Outcomes according to initial and subsequent therapies following intracranial progression in patients with EGFR-mutant lung cancer and brain metastasis

Clinical Management of Patients with Non-Small Cell Lung Cancer, Brain Metastases, and Actionable Genomic Alterations: A Systematic Literature Review

INTRODUCTION

Nearly 60% of patients with non-small cell lung cancer (NSCLC) present with metastatic disease, and approximately 20% have brain metastases (BrMs) at diagnosis. During the disease course, 25-50% of patients will develop BrMs. Despite available treatments, survival rates for patients with NSCLC and BrMs remain low, and their overall prognosis is poor. Even with newer agents for NSCLC, options for treating BrMs can be limited by their ineffective transport across the blood-brain barrier (BBB) and the unique brain tumor microenvironment. The presence of actionable genomic alterations (AGAs) is a key determinant of optimal treatment selection, which aims to maximize responses and minimize toxicities. The objective of this systematic literature review (SLR) was to understand the current landscape of the clinical management of patients with NSCLC and BrMs, particularly those with AGAs.

METHOD

A Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA)-compliant SLR was conducted to identify studies in patients with BrMs in NSCLC. Searches used the EMBASE and MEDLINE® databases, and articles published between January 1, 2017 and September 26, 2022 were reviewed.

RESULTS

Overall, 179 studies were included in the SLR. This subset review focused on 80 studies that included patients with NSCLC, BrMs, and AGAs (19 randomized controlled trials [RCTs], two single-arm studies, and 59 observational studies). Sixty-four of the 80 studies reported on epidermal growth factor receptor (EGFR) mutations, 14 on anaplastic lymphoma kinase (ALK) alterations, and two on both alterations. Ninety-five percent of studies evaluated targeted therapy. All RCTs allowed patients with previously treated, asymptomatic, or neurologically stable BrMs; the percentage of asymptomatic BrMs varied across observational studies.

CONCLUSIONS

Although targeted therapies demonstrate systemic benefits for patients with NSCLC, BrMs, and AGAs, there remains a continued need for effective therapies to treat and prevent BrMs in this population. Increased BBB permeability of emerging therapies may improve outcomes for this population.

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.

Intracranial and Extracranial Progression and Their Correlation With Overall Survival After Stereotactic Radiosurgery in a Multi-institutional Cohort With Brain Metastases

Importance

Clinical trials for metastatic malignant neoplasms are increasingly being extended to patients with brain metastases. Despite the preeminence of progression-free survival (PFS) as a primary oncologic end point, the correlation of intracranial progression (ICP) and extracranial progression (ECP) events with overall survival (OS) is poorly understood for patients with brain metastases following stereotactic radiosurgery (SRS).

Objective

To determine the correlation of ICP and ECP with OS among patients with brain metastases completing an initial SRS course.

Design, Setting, and Participants

This multi-institutional retrospective cohort study was conducted from January 1, 2015, to December 31, 2020. We included patients who completed an initial course of SRS for brain metastases during the study period, including receipt of single and/or multifraction SRS, prior whole-brain radiotherapy, and brain metastasis resection. Data analysis was performed on November 15, 2022.

Exposures

Non-OS end points included intracranial PFS, extracranial PFS, PFS, time to ICP, time to ECP, and any time to progression. Progression events were radiologically defined, incorporating multidisciplinary clinical consensus.

Main Outcomes and Measures

The primary outcome was correlation of surrogate end points to OS. Clinical end points were estimated from time of SRS completion via the Kaplan-Meier method, while end-point correlation to OS was measured using normal scores rank correlation with the iterative multiple imputation approach.

Results

This study included 1383 patients, with a mean age of 63.1 years (range, 20.9-92.8 years) and a median follow-up of 8.72 months (IQR, 3.25-19.68 months). The majority of participants were White (1032 [75%]), and more than half (758 [55%]) were women. Common primary tumor sites included the lung (757 [55%]), breast (203 [15%]), and skin (melanoma; 100 [7%]). Intracranial progression was observed in 698 patients (50%), preceding 492 of 1000 observed deaths (49%). Extracranial progression was observed in 800 patients (58%), preceding 627 of 1000 observed deaths (63%). Irrespective of deaths, 482 patients (35%) experienced both ICP and ECP, 534 (39%) experienced ICP (216 [16%]) or ECP (318 [23%]), and 367 (27%) experienced neither. The median OS was 9.93 months (95% CI, 9.08-11.05 months). Intracranial PFS had the highest correlation with OS (ρ = 0.84 [95% CI, 0.82-0.85]; median, 4.39 months [95% CI, 4.02-4.92 months]). Time to ICP had the lowest correlation with OS (ρ = 0.42 [95% CI, 0.34-0.50]) and the longest median time to event (median, 8.76 months [95% CI, 7.70-9.48 months]). Across specific primary tumor types, correlations of intracranial PFS and extracranial PFS with OS were consistently high despite corresponding differences in median outcome durations.

Conclusions and Relevance

The results of this cohort study of patients with brain metastases completing SRS suggest that intracranial PFS, extracranial PFS, and PFS had the highest correlations with OS and time to ICP had the lowest correlation with OS. These data may inform future patient inclusion and end-point selection for clinical trials.

Upfront brain radiotherapy improves intracranial progression-free survival but not overall survival in lung adenocarcinoma patients with brain metastases: a retrospective, single-institutional analysis from China

Aims: The optimal timing of brain radiotherapy (BRT) for lung adenocarcinoma patients with brain metastases (BM) remains controversial. In this retrospective study, we performed a retrospective review to investigate the differential benefit of upfront versus deferred BRT for lung adenocarcinoma patients with BM. Methods: A total of 354 lung adenocarcinoma patients with BM treated in the Affiliated Cancer Hospital of Shandong University met the inclusion criteria for the study. Patients were divided into two groups: upfront BRT and deferred BRT. Intracranial progression-free survival (PFS) and overall survival (OS) were measured from the date of brain metastases. Subgroup analyses according to gene mutation status were also performed. Results: Among the entire cohort, the median intracranial PFS with upfront BRT (16.3 months) was longer than that with deferred BRT (11.3 months, p=0.001). However, the median OS did not differ significantly between patients who received upfront BRT and deferred BRT (27.6 and 31.5 months, respectively, p=0.813). Subgroup analyses indicated that upfront BRT yielded a significantly longer intracranial PFS than deferred BRT (p=0.003) for patients without EGFR (19 or 21) mutation. In both subgroups, the median OS showed no significant difference between upfront BRT and deferred BRT. Conclusion: This single-institutional retrospective study showed that in lung adenocarcinoma patients with brain metastases, upfront BRT was associated with a significantly longer intracranial PFS but not improvement in OS compared with deferred BRT. Considering the neurocognitive toxicities of BRT previously reported in the literature, deferred BRT might be considered as an acceptable therapeutic option for the treatment of patients with lung adenocarcinoma and BM.

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.

Brain metastases in patients with oncogenic-driven non-small cell lung cancer: Pros and cons for early radiotherapy

Non-small cell lung cancer (NSCLC) with oncogenic driver mutations such as EGFR or ALK has a high predilection for brain metastases (BMs) compared to unselected patients. Historically, whole brain radiotherapy (WBRT) was adopted widely for patients with BM. More recently, stereotactic radiosurgery (SRS) has become a standard approach for patients with 1 - 4 metastatic brain lesions. However, data on overall survival benefit with WBRT/SRS compared to target agents are conflicting, with a significant compromise of loss of neurocognitive function. Newer target agents with improved CNS efficacy have challenged the use of early radiotherapy in NSCLC patients with oncogenic driver mutations. Optimal treatment approach and timing of radiotherapy remain unclear, especially under the various clinical contexts. The purpose of this review is to summarize the available data on the possible benefits and risks of early radiotherapy for oncogenic-driven NSCLC patients with brain metastases. Clinical decisions should consider both intracranial efficacy and patient quality of life, given that patients are surviving long enough to experience the long-term consequences of radiation therapy.

Predictive effect of DCE-MRI and DWI in brain metastases from NSCLC

Non-small cell lung cancer (NSCLC), a commonly diagnosed lung cancer, is characterized by a high incidence of metastatic spread to the brain, which adversely impacts prognosis. The present study aimed to assess the value of combined dynamic contrast-enhanced MRI (DCE-MRI) and diffusion-weighted imaging (DWI) in predicting the treatment outcomes of whole-brain radiotherapy (WBRT) and gefitinib in brain metastases from non-small cell lung cancer (NSCLC) from the perspectives of response rate and short- and long-term efficacy. These results suggested that the indicators measured by DCE-MRI combined with DWI can be used as key imaging-derived markers that predicted the efficacy of WBRT combined with gefitinib in NSCLC patients with brain metastases. Specifically, patients with higher ΔADC_mid and ΔADC_post values showed better treatment outcomes. ROC curve analysis indicated ADC_post, ΔADC_post, ΔADC_post (%), and tumor regression rate as the best predictors of efficacy of WBRT combined with gefitinib in these patients. The short-term and long-term effects noted were also significant. Taken together, the findings of this study reveal that tumor regression rate, ADC_post, ΔADC_post, and ΔADC_post (%) can be used as important imaging indicators that predict the therapeutic effect of WBRT combined with gefitinib in NSCLC patients with brain metastases.

Phase III randomized study of carboplatin pemetrexed with or without bevacizumab with initial versus "at progression" cerebral radiotherapy in advanced non squamous non-small cell lung cancer with asymptomatic brain metastasis

Background:

The role and timing of whole or stereotaxic brain radiotherapy (BR) in patients with advanced non-small cell lung cancer (aNSCLC) and asymptomatic brain metastases (aBMs) are not well established. This study investigates whether deferring BR until cerebral progression was superior to upfront BR for patients with aNSCLC and aBM.

Methods:

This open-label, multicenter, phase III trial, randomized (1:1) aNSCLC patients with aBMs to receive upfront BR and chemotherapy: platin–pemetrexed and bevacizumab in eligible patients, followed by maintenance pemetrexed with or without bevacizumab, BR arm, or the same chemotherapy with BR only at cerebral progression, chemotherapy (ChT) arm. Primary endpoint was progression-free survival (PFS), secondary endpoints were overall survival (OS), global, extra-cerebral and cerebral objective response rate (ORR), toxicity, and quality of life [ClinicalTrials.gov identifier: NCT02162537].

Results:

The trial was stopped early because of slow recruitment. Among 95 included patients, 91 were randomized in 24 centers: 45 to BR and 46 to ChT arms (age: 60 ± 8.1, men: 79%, PS 0/1: 51.7%/48.3%; adenocarcinomas: 92.2%, extra-cerebral metastases: 57.8%, without differences between arms.) Significantly more patients in the BR-arm received BR compare with those in the ChT arm (87% versus 20%; p < 0.001); there were no significant differences between BR and ChT arms for median PFS: 4.7, 95% confidence interval (CI):3.4–7.5 versus 4.8, 95% CI: 2.4–6.5 months, for median OS: 8.5, 95% CI:.6–11.1 versus 8.3, 95% CI:4.5–11.5 months, cerebral and extra-cerebral ORR (27% versus 13%, p = 0.064, and 30% versus 41%, p = 0.245, respectively). The ChT arm had more grade 3/4 neutropenia than the BR arm (13% versus 6%, p = 0.045); others toxicities were comparable.

Conclusion:

The significant BR rate difference between the two arms suggests that upfront BR is not mandatory in aNSCLC with aBM but this trial failed to show that deferring BR for aBM is superior in terms of PFS from upfront BR.

Whole-Brain Radiotherapy Can Improve the Survival of Patients with Multiple Brain Metastases from Non-Small Cell Lung Cancer Treated by Epidermal Growth Factor Receptor-Tyrosine Kinase Inhibitors

Objective

To observe whether whole-brain radiotherapy (WBRT) can bring survival benefits to patients with multiple brain metastases (BM) from non-small cell lung cancer (NSCLC) treated by epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) and determine the best time for WBRT intervention.

Methods

A retrospective analysis was performed on 148 patients diagnosed with EGFR gene-mutated NSCLC. All patients had multiple BM and received EGFR-TKI targeted therapy, which was performed to observe whether WBRT can bring survival benefits, and whether the choice of WBRT timing affects the survival of patients.

Results

Among the 148 patients with NSCLC treated with EGFR-TKI, 76 received WBRT; 72 were without WBRT. WBRT can reduce the intracranial progression rate in the patients (19.7% vs 33.3%, P=0.040), thus improving the intracranial progression-free survival (iPFS) (median iPFS: 11.9 months versus 10.2 months, P=0.039) and overall survival (OS) (median OS: 21.0 months versus 16.7 months, P=0.043). Multivariate analysis showed that WBRT (HR=0.606; 95% CI: 0.403-0.912, P=0.016) and the low Eastern Cooperative Oncology Group performance status (HR=1.884; 95% CI: 1.120-3.170, P=0.017) are independent prognostic factors in all patients. Further subgroup analysis showed that the choice of WBRT time had no effect on patient survival.

Conclusion

WBRT can improve the survival of patients with multiple BM from NSCLC receiving EGFR-TKI targeted therapy and is an independent prognostic factor. The choice of RT time has no effect on patient survival.