Association between vascular-poor area of primary tumors and epidermal growth factor receptor gene status in advanced lung adenocarcinoma

Worldwide Prevalence of Epidermal Growth Factor Receptor Mutations in Non-Small Cell Lung Cancer: A Meta-Analysis

Background

Identification of variable epidermal growth factor receptor (EGFR) gene mutations in non-small cell lung cancer (NSCLC) is important for the selection of appropriate targeted therapies. This meta-analysis was conducted to provide a worldwide overview of EGFR mutation and submutation (specifically exon 19 deletions, exon 21 L858R substitutions, and others) prevalence, and identify important covariates that influence EGFR mutation status in patients with advanced NSCLC to address this clinical data gap.

Methods

Embase^® and MEDLINE^® in Ovid were searched for studies published between 2004 and 2019 with cohorts of ≥ 50 adults with EGFR mutations, focusing on stage III/IV NSCLC (≤ 20% of patients with stage I/II NSCLC). Linear mixed-effects models were fitted to EGFR mutation endpoints using logistic transformation (logit), assuming a binomial distribution. The model included terms for an intercept reflecting European studies and further additive terms for other continents. EGFR submutations examined were exon 19 deletions, exon 21 L858R substitutions, and others.

Results

Of 3969 abstracts screened, 57 studies were included in the overall EGFR mutation analysis and 74 were included in the submutation analysis relative to the overall EGFR mutation population (Europe, n = 12; Asia, n = 51; North America, n = 5; Central America, n = 1; South America, n = 1; Oceania, n = 1; Global, n = 3). The final overall EGFR mutations model estimated Asian and European prevalence of 49.1% and 12.8%, respectively, and included an additive covariate for the proportion of male patients in a study. There were no significant covariates in the submutation analyses. Most submutations were actionable: exon 19 deletions (49.2% [Asia]; 48.4% [Europe]); exon 21 L858R substitutions (41.1% [Asia]; 29.9% [Europe]).

Conclusions

Although EGFR mutation prevalence was higher in Asian than Western countries, data support worldwide testing for EGFR overall and submutations to inform appropriate targeted treatment decisions.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40291-021-00563-1.

Tumor immune microenvironment in epidermal growth factor receptor-mutated non-small cell lung cancer before and after epidermal growth factor receptor tyrosine kinase inhibitor treatment: a narrative review

Objective

To review and summarize the characteristics of the tumor immune microenvironment (TIME) in EGFR-mutated non-small cell lung cancer (NSCLC) after EGFR-TKI treatment and its role in TKI resistance.

Background

Lung cancer is one of the most commonly diagnosed cancer and the leading cause of death from cancer in both men and women around the world. Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are considered a first-line treatment for EGFR-mutated NSCLC. However, almost all patients eventually develop acquired resistance to EGFR-TKIs, with a median progression-free survival (PFS) of 9–14 months. As immunotherapy has developed, it has become apparent that interactions between the TIME and tumor cells also affect EGFR-TKI treatment. The TIME comprises a variety of components but previous studies of the TIME following EGFR-TKI therapy of NSCLC are inconsistent. Here, we reviewed the characteristics of the TIME in NSCLC after EGFR-TKI treatment and its role in TKI resistance.

Methods

PubMed, Embase, and Web of Science were searched to July 1, 2021 with the following key words: “NSCLC”, “EGFR”, and “immunotherapy”.

Conclusions

The TIME of EGFR-mutated NSCLC is different from that of non-mutated NSCLC, an explanation for EGFR-mutated NSCLC displaying a poor response to ICIs. The TIME of EGFR-mutated NSCLC also changes during treatment with EGFR-TKIs. The TIME in EGFR-TKI-resistant lung cancer can be summarized as follows: (I) compared with EGFR-TKI-sensitive tumors, EGFR-TKI-resistant tumors have a greater number of immunosuppressive cells and fewer immune-activated cells, while the tumor microenvironment is in an immunosuppressive state; (II) tumor cells and immunosuppressive cells secrete multiple negative immune regulatory factors, inhibit the recognition and presentation of tumor antigens and the antitumor effect of immune cells, resulting in immune escape; 3.EGFR-TKI-resistant tumors promote EMT. These three characteristics interact, resulting in a regulatory signaling network, which together leads to EGFR-TKI resistance.