Prevalence and outcome of epidermal growth factor receptor mutations in non-squamous non-small cell lung cancer patients

Comprehensive molecular analysis of driver mutations in non-small cell lung carcinomas and its correlation with PD-L1 expression, An Indian perspective

BACKGROUND

The understanding of molecular mechanisms involved in non-small cell lung carcinoma (NSCLC) has revolutionized significantly in the recent years. These have helped to develop personalized management strategies by identifying specific molecular alterations such as mutations in EGFR, ROS1, BRAF, ERBB2, MET, ALK, and KRAS genes. These mutations are targetable ensuring a better clinical outcome. Next-generation sequencing (NGS) methodology is the recommended technique for the identification of driver mutations in the five hot-spot genes (EGFR, ALK, ROS1, MET, and BRAF) involved in the NSCLC. NGS has numerous advantages including multiplexing, tissue conservation, identification of rare and novel variants, and reduced cost over the sequential single gene testing. Herein, we sought to demonstrate the mutational profile in NSCLC and their clinicopathologic correlation in a contemporary cohort of Indian NSCLC patients. Additionally, we studied the correlation of oncogenic driver mutations with PD-L1 status in these patients.

MATERIALS AND METHODS

Five fifty-two stage IV NSCLC patients (adenocarcinoma=490; squamous cell carcinoma=51; adenosquamous carcinoma=5; large cell carcinoma=2; sarcomatoid carcinoma=3; spindle cell carcinoma=1) underwent broad molecular profiling by a custom-made, targeted DNA- and RNA-based five hot-spot genes lung cancer panel (EGFR, ALK, ROS1, BRAF, and MET), compatible with the NGS Ion S5 system. The mutations were correlated with the clinicopathologic characteristics. Additionally, PD-L1 expression status, available on 252 tumors, was correlated with the oncogenic drivers.

RESULTS

Validation of the 5 gene panel yielded the following results: a) specificity of 99.74%; b) sensitivity of 100% for single nucleotide variants (SNVs) (>5% variant allele frequency, VAF), indels (>10% VAF) and fusions; c) 100% intra- and inter-run reproducibility; d) 88% inter-laboratory agreement. Validated panel was then used to analyze clinical samples. Sixty percentage tumors harbored either one (54.71%) or multiple (3.26%) mutations. EGFR and BRAF V600E mutations, ALK and ROS1 rearrangements, and MET exon 14 skipping mutation were observed in 38.41% (n = 212) and 2.72% (n = 15) patients, 12.14% (n = 67) and 3.62% (n = 20) patients, and 1.09% (n = 6) patients, respectively. EGFR exon 19 deletion accounted for 52.83% of all mutations, followed by L858R (35.85%), T790M (5.19%), exon 20 insertions (6.6%), and other rare mutations (G719X, L861Q, S768I) (9.91%). Concurrent EGFR with ALK, EGFR with ROS1, EGFR with MET, and EGFR with BRAF were observed in 10, 4, 1, and 3 patients, respectively. PD-L1 was expressed in 134 patients (53.2%). Exon 19 deletion was more prevalent in PD-L1 negative tumors whereas exon 21 substitution (L858R) was seen more in PD-L1 positive tumors.

CONCLUSIONS

This is one of the largest cohorts of NSCLC for comprehensive targeted mutational profiling and correlation with the PD-L1 expression. The mutations are more prevalent in non-smoker females for all genes, except ALK (non-smoker males). MET and BRAF mutations are more common in elderly population whereas EGFR mutations, and ALK and ROS1 genes rearrangements are more prevalent in younger population. The most common histopathologic subtype/feature associated with various mutations was as follows: acinar with EGFR, solid with ALK, macronucleoli with ROS1, signet ring with MET, and micropapillary with BRAF.

Molecular patterns of egyptian patients with non-squamous non-small-cell lung cancers: a clinicopathological study

BACKGROUND

Driver molecular aberrations, such as epidermal growth factor receptor (EGFR) mutation and anaplastic lymphoma kinase (ALK) gene rearrangement, play an important role in the oncogenesis and progression of non-squamous non-small-cell lung cancers (NSCLC). Therefore, this study aimed to detect the incidence of driver mutations among non-squamous NSCLC.

PATIENTS AND METHODS

This was a retrospective-prospective cohort study on 131 patients with non-squamous NSCLC. Data on age, smoking status, chest symptoms, method of lung cancer diagnosis, molecular testing, including EGFR mutations in formalin-fixed paraffin-embedded (FFPE) tumor tissue and serum circulating tumor DNA using next-generation sequencing and ALK gene rearrangement by FFPE tumor tissue, and follow-up data regarding treatment modalities and outcomes were collected.

RESULTS

The median age of the patients was 57 years (range: 32-79 years). Out of 131 patients, 97 were males (74%), and 90 (68.7%) were smokers. Among 128 patients tested, 16 (12.5%) had EGFR mutations detected with either technique by formalin-fixed paraffin-embedded (FFPE) tumor tissue or/and serum circulating tumor DNA using next-generation sequencing, and 6 (4.7%) had ALK rearrangement by FFPE tumor tissue. The majority (62.6%) presented with metastatic disease. Among the 102 patients who received first-line systemic therapy, the objective response rate was 50.0% in mutated NSCLC versus 14.6% in non-mutated (p < 0.001). Among the eight mutated patients who received first-line tyrosine kinase inhibitors (TKIs), 7 patients achieved either complete response or partial response. Among the 22 mutated patients, the median overall survival was 3 months in those who did not receive targeted therapy versus not reached in those who received any type of targeted therapy (p < 0.001).

CONCLUSION

Screening patients with newly diagnosed non-squamous NSCLC for driver mutations is essential for major prognostic and therapeutic implications. Early administration of TKIs in mutated patients significantly improves disease outcomes.

Prevalence of highly actionable mutations among Indian patients with advanced non-small cell lung cancer: A systematic review and meta-analysis

BACKGROUND

Non-small cell lung cancer (NSCLC) remains a leading cause of cancer-related mortality in India. To clarify rates of actionable mutations, and thereby identify opportunities to improve the delivery of best available care for a large volume of patients, a comprehensive review of available data is warranted.

METHODS

Studies that reported prevalence of any actionable gene variant among adult Indian patients with advanced NSCLC were selected from three databases (PubMed, EMBASE, and Cochrane Library). Ranges in actionable variant prevalence were reported. Meta-analysis of proportions was completed among studies specifically evaluating mutational prevalence within ALK or EGFR. Sensitivity analyses were undertaken among populations sharing high heterogeneity.

RESULTS

Twenty-six studies were selected. Ranges in actionable mutational prevalence among NSCLC patients were as follows: ALK: 4.1-21.4%, BRAF: 1.5-3.5%, EGFR: 11.9-51.8%, HER2: 0-1.5%, KRAS: 4.5-6.4%, NTRK: 0-.7%, and ROS-1: 3.5-4.1%. Following sensitivity analysis, pooled ALK mutational prevalence rates were 8.3% (95% CIs: 6.6-10.4%) and 4.01% (95% CIs: 2.3-7.0) for adenocarcinoma and NSCLC patients, respectively. Pooled EGFR mutational prevalence rates were 28.7% (95% CIs: 23.5-34.6%) and 24.2% (95% CIs: 19.9-29.1%) for adenocarcinoma and NSCLC patients, respectively.

CONCLUSIONS

Nearly 40% of Indian patients with advanced adenocarcinoma and 30% with NSCLC share an actionable mutation in ALK or EGFR. Approximately one-half of adenocarcinoma patients have an actionable variant. Efforts should be directed toward efficiently identifying candidates for targeted agents and delivering such treatments.

Frequency of EGFR mutations in lung adenocarcinoma patients - A study from tertiary cancer center of South India

BACKGROUND AND OBJECTIVES

Epidermal growth factor receptor (EGFR) mutation analysis has become an important part of the initial workup of non-squamous non-small cell lung cancer (NS-NSCLC) patients. This study is attempted as South Indians population is comprised of ethnic groups with diverse genetic makeup and only very limited data on EGFR mutation is available from south India. A detailed understanding of EGFR mutation profile will help in better planning of treatment strategies and resource allocation.

METHODS

A retrospective analysis of EGFR mutation frequency in 350 patients diagnosed with adenocarcinoma of lung and its association with pathological characteristics was done.

RESULTS

Out of 350 cases of pulmonary adenocarcinoma, within an age group ranging from 30 to 86 years. EGFR mutations were identified in 34.8% (n = 122) cases, out of which 35.24% (n = 43) were in non-smoker females (P = 0.001). Of the 14 cases with resistant type of EGFR mutations, nine were in smoker males and the remaining five in non-smoker females.

INTERPRETATION AND CONCLUSION

Overall EGFR mutation frequency observed in our study was similar to other Indian studies. However, in our study, we observed that mutation in exon 21 was less frequent compared to other studies. A similar slightly increased frequency of rare mutations and double mutations were observed in our study. A detailed study of the molecular epidemiology of lung cancer and its association with different geographical zones of India is needed. This understanding will help in better planning of treatment strategies and resource allocation.

The Frequency of Epidermal Growth Factor Receptor (EGFR) mutations in Iraqi patients with Non-Small Cell Lung Cancer (NSCLC)

Objective:

Non-Small Cell Lung Cancer (NSCLC) Carcinogenesis could be caused by numerous genetic mutations, one of the most common is the mutation in the Epidermal Growth Factor Receptor (EGFR) which was used in the advanced stages of the disease as a therapeutic goal. This study aims to estimate the frequency of Epidermal Growth Factor Receptor mutations in Iraqi patients with Non-Small Cell Lung Cancer.

Methods:

One hundred thirty-eight patients confirmed with NSCLC have participated in this study, patients were sent for EGFR testing by different oncology centers in Iraq. Data and samples were collected. The Mutation was detected using COBAS^® DNA Sample Preparation Kit that designed to detect the following mutations: Exon 19: deletions and complex mutations; Exon 21: L861Q and L858R; Exon 18 mutation: G719X (G719A, G719C, and G719S); Exon 20: S768I, T790M, and insertions, this kit utilizes the technology of the real time Polymerase Chain Reaction.

Results:

This study was included 79 males and 59 females, with a mean age of 60.1±12.4 years. A positive EGFR mutations were found in 38 (27.53%) of samples. Exon 19 deletions (25/38, 65.8%) and substitution L858R in exon 21 10/38 (26.3%) were the most common mutations. Multiple mutations (Exon 20 and 19 combined together) were founded in 2/38 (5.3%), and 1/38 (2.6%) ALK mutation. Non-significant differences among age groups and gender in the incidence of mutations were found.

Conclusion:

The current study represents the first epidemiological study in Iraq to find EGFR mutations frequency among NSCLC patients that reveals the incidence rate of 27.53%, which is between the higher prevalence rate in Asian populations and lower rates in western countries. These results explain the genetic differences of NSCLC in the world due to ethnic differences of the population, more studies are needed in Arab countries to study the EGFR mutations, find the effect of ethnicity and environmental factors for lung cancer, and the subsequent therapy.

Predictive biomarkers in nonsmall cell carcinoma and their clinico-pathological association

Background:

Lung cancer is the leading cause of cancer-related mortality worldwide. Genome-directed therapy is less toxic, prolongs survival and provides a better quality of life. Predictive biomarker testing, therefore, has become a standard of care in advanced lung cancers. The objective of this study was to relate clinical and pathological features, including response to targeted therapy (TT) and progression-free survival (PFS) with positive driver mutation.

Materials and Methods:

Archival data of nonsmall cell carcinoma patients with Stage IV disease were retrieved. Those who tested positive for one of the four biomarkers (epidermal growth factor receptor [EGFR], anaplastic lymphoma kinase [ALK], MET, and ROS) were included. Patient demographics and clinical features were reviewed. Tumor histomorphology was correlated with oncological drivers. Treatment response, PFS, and overall survival were studied in three subcohorts of patients who received computed tomography (CT), CT followed by TT and those who received TT in the first line.

Results:

A total of 900 patients underwent biomarker evaluation of which 288 tested positive. Frequency of the four biomarkers observed was 26.6% (229/860), 6.6% (51/775), 6.6% (5/75), and 5.1% (3/59) for EGFR, ALK, MET, and ROS-1, respectively. The median PFS for EGFR-mutated cohort was 12 months, whereas it was 21 months for ALK protein overexpressing cases. Patients treated with first-line tyrosine kinase inhibitors performed better compared to those who were switched from chemotherapy to TT or those who received chemotherapy alone (P < 0.05).

Conclusion:

Biomarker testing has improved patient outcome. Genome-directed therapy accords best PFS with an advantage of nearly 10 months over cytotoxic therapy.

Clinical predictors of response to EGFR-tyrosine kinase inhibitors in EGFR-mutated non-small cell lung cancer: A real-world multicentric cohort analysis from India

BACKGROUND

The development of various targeted therapies against Epidermal Growth Factor Receptor (EGFR) has been a major step in therapeutic advancements in lung cancer. However, the response to tyrosine kinase inhibitors (TKI) therapy in a real-world setting has not been well elucidated.

METHODS

As part of a retrospective analysis, patients with EGFR mutated non-small cell lung cancer at 4 tertiary care Institutions in North India between December 2007 and August 2018 were evaluated. The overall response rate, disease control rate, progression-free survival (PFS) and factors affecting PFS were analyzed.

RESULTS

A total of 483 patients were included, including 52.4% males, with mean (±SD) age of 56.7 (±12.4) years. Majority (63.8%) had good performance status (Eastern Cooperative Oncology Group 0 or 1) and 77.4% were nonsmokers. Among the EGFR mutations, exon 19 deletion was the most common mutation detected (68.1%), followed by L858R mutation in exon 21 (26.9%). Extra-thoracic metastasis was present in 69.5% patients and majority of them had ≤ 2 metastatic sites (85.1%). TKIs were used as the first-line therapy in 64.8% patients, and gefitinib was the most frequently used TKI (67.3%), followed by erlotinib (26.7%). The overall response rate and disease control rate were 65.9% and 90.7% respectively. The median PFS was 9.3 months and brain was the exclusive site of progression in 18.0% patients. On univariate analysis, the factors that significantly affected PFS were, the number of metastatic sites and the type of EGFR mutation. On multivariate analysis, the number of metastatic sites was the only factor that affected the PFS [HR (95% CI): 2.5 (1.7-3.6); Pvalue <0.001]. Skin toxicity was the most common adverse event (32.3%), followed by involvement of the gastro-intestinal tract (22.5%).

CONCLUSION

In this one of the largest multicentric Indian study of treatment outcomes in EGFR-mutated non-small cell lung cancer in a real-world setting, we found that increased tumor burden (number of metastatic sites > 2) was the only significant factor associated with a worse PFS.

Multiplexed molecular profiling of lung cancer with malignant pleural effusion using next generation sequencing in Chinese patients

Lung cancer is the most common type of cancer and the leading cause of cancer-associated death worldwide. Malignant pleural effusion (MPE), which is observed in ~50% of advanced non-small cell lung cancer (NSCLC) cases, and most frequently in lung adenocarcinoma, is a common complication of stage III-IV NSCLC, and it can be used to predict a poor prognosis. In the present study, multiple oncogene mutations were detected, including 17 genes closely associated with initiation of advanced lung cancer, in 108 MPE samples using next generation sequencing (NGS). The NGS data of the present study had broader coverage, deeper sequencing depth and higher capture efficiency compared with NGS findings of previous studies on MPE. In the present study, using NGS, it was demonstrated that 93 patients (86%) harbored EGFR mutations and 62 patients possessed mutations in EGFR exons 18-21, which are targets of available treatment agents. EGFR L858R and exon 19 indel mutations were the most frequently observed alterations, with frequencies of 31 and 25%, respectively. In 1 patient, an EGFR amplification was identified and 6 patients possessed a T790M mutation. ALK + EML4 gene fusions were identified in 6 patients, a ROS1 + CD74 gene fusion was detected in 1 patient and 10 patients possessed a BIM (also known as BCL2L11) 2,903-bp intron deletion. In 4 patients, significant KRAS mutations (G12D, G12S, G13C and A146T) were observed, which are associated with resistance to afatinib, icotinib, erlotinib and gefitinib. There were 83 patients with ERBB2 mutations, but only two of these mutations were targets of available treatments. The results of the present study indicate that MPE is a reliable specimen for NGS based detection of somatic mutations.

Clinical profile of lung cancer in North India: A 10-year analysis of 1862 patients from a tertiary care center

Introduction:

Over the past few years, the demographic profile of lung cancer has changed. However, most reports are limited by small numbers, short follow-up period, and show an inconsistent pattern. A comprehensive evaluation of changing trends over a long period has not been done.

Materials and Methods:

Consecutive lung cancer patients were studied over a 10-year period from January 2008 to March 2018 at the All India Institute of Medical Sciences, New Delhi, and relevant clinical information, and survival outcomes were analyzed.

Results:

A total of 1862 patients were evaluated, with mean (SD) age of 59 (11.1) years, and comprising 82.9% males. Majority were smokers (76.2%) with median smoking index of 500 (interquartile range [IQR]: 300–800). Adenocarcinoma (ADC) was the most common type (34%), followed by squamous cell carcinoma (SCC – 28.6%) and small cell lung cancer (SCLC) (16.1%). Over the 10-year period, ADC increased from 9.5% to 35.9%, SCC from 25.4% to 30.6%, and non-small cell lung cancer -not otherwise specified (NSCLC-NOS) decreased from 49.2% to 21.4%. The proportion of females with lung cancer increased although smoking rates remained similar. Majority of NSCLC (95%) continued to be diagnosed at an advanced stage (3 or 4). Epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK) rearrangements were present in 25.3% and 11.5% ADC patients, respectively. The median overall survival was 8.8 months (IQR 3.7–19) for all patients and 12.57 (IQR 6.2–28.7) months among the 1013 patients who were initiated on specific treatment (chemotherapy, targeted therapy, radiotherapy, or surgery). Never-smokers were younger, more likely to be female and educated, had a higher prevalence of ADC and EGFR/ALK mutations, and had better survival.

Conclusion:

Among this large cohort, our center seems to follow the global trend with increasing incidence of ADC. EGFR mutation positivity was similar to existing reports, while higher ALK positivity was detected. A characteristic phenotype of never-smokers with lung cancer was elucidated which demonstrated better survival.

EGFR mutation frequency in Middle East and African non-small cell lung cancer patients: a systematic review and meta-analysis

BACKGROUND

Our goal was to investigate the prevalence of the epidermal growth factor receptor (EGFR) mutation in Middle East and African countries and to compare its prevalence with that shown in other populations.

METHODS

We used PubMed and the Cochrane Library databases to conduct a literature search using the terms "[EGFR] AND [mutation] AND [Non Small Cell Lung Cancer] AND [Middle East OR Africa]." We assessed studies published in English and French from 2004 until 2016.

RESULTS

Ten relevant studies were included in this systematic review. Overall, 1215 patients with non-small cell lung cancer (NSCLC) were included in this analysis. The overall ratio of male to female patients was 2.15. Of total patients included, 41.1% had never smoked and 85.8% had been diagnosed with adenocarcinoma. In 8 of the 10 studies, polymerase chain reaction (PCR) analyses were conducted to identify EGFR mutations. In total, 257 patients had an EGFR mutation, corresponding to a prevalence of 21.2%. The most frequent abnormality detected in all of the studies was in exon 19. In addition, all studies concluded the presence of a correlation between EGFR mutation status and female sex, non-smoking status, and adenocarcinoma subtype.

CONCLUSIONS

The EGFR mutation frequency in Middle East and African patients is higher than that shown in white populations but still lower than the frequency reported in Asian populations.

Serum EGFR gene mutation status via second-generation sequencing and clinical features of patients with advanced lung cancer

Objective: To detect the serum epithelial growth factor receptor (EGFR) gene mutation status in patients with lung cancer via second-generation sequencing and to analyze its correlations with the clinical features of patients and its therapeutic effects. Methods: A total of 110 patients with non-small cell lung cancer (NSCLC) treated in our hospital were recruited as subjects of our study. The distribution of the EGFR gene mutation in patients was detected via second-generation sequencing and then patients were divided into mutant-type EGFR group (n=37) and wild-type EGFR group (n=73). The clinical features and therapeutic effects were compared between the two groups of patients. Results: A total of 5 kinds of EGFR gene mutation [19del (45.95%), L858R (43.24%), L861Q (5.41%), S768I (2.70%), and G719X (2.70%)] were detected via second-generation sequencing. In the mutant-type EGFR group, the proportions of female patients, patients with adenocarcinoma, and those with no history of smoking were high, and the differences were statistically significant (P<0.05). Moreover, there were statistically significant differences in gender, type of cancer, tumor-node-metastasis (TNM) staging, and smoking history between the mutant-type EGFR group and the wild-type EGFR group (P<0.05). Results of a multivariate logistic regression analysis showed that the EGFR gene mutation status was significantly associated with the type of cancer, gender, TNM staging, and smoking history of patients with NSCLC (P<0.05). The clinical effective rate of patients in the mutant-type EGFR group was significantly higher than that in the wild-type EGFR group (54.05% vs. 19.18%) while progression-free survival (PFS) was significantly longer than that in the wild-type EGFR group [(9.75±1.64) months vs. (5.51±0.40) months] (P<0.05). The expression level of carcinoembryonic antigen (CEA) in patients in the mutant-type EGFR group was apparently higher than that in the wild-type EGFR group, but the levels of carbohydrate antigen 125 (CA125), CY21-1 and squamous cell carcinoma-related antigen (SCC-Ag) were apparently lower than those in the wild-type EGFR group. There were statistically significant differences in the expression levels of serum tumor markers between the two groups (P<0.05). Conclusion: EGFR mutation status is closely related to the clinical features of NSCLC patients, such as gender, type of cancer, tumor staging, smoking history, and clinical effect. The second-generation sequencing is an important detection method to identify EGFR gene mutation status, which provides an applicable scaffold for the clinical treatment of patients.

Phytanic acid activates NADPH oxidase through transactivation of epidermal growth factor receptor in vascular smooth muscle cells

BACKGROUND

Phytanic acid (PA) has been implicated in development of cancer and its defective metabolism is known to cause life-threatening conditions, such as Refsum disease, in children. To explore molecular mechanisms of phytanic acid-induced cellular pathology, we investigated its effect on NADPH oxidase (NOX) and epidermal growth factor receptor (EGFR) in rat aortic smooth muscle cells (RASMC).

METHODS

Smooth muscle cells were isolated from rat aortae using enzymic digestion with collagenase and elastase. Cultured RASMC were treated with varying concentrations (0.5-10 μg/ml) of phytanic acid in the presence/absence of fetal bovine serum (FBS) and/or EGFR inhibitor, AG1478. Following treatment with experimental agents, NOX activity was assayed in RASMC cultures by luminescence method. Gene expression of NOX-1 and p47phox was assessed using RT-PCR. NOX-1, p47phox and, total EGFR protein and its phosphorylated form were measured by Western blotting.

RESULTS

Treatment of RASMC with supraphysiological concentrations (>2.5 μg/ml) of PA significantly (p < 0.01) increased the NOX activity. PA also significantly increased gene/protein expression of NOX-1 and p47phox whereas p22phox and p67phox remained unaffected. Interestingly, PA (2.5-10 μg/ml) markedly (2-3 folds) increased the total and phosphorylated EGFR. Treatment of cells with EGFR inhibitor, AG1478, significantly blocked the PA-induced enhancement of NOX activity.

CONCLUSIONS

Our findings that PA transactivates EGFR and induces NOX activity in vascular smooth muscle cells provide new insights into molecular mechanisms of PA's role in cancer and Refsum disease.