Therapeutic Effect of First-line Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor (EGFR-TKI) Combined with Whole Brain Radiotherapy on Patients with EGFR Mutation-positive Lung Adenocarcinoma and Brain Metastases

In-depth exploration of the focus issues of TKI combined with radiotherapy for EGFR-mutant lung adenocarcinoma patients with brain metastasis: a systematic analysis based on literature metrology, meta-analysis, and real-world observational data

BACKGROUND

There is a growing interest in utilizing a combination of brain radiotherapy (RT) and tyrosine kinase inhibitors (TKIs) for patients diagnosed with brain metastases (BM) in epidermal growth factor receptor (EGFR) mutation-positive lung adenocarcinoma (LAC). The current status of this treatment strategy remains a subject of debate.

METHODS

We initiated our study by conducting a comprehensive literature search using the SCI-expanded database of Web of Science Core Collection (WoSCC). We utilized the VOSPviewer software to analyze various aspects of the research, including the year of publication, authorship, keywords, and country.Subsequently, we performed an extensive and systematic literature search on popular online databases. Our primary outcome measures were overall survival (OS) and intracranial progression-free survival (iPFS), both quantified by hazard ratios (HRs). Additionally, for data verification, we included data from patients in non-small cell lung cancer with brain metastasis who underwent therapeutic intervention at the Cancer Prevention and Treatment Center of Sun Yat-sen University and the Radiotherapy Department of Hanzhong Central Hospital between August 2012 and November 2021.

RESULTS

The bibliometric analysis revealed an increasing trend in research focused on the combination of RT and TKIs for the management of lung cancer brain metastases over the previous decade. Then, nine studies consistent with the research direction were included for meta-analysis. The meta-analysis showed that the OS (HR = 0.81, 95% confidence interval: 0.69-0.94; P = 0.007) and iPFS (HR = 0.71, 95% confidence interval: 0.61-0.82; P < 0.001) of the combination therapy were significantly prolonged. Finally, 168 EGFR-mutated BM advanced LAC patients in the real world were verified, and the median iPFS of the combination therapy (n = 88 and EGFR-TKIs alone (n = 80) were 16.0 and 9.0 months, respectively, (P < 0.001). The median OS was 29.0 and 27.0 months, respectively, with no dramatic difference (P = 0.188).

CONCLUSIONS

Research on EGFR-mutant LAC brain metastasis has turned towards exploring optimal treatment strategies for this condition. Our meta-analysis and real-world data analysis consistently demonstrate that combination therapy offers a substantial improvement in patient survival compared to EGFR-TKI monotherapy. Notably, among patients undergoing salvage radiotherapy (RT), our subgroup analysis reveals that those initially treated with third-generation TKIs experience more significant benefits than those treated with first- or second-generation TKIs.

EGFR-Tyrosine Kinase Inhibitor Combined with Radiotherapy in 105 Patients of Lung Adenocarcinoma with Brain Metastasis: A Retrospective Study of Prognostic Factor Analysis

INTRODUCTION

This study aimed to retrospectively analyse the response and prognosis factors for patients with lung adenocarcinoma exhibiting brain metastasis and epidermal growth factor receptor (EGFR) mutations, who were treated with a combination of EGFR-tyrosine kinase inhibitor (TKI) and brain radiotherapy (RT).

METHODS

Clinicopathological data of patients with lung adenocarcinoma were collected from January 2021 to January 2024 at the First Affiliated Hospital of Hebei North University. Statistical analysis was performed using SPSS version 26.0, with significance set at p < 0.05.

RESULTS

A total of 105 patients were included. The overall survival (OS) rates at 1, 2, and 3 years were 82.9%, 61.2%, and 33.7%, respectively. The progression-free survival 1 (PFS1) rates at 1, 2, and 3 years were 62.7%, 36.6%, and 22.1%, respectively. The progression-free survival 2 (PFS2) rates at 1, 2, and 3 years were 80.8%, 54.6%, and 31.4%, respectively. The median OS, PFS1, and PFS2 were 29.8, 18.0, and 28.1 months, respectively. Cox multivariate analysis identified gene mutation status and brain radiation dose as independent prognostic factors for OS. For PFS1, gene mutation status, brain radiation dose, and initial treatment response were independent prognostic factors. Clinical stage, gene mutation status, brain radiation dose, and initial treatment response were independent prognostic factors for PFS2.

CONCLUSION

The combination of TKIs and brain RT is effective for patients with lung adenocarcinoma with EGFR mutations and brain metastases. Patients with exon 19 Del or exon 21 L858R mutations and brain radiation doses ≥40 Gy exhibit longer OS, PFS1, and PFS2. Additionally, complete remission + partial remission is associated with extended PFS1 and PFS2, while patients in stage IVA show longer PFS2.

First-line treatment with TKI plus brain radiotherapy versus TKI alone in EGFR-mutated non-small cell Lung cancer with brain metastases: a systematic review and meta-analysis

BACKGROUND

It remains uncertain whether first-line treatment with upfront brain radiotherapy (RT) in combined with epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) is superior to EGFR-TKIs alone for EGFR-mutated non-small cell lung cancer with newly diagnosed brain metastases (BMs). Therefore, we performed a meta-analysis to address this issue.

METHODS

We searched PubMed, Embase, Cochrane Library, and Web of Science databases for eligible studies published until February 28, 2023. The primary outcomes of interest were overall survival (OS) and intracranial progression-free survival (iPFS), reported as hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

Twenty-four retrospective studies with 3184 patients were included. First- or second-generation EGFR-TKIs were used in each study. Upfront brain RT plus EGFR-TKIs significantly prolonged OS (HR = 0.75, 95% CI: 0.64-0.88) and iPFS (HR = 0.61, 95% CI: 0.52-0.72) compared to EGFR-TKIs alone. There were no significant differences in OS and iPFS benefits from the combination therapy between asymptomatic and symptomatic patients, patients with exon 19 and 21 mutations, patients with 1-3 and > 3 BMs, and males and females, respectively (HRs interaction, P > 0.05 for each subgroup comparison).

CONCLUSIONS

First-line treatment with upfront brain RT plus EGFR-TKIs is likely to be more effective than EGFR-TKIs alone. The benefits of combination therapy did not appear to be significantly affected by BM-related symptoms, EGFR mutation subtype, number of BMs, or sex.

The efficacy of EGFR-tyrosine kinase inhibitor in non-small cell lung cancer patients with synchronous brain metastasis: a real-world study

BACKGROUND/AIMS

The optimal treatment (Tx) for epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) patients with brain metastasis (BM) remains to be determined.

METHODS

A retrospective review was conducted on 77 NSCLC patients with synchronous BM who underwent first-line EGFR-tyrosine kinase inhibitor (TKI) Tx. The outcomes of patients were analyzed according to the clinicopathological characteristics including local Tx modalities.

RESULTS

Fifty-nine patients underwent local Tx for BM (gamma knife surgery [GKS], 37; whole brain radiotherapy [WBRT], 18; others, four) concurrently or sequentially with EGFR-TKI. Patients treated with TKI alone showed significantly lower incidence of central nervous system (CNS) symptoms. The median progression-free survival (PFS) and overall survival (OS) after the initiation of EGFR-TKI for all patients were 9 and 19 months, respectively. In 60 patients with follow-up brain imaging, the median time to CNS progression was 15 months. Patients with EGFR exon 19 deletion had a significantly longer median OS than those with other mutations including L858R (23 months vs. 17 months). Other clinical characteristics, including CNS symptoms, number of BM, and the use of local Tx were not associated with OS, as well as PFS. In terms of the local optimal Tx modality, no difference was found between GKS and WBRT in the OS and PFS.

CONCLUSION

This study suggests that EGFR-TKI may result in a favorable outcome in NSCLC patients with synchronous BM, especially in deletion 19 mutant, regardless of the extent of BM lesions or local Tx modalities. Patients with asymptomatic BM can be treated with EGFR-TKI and careful surveillance.

Treatment for Brain Metastases: ASCO-SNO-ASTRO Guideline

PURPOSE

To provide guidance to clinicians regarding therapy for patients with brain metastases from solid tumors.

METHODS

ASCO convened an Expert Panel and conducted a systematic review of the literature.

RESULTS

Thirty-two randomized trials published in 2008 or later met eligibility criteria and form the primary evidentiary base.

RECOMMENDATIONS

Surgery is a reasonable option for patients with brain metastases. Patients with large tumors with mass effect are more likely to benefit than those with multiple brain metastases and/or uncontrolled systemic disease. Patients with symptomatic brain metastases should receive local therapy regardless of the systemic therapy used. For patients with asymptomatic brain metastases, local therapy should not be deferred unless deferral is specifically recommended in this guideline. The decision to defer local therapy should be based on a multidisciplinary discussion of the potential benefits and harms that the patient may experience. Several regimens were recommended for non-small-cell lung cancer, breast cancer, and melanoma. For patients with asymptomatic brain metastases and no systemic therapy options, stereotactic radiosurgery (SRS) alone should be offered to patients with one to four unresected brain metastases, excluding small-cell lung carcinoma. SRS alone to the surgical cavity should be offered to patients with one to two resected brain metastases. SRS, whole brain radiation therapy, or their combination are reasonable options for other patients. Memantine and hippocampal avoidance should be offered to patients who receive whole brain radiation therapy and have no hippocampal lesions and 4 months or more expected survival. Patients with asymptomatic brain metastases with either Karnofsky Performance Status ≤ 50 or Karnofsky Performance Status < 70 with no systemic therapy options do not derive benefit from radiation therapy.Additional information is available at www.asco.org/neurooncology-guidelines.

Value and significance of brain radiation therapy during first-line EGFR-TKI treatment in lung adenocarcinoma with EGFR sensitive mutation and synchronous brain metastasis: Appropriate timing and technique

Background

For lung adenocarcinoma patients with epidermal growth factor receptor (EGFR) sensitive mutation and synchronous brain metastasis (syn‐BM), when and how to apply radiotherapy (RT) during first‐line tyrosine kinase inhibitor (TKI) treatment remains debatable.

Methods

From a real‐world multicenter database, EGFR‐mutant patients with syn‐BM diagnosed between 2010–2020 and treated with first‐line TKIs were enrolled and divided into upfront TKI + RT and upfront TKI groups. Median intracranial progression‐free survival (mIC‐PFS), median overall survival (mOS), and their risk factors were estimated.

Results

There were 60 and 186 patients in the upfront TKI + RT group and upfront TKI group, respectively. Their mIC‐PFS were 28.9 months (m) and 17.5 m (p = 0.023), and mOS were 42.7 m and 40.1 m (p = 0.51). Upfront brain RT improved mIC‐PFS in patients ≤60‐year‐old (p = 0.035), with symptomatic BM (p = 0.002), and treated with first‐generation TKIs (p = 0.012). There was no significant difference in mOS in any subgroup. Upfront brain stereotactic radiosurgery (SRS) showed a trend of better mIC‐PFS and mOS. mIC‐PFS was independently correlated with symptomatic BM (HR = 1.54, p = 0.030), EGFR L858R mutation (HR = 1.57, p = 0.019), and upfront brain RT (HR = 0.47, p = 0.001). mOS was independently correlated with being female (HR = 0.54, p = 0.007), ECOG 3–4 (HR = 10.47, p < 0.001), BM number>3 (HR = 2.19, p = 0.002), and third‐generation TKI (HR = 0.54, p = 0.044) or antiangiogenic drugs (HR = 0.11, p = 0.005) as first/second‐line therapy.

Conclusions

Upfront brain RT based on first‐line EGFR‐TKI might improve IC‐PFS but not OS in EGFR‐mutant lung adenocarcinoma patients, indicating potential survival benefit from brain SRS and early application of drugs with higher intracranial activity.

EGFR-mutated stage IV non-small cell lung cancer: What is the role of radiotherapy combined with TKI?

Lung cancer is the leading cause of cancer-related death globally and poses a considerable threat to public health. Asia has the highest prevalence of epidermal growth factor receptor (EGFR) mutations in patients with non-small cell lung cancer (NSCLC). Despite the reasonable response and prolonged survival associated with EGFR-tyrosine kinase inhibitor (TKI) therapy, the acquisition of resistance to TKIs remains a major challenge. Additionally, patients with EGFR mutations are at a substantially higher risk of brain metastasis compared with those harboring wild-type EGFR. The role of radiotherapy (RT) in EGFR-mutated (EGFRm) stage IV NSCLC requires clarification, especially with the advent of next-generation TKIs, which are more potent and exhibit greater central nervous system activity. In particular, the feasible application of RT, including the timing, site, dose, fraction, and combination with TKI, merits further investigation. This review focuses on these key issues, and provides a flow diagram with proposed treatment options for metastatic EGFRm NSCLC, aiming to provide guidance for clinical practice.

Biomarkers of Targeted Therapy and Immuno-Oncology in Cancers Metastatic to the Breast

The breast is a rare site for metastases, and their molecular characteristics have not been studied yet. Intrinsic molecular genetics, cancer characteristics, and breast tissue immune responses in diverse metastases to the breast have not been previously studied. We identified 64 patients with cancers metastatic to the breast: 51 carcinomas and 13 melanomas. Programmed death ligand 1 (PD-L1), steroid receptors, and HER2/neu expressions were evaluated using immunohistochemistry. Gene sequencing, copy number alterations, microsatellite instability, and tumor mutational burden were performed using next-generation sequencing platforms. The 3 most common primary sites for metastatic carcinomas were lung (37%), ovary (29%), and fallopian tubes/peritoneum (14%). TP53 mutations were commonly (50%) observed among the carcinoma cases, while other mutations were characteristic for the primary cancers (VHL in renal, BRCA1 in the fallopian tube, and BRAF in melanomas). High tumor mutational burden was detected in 5/14 carcinomas and 3/7 melanomas. Tumor cell PD-L1 expression was detected in 6 carcinomas, but not in any of the melanomas, whereas immune cells' expression of PD-L1 was seen in 17 carcinomas and 6 melanomas. Estrogen receptor status was positive in 13/49 carcinomas including 12 adenocarcinomas originating from the ovary and fallopian tube or peritoneum and 1 duodenal neuroendocrine carcinoma. No carcinoma was HER2/neu positive. Intrinsic genetic characteristics of the metastases to the breast followed the pattern commonly seen in primary tumors. Biomarkers of potential benefit to immune checkpoint inhibition therapy were limited to PD-L1-positive non-small cell lung cancer. No common characteristics of the heterogeneous group of tumor metastases to this organ were identified.

m6A RNA Methylation Regulators Participate in the Malignant Progression and Have Clinical Prognostic Value in Lung Adenocarcinoma

Abnormal methylation of N6 adenosine (m6A) in RNA plays a crucial role in the pathogenesis of many types of tumors. However, little is known about m6A RNA methylation in lung adenocarcinoma. This study aimed to identify the value of m6A RNA methylation regulators in the malignant progression and clinical prognosis of lung adenocarcinoma. The RNA-seq transcriptome data and corresponding clinical information of lung adenocarcinoma were downloaded from The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) database. Then the identification of differentially expressed m6A RNA methylation regulators between cancer samples and normal control samples, different subgroups by consensus expression of these regulators and the prognostic signature were achieved using R software with multiple corresponding packages. The results showed that the expression levels of HNRNPC, YTHDF1, KIAA1429, RBM15, YTHDF2, and METTL3 in cancer group were significantly up-regulated (P < 0.05), while expression levels of FTO, ZC3H13, METTL14, YTHDC1 and WTAP in cancer group were significantly down-regulated (P < 0.05) compared with control group. Two subgroups identified by consensus expression of these regulators were closely related to the clinicopathological features, clinical outcomes and malignancy of lung adenocarcinoma. In addition, a 3-gene risk signature including KIAA1429, RBM15, and HNRNPC was constructed and the lung adenocarcinoma patients in TCGA database were divided into high-risk group and low-risk group based on the median risk score. In conclusion, the prognostic signature-based risk score calculated according to the expression levels of KIAA1429, RBM15, and HNRNPC, was not only strongly associated with clinical outcomes and clinicopathological features, but also an independent prognostic factor in lung adenocarcinoma.

Systemic treatment of brain metastases in non-small cell lung cancer

Brain metastases (BrMs) are associated with significant morbidity and are found in up to 50% of patients with advanced non-small cell lung cancer (NSCLC). Most of the literature focuses on symptomatic BrMs, with a lack of baseline brain imaging in asymptomatic patients. Unfortunately, much of the data on local treatments with or without systemic treatment is retrospective. Clinical trials of systemic treatments largely exclude patients with BrMs. Chemotherapy is an active treatment for BrM with response rates in the brain similar to other sites of disease. Targeted systemic treatments in patients with driver mutations (EGFR and ALK-MET to date) have impressive central nervous system (CNS) penetrance and response rates. Unfortunately, no prospective data can currently guide the timings or modality of local therapies with systemic treatments in these patients who have a high incidence of CNS disease, but retrospective data suggest that early local therapies may give better intracranial progression-free survival (ICPFS). Recent immunotherapy trials have included patients with BrMs. These patients have largely been pre-treated with local therapies and are asymptomatic. Thus, the current standard is becoming, early local therapies before or in conjunction with immunotherapy agents. The approach seems to be safe. Prospective studies are needed in NSCLC BrMs patients to make sure any benefit from local therapies on the ICPFS and quality of life is not overlooked. Here we report what we think are reasonable conclusions from the available data and make suggestions for future clinical trials in the management of NSCLC BrMs.

A study on different therapies and prognosis-related factors for brain metastases in lung adenocarcinoma patients with driver mutation

Brain metastases (BMs) are frequently occurred in lung adenocarcinoma with driver mutation. There is a need to explore multi-discipline treatments and prognostic factors in those patients with most frequent driver mutations: EGFR mutation and ALK fusion. In the retrospective study, different therapies and prognostic factors were compared between EGFR and ALK-driven lung adenocarcinoma with BMs. 516 patients with EGFR mutation and 76 with ALK fusion were screened for this study, 303 (58.7%) and 34 (44.7%) had BM respectively. In multivariate analyses, the pretreatment factors including delayed BMs and asymptomatic BMs, treatment strategies including the first-generation tyrosine kinase inhibitor (TKI) and cranial radiotherapy (RT) treatment, were associated with much better OS in EGFR mutation patients. Moreover, we found EGFR-mutation patients receiving erlotinib would achieve better survival than those receiving gefitinib (P = 0.032). However, BM patients with ALK fusion treated by only the first generation TKI (HR = 0.23, P = 0.036) or cranial RT (HR = 0.12, P = 0.003), had better OS. After balancing of baseline characteristics of the two groups, there was no significant difference in the survival between BM patients with EGFR mutation and ALK fusion. And only cranial RT was associated with better survival in those patients (HR = 0.52, P < 0.001). In the BM patients of lung adenocarcinoma with driver mutation, TKI underlie the therapy strategies, but cranial RT still plays an important role while receiving the first generation TKI.

The optional approach of oncogene-addicted non-small cell lung cancer with brain metastases in the new generation targeted therapies era

In recent years, the study of the molecular characteristics of non-small cell lung cancer (NSCLC) has highlighted a specific role of some genes that represent important therapeutic targets, including epidermal growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK), c-ros oncogene 1 (ROS-1) and v-Raf murine sarcoma viral oncogene homolog B1 (BRAF). Patients with oncogene-addicted cancer benefit more from therapy with tyrosine kinase inhibitors (TKIs) than from chemotherapy. The brain is a preferred site for tumor spread in these patients. In addition, given greater control of extracranial disease and prolonged survival, the brain is often the first site of progression. Therefore, there is great interest in therapeutic approaches that optimize the control of intracranial disease associated with systemic drugs that, by penetrating the blood-brain barrier (BBB), may improve local control. On the latter, radiotherapy provides excellent efficacy but following the results of clinical trials with new brain penetrant drugs, the question of how and especially when to perform brain radiotherapy in patients with oncogene-addicted NSCLC remains open. Prospective studies may indicate which patients are most likely to benefit from combined use or in what sequence they will undergo systemic and radiotherapy treatment. Due to the heterogeneity of patients and the introduction of new generation TKIs, a multidisciplinary assessment for the best management of therapies in NSCLC patients with molecular driver alterations and brain metastases (BM) is required.

Combination of Whole-Brain Radiotherapy with Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors Improves Overall Survival in EGFR-Mutated Non-Small Cell Lung Cancer Patients with Brain Metastases

Brain metastases (BM) cause morbidity and mortality in patients with non-small cell lung cancer (NSCLC). The use of upfront epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) and withholding of whole-brain radiation therapy (WBRT) is controversial. We aim to investigate the impact of WBRT on overall survival (OS). After screening 1384 patients, a total of 141 EGFR-mutated patients with NSCLC and BM were enrolled. All patients received EGFR-TKIs between 2011 and 2015. Ninety-four patients (66.7 %) were treated with WBRT (TKI + WBRT group). With a median follow-up of 20.3 months (95% confidence interval (CI), 16.9-23.7), the median OS after the diagnosis of BM was 14.3 months (95% CI, 9.5 to 18.3) in the TKI + WBRT group and 2.3 months (95% CI, 2 to 2.6) in the TKI alone group. On multivariate analysis, WBRT (p < 0.001), female, surgery to primary lung tumor, and surgery to BM were associated with improved OS. The 1-year OS rate was longer in the TKI+WBRT group than that in the TKI alone group (81.9% vs 59.6%, p = 0.002). In conclusion, this is the first study to demonstrate the negative survival impact from the omission of WBRT in patients with EGFR-mutant NSCLC.

EGFR-TKI plus brain radiotherapy versus EGFR-TKI alone in the management of EGFR-mutated NSCLC patients with brain metastases

Background

It has been confirmed that epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) presented better efficacy than brain radiotherapy (brain RT) in the treatment of brain metastasis (BM) in EGFR mutated NSCLC patients. However, whether the combination of EGFR-TKIs and brain RT is better than EGFR-TKIs alone remains unclear. We aim to compare the outcomes of adding brain RT to EGFR-TKIs and to screen for the beneficial population by a meta-analysis of currently available data.

Methods

A systematic search for relevant articles was conducted in six databases. The outcomes were overall survival (OS) and intracranial progression-free survival (iPFS) between groups, both were measured as hazard ratios (HRs). Meta-regression and dominant subgroup analysis were used to explore advantageous subgroups.

Results

A total of 12 retrospective studies involving 1,553 EGFR mutated patients with BM at the first diagnosis were included. EGFR-TKIs plus brain RT showed a significant prolonged OS (HR =0.64, 95% CI: 0.52-0.78; P<0.001) and iPFS (HR =0.62, 95% CI: 0.50-0.78; P<0.001) compared to EGFR-TKIs alone. Meta-regression analyses showed that potential factors contributed to the heterogeneity were the proportion of ECOG performance score (2+ vs. 0-1, P=0.070) and brain symptomatic patients (no vs. yes, P=0.077) regarding iPFS and was age (younger vs. older, P=0.075) for OS. Dominant subgroup analyses suggested that symptomatic patients (HR 0.46 vs. 0.74, interaction P=0.01) for iPFS, and older patients (HR 0.55 vs. 0.75, interaction P=0.03) and 19Del mutation (HR 0.55 vs. 0.74, interaction P=0.04) for OS, seemed to benefit more from the combination therapy than their counterparts. However, direct subgroup results based on only two studies did not show significant difference in iPFS benefit between age, mutation type and sex subgroup.

Conclusions

EGFR-TKIs plus brain RT is superior to EGFR-TKIs alone in the management of EGFR-mutated NSCLC patients with BM, of which the benefits might be influenced by age, BM-related symptoms and mutation type.