Prevalence of EGFR Mutations in Lung Cancer in Uruguayan Population

Geographic differences in lung cancer: focus on carcinogens, genetic predisposition, and molecular epidemiology

Lung cancer poses a global health challenge and stands as the leading cause of cancer-related deaths worldwide. However, its incidence, mortality, and characteristics are not uniform across all regions worldwide. Understanding the factors contributing to this diversity is crucial in a prevalent disease where most cases are diagnosed in advanced stages. Hence, prevention and early diagnosis emerge as the most efficient strategies to enhance outcomes. In Western societies, tobacco consumption constitutes the primary risk factor for lung cancer, accounting for up to 90% of cases. In other geographic locations, different significant factors play a fundamental role in disease development, such as individual genetic predisposition, or exposure to other carcinogens such as radon gas, environmental pollution, occupational exposures, or specific infectious diseases. Comprehensive clinical and molecular characterization of lung cancer in recent decades has enabled us to distinguish different subtypes of lung cancer with distinct phenotypes, genotypes, immunogenicity, treatment responses, and survival rates. The ultimate goal is to prevent and individualize lung cancer management in each community and improve patient outcomes.

Prevalence of oncogenic driver mutations in Hispanics/Latin patients with lung cancer. A systematic review and meta-analysis

INTRODUCTION

The frequency of actionable mutations varies between races, and Hispanic/Latino (H/L) people are a population with different proportions of ancestry. Our purpose was to establish prevalence of actionable mutations in the H/L population with NSCLC.

METHODS

EMBASE, LILACS, MEDLINE, and Virtual Health Library were searched for studies published up to April 2023 that evaluated the prevalence of ALK, BRAF, EGFR, HER-2, KRAS, MET, NTRK, RET, ROS1 in H/L patients. Meta-analyses were done to determine prevalence using a random effects model.

RESULTS

Fifty-five articles were included. EGFR and KRAS were the most prevalent genes with high heterogeneity across the countries. The overall mutation frequency for EGFR was 22%. The most frequent mutations in the EGFR gene were del19 (10%) and L858R (7%). The mean of KRAS mutation was a 14% prevalence. KRASG12C was the most frequent mutation with a 7% prevalence in an entire population. The overall frequency of ALK rearrangement was 5%. The mean frequency of ROS-1 rearrangement was 2%, and the frequencies of HER-2, MET, BRAF, RET, NTRK molecular alterations were 4%, 3%, 2%, 2%, and 1% respectively. Almost half of the cases were male, and 65.8% had a history of tobacco exposure. The most common clinical stage was IV.

CONCLUSIONS

The prevalence of driver mutations such as EGFR and KRAS in LA populations differs from what is reported in Asians and Europeans. In the present article, countries with a high proportion of Amerindian ancestry show a greater prevalence of EGFR in contrast to countries with a high proportion of Caucasians. Lack of information on some countries or studies with a small sample size affects the real prevalence data for the region.

Management of Oligometastasis and Oligoprogression in Patients with Epidermal Growth Factor Receptor Mutation-Positive NSCLC in the Era of Third-Generation Tyrosine Kinase Inhibitors

This review covers the importance of local consolidative therapy (LCT) in patients with epidermal growth factor receptor (EGFR) mutation-positive with oligometastatic and oligoprogressive non-small-cell lung cancer (NSCLC). With the advent of third-generation EGFR tyrosine kinase inhibitors, a more updated review is necessary. We review the efficacy of LCT, pathophysiological background, and treatment modalities other than radiotherapy. In addition, we also discussed when and how LCT should be applied to patients with oligometastatic and oligoprogressive NSCLC.

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.

Genomic Diversity in Sporadic Breast Cancer in a Latin American Population

Among Latin American women, breast cancer incidences vary across populations. Uruguay and Argentina have the highest rates in South America, which are mainly attributed to strong, genetic European contributions. Most genetic variants associated with breast cancer were described in European populations. However, the vast majority of genetic contributors to breast cancer risk remain unknown. Here, we report the results of a candidate gene association study of sporadic breast cancer in 176 cases and 183 controls in the Uruguayan population. We analyzed 141 variants from 98 loci that have been associated with overall breast cancer risk in European populations. We found weak evidence for the association of risk variants rs294174 (ESR1), rs16886165 (MAP3K1), rs2214681 (CNTNAP2), rs4237855 (VDR), rs9594579 (RANKL), rs8183919 (PTGIS), rs2981582 (FGFR2), and rs1799950 (BRCA1) with sporadic breast cancer. These results provide useful insight into the genetic susceptibility to sporadic breast cancer in the Uruguayan population and support the use of genetic risk scores for individualized screening and prevention.

Analysis of Predictive Biomarkers in Patients With Lung Adenocarcinoma From Southern Brazil Reveals a Distinct Profile From Other Regions of the Country

PURPOSE

Adenocarcinoma is the most common histologic subtype of non–small-cell lung cancer, representing 40% of all diagnoses. Several biomarkers are currently used to determine patient eligibility for targeted treatments, including analysis of molecular alterations in EGFR and ALK, as well as programmed death-ligand 1 (PD-L1) protein expression. Epidemiologic data reporting the frequency of these biomarkers in Brazilian patients with lung adenocarcinoma (LUAD) are limited, and existing studies predominantly included patients from the southeast region of the country.

MATERIALS AND METHODS

The goal of this study was to investigate the frequency of somatic mutations in the EGFR, KRAS, NRAS, and BRAF genes, ALK, and PD-L1 expression in a series of Brazilian patients diagnosed with LUAD predominantly recruited from centers in southern Brazil. Molecular analysis of the EGFR, KRAS, NRAS, and BRAF genes was performed by next-generation sequencing using DNA extracted from tumor tissue. Immunohistochemistry was used to detect ALK and PD-L1 expression.

RESULTS

Analysis of 619 tumors identified KRAS mutations in 189 (30.2%), EGFR mutations in 120 (19.16%), and BRAF mutations in 19 (3%). Immunohistochemistry demonstrated ALK and PD-L1 expression in 4% and 35.1% of patients, respectively.

CONCLUSION

To our knowledge, this is the first study investigating the molecular epidemiology of patients with LUAD from southern Brazil and the largest assessing the frequency of multiple predictive biomarkers for this tumor in the country. The study also reveals a distinct mutation profile compared with data originating from other regions of Brazil.

T790M mutations identified by circulating tumor DNA test in lung adenocarcinoma patients who progressed on first-line epidermal growth factor receptor-tyrosine kinase inhibitors

Background:

Plasma circulating tumor deoxyribonucleic acid (ctDNA) test is an alternative method to detect the T790M mutation. Compared to conventional tumor rebiopsy, ctDNA possesses several advantages including less invasive, faster, lower costs, and having minimal risk of complications for patients.

Objective:

The main objective of the study is to identify the prevalence of T790M mutations in lung adenocarcinoma patients who progressed after tyrosine kinase inhibitors (TKIs) therapy using ctDNA examination.

Materials and Methods:

This was a retrospective cohort study based on medical records of lung adenocarcinoma patients in the Oncology Outpatient Clinic of Dr. Soetomo General Hospital within the period of January 2017–June 2018. Patients who progressed after receiving first-line epidermal growth factor receptor-TKI (EGFR-TKI) undergone plasma ctDNA examination and genotyping using digital platforms (Droplet Digital™ PCR) method.

Results:

In total, there were 39 patients who met the criteria for ctDNA testing. Thirty-three patients (84.6%) received first-line gefitinib, while the other six (15.4%) received erlotinib. The T790M mutations were detected in 46.2% of patients. In addition, EGFR common mutation in exon 19 and exon 21 were detected in 87.2% of patients. Median progression-free survival of patients receiving first-line gefitinib or erlotinib were both around 9 months and did not differ significantly.

Conclusions:

CtDNA examination successfully detected T790M mutation in a certain proportion of lung adenocarcinoma patients who progressed after first-line EGFR-TKI without the need for difficult and invasive rebiopsy.

Prevalence of EGFR Mutations and Clinico-Pathological Characteristics of Chilean Lung Cancer Patients

Background:

Lung cancer (LC) is the second leading cause of cancer death in Chile, causing >3,000 deaths every year. Epidemiological LC data in Chile is scarce and scattered. Here, we aimed to quantify the prevalence of Epidermal Growth Factor Receptor (EGFR) gene mutations in a Chilean cancer center. These data may identify individuals that could benefit from targeted therapies such as Tyrosine Kinase Inhibitors (TKIs).

Methods:

A total of 1,405 Biopsies from 1,381 LC patients were retrospectively analyzed retrieving clinical data from EGFR mutants including age, gender, histological type, smoking habits and type of EGFR mutation. We also analyzed overall survival (OS) rates.

Results:

From all patients 21.7% had clinically relevant EGFR mutations, and a median age at diagnosis of 65 years. Most were female (64%), classified as adenocarcinomas (94.5%), and non-smokers/light smokers (93.1%). The most prevalent mutation was exon-19 deletions (50.6%) followed by Leucine-to Arginine 858; OS was 15 months. Clinical follow-up information was available for 83 patients. The use of TKIs in these patients significantly improved OS.

Conclusion:

The prevalence of EGFR mutations in the studied population was 21.7%, comparable to other countries in Latin America. The most frequent EGFR mutation was exon-19 deletion, OS in this group was 15 months, and TKIs significantly improved OS.