Treatment options for patients with brain metastases from EGFR / ALK -driven lung cancer

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.

Improved survival and intracranial tumor control of EGFR-mutated NSCLC patients with newly developed brain metastases following stereotactic radiosurgery and EGFR-TKI: a large retrospective cohort study and meta-analyses

PURPOSE

To examine the differential effects of SRS and TKI on EGFR-mutated NSCLC patients with brain metastases (BMs) and outcomes following continuation of the same TKI agent in case of new BMs.

METHODS

This study included 608 NSCLC patients (2,274 BMs) while meta-analyses included 1,651 NSCLC patients (> 3,944 BMs). Overall survival (OS) and intracranial progression free survival (iPFS) were estimated using Kaplan-Meier methods. Hazard ratios (95% CI) of prognostic factors were estimated using Cox regression models.

RESULTS

The median OS/iPFS (95% CI) (months) for patients with wildtype EGFR/ALK, EGFR mutations, and ALK rearrangements were 17.7 (12.9-23.6)/12.1 (9.8-15.6), 28.9 (23.8-33.3)/17.7 (14.8-21.2), and 118.0 (not reached)/71.7 (15.1-not reached), respectively. In EGFR-mutated patients, meta-analyses combining our data showed significantly improved OS and iPFS of patients who received SRS and TKI (OS:35.1 months, iPFS:20.0 months) when compared to those who have SRS alone (OS:20.8 months, iPFS:11.8 months) or TKI alone (OS:24.3 months, iPFS:13.8 months). Having SRS for newly diagnosed BMs while keeping the existing TKI agent yielded OS (30.0 vs. 32.1 months, p = 0.200) non-inferior to patients who started combined SRS and TKI therapy for their newly diagnosed NSCLC with BMs. Multivariable analyses showed that good performance score and TKI therapy were associated with improved outcomes.

CONCLUSIONS

Combined SRS and TKI resulted in favorable outcomes in EGFR-mutated NSCLC patients with newly diagnosed BMs. Continuation of the same TKI agent plus SRS in case of new brain metastases yielded good clinical outcomes and may be considered a standard-of-care treatment.

Real-world treatment and prognostic factors for survival in ALK+ non-small cell lung cancer (NSCLC) patients with brain metastases in China

BACKGROUND

To explore the efficacy and prognostic factors of different treatment modalities on anaplastic lymphoma kinase (ALK)+ non-small cell lung cancer (NSCLC) patients with brain metastases (BMs).

METHODS

A total of 86 patients were enrolled into the study. They were divided into two cohorts based on their history of treatment with ALK tyrosine kinase inhibitors (ALK-TKIs) prior to the incidence of BMs. ALK-TKI-naïve patients with BMs were included in cohort 1 (n = 59); patients who developed BMs after ALK-TKIs treatment were enrolled in cohort 2 (n = 27). Prognostic factors related with overall survival (OS) when treated with ALK-TKIs were assessed in multivariable analysis.

RESULTS

With a median follow-up of 41.8 months, the median OS was 34.8 months. In cohort 1, the OS, intracranial progression-free survival (iPFS), and progression-free survival (PFS) were 38.7 months (95% CI: 23.3 to 54.1), 18.5 months (95% CI: 9.6 to 27.4), and 19.1 months (95% CI: 13.7 to 24.5), respectively. Significantly improved OS and iPFS were noted in those patients in which second-generation ALK-TKIs versus crizotinib were initiated (OS: not reached vs. 29.0 months, p = 0.040; iPFS: 22.8 vs. 11.9 months, p = 0.035). In cohort 2, patients who experienced BMs as a result of the treatment failure of ALK-TKIs had a median OS of 27.1 months. Considerable duration of stable disease in patients with measurable BMs was observed (iPFS: 11.5 months, 95% CI: 4.4 to 18.6; PFS: 12.2 months, 95% CI: 3.2 to 21.1).

CONCLUSION

Second-generation ALK-TKIs further improved the duration of intracranial response and survival in ALK+ NSCLC patients with BMs in a real-world setting. The potent intracranial efficacy of second-generation ALK-TKIs might generate the lowered urgency of local treatment.

Real-world analysis of different intracranial radiation therapies in non-small cell lung cancer patients with 1–4 brain metastases

Purpose

Stereotactic radiosurgery (SRS) has become a standard approach for the treatment of patients with few metastatic brain lesions. However, the optimal treatment approach for the use radiotherapy in the treatment of non-small cell lung cancer (NSCLC) patients with brain metastases (BMs) remain unclear. This study aimed to compare the survival outcomes and intracranial local control in NSCLC patients with 1–4 BMs who are treated with SRS using linear accelerators (LINAC-SRS), whole-brain radiotherapy (WBRT), or WBRT plus radiotherapy boost (WBRT + RTB).

Materials and methods

We retrospectively analyzed 156 NSCLC patients with 1–4 BMs who received LINAC-SRS, WBRT, and WBRT + RTB. The median overall survival (OS), intracranial progression-free survival (iPFS), and distant brain failure-free survival (DBF-FS) and related prognostic factors were analyzed.

Results

The median follow-up period was 31.6 months. The median OS times in the LINAC-SRS, WBRT, and WBRT + RTB groups were not reached, 33.3 months and 27.9 months, respectively. The difference in survival rate was non-significant (P = 0.909). The 2-year iPFS and DBF-FS rates in the LINAC-SRS, WBRT and WBRT + RTB groups were 51.6% and 37.5%; 42.0% and 50.4%; and 51.1% and 56.1%, respectively. There was no significant difference in 2-year iPFS or DBF-FS among the three groups (P = 0.572 for iPFS, P = 0.628 for DBF-FS). Multivariate analysis showed that the independent adverse prognostic factors for OS, iPFS, and DBF-FS were neurological symptoms, recursive partitioning analysis (RPA) class, and targeted therapy.

Conclusion

LINAC-SRS did not result in significantly superior survival times or intracranial local control compared to WBRT or WBRT + RTB in the treatment of NSCLC patients with 1–4 BMs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-10083-8.

Brain Metastases Management in Oncogene-Addicted Non-Small Cell Lung Cancer in the Targeted Therapies Era

The therapeutic landscape in patients with advanced non-small-cell lung cancer harboring oncogenic biomarkers has radically changed with the development of targeted therapies. Although lung cancers are known to frequently metastasize to the brain, oncogene-driven non-small-cell lung cancer patients show a higher incidence of both brain metastases at baseline and a further risk of central nervous system progression/relapse. Recently, a new generation of targeted agents, highly active in the central nervous system, has improved the control of intracranial disease. The intracranial activity of these drugs poses a crucial issue in determining the optimal management sequence in oncogene-addicted non-small-cell lung cancer patients with brain metastases, with a potential change of paradigm from primary brain irradiation to central nervous system penetrating targeted inhibitors.

Prediction of Short and Long Survival after Surgery for Breast Cancer Brain Metastases

Background: Brain metastases requiring surgical treatment determine the prognosis of patients with breast cancer. We aimed to develop the scores for the prediction of short (<6 months) and long (≥3 years) survival after BCBM surgery. Methods: Female patients with BCBM surgery between 2008 and 2019 were included. The new scores were constructed upon independent predictors for short and long postoperative survival. Results: In the final cohort (n = 95), 18 (18.9%) and 22 (23.2%) patients experienced short and long postoperative survival, respectively. Breast-preserving surgery, presence of multiple brain metastases and age ≥ 65 years at breast cancer diagnosis were identified as independent predictors of short postoperative survival. In turn, positive HER2 receptor status in brain metastases, time interval ≥ 3 years between breast cancer and brain metastases diagnosis and KPS ≥ 90% independently predicted long survival. The appropriate short and long survival scores showed higher diagnostic accuracy for the prediction of short (AUC = 0.773) and long (AUC = 0.775) survival than the breast Graded Prognostic Assessment score (AUC = 0.498/0.615). A cumulative survival score (total score) showed significant association with overall survival (p = 0.001). Conclusion: We identified predictors independently impacting the prognosis after BCBM surgery. After external validation, the presented scores might become useful tools for the selection of proper candidates for BCBM surgery.

Integrated genomic and DNA methylation analysis of patients with advanced non-small cell lung cancer with brain metastases

BACKGROUND

Brain metastasis is a common and lethal complication of non-small cell lung cancer (NSCLC). It is mostly diagnosed only after symptoms develop, at which point very few treatment options are available. Therefore, patients who have an increased risk of developing brain metastasis need to be identified early. Our study aimed to identify genomic and epigenomic biomarkers for predicting brain metastasis risk in NSCLC patients.

METHODS

Paired primary lung tumor tissues and either brain metastatic tissues or cerebrospinal fluid (CSF) samples were collected from 29 patients with treatment-naïve advanced NSCLC with central nervous system (CNS) metastases. A control group comprising 31 patients with advanced NSCLC who died without ever developing CNS metastasis was also included. Somatic mutations and DNA methylation levels were examined through capture-based targeted sequencing with a 520-gene panel and targeted bisulfite sequencing with an 80,672 CpG panel.

RESULTS

Compared to primary lung lesions, brain metastatic tissues harbored numerous unique copy number variations. The tumor mutational burden was comparable between brain metastatic tissue (P = 0.168)/CSF (P = 0.445) and their paired primary lung tumor samples. Kelch-like ECH-associated protein (KEAP1) mutations were detected in primary lung tumor and brain metastatic tissue samples of patients with brain metastasis. KEAP1 mutation rate was significantly higher in patients with brain metastasis than those without (P = 0.031). DNA methylation analysis revealed 15 differentially methylated blocks between primary lung tumors of patients with and without CNS metastasis. A brain metastasis risk prediction model based on these 15 differentially methylated blocks had an area under the curve of 0.94, with 87.1% sensitivity and 82.8% specificity.

CONCLUSIONS

Our analyses revealed 15 differentially methylated blocks in primary lung tumor tissues, which can differentiate patients with and without CNS metastasis. These differentially methylated blocks may serve as predictive biomarkers for the risk of developing CNS metastasis in NSCLC. Additional larger studies are needed to validate the predictive value of these markers.

Outcomes of Gamma Knife Radiosurgery for Brain Metastases From Anaplastic Lymphoma Kinase Rearrangement-Positive and EGFR Mutation-Positive Non-Small Cell Lung Cancer

Introduction

The outcomes after gamma knife radiosurgery (GKRS) were retrospectively analysed in patients with brain metastases from anaplastic lymphoma kinase (ALK) rearrangement-positive and epidermal growth factor receptor (EGFR) mutation-positive non-small cell lung cancer (NSCLC) to evaluate the efficacy, safety and difference for overall survival and local tumor control.

Methods

The medical records were retrospectively reviewed of 607 patients (25 ALK-positive, 171 EGFR-positive, and 411 wild type) with 2959 tumors who had undergone GKRS.

Results

The median overall survival time after initial GKRS was 14 months. Driver gene mutation-positive patients had significantly longer overall survival than wild type patients (p < 0.0001), and ALK-positive patients survived significantly longer than EGFR-positive patients (p = 0.04). Multivariate analysis showed the unfavorable factors significantly affecting overall survival outcomes were older age, lower Karnofsky Performance Status score, multiple intracranial metastases, uncontrolled primary cancer, uncontrolled extracranial metastases, no administration of immune checkpoint inhibitors, and driver gene mutation-negative cases. Seventy-three patients died of uncontrolled brain metastases at a median of 12 months. Driver gene mutations had no influence (p = 0.33), and ALK-positive and EGFR-positive patients showed no significant difference in neurological survival (p = 0.83). A total of 174 patients demonstrated distant brain control failure at a median of 15 months. ALK-positive type was significant compared with EGFR-positive type (p = 0.047), but driver gene mutation-positive and -negative types showed no significant difference in the development of new brain metastases (p = 0.2). The median tumor volume was 1.06 cm³ in the driver gene mutation-positive type and 1.85 cm³ in wild type. The median marginal dose was 20 Gy in both types. The 6-, 12-, and 24-month local tumor control rates were 97.3%, 96.1%, and 95.9%, respectively. Driver gene mutations had a significantly positive impact on local tumor control (p = 0.001), and ALK-positive and EGFR-positive types showed no significant difference (p = 0.95). A total of 193 tumors had radiation injury at a median of 12 months after GKRS. The 6-, 12-, and 24-month GKRS-related complication rates were 3.3%, 8.1%, and 8.7%, respectively. Driver gene mutations significantly induced radiation damage (p = 0.021), and the ALK-positive type was affected more than the EGFR-positive type (p = 0.02).

Conclusions

ALK rearrangement-positive NSCLC patients tended to have significantly longer survival, but had higher incidence of new intracranial metastases due to long-term survival after GKRS, compared with EGFR mutation-negative and driver gene mutation-negative NSCLC patients. GKRS induced significantly satisfactory local tumor control in driver gene mutation-positive tumors but GKRS-related complication frequency was higher, especially in ALK-positive NSCLC patients. Therefore, more careful imaging follow-up is necessary after GKRS for patients with driver gene mutation-positive NSCLC.

A narrative review of evolving roles of radiotherapy in advanced non-small cell lung cancer: from palliative care to active player

Radiotherapy, along with other loco-regional interventions, is conventionally utilized as a palliative approach to alleviate symptoms and mitigate oncological emergencies in advanced non-small cell lung cancer (NSCLC). Thanks to the ongoing improvement of medical treatments in the last decade, such as targeted therapy and immunotherapy, the survival of patients with advanced NSCLC has been considerably prolonged, making it feasible and clinically beneficial for radiotherapy to play a more active role in highly selected subpopulations. In this review, we will focus on the evolving roles of radiotherapy in advanced NSCLC. First of all, among patients who are initially unable to tolerate aggressive treatment due to severe symptoms caused by metastases and/or tumor emergencies, timely radiotherapy could significantly improve their performance status (PS) and general condition, thus giving them a chance for intensive treatment and prolonged survival. The efficacy, potential candidates, and optimal dose-fractionation regimens of radiotherapy in this clinical scenario will be discussed. Additionally, radiotherapy can play a curative role as a concurrent therapy, consolidation therapy, and salvage therapy for patients with oligo-metastatic, oligo-residual, and oligo-progressive disease, respectively. Accumulating evidence from recent clinical trials, basic research, and translational investigations regarding the potentially curative roles of radiotherapy in NSCLC patients with oligo-metastatic disease will be summarized. Moreover, with the advent of various small molecular tyrosine kinase inhibitors (TKIs), the treatment efficacy and overall survival of oncogene-addicted NSCLC with brain metastases have been significantly improved, and the clinical value and optimal timing of cranial radiotherapy have become topics of much debate. Finally, synergistic antitumor interactions between radiotherapy and immunotherapy have been repeatedly demonstrated. Thus, the immune sensitizing role of radiotherapy in advanced NSCLC is also highlighted in this review.

Clinicopathologic and Treatment Features of Long-Term Surviving Brain Metastasis Patients

Background: The purpose of our study was to characterize clinical features among brain metastasis (BM) patients who were long term survivors (LTS). Methods: We reviewed a registry of BM patients referred to our multidisciplinary BM clinic between 2006 and 2014 and identified 97 who lived ≥ 3 years following BM diagnosis. The clinical and treatment characteristics were obtained from a prospectively maintained database, and additional information was obtained through review of electronic medical records and radiologic images. Survival analyses were performed using the Kaplan-Meier method. Results: Median follow up for LTS was 67 months (range 36–181). Median age was 54 years, 65% had single BM, 39% had stable extracranial disease at the time of BM treatment, and brain was the first site of metastasis in 76%. Targetable mutations were present in 39% of patients and 66% received treatment with targeted-, hormonal-, or immuno-therapy. Brain surgery at the time of diagnosis was performed in 40% and stereotactic radiosurgery (SRS) or whole brain radiotherapy (alone or combination) in 52% and 56%, respectively. Following initial BM treatment, 5-year intracranial disease-free survival was 39%, and the cumulative incidence of symptomatic radio-necrosis was 16%. Five and ten-year overall survival was 72% and 26%, respectively. Conclusion: Most LTS were younger than 60 years old and had a single BM. Many received treatment with surgery or targeted, immune, or hormonal therapy.

[Treatment for Brain Metastases from EGFR Mutations NSCLC Patients: How Should We Choose in Clinical Practice?]

Brain metastasis of epidermal growth factor receptor (EGFR) sensitive mutations is a hot and difficult point in targeted era of non-small cell lung cancer (NSCLC) treatment, meanwhile it is also the central issue of controversy in the field of lung cancer treatment. Different results of different studies and different understanding of different disciplines, this field of treatment has been accompanied by different voices, patients without clinical symptoms can use targeted therapy first, and then start local radiotherapy with clinical symptoms or disease progression. It is a major model of the medical oncology. That is to say, taking symptoms and progress as indication and standard of local treatment intervention. In the absence of symptoms, local radiotherapy may increase patients' pain, which belongs to overtreatment. However, the perspective of radiotherapy is that brain metastases need to be treated clinically as early as possible, if not, it may affect the survival of patients. Early treatment of local lesions and increasing the depth of treatment are helpful to prolong the survival time of patients. This article refers to relevant literatures and summarizes the discussion from the perspective of pursuing the truth of disease treatment and problem solving in order to provide reference for patients' clinical practice.

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.

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

In patients with epidermal growth factor receptor (EGFR)-mutant non–small-cell lung cancer (NSCLC) with brain metastases, it remains controversial whether the use of EGFR-tyrosine kinase inhibitor (TKI) alone without radiotherapy (RT) is an optimal approach. Here, we investigated the clinical outcomes according to the use of upfront RT as well as the subsequent therapy following intracranial progression. This single-centre retrospective study included a total of 173 patients who were treated with EGFR-TKI alone (TKI alone group) or with upfront whole-brain RT (WBRT) or stereotactic radiosurgery (SRS) followed by EGFR-TKI (RT plus TKI group). Clinical outcomes according to initial and subsequent therapies following intracranial progression were analysed. There was no significant difference in OS according to the use of upfront RT (TKI alone group, 24.5 months vs. WBRT group, 20.0 months vs. SRS group, 17.8 months; P = 0.186). Intracranial progression was found in 35 (32.7%) of 107 patients in the TKI alone group. Among them, 19 patients who received salvage RT had the better prognosis than others [median overall survival (OS); 28.6 vs. 11.2 months; P = 0.041]. In the RT plus TKI group, 12 (18.1%) of the 66 patients experienced intracranial progression and 3 of them received salvage RT (median OS; 37.4 vs. 20.0 months; P = 0.044). In multivariate analysis, upfront WBRT was associated with trends towards a lower probability of intracranial progression, whereas upfront SRS was found to be an independent risk factor for poor OS. In conclusion, using EGFR-TKI alone for brain metastasis in EGFR-mutant lung cancer patients showed outcomes comparable to those using upfront RT followed by EGFR-TKI. Patients who could not receive salvage RT following intracranial progression had the worst survival regardless of the type of initial treatment.

Upfront radiosurgery plus targeted agents followed by active brain control using radiosurgery delays neurological death in non-small cell lung cancer with brain metastasis

The role of radiosurgery has become further accentuated in the era of targeted agents (TA). Thus, the neurologic outcome of radiosurgery in brain metastasis (BM) of non-small cell lung cancer (NSCLC) was reviewed. We analyzed 135 patients with BM of NSCLC who were administered Cyberknife radiosurgery (CKRS) as either initial or salvage therapy. We evaluated local failure (LF), intracranial failure (IF), and neurological death (ND) due to BM. Primary outcome was neurological death-free survival (NDFS). Median follow-up was 16.2 months. Median CKRS dose of 22 Gy was administered to median 2 targets per patient. Among 99 deaths, 14 (14%) were ND. Upfront treatment for BM included CKRS alone in 85 patients (63%), CKRS + TA in 26 patients (19%), and WBRT in 24 patients (18%). No patients or tumor related factors were associated with ND. However, the type of upfront treatment for BM was significantly associated with ND [HR 0.07 (95% CI 0.01-0.57) for CKRS + TA, HR 0.56 (95% CI 0.19-1.68) for CKRS alone] compared with the WBRT group (P = 0.01). The 2-year NDFS rates for the CKRS + TA, CRKS alone, and WBRT groups were 94%, 87%, and 78%, respectively (P = 0.03). Upfront CKRS showed significantly higher 2-year LF-free survival rate (P < 0.01). IF rate was insignificantly lower in the WBRT group compared with CKRS group (P = 0.38). Upfront CKRS + TA was associated with the best neurological outcome with high NDFS. Active brain control by early delivery of radiosurgery could achieve better neurological outcome in NSCLC with BM.

Separating or combining immune checkpoint inhibitors (ICIs) and radiotherapy in the treatment of NSCLC brain metastases

With the advancement of imaging technology, systemic disease control rate and survival rate, the morbidity of brain metastases (BMs) from non-small cell lung cancer (NSCLC) has been riding on a steady upward trend (40%), but management of BMs from NSCLC remains obscure. Systemic therapy is anticipated to offer novel therapeutic avenues in the management of NSCLC BMs, and radiotherapy (RT) and immunotherapy have their own advantages. Recently, it was confirmed that immune checkpoint inhibitors (ICIs) and RT could mutually promote the efficacy in the treatment of BMs from NSCLC. In this paper, we provide a review on current understandings and practices of separating or combining ICIs and RT, which could provide a reference for the coming laboratory and clinical studies and contribute to the development of new approaches in NSCLC BMs.

Brain metastases from non-small cell lung cancer with EGFR or ALK mutations: A systematic review and meta-analysis of multidisciplinary approaches

BACKGROUND AND PURPOSE

To analyze outcomes of non-small cell lung cancer (NSCLC) patients with brain metastases harboring EGFR or ALK mutations and examine for differences between tyrosine kinase inhibitors (TKIs) alone, radiotherapy (RT) alone (either whole brain radiation therapy (WBRT) or stereotactic radiosurgery (SRS)), or combined TKIs and RT.

MATERIALS AND METHODS

Thirty studies were identified.

PATIENTS

with brain metastases from NSCLC.

INTERVENTION

initial TKIs alone with optional salvage RT, RT alone, or TKIs and RT.

CONTROL

wild-type NSCLC and TKIs alone for mutational and treatment analysis, respectively.

OUTCOMES

overall survival (OS) and intracranial progression-free survival (PFS).

SETTING

studies with mutation information.

RESULTS

A total of 2649 patients were included. Patients with ALK and EGFR mutations had significantly higher median OS (48.5 months, p < 0.0001; and 20.9 months; p = 0.0006, respectively) compared to wild-type patients (9.9 months). Similar median OS was noted between TKIs and RT (28.3 months), RT alone (32.2 months; p = 0.22), or TKIs alone (23.9 months; p = 0.2). Patients treated with TKIs and RT had higher median PFS (18.6 months; p = 0.06) compared to TKIs alone (13.6 months) with no difference between TKIs and RT vs. RT alone (16.9 months; p = 0.72). No PFS difference was found between WBRT and TKI (23.2 months; p = 0.72) vs. WBRT alone (24 months) or SRS and TKI (16.7 months; p = 0.56) vs. SRS alone (13.6 months).

CONCLUSION

NSCLC patients with brain metastases harboring EGFR or ALK mutations have superior OS compared to wild-type patients. No PFS or OS benefit was found with the addition of TKIs to RT.

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.

Neurological Death is Common in Patients With EGFR Mutant Non-Small Cell Lung Cancer Diagnosed With Brain Metastases

Purpose

Brain metastases (BrM) are common in patients with epidermal growth factor receptor (EGFRm) mutant non-small cell lung cancer (NSCLC). We sought to determine the rate of neurologic death (ND) in this population.

Methods and Materials

We analyzed data from 198 patients who received a diagnosis of BrM from EGFRm NSCLC between 2004 and 2016, comparing patients whose initial treatment for BrM was stereotactic radiosurgery with or without tyrosine kinase inhibitors (TKI), whole brain radiation therapy (WBRT) with or without TKI, or TKI alone. The incidence of ND was determined using a competing risks analysis. Univariate and multivariate analyses were used to identify clinical variables associated with this outcome.

Results

The percentage of patients who initially received stereotactic radiosurgery, whole brain radiation therapy, or TKI alone was 22%, 61%, and 17%, respectively. Median overall survival in these subgroups was 31.1, 14.6, and 24.6 months, respectively (P = .0016). The 5-year incidence of ND among all patients was 40% and did not significantly vary according to treatment group. In a multivariable model, only leptomeningeal disease at any point in a patient’s disease course significantly correlated with ND (hazard ratio 4.75, P <.001).

Conclusions

Among our cohort of patients with BrM from EGFRm NSCLC, the incidence of ND was significantly higher than suggested by previous reports. BrM should be considered a driver of mortality in many patients with EGFRm NSCLC, and treatments providing better control of BrM, lower neurocognitive side effects, and maintenance of quality of life are needed.

Effects of different brain surveillance strategies on outcomes for patients with EGFR-mutant metastatic lung adenocarcinoma under targeted therapy

OBJECTIVES

Brain metastasis (BM) is common in patients with epidermal growth factor receptor (EGFR)-mutant lung cancer. However, the brain surveillance strategy during treatment in advanced lung cancer patients varies, and the impact on clinical outcome is unclear. Here we aimed to evaluate the effect of different brain surveillance strategies on the clinical characteristics and treatment outcome in patients with EGFR-mutant lung adenocarcinoma treated with first-line EGFR tyrosine kinase inhibitors (EGFR-TKIs).

MATERIALS AND METHODS

This is a retrospective observational study conducted in a medical center in an area with high prevalence of EGFR mutation. Patients with initially diagnosed stage IV EGFR-mutant lung adenocarcinoma were included. Patients undergoing regular brain magnetic resonance imaging (MRI) every 3-6 months were categorized in the regular follow-up (RFU) group, and the rest were categorized in the liberal follow-up (LFU) group. Clinical outcomes were collected and analyzed.

RESULTS

A total of 310 patients were included, and 43.5% initially had brain metastases. Patients in the LFU group were significantly older than those in the RFU group (median age: 67 vs 62, p < 0.001). The overall survival and time-to-treatment failure of patients with initial EGFR-TKIs treatment showed no statistical difference between the two groups. However, the intracranial progression free survival was significantly shorter in the RFU group than in the LFU group (p = 0.009). The risk of mortality was similar in the LFU and RFU groups. There was no difference in the intracranial progression patterns and cause of death between the two groups.

CONCLUSIONS

For EGFR-mutant lung adenocarcinoma patients who used EGFR-TKIs as the frontline therapy, regular or liberal brain MRI follow-up showed no significant impact on the outcome, irrespective of initial brain metastasis.

Therapeutic Effect Of First-Line EGFR-TKIs Combined With Concurrent Cranial Radiotherapy On NSCLC Patients With EGFR Activating Mutation And Brain Metastasis: A Retrospective Study

Purpose

Non-small cell lung cancer (NSCLC) patients with EGFR mutation are suffering from a high incidence of brain metastasis (BM). It is still controversial whether cranial radiotherapy could be delayed when the EGFR-tyrosine kinase inhibitors (TKIs) used as first-line therapy for EGFR-positive patients with BM. This study aims to investigate the therapeutic effect of TKIs combined with concurrent cranial radiotherapy on BM.

Patients and methods

NSCLC patients with EGFR mutation and BM were retrospectively analyzed from January 2013 to December 2016 in Shandong Cancer Hospital. Identified cases were treated with first-line EGFR-TKIs with or without concurrent cranial radiation.

Results

A total of 64 eligible patients were enrolled in this study, while 35 patients received first-line EGFR-TKIs plus cranial radiotherapy (RT+TKI group) and 29 patients received first-line EGFR-TKIs only (TKI alone group). The intracranial progression-free survival (PFS) of the RT+TKI group was significantly longer than the TKI alone group (25 vs 16 months; p=0.019), but no significant differences were observed between the two groups on extracranial PFS (20 vs 17 months, p=0.660). The median overall survival was also longer in the RT+TKI group (31 vs 24 months, p=0.019).

Conclusion

Our retrospective data suggest that first-line TKIs plus concurrent cranial radiotherapy is a promising therapeutic strategy that led to remarkable intracranial PFS improvement and survival benefits for EGFR-mutant NSCLC with BM. Hence, it should be considered as a crucial treatment method during clinical management.

Quantitative mathematical modeling of clinical brain metastasis dynamics in non-small cell lung cancer

Brain metastases (BMs) are associated with poor prognosis in non-small cell lung cancer (NSCLC), but are only visible when large enough. Therapeutic decisions such as whole brain radiation therapy would benefit from patient-specific predictions of radiologically undetectable BMs. Here, we propose a mathematical modeling approach and use it to analyze clinical data of BM from NSCLC. Primary tumor growth was best described by a gompertzian model for the pre-diagnosis history, followed by a tumor growth inhibition model during treatment. Growth parameters were estimated only from the size at diagnosis and histology, but predicted plausible individual estimates of the tumor age (2.1-5.3 years). Multiple metastatic models were further assessed from fitting either literature data of BM probability (n = 183 patients) or longitudinal measurements of visible BMs in two patients. Among the tested models, the one featuring dormancy was best able to describe the data. It predicted latency phases of 4.4-5.7 months and onset of BMs 14-19 months before diagnosis. This quantitative model paves the way for a computational tool of potential help during therapeutic management.

Multiinstitutional prospective observational study of stereotactic radiosurgery for patients with multiple brain metastases from non-small cell lung cancer (JLGK0901 study-NSCLC)

OBJECTIVEPrevious Japanese Leksell Gamma Knife Society studies (JLGK0901) demonstrated the noninferiority of stereotactic radiosurgery (SRS) alone as the initial treatment for patients with 5-10 brain metastases (BMs) compared with those with 2-4 BMs in terms of overall survival and most secondary endpoints. The authors studied the aforementioned treatment outcomes in a subset of patients with BMs from non-small cell lung cancer (NSCLC).METHODSPatients with initially diagnosed BMs treated with SRS alone were enrolled in this prospective observational study. Major inclusion criteria were the existence of up to 10 tumors with a maximum diameter of less than 3 cm each, a cumulative tumor volume of less than 15 cm3, and no leptomeningeal dissemination in patients with a Karnofsky Performance Scale score of 70% or better.RESULTSAmong 1194 eligible patients, 784 with NSCLC were categorized into 3 groups: group A (1 tumor, n = 299), group B (2-4 tumors, n = 342), and group C (5-10 tumors, n = 143). The median survival times were 13.9 months in group A, 12.3 months in group B, and 12.8 months in group C. The survival curves of groups B and C were very similar (hazard ratio [HR] 1.037; 95% CI 0.842-1.277; p < 0.0001, noninferiority test). The crude and cumulative incidence rates of neurological death, deterioration of neurological function, newly appearing lesions, and leptomeningeal dissemination did not differ significantly between groups B and C. SRS-induced complications occurred in 145 (12.1%) patients during the median post-SRS period of 9.3 months (IQR 4.1-17.4 months), including 46, 54, 29, 11, and 5 patients with a Common Terminology Criteria for Adverse Events v3.0 grade 1, 2, 3, 4, or 5 complication, respectively. The cumulative incidence rates of adverse effects in groups A, B, and C 60 months after SRS were 13.5%, 10.0%, and 12.6%, respectively (group B vs C: HR 1.344; 95% CI 0.768-2.352; p = 0.299). The 60-month post-SRS rates of neurocognitive function preservation were 85.7% or higher, and no significant differences among the 3 groups were found.CONCLUSIONSIn this subset analysis of patients with NSCLC, the noninferiority of SRS alone for the treatment of 5-10 versus 2-4 BMs was confirmed again in terms of overall survival and secondary endpoints. In particular, the incidence of neither post-SRS complications nor neurocognitive function preservation differed significantly between groups B and C. These findings further strengthen the already-reported noninferiority hypothesis of SRS alone for the treatment of patients with 5-10 BMs.

Treatment modes for EGFR mutations in patients with brain metastases from non-small cell lung cancer: controversy, causes, and solutions

Brain metastasis from non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) mutations is a hot research topic, but also a difficulty in targeted NSCLC therapy, and is also the focus of controversy in the field of lung cancer treatment. According to medical oncology, asymptomatic patients were initially treated with targeted therapy, followed by local radiotherapy when symptoms present or disease progresses. However, from the perspective of the discipline of radiotherapy, brain metastases need to be treated before drug resistance, as it may affect survival. Controversies between disciplines have brought much confusion to the treatment choices of clinicians. We summarized and discussed relevant literatures in this article to seek the truth in providing reference in clinical practice for treating diseases and solving problems.

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.

Management of CNS disease in ALK-positive non-small cell lung cancer: Is whole brain radiotherapy still needed?

Anaplastic lymphoma kinase (ALK)-positive non-small cell lung cancer (3 to 5% of all non-small cell lung cancers) carries a particularly high risk of central nervous system dissemination (60% to 90%). As the use of ALK inhibitors improves treatment outcomes over chemotherapy, the determent of central nervous system metastases has become an increasingly relevant therapeutic dilemma considering young age and possible extended overall survival. The goal of brain metastases management is to optimize both overall survival and quality of life, with the high priority of neurocognitive function preservation. Unfortunately in the first year on crizotinib, the pioneering ALK inhibitors, approximately one third of these patients fail in the central nervous system, which is explained by an inadequate central nervous system drug penetration through the blood-brain barrier. Central nervous system-directed radiotherapy represents the most important strategy to control intracranial disease burden and extend the survival benefit with crizotinib. The role of whole brain irradiation in the treatment of brain metastases diminishes, as this technique is associated with the risk of neurocognitive decline. Stereotactic radiotherapy represents an alternative technique that delivers ablative doses of ionizing radiation to the limited volume of oligometastatic brain disease, offering sparing of the adjacent brain parenchyma and reduced neurotoxicity. The next generation ALK inhibitors were designed to cross the blood-brain barrier more efficiently than crizotinib and achieve higher concentration in the cerebrospinal fluid, offering prominent ability to control central nervous system spread. In the phase III ALEX trial the intracranial control was significantly better with alectinib as compared to crizotinib and it translated into survival benefit. Other next generation ALK inhibitors (i.e. ceritinib, brigatinib, lorlatinib) also demonstrated promising activity in the central nervous system.

CNS response to osimertinib in patients with T790M-positive advanced NSCLC: pooled data from two phase II trials

Background

Central nervous system (CNS) metastases are common in patients with non-small-cell lung cancer (NSCLC). Osimertinib has shown systemic efficacy in patients with CNS metastases, and early clinical evidence shows efficacy in the CNS. To evaluate osimertinib activity further, we present a pre-specified subgroup analysis of CNS response using pooled data from two phase II studies: AURA extension (NCT01802632) and AURA2 (NCT02094261).

Patients and methods

Patients with T790M-positive advanced NSCLC, who had progressed following prior epidermal growth factor receptor-tyrosine kinase inhibitor treatment, received osimertinib 80 mg od (n = 411). Patients with stable, asymptomatic CNS metastases were eligible for enrolment; prior CNS treatment was allowed. Patients with ≥1 measurable CNS lesion (per RECIST 1.1) on baseline brain scan by blinded independent central neuroradiology review (BICR) were included in the evaluable for CNS response set (cEFR). The primary outcome for this CNS analysis was CNS objective response rate (ORR) by BICR; secondary outcomes included CNS duration of response, disease control rate (DCR) and progression-free survival (PFS).

Results

Of 128 patients with CNS metastases on baseline brain scans, 50 were included in the cEFR. Confirmed CNS ORR and DCR were 54% [27/50; 95% confidence interval (CI) 39-68] and 92% (46/50; 95% CI 81-98), respectively. CNS response was observed regardless of prior radiotherapy to the brain. Median CNS duration of response (22% maturity) was not reached (range, 1-15 months); at 9 months, 75% (95% CI 53-88) of patients were estimated to remain in response. Median follow-up for CNS PFS was 11 months; median CNS PFS was not reached (95% CI, 7, not calculable). The safety profile observed in the cEFR was consistent with the overall patient population.

Conclusions

Osimertinib demonstrated clinically meaningful efficacy against CNS metastases, with a high DCR, encouraging ORR, and safety profile consistent with that reported previously.

ClinicalTrials.gov number

NCT01802632; NCT02094261.

Multidisciplinary expert opinion on the treatment consensus for patients with EGFR mutated NSCLC with brain metastases

The presence of an epidermal growth factor receptor (EGFR) mutation is associated with higher incidence of brain metastases in patients with non-small cell lung cancer (NSCLC); however, patients with synchronous brain metastases at diagnosis have generally been excluded from clinical trials. As there is limited clinical evidence for managing this patient population, a multidisciplinary group of Spanish medical and radiation oncologists, and neuro-oncologist with expertise treating brain metastases in lung cancer patients met with the aim of reaching and developing an expert opinion consensus on the management of patients with EGFR mutated NSCLC with brain metastases. This consensus contains 26 recommendations and 20 conclusion statements across 21 questions in 7 areas, as well as a first-line treatment algorithm.

CNS Metastases in Epidermal Growth Factor Receptor Mutation-Positive Non-Small-Cell Lung Cancer: Impact on Health Resource Utilization

PURPOSE

Patients with epidermal growth factor receptor (EGFR) mutation-positive (EGFRm) non-small-cell lung cancer commonly experience disease progression in the CNS. Here, we assess the impact of CNS disease on resource utilization and outcomes in patients who are EGFRm.

METHODS

We completed a retrospective review of all advanced patients who were EGFRm, referred to BC Cancer, and treated with a first- and/or second-generation EGFR tyrosine kinase inhibitor from 2010 to 2015. Baseline characteristics, systemic treatment, and CNS management were collected. We compared health resource utilization (HRU) between patients with CNS-negative disease and those with CNS metastases from the median time of CNS metastases diagnosis to death or last follow-up (9.1 months) and at 9 months preceding death or last follow-up for the CNS-negative group.

RESULTS

Four hundred ninety-nine patients were referred, of which 68% were female; 51% were of Asian ethnicity; and 57%, 37%, and 6% were exon 19, 21, or other, respectively; with a median age of 66 years. Two hundred twenty-nine (46%) of 499 patients developed CNS metastases-39% at diagnosis and 61% over the course of disease. CNS metastases were managed with surgery with or without whole-brain radiotherapy (WBRT; 13%) WBRT alone (73%), stereotactic radiosurgery with or without WBRT (5%), or no CNS-directed therapy (9%). The median time from the development of CNS metastases diagnosis to death was 9.1 months. CNS-negative patients used less HRU versus patients that were CNS-positive in the 9 months preceding death or last follow-up-in the average number of clinic visits (8.53 v 12.71, respectively; P < .001), hospitalizations (0.43 v 0.76, respectively; P < .001), CNS imaging investigations (0.52 v 2.65, respectively; P < .001), emergency room visits (0.03 v 0.14, respectively; P = .001), palliative care unit admission (8% v 10%, respectively; P = .64), and hospice admission (3% v 19%, respectively; P < .001).

CONCLUSION

The incidence of CNS metastases in patients with EGFRm is high and associated with increased HRU. Prevention or delay of CNS metastases with newer systemic therapy options may translate into lower resource utilization.

Efficacy of ALK inhibitors on NSCLC brain metastases: A systematic review and pooled analysis of 21 studies

Background

Patients with anaplastic lymphoma kinase rearranged (ALK+) non-small cell lung cancer (NSCLC) have a higher risk of developing brain metastases (BMs) than patients with other NSCLC sub-types. ALK inhibitors have activity in BMs due to ALK+ NSCLC. We performed a systematic review of the literature with the aim of assessing the efficacy of ALK inhibitors on BMs.

Material and methods

A systematic search of the literature was performed using the databases Pubmed, EMBASE, Web of Science, The Cochrane Library, and SCOPUS. Relevant publications reporting activity of ALK inhibitors in NSCLC BMs were retrieved. Data were pooled using the number of events/number of evaluable patients according to fixed or random effect models. Intracranial tumour response was assessed through overall response rate (ORR), disease control rate (DCR: ORR + stable disease rate), median progression-free survival (PFS), and overall survival (OS). The primary endpoint was intracranial overall response rate (IC ORR).

Results

A total of 1,016 patients with BMs from 21 studies were analysed. In patients receiving ALK inhibitors in the first line setting, the pooled IC ORR was 39.17% (95%CI 13.1–65.2%), while the pooled IC ORR observed in further lines was 44.2% (95%CI 33.3–55.1%). Intracranial disease control rate (IC DCR) was 70.3% and 78.2% in naïve and pre-treated patients, respectively. Patients who had not received brain radiation attained an IC ORR of 49.0%.

Conclusions

Based on these data, ALK inhibitors are effective in both naive and pre-treated patients with similar IC ORR and IC DCR, irrespective of the line of therapy.

Efficacy and Safety of Radiotherapy Plus EGFR-TKIs in NSCLC Patients with Brain Metastases: A Meta-Analysis of Published Data

Background: The role of radiotherapy (RT) combined with epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) in non-small cell lung cancer (NSCLC) patients with brain metastasis (BM) remains controversial. Therefore, we conducted a meta-analysis to comprehensively evaluate the efficacy and safety of RT plus EGFR-TKIs in those patients. Materials and Methods: Relevant literatures published between 2012 and 2017 were searched. Objective response rate(ORR), disease control rate (DCR), overall survival (OS), intracranial progression-free survival (I-PFS) and adverse events (AEs) were extracted. The combined hazard ratios (HRs) and relative risks (RRs) were calculated using random effects models. Results: Twenty-four studies (2810 patients) were included in the analysis. Overall, RT plus EGFR-TKIs had higher ORR (RR = 1.32, 95%CI: 1.13–1.55), DCR (RR = 1.12, 95%CI: 1.04–1.22), and longer OS (HR = 0.72, 95%CI: 0.59–0.89), I-PFS (HR = 0.64, 95%CI: 0.50–0.82) than monotherapy, although with higher overall AEs (20.2% vs 11.8%, RR = 1.34, 95% CI: 1.11–1.62). Furthermore, subgroup analyses found concurrent RT plus EGFR-TKIs could prolong OS (HR = 0.69, 95%CI: 0.55–0.86) and I-PFS (HR = 0.57, 95%CI: 0.44–0.75). Asian ethnicity and lung adenocarcinoma (LAC) patients predicted a more favorable prognosis (HR = 0.69,95%CI: 0.54–0.88, HR = 0.66, 95%CI: 0.53–0.83, respectively). Conclusion: RT plus EGFR-TKIs had higher response rate, longer OS and I-PFS than monotherapy in NSCLC patients with BM. Asian LAC patients with EGFR mutation had a better prognosis with concurrent treatment. The AEs of RT plus EGFR-TKIs were tolerated.

Resistance to epidermal growth factor receptor tyrosine kinase inhibitors, T790M, and clinical trials

Tumours with sensitizing mutations in the EGFR gene constitute a distinct molecular subgroup of non-small-cell lung cancers (nsclcs) that benefit from precision medicine. First- and second-generation epidermal growth factor receptor (egfr) tyrosine kinase inhibitors (tkis) are recommended as upfront therapy for EGFR-mutated advanced nsclc and, compared with chemotherapy, have resulted in superior progression-free survival, improved tumour response rates, and improved quality of life. However, resistance inevitably develops, and the third-generation tki osimertinib has been approved to target the gatekeeper EGFR mutation T790M, which is responsible for resistance in 60% of cases. Multiple drivers of tki resistance have now been identified, and many new drugs are in development. With respect to this rapidly evolving field, our review highlights the current status of treatment options for patients with EGFR-mutated advanced nsclc, focusing especially on identified causes of resistance, challenges, and clinical trials aiming to improve outcomes in this patient population.

Treating brain metastases in non-small cell lung cancer patients: what have we learnt from pharmaceutical recent clinical trials?

INTRODUCTION

Brain metastases (BMs) develop in up to 40% of patients with non-small cell lung cancer (NSCLC). In many recent practice-changing clinical trials, patients with BM were included; however, only few trials reported intracranial efficacies in either post hoc or pre-planned analysis. Clinically meaningful intracranial efficacy data of novel agents have not been completely disclosed.

AREAS COVERED

The authors performed a systemic review of recent pharmaceutical clinical trials, mainly pivotal or practice-changing trials. Some of the prospective clinical trials focused on patients with NSCLC and BM. The authors collected and compared intracranial efficacy reports of chemotherapy, epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), ALK inhibitors, and immune checkpoint inhibitors.

EXPERT OPINION

Many clinical trials, especially those on 'brain-active' EGFR-TKIs and ALK inhibitors, have robust reports of intracranial efficacies either as post hoc or pre-planned analysis. Physicians should interpret this data with caution and apply the results to patients accordingly. For the design of future clinical trials, enrolling patients with only BM, incorporating novel risk classifications, pre-planning intracranial efficacy endpoints, reporting prior local brain therapies, and applying novel response evaluation criteria are emerging trends in this area.

Role of Epidermal Growth Factor Receptor (EGFR) Inhibitors and Radiation in the Management of Brain Metastases from EGFR Mutant Lung Cancers

The growth of genotype-directed targeted therapies, such as inhibitors of the epidermal growth factor receptor (EGFR), has revolutionized treatment for some patients with oncogene-addicted lung cancer. However, as systemic control for these patients has improved, brain metastases remain an important source of morbidity and mortality. Traditional treatment for brain metastases has been radiotherapy, either whole-brain radiation or stereotactic radiosurgery. The growing availability of drugs that can cross the blood-brain barrier and have activity in the central nervous system (CNS) has led to many studies investigating whether targeted therapy can be used in combination with or in lieu of radiation. In this review, we summarize the key literature about the incidence and nature of EGFR-mutant brain metastases (EGFR BMs), the data about the activity of EGFR inhibitors in the CNS, and whether they can be used as front-line therapy for brain metastases. Although initial use of tyrosine kinase inhibitors for EGFR BMs can often be an effective treatment strategy, multidisciplinary evaluation is critical, and prospective studies are needed to clarify which patients may benefit from early radiotherapy.

IMPLICATIONS FOR PRACTICE

Management of brain metastases in epidermal growth factor receptor (EGFR) mutant lung cancer is a common clinical problem. The question of whether to start initial therapy with an EGFR inhibitor or radiotherapy (either whole-brain radiotherapy or stereotactic radiosurgery) is controversial. The development of novel EGFR inhibitors with enhanced central nervous system (CNS) penetration is an important advance in the treatment of CNS disease. Multidisciplinary evaluation and evaluation of extracranial disease status are critical to choosing the best treatment option for each patient.

Bevacizumab Reduces S100A9-Positive MDSCs Linked to Intracranial Control in Patients with EGFR-Mutant Lung Adenocarcinoma

INTRODUCTION

In vitro models have demonstrated immune-modulating effects of bevacizumab (BEV). Combinations of an EGFR tyrosine kinase inhibitor (TKI) with BEV improve progression-free survival (PFS) in patients with EGFR-mutated lung adenocarcinoma. How BEV confers this clinical effect and the underlying mechanisms of its effect are not clear.

METHODS

A total of 55 patients with stage 4 EGFR-mutated lung adenocarcinoma were enrolled. Myeloid-derived suppressor cells (MDSCs), type 1 and type 2 helper T cells, and cytotoxic T lymphocytes were analyzed by flow cytometry. Clinical data were collected for analysis.

RESULT

In all, 25 patients received EGFR TKI and BEV combination therapy (the BEV/TKI group) and 30 patients received EGFR TKI monotherapy (the TKI-only group). The BEV/TKI group had longer PFS (23.0 versus 8.6 months [p = 0.001]) and, in particular, better intracranial control rates (80.0% versus 43.0% [p = 0.03]), a longer time to intracranial progression (49.1 versus 12.9 months [p = 0.002]), and fewer new brain metastases (38.0% versus 71.0% [p = 0.03]) than the TKI-only group did. The BEV/TKI group had a lower percentage of circulating MDSCs (20.4% ± 6.5% before treatment versus 12.8% ± 6.6% after treatment, respectively [p = 0.02]), and higher percentages of type 1 helper T cells (22.9% ± 15.3% versus 33.2% ± 15.6% [p < 0.01]) and cytotoxic T lymphocytes (15.5% ± 7.2% versus 21.2% ± 5.6% [p < 0.01]) after treatment, changes that were not seen in the TKI-only group. Pretreatment percentage of MDSCs was correlated with PFS, with this correlation attenuated after BEV/TKI treatment. Percentage of MDSCs was also associated with shorter time to intracranial progression.

CONCLUSION

Combining a EGFR TKI with BEV extended PFS and protected against brain metastasis. Those effects were probably due to the reduction of circulating S100A9-positive MDSCs by BEV, which leads to restoration of effective antitumor immunity. Our data also support the rationale for a BEV-immune checkpoint inhibitor combination.

Recent advances in the biology and treatment of brain metastases of non-small cell lung cancer: summary of a multidisciplinary roundtable discussion

This article is the result of a round table discussion held at the European Lung Cancer Conference (ELCC) in Geneva in May 2017. Its purpose is to explore and discuss the advances in the knowledge about the biology and treatment of brain metastases originating from non-small cell lung cancer. The authors propose a series of recommendations for research and treatment within the discussed context.

The Current Role of Whole Brain Radiation Therapy in Non-Small Cell Lung Cancer Patients

The incidence of brain metastases has increased in patients with NSCLC as a result of better systemic disease control and advances in imaging modalities. Whole brain radiotherapy (WBRT) has been the mainstay treatment of multiple symptomatic brain metastases for years. A number of recent publications have questioned its place in the absence of a survival and quality of life benefit and the possible risk for long-term neurotoxicity. Omission or deferral of WBRT and strategies consisting of stereotactic radiosurgery or delivery of systemic therapies alone are being proposed more and more. However, critical analysis of the literature shows that WBRT still has relevant indications in well-selected patients. Within this review, we discuss the place of WBRT in the modern management of patients with NSCLC.