK3CA, PTEN, and MEK1 mutations were 35.5%, 9.1%, 3.6%, 0.9%, and 0.9%, respectively. No mutation was found in the HER2, NRAS, or BRAF genes. Three of the 51 mutant samples harbored double mutations: two PIK3CA mutations coexisted with KRAS or EGFR mutations, and another KRAS mutation coexisted with a PTEN mutation. Among the 110 samples, 47 were surgical specimens, 60 were biopsy specimens, and 3 were cytological specimens; the corresponding mutation frequencies were 51.1%, 41.7%, and 66.7%, respectively (P = 0.532). Compared to Sanger sequencing, Snapshot specificity was 98.4% and sensitivity was 100% (positive predictive value, 97.9%; negative predictive value, 100%). The Snapshot assay is a sensitive and easily customized assay for multigene mutation testing in clinical practice.

EGFR activating mutations and their association with response to platinum-doublet chemotherapy in Brazilian non-small cell lung cancer patients.

The aim of the study was to analyze the frequency of epidermal growth factor receptor (EGFR) mutations in Brazilian non-small cell lung cancer patients and to correlate these mutations with response to benefit of platinum-based chemotherapy in non-small cell lung cancer (NSCLC). Our cohort consisted of prospective patients with NSCLCs who received chemotherapy (platinum derivates plus paclitaxel) at the [UNICAMP], Brazil. EGFR exons 18-21 were analyzed in tumor-derived DNA. Fifty patients were included in the study (25 with adenocarcinoma). EGFR mutations were identified in 6/50 (12%) NSCLCs and in 6/25 (24%) adenocarcinomas; representing the frequency of EGFR mutations in a mostly self-reported White (82.0%) southeastern Brazilian population of NSCLCs. Patients with NSCLCs harboring EGFR exon 19 deletions or the exon 21 L858R mutation were found to have a higher chance of response to platinum-paclitaxel (OR 9.67 [95% CI 1.03-90.41], p = 0.047). We report the frequency of EGFR activating mutations in a typical southeastern Brazilian population with NSCLC, which are similar to that of other countries with Western European ethnicity. EGFR mutations seem to be predictive of a response to platinum-paclitaxel, and additional studies are needed to confirm or refute this relationship.

Routine implementation of EGFR mutation testing in clinical practice in Flanders: ‘HERMES’ project

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) is the recommended first-line treatment in metastatic EGFR-mutation-positive non-small cell lung cancer (NSCLC) patients. Such a personalized treatment requires fast EGFR mutation testing. This study was performed to determine the turn around time (TAT) for EGFR mutation testing on tumour samples of NSCLC in the clinical care in the region of Antwerp (Belgium). The secondary aim was to determine the frequency of EGFR mutations in this Flemish population. Tumour tissue was prospectively obtained from lung cancer patients in participating hospitals and sent from the local pathology laboratory (lab) to two central laboratories (labs) where EGFR-mutation analysis was performed. Results were returned from the central labs to the clinicians and the local pathology lab. TAT was defined as the interval between the request from the oncologist and the result obtained by the oncologist. One hundred and seven specimens were analysed. The clinician got the result from the local lab in a median time of 10 days (3–37 days) and from the central lab in 9 days (3–29 days). We detected seven mutations (7%) in this study population, all occurring in tumours with an adenocarcinoma histology, four (57%) in men and five (71%) in (ex-)smokers. There were six exon 19 deletions and one L858R mutation. It is possible to implement EGFR-mutation testing with timely reporting of the EGFR-mutation status. EGFR-mutation occurs in 7% of Flemish patients with NSCLC. Patients with advanced non-squamous NSCLC should be tested for EGFR mutation regardless of their gender and smoking history.

Lung Cancers with Concomitant EGFR Mutations and ALK Rearrangements: Diverse Responses to EGFR-TKI and Crizotinib in Relation to Diverse Receptors Phosphorylation

We investigated the incidence of concomitant epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK) rearrangements in Chinese patients with non-small cell lung cancer (NSCLC), and assessed responses to EGFR tyrosine kinase inhibitors (EGFR-TKIs) and crizotinib in such tumors. We screened 977 consecutive patients with NSCLC for the presence of concomitant EGFR mutations and ALK rearrangements by rapid amplification of cDNA ends-coupled PCR sequencing and FISH. Immunohistochemistry (IHC) and Western blotting were used to correlate the activation of EGFR, ALK, and downstream proteins with responses to EGFR-TKIs and crizotinib. The overall frequency of concomitant EGFR mutations and ALK rearrangements was 1.3% (13/977). EGFR/ALK co-alterations were found in 3.9% (13/336) EGFR-mutant and 18.6% (13/70) ALK-rearranged patients. Ten tumors were treated with first-line EGFR-TKIs, with a response rate of 80% (8/10). Two tumors with high phospho-ALK levels and low phospho-EGFR levels achieved stable and progressive disease, respectively. Median progression-free survival was 11.2 months. Coexpression of mutant EGFR and ALK fusion proteins in the same tumor cell populations was detected by IHC. Two cases with high phospho-ALK levels treated with crizotinib achieved partial responses; two cases with low phospho-ALK levels had progressive or stable disease. ALK rearrangements and EGFR mutations could coexist in a small subgroup of NSCLC. Advanced pulmonary adenocarcinomas with such co-alterations could have diverse responses to EGFR-TKIs and crizotinib. Relative phospho-ALK and phospho-EGFR levels could predict the efficacy of EGFR-TKI and crizotinib.

A Prospective, Molecular Epidemiology Study of EGFR Mutations in Asian Patients with Advanced Non–Small-Cell Lung Cancer of Adenocarcinoma Histology (PIONEER)

Introduction:PIONEER (NCT01185314) was a prospective, multinational, epidemiological study of epidermal growth factor receptor (EGFR) mutations in patients from Asia with newly diagnosed advanced lung adenocarcinoma.Methods:Eligible patients (aged ≥20 years) had untreated stage IIIB/IV adenocarcinoma. The EGFR mutation status (primary end point: positive, negative, or undetermined) of tumor samples (biopsy, surgical specimen, or cytology) was determined (Scorpion amplification refractory mutation system). EGFR mutation frequency was calculated and compared between demographic and clinical subgroups.Results:Of 1482 patients from seven Asian regions, 43.4% of patients were female, median age was 60 years (range, 17–94), and 52.6% of patients were never-smokers. EGFR mutation status was evaluable in tumors from 1450 patients (97.8%) (746 [51.4%] positive; 704 [48.6%] negative). Country, sex, ethnicity, smoking status, pack-years (all p < 0.001), disease stage (p = 0.009), and histology type (p = 0.016) correlated significantly with EGFR mutation frequency. Mutation frequency was 61.1% in females, 44.0% in males; lower in patients from India (22.2%) compared with other areas (47.2%–64.2%); highest among never-smokers (60.7%); and decreased as pack-year number increased (>0–10 pack-years, 57.9%; >50 pack-years, 31.4%) (similar trend by sex). Ethnic group (p < 0.001) and pack-years (p < 0.001) had statistically significant associations with mutation frequency (multivariate analysis); sex was not significant when adjusted for smoking status.Conclusion:PIONEER is the first prospective study to confirm high EGFR mutation frequency (51.4% overall) in tumors from Asian patients with adenocarcinoma. The observed high mutation frequency in demographic/clinical subgroups compared with white populations suggests that mutation testing should be considered for all patients with stage IIIB/IV adenocarcinoma, even males and regular smokers, among Asian populations.

EGFR Mutation and Brain Metastasis in Pulmonary Adenocarcinomas

This study aimed to explore the potential association of mutation in the epidermal growth factor receptor (EGFR) with brain metastases in patients with pulmonary adenocarcinoma. We analyzed clinical data on 314 patients who were tested for EGFR mutation and underwent brain magnetic resonance imaging at diagnosis. The relationship between EGFR mutation status and brain metastases at the initial presentation was analyzed. In addition, prognostic significance of EGFR mutational status on the risk of brain metastasis was evaluated in subgroups of surgically treated patients. Of the 314 patients, 138 patients (43.9%) had EGFR mutations. The frequency of EGFR mutation was statistically higher for patients with brain metastases (64.7%, brain metastases; 39.8%, no metastases; 40.2%, extracranial metastases; p = 0.005). A strong association between EGFR mutation status and brain metastasis was observed (adjusted odds ratio = 3.83, p = 0.001), whereas no association was observed between EGFR mutation status and extracranial metastases (adjusted odds ratio = 1.73, p = 0.079). In addition, the number of brain metastases was significantly correlated with the EGFR mutation status (p = 0.029). Further analysis of 133 patients treated with surgical resection showed that EGFR mutation status was a poor prognostic factor for the risk of brain metastasis (hazard ratio = 4.49, p = 0.026) after adjustment for pathologic N stage. We found a significant association between EGFR mutation and risk of brain metastases at the time of diagnosis and follow-up after curative resection for pulmonary adenocarcinoma. This result indicates the distinct clinical features of EGFR-mutated tumors in terms of brain metastases.

Usage patterns of biomarkers in non-small-cell lung cancer patients in India: Findings from a systematic review and survey.

Introduction:Personalized medicine has facilitated improved management of non-small cell lung cancer (NSCLC) patients by identifying predictive and prognostic biomarkers for enhanced efficiency of detection and efficacy of treatment. This systematic review and survey assessed the patterns of biomarker usage, molecular testing techniques to diagnose patients with NSCLC in India and testing techniques recommended by cancer societies.Materials and Methods:Studies were retrieved from Embase, PubMed, and Cochrane databases for the last 12 years, using relevant search strategies as per the Cochrane methodology for systematic reviews. Outcomes of interest were biomarkers for NSCLC, patterns of biomarker testing, diagnostic methods, guidelines and cost of biomarker testing.Results:In all, 499 studies were identified for screening and 17 primary publications were included in the review. Epidermal growth factor receptor (EGFR) expression and epithelial markers (particularly cytokeratins (CK)) were the most commonly reported biomarkers (7/17) and immunohistochemical (IHC) staining was the most common technique for detection of biomarkers. The frequency of EGFR mutations was higher among women than men. Significantly elevated levels of CK-18 were observed in patients with squamous cell carcinoma and of CK-19 in patients with adenocarcinoma, squamous cell carcinoma, and NSCLC (P < 0.001). Prognostic or predictive role of cytokines and angiogenic markers as well as DNA expression were evaluated. The survey also showed that IHC was the most common technique for detection of biomarkers.Conclusions:This systematic review and survey provides valuable information on biomarker usage in the Indian population, and highlights the need for initiatives required for future biomarker testing in India.

Histological subtype and smoking status, but not gender, are associated with epidermal growth factor receptor mutations in non-small-cell lung cancer

Mutations in epidermal growth factor receptor (EGFR) commonly occur in non-small-cell lung cancer (NSCLC) patients characterized by female gender, never-smoker status and adenocarcinoma histology. The aim of this study was to determine whether gender is a confounding factor for EGFR mutations in NSCLC. To elucidate the confounding effect, Pearson's χ2 test and logistic regression models were used to correlate these characteristics with EGFR mutations in 426 NSCLC patients treated at our institutes. Of those 426 NSCLC patients, 47% were females, 57% were non-smokers and 84% had adenocarcinomas. The multivariate logistic regression analysis demonstrated that never-smoker status [odds ratio (OR)=3.49, 95% confidence interval (CI): 1.99-6.13; P<0.001)] and adenocarcinoma (OR=9.43, 95% CI 3.62-24.56; P<0.001) were associated with EGFR mutations; however, gender was not (OR=1.25, 95% CI: 0.73-2.15; P=0.416). Furthermore, gender was not associated with EGFR mutation subtypes (OR=1.19, 95% CI: 0.56-2.50; P=0.650). The frequency of EGFR mutations among females and males was not different in non-smokers (64.8 vs. 55.8%, P=0.204) or ever-smokers (27.8 vs. 24.2%, P=0.775). Therefore, if the assessment for EGFR mutation status was limited to non-smoking females with adenocarcinoma, up to 40% of the patients harboring EGFR mutations would be precluded from the benefit of EGFR inhibitor therapy. Our results indicated that gender is a confounding factor for EGFR mutations in NSCLC and suggested that gender may not be associated with tumorigenesis in NSCLC-harboring EGFR mutations.