Brain metastases from lung cancer responding to erlotinib: the importance of EGFR mutation

Targeting programmed cell death protein 1 (PD-1) for treatment of non-small-cell lung carcinoma (NSCLC); the recent advances

The immune system uses various immune checkpoint axes to adjust responses, support homeostasis, and deter self-reactivity and autoimmunity. Nevertheless, non-small-cell lung carcinoma (NSCLC) can use protective mechanisms to facilitate immune evasion, which leads to potentiated cancer survival and proliferation. In this light, many blocking anti-bodies have been developed to negatively regulate checkpoint molecules, in particular, programmed cell death protein 1 (PD-1) / PD-ligand 1 (L1), and bypass these immune suppressive mechanisms. Meanwhile, anti-PD-1 anti-bodies such as nivolumab, pembrolizumab, cemiplimab, and sintilimab have shown excellent competence in successfully inspiring immune responses versus NSCLC. Accordingly, the United States Food and Drug Administration (FDA) has recently approved nivolumab (alone or in combination with ipilimumab) and pembrolizumab (alone or in combination with chemotherapy) as first-line treatment for advanced NSCLC patients. However, PD-1 blockade monotherapy remains inefficient in more than 60% of NSCLC patients, and many patients don't respond or acquire resistance to this modality. Also, toxicities related to anti-PD-1 anti-body have been progressively identified in clinical trials and oncology practice. Herein, we will outline the clinical benefits of PD-1 blockade therapy alone or in combination with other treatments (e.g., chemotherapy, radiotherapy, anti-angiogenic therapy) in NSCLC patients. Moreover, we will take a glimpse into the recently identified predictive biomarkers to determine patients most likely to suffer serious adverse events to decrease untoward toxicity risk and diminish treatment costs.

The role of targeted therapy and immune therapy in the management of non-small cell lung cancer brain metastases

Brain metastases are a significant source of morbidity and mortality in patients with non-small cell lung cancer. Historically, surgery and radiation therapy have been essential to maintaining disease control within the central nervous system due to poorly penetrant conventional chemotherapy. With the advent of targeted therapy against actionable driver mutations, there is potential to control limited and asymptomatic intracranial disease and delay local therapy until progression. In this review paper, intracranial response rates and clinical outcomes to biological and immune therapies are summarized from the literature and appraised to assist clinical decision making and identify areas for further research. Future clinical trials ought to prioritize patient-centered quality of life and neurocognitive measures as major outcomes and specifically stratify patients based on mutational marker status, disease burden, and symptom acuity.

Treatment Strategies for Non-Small Cell Lung Cancer Harboring Common and Uncommon EGFR Mutations: Drug Sensitivity Based on Exon Classification, and Structure-Function Analysis

Simple Summary

The advent of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (EGFR-TKIs) has led to a dramatic improvement in the prognosis of patients having advanced EGFR-mutant non-small cell lung cancer (NSCLC). NSCLCs harboring “common” EGFR mutations, including exon 19 deletions and exon 21 L858R mutation substitutions, are sensitive to EGFR-TKIs. However, NSCLCs harboring “uncommon” EGFR mutations have poor sensitivity to EGFR-TKIs, and patients harboring uncommon mutations often experience poor outcomes. Here, we review the current EGFR-TKI therapy and the development of treatment strategies, including combined treatment and the exploration of new drugs. In addition, we discuss EGFR-TKI sensitivity based on structure-function analysis.

Abstract

The identification of epidermal growth factor receptor (EGFR) mutations and development of EGFR tyrosine kinase inhibitors (EGFR-TKIs) have dramatically improved the prognosis of advanced EGFR-mutated non-small cell lung cancer (NSCLC), setting a landmark in precision oncology. Exon 19 deletions and exon 21 L858R substitutions, which comprise the majority of common EGFR mutations, are predictors of good sensitivity to EGFR-TKIs. However, not all cancers harboring EGFR mutations are sensitive to EGFR-TKIs. Most patients harboring uncommon EGFR mutations demonstrate a poorer clinical response than those harboring common EGFR mutations. For example, cancers harboring exon 20 insertions, which represent approximately 4–12% of EGFR mutations, are generally insensitive to first- and second-generation EGFR-TKIs. Although understanding the biology of uncommon EGFR mutations is essential for developing treatment strategies, there is little clinical data because of their rarity. Moreover, clarifying the acquired resistance of EGFR-mutated NSCLC may lead to more precise treatments. Sequencing and structure-based analyses of EGFRmutated NSCLC have revealed resistance mechanisms and drug sensitivity. In this review, we discuss the strategies in development for treating NSCLC harboring common and uncommon EGFR mutations. We will also focus on EGFR-TKI sensitivity in patients harboring EGFR mutations based on the structural features.

The Value of Radiotherapy for Advanced Non-Small Cell Lung Cancer With Oncogene Driver-Mutation

Due to the widespread use of tyrosine kinase inhibitors (TKIs), which have largely supplanted cytotoxic chemotherapy as the first-line therapeutic choice for patients with advanced non-small cell lung cancer (NSCLC) who have oncogene driver mutations, advanced NSCLC patients with oncogene driver mutations had much long median survival. However, TKIs’ long-term efficacy is harmed by resistance to them. TKIs proved to have a limited potential to permeate cerebrospinal fluid (CSF) as well. Only a small percentage of plasma levels could be found in CSF at usual doses. Therefore, TKIs monotherapy may have a limited efficacy in individuals with brain metastases. Radiation has been demonstrated to reduce TKIs resistance and disrupt the blood-brain barrier (BBB). Previous trials have shown that local irradiation for bone metastases might improve symptoms, in addition, continuous administration of TKIs combined with radiotherapy was linked with beneficial progression-free survival (PFS) and overall survival (OS) for oligometastasis or bone metastasis NSCLC with oncogene driver mutations. The above implied that radiotherapy combined with targeted therapy may have a synergistic impact in patients with advanced oncogene driver-mutated NSCLC. The objective of this article is to discuss the value of radiotherapy in the treatment of those specific individuals.

Brain metastases: An update on the multi-disciplinary approach of clinical management

IMPORTANCE

Brain metastasis (BM) is the most common malignant intracranial neoplasm in adults with over 100,000 new cases annually in the United States and outnumbering primary brain tumors 10:1.

OBSERVATIONS

The incidence of BM in adult cancer patients ranges from 10-40%, and is increasing with improved surveillance, effective systemic therapy, and an aging population. The overall prognosis of cancer patients is largely dependent on the presence or absence of brain metastasis, and therefore, a timely and accurate diagnosis is crucial for improving long-term outcomes, especially in the current era of significantly improved systemic therapy for many common cancers. BM should be suspected in any cancer patient who develops new neurological deficits or behavioral abnormalities. Gadolinium enhanced MRI is the preferred imaging technique and BM must be distinguished from other pathologies. Large, symptomatic lesion(s) in patients with good functional status are best treated with surgery and stereotactic radiosurgery (SRS). Due to neurocognitive side effects and improved overall survival of cancer patients, whole brain radiotherapy (WBRT) is reserved as salvage therapy for patients with multiple lesions or as palliation. Newer approaches including multi-lesion stereotactic surgery, targeted therapy, and immunotherapy are also being investigated to improve outcomes while preserving quality of life.

CONCLUSION

With the significant advancements in the systemic treatment for cancer patients, addressing BM effectively is critical for overall survival. In addition to patient's performance status, therapeutic approach should be based on the type of primary tumor and associated molecular profile as well as the size, number, and location of metastatic lesion(s).

Current understanding of hexavalent chromium [Cr(VI)] neurotoxicity and new perspectives

Hexavalent chromium [Cr(VI)] is a global environmental pollutant that increases risk for several types of cancers and is increasingly being recognized as a neurotoxicant. Traditionally, the brain has been viewed as a largely post-mitotic organ due to its specialized composition of neurons, and consequently, clastogenic effects were not considered in neurotoxicology. Today, we understand the brain is composed of at least eight distinct cell types - most of which continue mitotic activity throughout lifespan. We have learned these dividing cells play essential roles in brain and body health. This review focuses on Cr(VI), a potent clastogen and known human carcinogen, as a potentially neurotoxic agent targeting mitotic cells of the brain. Despite its well-established role as a human carcinogen, Cr(VI) neurotoxicity studies have failed to find a significant link to brain cancers. In the few studies that did find a link, Cr(VI) was identified as a risk for gliomas. Instead, in the human brain, Cr(VI) appears to have more subtle deleterious effects that can impair childhood learning and attention development, olfactory function, social memory, and may contribute to motor neuron diseases. Studies of Cr(VI) neurotoxicity with animal and cell culture models have demonstrated elevated markers of oxidative damage and redox stress, with widespread neurodegeneration. One study showed mice exposed to Cr(VI)-laden tannery effluent exhibited longer periods of aggressive behavior toward an "intruder" mouse and took longer to recognize mice previously encountered, recapitulating the social memory deficits observed in humans. Here we conducted a critical review of the available literature on Cr(VI) neurotoxicity and synthesize the collective observations to thoroughly evaluate Cr(VI) neurotoxicity - much remains to be understood and recognized.

Overall survival benefit of Osimertinib and clinical value of upfront cranial local therapy in untreated EGFR-mutant non-small cell lung cancer with brain metastasis

Osimertinib, as a third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI), showed more potent efficacy against brain metastasis (BM) in untreated EGFR-mutant non-small cell lung cancer (NSCLC) in the FLAURA study. However, the overall survival (OS) benefit of Osimertinib and clinical value of cranial local therapy (CLT) in these patients remain undetermined. Here we conducted a retrospective study involving untreated EGFR-mutant NSCLC patients with BMs receiving first-line osimertinib or first-generation EGFR-TKIs. Upfront CLT was defined as CLT performed before disease progression to the first-line EGFR-TKIs. Pattern of treatment failure and survival outcomes were extensively investigated. Among the 367 patients enrolled, first-generation EGFR-TKI was administered in 265, osimertinib in 102 and upfront CLT performed in 140. Patients receiving osimertinib had more (p<0.001) and larger BMs (p=0.003) than those receiving first-generation EGFR-TKIs. After propensity score matching (PSM), osimertinib was found to prolong OS (37.7 months vs. 22.2 months, p=0.027). Pattern of failure analyses found that 51.8% of the patients without upfront CLT developed their initial progressive disease (PD) in the brain and 59.0% of the cranial PD occurred at the original sites alone, suggesting potential clinical value of upfront CLT. Indeed, upfront stereotactic radiosurgery (SRS) and/or surgery was associated with improved OS among those receiving first-generation EGFR-TKIs (p=0.019) and those receiving osimertinib (p=0.041). In summary, compared with first-generation EGFR-TKIs, osimertinib is associated with improved OS in untreated EGFR-mutant NSCLC with BMs. Meanwhile, upfront SRS and/or surgery may provide extra survival benefit, which needs to be verified in future studies. This article is protected by copyright. All rights reserved.

Anti-PD1 Therapy Plus Whole-Brain Radiation Therapy May Prolong PFS in Selected Non-Small Cell Lung Cancer Patients with Brain Metastases: A Retrospective Study

Background

Whole-brain radiotherapy (WBRT) remains an essential modality of treatment for brain metastases (BMs) derived from non-small cell lung cancer (NSCLC) patients and anti-PD-1 therapy has demonstrated intracranial responses in these patients. We aimed to evaluate if the combination of the two treatments could yield additive efficacy.

Methods

A retrospective review of our institution’s database was carried out to identify NSCLC patients with BMs who had been treated with anti-PD1 therapy and/or WBRT between 2015 and 2020. Patient characteristics, main outcomes, including progression-free survival (PFS) and overall survival (OS), and factors affecting these outcomes were analyzed. SPSS 24 was used for statistical analysis. Appropriate statistical tests were employed according to the type of data.

Results

Overall, 21 NSCLC BM patients were identified that had received WBRT. Of these, ten had been additionally treated with anti-PD1 therapy within 30 days of WBRT initiation. Median PFS was 3 (95% CI 0.8–5.1) months with WBRT alone versus 11 (95% CI 6.3–15.6) months with combined treatment. Risk of disease progression was 71% lower with the combined approach (HR 0.29, 95% CI 0.11–0.80; p=0.016). A trend toward improved OS was also observed with the combined approach (HR 0.33, 95% CI 0.08–1.12; p=0.107). Concurrent treatment (p=0.028) and male sex (p=0.052) were associated with improved PFS, while OS was associated only with age (p=0.02).

Conclusion

Concurrent WBRT and anti-PD1 therapy may delay progression and improve survival in BM patients with confirmed EGFR- and ALK-negative NSCLC histology. Prospective studies are warranted to validate and elucidate on the additive effect of the two modalities.

Dose-Response Effect and Dose-Toxicity in Stereotactic Radiotherapy for Brain Metastases: A Review

Simple Summary

Brain metastases are one of the most frequent complications for cancer patients. Stereotactic radiosurgery is considered a cornerstone treatment for patients with limited brain metastases and the ideal dose and fractionation schedule still remain unknown. The aim of this literature review is to discuss the dose-effect relation in brain metastases treated by stereotactic radiosurgery, accounting for fractionation and technical considerations.

Abstract

For more than two decades, stereotactic radiosurgery has been considered a cornerstone treatment for patients with limited brain metastases. Historically, radiosurgery in a single fraction has been the standard of care but recent technical advances have also enabled the delivery of hypofractionated stereotactic radiotherapy for dedicated situations. Only few studies have investigated the efficacy and toxicity profile of different hypofractionated schedules but, to date, the ideal dose and fractionation schedule still remains unknown. Moreover, the linear-quadratic model is being debated regarding high dose per fraction. Recent studies shown the radiation schedule is a critical factor in the immunomodulatory responses. The aim of this literature review was to discuss the dose–effect relation in brain metastases treated by stereotactic radiosurgery accounting for fractionation and technical considerations. Efficacy and toxicity data were analyzed in the light of recent published data. Only retrospective and heterogeneous data were available. We attempted to present the relevant data with caution. A BED10 of 40 to 50 Gy seems associated with a 12-month local control rate >70%. A BED10 of 50 to 60 Gy seems to achieve a 12-month local control rate at least of 80% at 12 months. In the brain metastases radiosurgery series, for single-fraction schedule, a V12 Gy < 5 to 10 cc was associated to 7.1–22.5% radionecrosis rate. For three-fractions schedule, V18 Gy < 26–30 cc, V21 Gy < 21 cc and V23 Gy < 5–7 cc were associated with about 0–14% radionecrosis rate. For five-fractions schedule, V30 Gy < 10–30 cc, V 28.8 Gy < 3–7 cc and V25 Gy < 16 cc were associated with about 2–14% symptomatic radionecrosis rate. There are still no prospective trials comparing radiosurgery to fractionated stereotactic irradiation.

The Value of the Systemic Immune-Inflammation Index in Predicting Survival Outcomes in Patients with Brain Metastases of Non-Small-Cell Lung Cancer Treated with Stereotactic Radiotherapy

Background

As a parameter integrating platelet (P), neutrophil (N), and lymphocyte (L) levels, the systemic immune-inflammation index (SII) has been used as a prognostic marker for patient survival in various types of solid malignant tumors. However, there is no in-depth study in non-small-cell lung cancer (NSCLC) patients with brain metastases after stereotactic radiotherapy. Therefore, we performed a retrospective analysis to determine the clinical and prognostic value of the SII in NSCLC patients with brain metastases who underwent stereotactic radiotherapy.

Materials and Methods

We enrolled 124 NSCLC patients with brain metastases treated with stereotactic radiotherapy in our hospital between May 2015 and June 2018. We obtained all baseline blood samples within one week prior to stereotactic radiotherapy. The SII was calculated by the following formula: neutrophil counts × platelet counts/lymphocyte counts. The optimal cutoff value of the SII for predicting prognosis was assessed by receiver operating characteristic (ROC) curves with the maximum log-rank values. The discriminative ability of predicting prognosis was calculated and compared using the Kaplan–Meier method and log-rank test. The hazard ratio (HR) and 95% confidence interval (CI) were combined to evaluate the prognostic impact of the blood index on overall survival (OS) and progression-free survival (PFS). Only those parameters that proved to be associated with statistically significant differences in clinical outcomes were compared in multivariate analysis using a multiple Cox proportional hazard regression model to identify independent prognostic factors.

Results

Of the total enrolled patients, 53.2% and 46.8% have high SII and low SII, respectively. In this study, Kaplan–Meier curve analysis revealed that the median PFS was 9 months (range: 2–22 months) and the median OS was 18 months (range: 4–37 months). Applying an optimal cutoff of 480 (SII), the median PFS was better in the low SII group patients (11.5 vs. 9 months), and the median OS was significantly longer in the low SII group patients (20 vs. 18 months). A SII > 480 was significantly associated with worse OS (HR: 2.196; 95% CI 1.259–3.832; P = 0.006) and PFS (HR: 2.471; 95% CI 1.488–4.104; P < 0.001) according to univariate analysis. In multivariate analysis, only age (HR: 2.159; 95% CI 1.205–3.869; P = 0.010), KPS (HR: 1.887; 95% CI 1.114–3.198; P = 0.018), and SII (HR: 1.938; 95% CI 1.046–3.589; P = 0.035) were independently correlated with OS, and SII (HR: 2.224; 95% CI 1.298–3.810; P = 0.004) was an independent prognostic predictor of PFS, whereas we found that other inflammation-based indices lost their independent value.

Conclusions

The SII, which is an integrated blood parameter based on platelet, neutrophil, and lymphocyte counts, may be an independent prognostic indicator and may be useful for the identification of NSCLC patients with brain metastases after stereotactic radiotherapy at high risk for recurrence.

Development of Brain Metastases in Patients With Non-Small Cell Lung Cancer and No Brain Metastases at Initial Staging Evaluation: Cumulative Incidence and Risk Factor Analysis

Background: While established guidelines give indications for performing staging brain MRI at initial non-small cell lung cancer (NSCLC) diagnosis, guidelines are lacking for performing surveillance brain MRI in patients without brain metastases at presentation. Objective: To estimate the cumulative incidence of, and risk factors associated with, brain metastasis development in patients with NSCLC without brain metastases at initial presentation. Methods: This retrospective study included 1495 patients with NSCLC (mean age 65±10 years; 920 men, 575 women) without brain metastases at initial evaluation that included brain MRI. Follow-up brain MRI was ordered at referrer physicians' discretion. MRI examinations were reviewed in combination with clinical records for brain metastasis development; patients not undergoing MRI were deemed to have not developed metastases through last clinical follow-up. Cumulative incidence of brain metastases was determined with death as a competing risk and stratified by clinical stage group, cell type, and epidermal growth factor receptor (EGFR) status. Univariable and multivariable Cox proportional hazards regression analyses were performed. Results: A total of 258/1495 (17.3%) patients underwent follow-up brain MRI, and 72/1495 (4.8%) developed brain metastases at a median of 12.3 months after initial NSCLC diagnosis. Among the 72 patients developing metastases, 44% had no neurologic symptoms, and 58% had stable primary thoracic disease. Cumulative incidence of brain metastases at 6, 12, 18, and 24 months was 0.6%, 2.1%, 4.2% and 6.8%, respectively. Cumulative incidence was higher (P<.001) in clinical stage III-IV (1.3%, 3.9%, 7.7%, and 10.9%) than I-II (0.0%, 0.8%, 1.2%, and 2.6%) disease, and higher (P<.001) in EGFR positive (0.7%, 2.5%, 6.3%, and 12.3%) than EGFR negative (0.4%, 1.8%, 2.9%, and 4.4%) adenocarcinoma. Among 1109 patients with adenocarcinoma, independent risk factors for brain metastasis development were clinical stage III-IV (hazard ratio [HR]=9.39; P<.001) and EGFR positivity (HR=1.78; P=.04). Brain metastasis incidence over the study interval was 8.7% in clinical stage III-IV disease and 8.6% in EGFR positive adenocarcinoma. Conclusion: Clinical stage III-IV and EGFR positive adenocarcinoma are independent risk factors for brain metastasis development. Clinical impact: Surveillance brain MRI may be warranted 12 months after initial evaluation in clinical stage III-IV disease or EGFR-positive adenocarcinoma.

Challenges and Novel Opportunities of Radiation Therapy for Brain Metastases in Non-Small Cell Lung Cancer

Simple Summary

Lung cancer is the most common primary malignancy that tends to metastasize to the brain. Owing to improved survival of lung cancer patients, the prevalence of brain metastases is a matter of growing concern. Brain radiotherapy remains the mainstay in the management of metastatic CNS disease. However, new targeted therapies such as the tyrosine kinase or immune checkpoint inhibitors have demonstrated intracranial activity and promising tumor response rates. Here, we review the current and emerging therapeutical strategies for brain metastases from non-small cell lung cancer, both brain-directed and systemic, as well as the uncertainties that may arise from their combination.

Abstract

Approximately 20% patients with non-small cell lung cancer (NSCLC) present with CNS spread at the time of diagnosis and 25–50% are found to have brain metastases (BMs) during the course of the disease. The improvement in the diagnostic tools and screening, as well as the use of new systemic therapies have contributed to a more precise diagnosis and prolonged survival of lung cancer patients with more time for BMs development. In the past, most of the systemic therapies failed intracranially because of the inability to effectively cross the blood brain barrier. Some of the new targeted therapies, especially the group of tyrosine kinase inhibitors (TKIs) have shown durable CNS response. However, the use of ionizing radiation remains vital in the management of metastatic brain disease. Although a decrease in CNS-related deaths has been achieved over the past decade, many challenges arise from the need of multiple and repeated brain radiation treatments, which carry along not insignificant risks and toxicity. The combination of stereotactic radiotherapy and systemic treatments in terms of effectiveness and adverse effects, such as radionecrosis, remains a subject of ongoing investigation. This review discusses the challenges of the use of radiation therapy in NSCLC BMs in view of different systemic treatments such as chemotherapy, TKIs and immunotherapy. It also outlines the future perspectives and strategies for personalized BMs management.

ctDNA-Based Liquid Biopsy of Cerebrospinal Fluid in Brain Cancer

The correct characterisation of central nervous system (CNS) malignancies is crucial for accurate diagnosis and prognosis and also the identification of actionable genomic alterations that can guide the therapeutic strategy. Surgical biopsies are performed to characterise the tumour; however, these procedures are invasive and are not always feasible for all patients. Moreover, they only provide a static snapshot and can miss tumour heterogeneity. Currently, monitoring of CNS cancer is performed by conventional imaging techniques and, in some cases, cytology analysis of the cerebrospinal fluid (CSF); however, these techniques have limited sensitivity. To overcome these limitations, a liquid biopsy of the CSF can be used to obtain information about the tumour in a less invasive manner. The CSF is a source of cell-free circulating tumour DNA (ctDNA), and the analysis of this biomarker can characterise and monitor brain cancer. Recent studies have shown that ctDNA is more abundant in the CSF than plasma for CNS malignancies and that it can be sequenced to reveal tumour heterogeneity and provide diagnostic and prognostic information. Furthermore, analysis of longitudinal samples can aid patient monitoring by detecting residual disease or even tracking tumour evolution at relapse and, therefore, tailoring the therapeutic strategy. In this review, we provide an overview of the potential clinical applications of the analysis of CSF ctDNA and the challenges that need to be overcome in order to translate research findings into a tool for clinical practice.

Predicting Survival Duration With MRI Radiomics of Brain Metastases From Non-small Cell Lung Cancer

Background: Brain metastases are associated with poor survival. Molecular genetic testing informs on targeted therapy and survival. The purpose of this study was to perform a MR imaging-based radiomic analysis of brain metastases from non-small cell lung cancer (NSCLC) to identify radiomic features that were important for predicting survival duration.

Methods: We retrospectively identified our study cohort via an institutional database search for patients with brain metastases from EGFR, ALK, and/or KRAS mutation-positive NSCLC. We segmented the brain metastatic tumors on the brain MR images, extracted radiomic features, constructed radiomic scores from significant radiomic features based on multivariate Cox regression analysis (p < 0.05), and built predictive models for survival duration.

Result: Of the 110 patients in the cohort (mean age 57.51 ± 12.32 years; range: 22–85 years, M:F = 37:73), 75, 26, and 15 had NSCLC with EGFR, ALK, and KRAS mutations, respectively. Predictive modeling of survival duration using both clinical and radiomic features yielded areas under the receiver operative characteristic curve of 0.977, 0.905, and 0.947 for the EGFR, ALK, and KRAS mutation-positive groups, respectively. Radiomic scores enabled the separation of each mutation-positive group into two subgroups with significantly different survival durations, i.e., shorter vs. longer duration when comparing to the median survival duration of the group.

Conclusion: Our data supports the use of radiomic scores, based on MR imaging of brain metastases from NSCLC, as non-invasive biomarkers for survival duration. Future research with a larger sample size and external cohorts is needed to validate our results.

Brain metastasis models: What should we aim to achieve better treatments?

Brain metastasis is emerging as a unique entity in oncology based on its particular biology and, consequently, the pharmacological approaches that should be considered. We discuss the current state of modelling this specific progression of cancer and how these experimental models have been used to test multiple pharmacologic strategies over the years. In spite of pre-clinical evidences demonstrating brain metastasis vulnerabilities, many clinical trials have excluded patients with brain metastasis. Fortunately, this trend is getting to an end given the increasing importance of secondary brain tumors in the clinic and a better knowledge of the underlying biology. We discuss emerging trends and unsolved issues that will shape how we will study experimental brain metastasis in the years to come.

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.

A real-world study in advanced non-small cell lung cancer with de novo brain metastasis

Brain metastases are the major cause of life-expectancy shortened for patients with lung cancer. The prognostic value of EGFR mutation subtypes and survival benefit of EGFR-tyrosine kinase inhibitors (TKIs) in advanced non-small cell lung cancer (NSCLC) patients with de novo brain metastasis is still not clear. Here, we present a real-world study nation-wide focusing on the prognostic value of genomic and therapeutic factors in overall survival (OS) of those patients. We enrolled a total of 233 patients diagnosed with advanced NSCLC and de novo BM from multi-medical centers across China. The enrolled patients were divided into 4 groups, including EGFR 19del, EGFR L858R, EGFR wild-type, and EGFR unknown groups. The median OS of patients with EGFR mutations and all patients were 29.0 and 25.0 months, respectively. There was significant difference in OS of patients among EGFR 19del (n=76), EGFR L858R (n=94), EGFR wild-type (n=46) and EGFR unknown (n=17) groups (30.5 vs 27.5 vs 16.0 vs 25.0, P=0.025). Patients treated by icotinib showed better OS than gefitinib and erlotinib (31.0 vs 25.5 vs 26.5, P=0.02). There was a difference in OS of patients received the whole-brain radiotherapy (WBRT), stereotactic radiosurgery (SRS), or WBRT+SRS (20.0 vs 31.0 vs 30.0 months, P<0.001), respectively. In multivariate analysis, patients treated with icotinib had superior iPFS benefit than gefitinib and erlotinib (HR=0.86[95%CI (0.74-1.0)], P=0.04). Besides, the histology of non-adenocarcinomas, the number of BM (>3), and extracranial metastases status could have an independent negative impact on the OS of all patients (P<0.001). EGFR mutant NSCLC patients with de novo BM had a better OS than patients with EGFR wild type. Patients treated with icotinib had longer iPFS than gefitinib and erlotinib but not in OS. Non-adenocarcinomas, number of BM (>3) and extracranial metastases were independent negative prognostic factors in iPFS and OS of all patients. Prospective clinical trials are warranted to explore more effective multimodality in this population.

Central nervous system metastases and oligoprogression during treatment with tyrosine kinase inhibitors in oncogene-addicted non-small cell lung cancer: how to treat and when?

Up to 70% of non-small cell lung cancer (NSCLC) patients develop central nervous system (CNS) metastases during the course of their disease, especially those with oncogenic drivers treated with a first-generation tyrosine kinase inhibitor (TKI), because of the relatively poor CNS penetration. CNS metastases are associated with a negative impact on quality of life and survival. As, with the introduction of newer generation TKIs, the survival rates are increasing in this particular population, treatment and/or prevention of CNS metastases becomes even more relevant and the TKI with the best CNS efficacy should be selected. Unfortunately, CNS efficacy data in clinical trials are not fully comparable. Furthermore, oligoprogression to the brain without extracranial progression regularly occurs in the oncogenic driver population and both local therapy and switch of systemic therapy are possible treatment options. However, the best order of systemic and local therapy is still not precisely known. In this narrative review, we will summarize incidence and treatment of CNS metastases in oncogene driven NSCLC, including the optimal treatment of CNS oligometastatic disease (synchronous as well as oligoprogressive).

Destabilizing single chain major histocompatibility complex class I protein for repurposed enterokinase proteolysis

The lack of a high throughput assay for screening stabilizing peptides prior to building a library of peptide-major histocompatibility complex class I (pMHC-I) molecules has motivated the continual use of in silico tools without biophysical characterization. Here, based on de novo protein fragmentation, the EASY MHC-I (EZ MHC-I) assay favors peptide antigen screening to an unheralded hands-on time of seconds per peptide due to the empty single chain MHC-I protein instability. Unlike tedious traditional labeling- and antibody-based MHC-I assays, repurposed enterokinase directly fragments the unstable single MHC-I chain protein unless rescued by a stabilizing peptide under luminal condition. Herein, the principle behind EZ MHC-I assay not only characterizes the overlooked stability as a known better indicator of immunogenicity than classical affinity but also the novel use of enterokinase from the duodenum to target destabilized MHC-I protein not bearing the standard Asp-Asp-Asp-Asp-Lys motif, which may protend to other protein instability-based assays.

Diffusion tensor and postcontrast T1-weighted imaging radiomics to differentiate the epidermal growth factor receptor mutation status of brain metastases from non-small cell lung cancer

PURPOSE

To assess whether the radiomic features of diffusion tensor imaging (DTI) and conventional postcontrast T1-weighted (T1C) images can differentiate the epidermal growth factor receptor (EGFR) mutation status in brain metastases from non-small cell lung cancer (NSCLC).

METHODS

A total of 99 brain metastases in 51 patients who underwent surgery or biopsy with underlying NSCLC and known EGFR mutation statuses (57 from EGFR wild type, 42 from EGFR mutant) were allocated to the training (57 lesions in 31 patients) and test (42 lesions in 20 patients) sets. Radiomic features (n = 526) were extracted from preoperative MR images including T1C and DTI. Radiomics classifiers were constructed by combinations of five feature selectors and four machine learning algorithms. The trained classifiers were validated on the test set, and the classifier performance was assessed by determining the area under the curve (AUC).

RESULTS

EGFR mutation status showed an overall discordance rate of 12% between the primary tumors and corresponding brain metastases. The best performing classifier was a combination of the tree-based feature selection and linear discriminant algorithm and 5 features were selected (1 from ADC, 2 from fractional anisotropy, and 2 from T1C images), resulting in an AUC, accuracy, sensitivity, and specificity of 0.73, 78.6%, 81.3%, and 76.9% in the test set, respectively.

CONCLUSIONS

Radiomics classifiers integrating multiparametric MRI parameters may have potential in differentiating the EGFR mutation status in brain metastases from NSCLC.

First-in-Human Phase 1 Study of ES-072, an Oral Mutant-Selective EGFR T790M Inhibitor, in Non-Small-Cell Lung Cancer

BACKGROUND

Third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are rapidly being developed for treatment of non-small-cell lung cancer (NSCLC) in patients harboring EGFR T790M mutations. This first-in-human phase 1 study evaluated the maximum tolerated dose, recommended phase 2 dose (RP2D), safety, tolerability, and pharmacokinetics (PK), and preliminarily determined the antitumor activity of ES-072 in NSCLC patients with EGFR T790M mutations.

PATIENTS AND METHODS

Dose escalation and expansion studies were performed using an accelerated titration method. Oral ES-072 doses (25-450 mg) were administrated once daily for single- and multiple-dose escalation trials. Characteristic PK parameters were assessed in the single-dose escalation phase and in the first cycle of the multiple-dose escalation phase. Tumor responses were assessed using the Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 to evaluate ES-072 antitumor activity.

RESULTS

Nineteen patients were enrolled onto this study, 16 to the dose-escalation phase and 3 to the dose-expansion phase. The most common adverse events were QT interval prolongation (11/19, 57.9%), anemia (5/19, 26.3%), mouth ulceration (4/19, 21.1%), keratosis (4/19, 21.1%), and cough (4/19, 21.1%). Safety and tolerability evaluation of ES-072 showed an maximum tolerated dose of 300 mg, and the RP2D dose was therefore 300 mg once daily. PK analysis showed an ES-072 half-life of 24.5 hours and a T_max of approximately 4 hours. The total objective response rate and disease control rate were 46.2% and 76.9%, respectively.

CONCLUSION

ES-072 was safe and well tolerated in NSCLC patients harboring EGFR T790M mutations, and adverse events were controllable and reversible. A RP2D of 300 mg once daily was determined, and preliminary investigations showed promising antitumor activity.

Medical management of brain metastases

The development of brain metastases occurs in 10–20% of all patients with cancer. Brain metastases portend poor survival and contribute to increased cancer mortality and morbidity. Despite multimodal treatment options, which include surgery, radiotherapy, and chemotherapy, 5-year survival remains low. Besides, our current treatment modalities can have significant neurological comorbidities, which result in neurocognitive decline and a decrease in a patient’s quality of life. However, innovations in technology, improved understanding of tumor biology, and new therapeutic options have led to improved patient care. Novel approaches in radiotherapy are minimizing the neurocognitive decline while providing the same therapeutic benefit. In addition, advances in targeted therapies and immune checkpoint inhibitors are redefining the management of lung and melanoma brain metastases. Similar approaches to brain metastases from other primary tumors promise to lead to new and effective therapies. We are beginning to understand the appropriate combination of these novel approaches with our traditional treatment options. As advances in basic and translational science and innovative technologies enter clinical practice, the prognosis of patients with brain metastases will continue to improve.

Neurologic complications of lung cancer

Lung cancer and its associated treatments can cause various neurologic complications, including brain and leptomeningeal metastases, epidural spinal cord compression, cerebrovascular events, and treatment-related neurotoxicities. Lung cancer care has significantly changed in the last 5 to 10 years, with novel therapies that have affected aspects of neurologic complication management. Herein, the authors review the potential neurologic complications of lung cancer, including important clinical and therapeutic aspects of care.

Ubiquilin proteins regulate EGFR levels and activity in lung adenocarcinoma cells

Ubiquilin (UBQLN) proteins are involved in diverse cellular processes like endoplasmic reticulum-associated degradation, autophagy, apoptosis, and epithelial-to-mesenchymal transition. UBQLNs interact with a variety of substrates, including cell surface receptors, transcription factor regulators, proteasomal machinery proteins, and transmembrane proteins. In addition, previous work from our lab shows that UBQLN1 interacts with insulin-like growth factor receptor family members (IGF1R, IGF2R, and INSR) and this interaction regulates the activity and proteostasis of IGFR family members. We wondered whether UBQLN proteins could also bind and regulate additional receptor tyrosine kinases. Thus, we investigated a link between UBQLN and the oncogene epidermal growth factor receptor (EGFR) in lung adenocarcinoma cells. Loss of UBQLN1 occurs at high frequency in human lung cancer patient samples and we have shown that the loss of UBQLN1 is capable of altering processes involved in cell proliferation, migration, invasion, and epithelial-to-mesenchymal transition in lung adenocarcinoma cell lines. Here, we present data that loss of UBQLN1 resulted in increased turnover of total EGFR while increasing the relative amount of phosphorylated EGFR in lung adenocarcinoma cells, especially in the presence of its ligand EGF. Furthermore, the loss of UBQLN1 led to a more invasive cell phenotype as manifested by increased proliferation, migration, and speed of movement of these lung adenocarcinoma cells. Taken together, UBQLN1 regulates the expression and stability of EGFR in lung cancer cells.

Prognostic value of lymphocyte-to-monocyte ratio and systemic immune-inflammation index in non-small-cell lung cancer patients with brain metastases

Aim: We aimed to evaluate the prognostic values of neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR) and systemic immune-inflammation index (SII) in patients with brain metastases from non-small-cell lung cancer (NSCLC). Materials & methods: We conducted Kaplan-Meier analysis and multivariable Cox analysis to evaluate the prognostic values of NLR, PLR, LMR and SII. Results: Kaplan-Meier analysis showed that the patients in low LMR, high NLR, PLR and SII groups were associated with shorter overall survival. Multivariable Cox analysis revealed LMR and SII were independent prognostic factors for overall survival (p = 0.002 and p = 0.004, respectively). Conclusion: LMR and SII are of significant values in clinical prognostic evaluation for patients with brain metastases from NSCLC.

The Clinical Prognostic Value of the Neutrophil-to-Lymphocyte Ratio in Brain Metastases from Non-Small Cell Lung Cancer-Harboring EGFR Mutations

Purpose

Several studies have explored the correlation between the neutrophil-to-lymphocyte ratio (NLR) and the prognosis of patients with lung cancer. However, little is known about the correlation between the pretreatment NLR and the prognosis of patients with brain metastases from non-small cell lung cancer (NSCLC)-harboring mutations in the epidermal growth factor receptor (EGFR) gene. We sought to evaluate the predictive values in brain metastasis from lung adenocarcinoma with EGFR mutations.

Methods

We retrospectively examined 133 patients with brain metastases (BMs) from lung adenocarcinoma with EGFR mutations. NLR was calculated using N/L, where N and L, respectively, refer to peripheral blood neutrophil (N) and lymphocyte (L) counts. The cut-off value of NLR was assessed by the area under the curve (AUC). The Log rank test and Cox proportional hazard model were used to confirm the impact of NLR and other variables on survival.

Results

An NLR value equal to or less than 2.99 was associated with prolonged survival in this cohort of patients in both variable and multivariable analysis.

Conclusion

We concluded that NLR is an independent prognostic factor in BMs from lung adenocarcinoma with EGFR mutations. This could serve as a useful prognostic biomarker and could be incorporated in the clinical prognostic index specific to patients with BMs.

Safety and CSF distribution of high-dose erlotinib and gefitinib in patients of non-small cell lung cancer (NSCLC) with brain metastases

PURPOSE

Patients of non-small cell lung cancer (NSCLC) with brain metastases have limited treatment options. High-dose erlotinib (HDE) and gefitinib (HDG) have been tried in the past. This study investigates the cerebrospinal fluid (CSF) disposition and safety of both, high-dose erlotinib and gefitinib regimens.

METHODS

Eleven and nine patients were treated with erlotinib and gefitinib, respectively. All patients received 1 week of standard dose of erlotinib (150 mg OD) or gefitinib (250 mg OD), followed by the high dose (1500 mg weekly for erlotinib and 1250 mg OD for gefitinib) from day 8. Blood and CSF samples were collected on days 7 and 15, 4 h after the morning dose and drug levels determined using LC-MS/MS. Adverse events were documented as per CTCAE 4.03 till day 15.

RESULTS

Pulsatile HDE and daily HDG resulted in 1.4- and 1.9-fold increase in CSF levels, respectively. A constant 2% CSF penetration rate was observed across both doses of erlotinib, while for gefitinib the penetration rate for high dose was half that of the standard dose suggesting a nonlinear disposition. Three patients on HDE treatment discontinued treatment after the first dose due to intolerable toxicities, whereas HDG was better tolerated with no treatment discontinuations. Since CSF disposition of gefitinib followed saturable kinetics, a lower dose of 750 mg was found to achieve CSF concentrations comparable to that of the 1250 mg dose.

CONCLUSIONS

HDG was better tolerated than HDE. CSF disposition of gefitinib was found to be saturable at a higher dose. Based on these findings, the dose of 750 mg OD should be considered for further evaluation in this setting.

Current approaches to the management of brain metastases

Brain metastases are a very common manifestation of cancer that have historically been approached as a single disease entity given the uniform association with poor clinical outcomes. Fortunately, our understanding of the biology and molecular underpinnings of brain metastases has greatly improved, resulting in more sophisticated prognostic models and multiple patient-related and disease-specific treatment paradigms. In addition, the therapeutic armamentarium has expanded from whole-brain radiotherapy and surgery to include stereotactic radiosurgery, targeted therapies and immunotherapies, which are often used sequentially or in combination. Advances in neuroimaging have provided additional opportunities to accurately screen for intracranial disease at initial cancer diagnosis, target intracranial lesions with precision during treatment and help differentiate the effects of treatment from disease progression by incorporating functional imaging. Given the numerous available treatment options for patients with brain metastases, a multidisciplinary approach is strongly recommended to personalize the treatment of each patient in an effort to improve the therapeutic ratio. Given the ongoing controversies regarding the optimal sequencing of the available and expanding treatment options for patients with brain metastases, enrolment in clinical trials is essential to advance our understanding of this complex and common disease. In this Review, we describe the key features of diagnosis, risk stratification and modern paradigms in the treatment and management of patients with brain metastases and provide speculation on future research directions.

Icotinib is as efficacious as gefitinib for brain metastasis of EGFR mutated non-small-cell lung cancer

BACKGROUND

The prognosis of non-small-cell lung cancer (NSCLC) with brain metastases is very poor. Currently, therapeutic methods for this patient population include whole-brain radiation therapy (WBRT), surgery, radiosurgery and systemic treatment. Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) could be effective on cerebral metastases of mutated NSCLC. However, which EGFR-TKIs is more appropriate is still unknown.

METHODS

We conducted a retrospective analysis of advanced NSCLC patients with brain metastases for EGFR targeted therapy from November 2013 to April 2018 at Dongguan People's Hospital, Southern Medical University, China. A total of 43 patients were recruit in this study. Among them, 21 cases received icotinib (125 mg, thrice a day) and 22 cases received gefitinib (250 mg, once a day) until disease progression or unacceptable toxicity. The primary end point of this study was intracranial PFS (iPFS). The relationships between therapeutic arms and patients characteristics were performed using Pearson's chi-square test or Fisher's exact test. The differences in PFS among the two arms were analyzed using Kaplan-Meier curves and log rank tests.

RESULTS

There was no significant difference of intracranial ORR (66.6% versus 59.1%, P = 0.62) and DCR (85.7% versus 81.8%, P = 0.73) between the two arms. The median intracranial PFS (iPFS) for icotinib and gefitinib arms were 8.4 months (95% CI, 5.4 to 11.3 months) and 10.6 months (95% CI, 6.3 to 14.8 months), respectively (P = 0.17). Adverse events of the two study arms were generally mild. None of the patients experienced dose reduction of EGFR-TKIs.

CONCLUSIONS

Our study showed that icotinib and gefitinib had similar efficacy for brain metastasis of EGFR mutated NSCLC. Large randomized studies are suggested to further illuminate the effect of these two EGFR-TKIs on cerebral lesions of NSCLC.

Dual Targeting of the Epidermal Growth Factor Receptor Using Combination of Nimotuzumab and Erlotinib in Advanced Non-Small-Cell Lung Cancer with Leptomeningeal Metastases: A Report of Three Cases

Leptomeningeal metastases (LM) occur in 3-5% of patients with advanced non-small-cell lung cancer (NSCLC) and are associated with a dismal prognosis. We report three cases of NSCLC with LM who were treated with the combination of nimotuzumab and erlotinib. Magnetic Resonance Imaging (MRI) evaluation during follow-up showed significant improvement in cancer symptoms and decreased tumor size in all three patients. Grade 3 and 4 toxicities were rarely seen. Based on apparent efficacy of the regimen and fewer side effects, we suggest that nimotuzumab in combination with erlotinib may be a promising option for the treatment of NSCLC with LM.

HB-EGF-EGFR Signaling in Bone Marrow Endothelial Cells Mediates Angiogenesis Associated with Multiple Myeloma

Epidermal growth factor receptor (EGFR) and its ligand heparin-binding EGF-like growth factor (HB-EGF) sustain endothelial cell proliferation and angiogenesis in solid tumors, but little is known about the role of HB-EGF–EGFR signaling in bone marrow angiogenesis and multiple myeloma (MM) progression. We found that bone marrow endothelial cells from patients with MM express high levels of EGFR and HB-EGF, compared with cells from patients with monoclonal gammopathy of undetermined significance, and that overexpressed HB-EGF stimulates EGFR expression in an autocrine loop. We also found that levels of EGFR and HB-EGF parallel MM plasma cell number, and that HB-EGF is a potent inducer of angiogenesis in vitro and in vivo. Moreover, blockade of HB-EGF–EGFR signaling, by an anti-HB-EGF neutralizing antibody or the EGFR inhibitor erlotinib, limited the angiogenic potential of bone marrow endothelial cells and hampered tumor growth in an MM xenograft mouse model. These results identify HB-EGF–EGFR signaling as a potential target of anti-angiogenic therapy, and encourage the clinical investigation of EGFR inhibitors in combination with conventional cytotoxic drugs as a new therapeutic strategy for MM.

The Effect of Epidermal Growth Factor Receptor Mutation on Intracranial Progression-Free Survival of Non-Small Cell Lung Cancer Patients with Brain Metastasis Underwent Gamma Knife Radiosurgery

BACKGROUND

The aim of this study was to survey prognostic factors, particularly those focusing on epidermal growth factor receptor (EGFR) mutations, of patients with non-small cell lung cancer (NSCLC) after Gamma Knife Radiosurgery (GKRS) for metastatic brain tumors.

METHODS

We retrospectively reviewed the medical records of 98 patients with NSCLC who underwent GKRS for brain metastases from August 2010 to July 2017. The primary endpoint was progression-free survival (PFS) of the intracranial disease. We analyzed variables such as age, sex, Karnofsky Performance Status, recursive partitioning analysis (RPA) class, smoking status, primary cancer pathology, EGFR mutations, and time to brain metastases as prognostic factors.

RESULTS

The median overall survival (OS) of the patients was 16 months [95% confidence interval (CI), 13-21 months]. Median systemic PFS and intracranial PFS were 9 months (95% CI, 8-11 months) and 11 months (95% CI, 7-14 months), respectively. Kaplan-Meier survival analysis revealed that the patients with EGFR mutations had longer intracranial PFS than those without EGFR mutation (median intracranial PFS: 19 vs. 10 months with p=0.01) while they had no benefits in OS and systemic PFS. Furthermore, the patients harboring adenocarcinoma had longer OS (p<0.01) and intracranial PFS (p<0.01) and the patients with lower RPA class had longer OS (p=0.02) and intracranial PFS (p=0.03).

CONCLUSION

EGFR mutations, primary cancer pathology, and RPA class may be proposed as prognostic factors for intracranial PFS in NSCLC patients after GKRS for brain metastasis in this study.

Therapeutic effect of whole brain radiotherapy on advanced NSCLC between EGFR TKI-naïve and TKI-resistant

Background

The development of epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) has dramatically improved the prognosis of patients with EGFR-mutant non-small-cell lung cancer (NSCLC). The purpose of this study is to investigate the clinical outcome with or without EGFR-TKI resistance before WBRT and the sequence between EGFT-TKIs and whole brain radiotherapy (WBRT) of EGFR-mutant NSCLC patients who developed multiple brain metastases (BMs).

Patients and methods

Three hundred forty-four EGFR-mutant NSCLC patients with multiple BMs were reviewed. Enrolled patients were divided into TKI-naïve group and TKI-resistant group. The intracranial progression-free survival (PFS) and overall survival (OS) were analyzed via the Kaplan-Meier method.

Results

For patients with multiple BMs treated by WBRT, the median intracranial PFS and OS were longer in the TKI-naïve group than those in the TKI-resistant group, but there were no statistically significant between two groups (Intracranial PFS: 7.7 vs. 5.4 months, p = 0.052; OS: 11.2 vs. 9.2 months, p = 0.106). For patients with Lung-molGPA 0–2, no significant differences in median intracranial PFS (6.2 vs. 5.2 months, p = 0.123) and OS (7.8 vs. 6.7 months, p = 0.514) between TKI-naïve and TKI-resistant groups. For patients with Lung-molGPA 2.5–4, intracranial PFS: 12.8 vs. 10.1 months; OS: 23.3 vs. 15.3 months.

Conclusions

Our study found that there were no difference in intracranial PFS and OS in all patients between the two groups of TKI-naïve and TKI-resistant. But for patients in subgroup of Lung-molGPA 2.5–4, there were a better intracranial PFS and OS in TKI-naïve group.

The impact of systemic treatment on brain metastasis in patients with non-small-cell lung cancer: A retrospective nationwide population-based cohort study

To compare the incidence of brain metastases of advanced non-small cell lung cancer (NSCLC) treated with systemic cytotoxic chemotherapy (CC) and targeted therapy (TT), we performed a large-scale, retrospective, nationwide, cohort study. The population data were extracted from the Health Insurance Review and Assessment Service of Korea database from January 1, 2011, to November 30, 2016. Of the 29,174 patients newly diagnosed with stage IIIB or IV NSCLC who received systemic treatment, we investigated the initial and subsequent incidence of brain metastases. Besides, among 22,458 patients without initial brain metastasis, the overall cumulative incidence of subsequent brain metastases was compared according to systemic treatment administered. In total, 1,126 (5.0%) patients subsequently developed brain metastasis. The overall cumulative incidence of brain metastasis was significantly higher in the TT group than in the CC group (1-year cumulative incidence: 8.7% vs. 3.8%; 3-year: 17.2% vs. 5.0%; P < 0.001). Younger age, female sex, and first-line TT were significant risk factors for subsequent brain metastasis. In conclusion, the overall cumulative incidence of brain metastasis was significantly higher in patients received TT as the first-line treatment than in those received CC.

Emerging insights of tumor heterogeneity and drug resistance mechanisms in lung cancer targeted therapy

The biggest hurdle to targeted cancer therapy is the inevitable emergence of drug resistance. Tumor cells employ different mechanisms to resist the targeting agent. Most commonly in EGFR-mutant non-small cell lung cancer, secondary resistance mutations on the target kinase domain emerge to diminish the binding affinity of first- and second-generation inhibitors. Other alternative resistance mechanisms include activating complementary bypass pathways and phenotypic transformation. Sequential monotherapies promise to temporarily address the problem of acquired drug resistance, but evidently are limited by the tumor cells' ability to adapt and evolve new resistance mechanisms to persist in the drug environment. Recent studies have nominated a model of drug resistance and tumor progression under targeted therapy as a result of a small subpopulation of cells being able to endure the drug (minimal residual disease cells) and eventually develop further mutations that allow them to regrow and become the dominant population in the therapy-resistant tumor. This subpopulation of cells appears to have developed through a subclonal event, resulting in driver mutations different from the driver mutation that is tumor-initiating in the most common ancestor. As such, an understanding of intratumoral heterogeneity-the driving force behind minimal residual disease-is vital for the identification of resistance drivers that results from branching evolution. Currently available methods allow for a more comprehensive and holistic analysis of tumor heterogeneity in that issues associated with spatial and temporal heterogeneity can now be properly addressed. This review provides some background regarding intratumoral heterogeneity and how it leads to incomplete molecular response to targeted therapies, and proposes the use of single-cell methods, sequential liquid biopsy, and multiregion sequencing to discover the link between intratumoral heterogeneity and early adaptive drug resistance. In summary, minimal residual disease as a result of intratumoral heterogeneity is the earliest form of acquired drug resistance. Emerging technologies such as liquid biopsy and single-cell methods allow for studying targetable drivers of minimal residual disease and contribute to preemptive combinatorial targeting of both drivers of the tumor and its minimal residual disease cells.

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.

Brain metastases in oncogene-driven non-small cell lung cancer

Molecular targeted therapies have significantly improved the treatment outcome of patients with non-small cell lung cancer (NSCLC) harboring driver gene mutations such as receptor (EGFR) or anaplastic lymphoma kinase (ALK). However, the brain is a frequent site of recurrence, and it significantly deteriorates the prognosis of these patients. Treatment strategies include surgical resection, whole-brain radiation therapy, stereotactic radiotherapy, and drug therapy depending on patient condition. First-generation EGFR/ALK tyrosine kinase inhibitors (TKI) demonstrates only limited efficacy for intracranial lesions probably because of low penetration through the blood-brain barrier (BBB). However, newly developed TKIs with improved penetration such as osimertinib for EGFR and alectinib, ceritinib, brigatinib, or lorlatinib for ALK have demonstrated significant intracranial activity that should contribute to improved overall survival. Whole-brain radiation therapy used to be a standard of care that confers alleviation of symptom and modest survival benefit. However, it potentially causes neurological and cognitive deficits as a chronic toxicity. With the prolonged survival owing to newer generation drugs, this toxicity is becoming more relevant. Stereotactic radiotherapy is considered when there are three or fewer lesions, and the lesions are <3 cm as local control of tumor is excellent, and neurotoxicity is less. In this review, we discuss the various aspects of brain metastases occurring in NSCLC patients with driver gene mutations. We also propose a treatment algorithm for these patients.

Osimertinib and other third-generation EGFR TKI in EGFR-mutant NSCLC patients

Osimertinib was the first third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) to receive FDA and EMA approval for metastatic EGFR-mutant non-small-cell lung cancer (NSCLC) patients that have acquired the EGFR T790M resistance mutation. Clinical trials have demonstrated the efficacy of osimertinib in this patient population and clinical trials of other third-generation EGFR TKI are currently under way. Additional challenges in this patient population, such as the upfront efficacy of osimertinib, validation of T790M in liquid biopsies as a dynamic predictive marker of efficacy, along with combination with immune checkpoint inhibitors are being explored, representing an extraordinary time of development for EGFR-mutant NSCLC.

Mechanisms of acquired resistance to first- and second-generation EGFR tyrosine kinase inhibitors

Patients with non-small-cell lung cancer (NSCLC) whose tumours harbour activating mutations within the epidermal growth factor receptor (EGFR) frequently derive significant clinical and radiographic benefits from treatment with EGFR tyrosine kinase inhibitors (TKIs). As such, prospective identification of EGFR mutations is now the standard of care worldwide. However, acquired therapeutic resistance to these agents invariably develops. Over the past 10 years, great strides have been made in defining the molecular mechanisms of EGFR TKI resistance in an effort to design rational strategies to overcome this acquired drug resistance. Approximately 60% of patients with acquired resistance to the EGFR TKIs (erlotinib, gefitinib, and afatinib) develop a new mutation within the drug target. This mutation-T790M-has been shown to alter drug binding and enzymatic activity of the mutant EGF receptor. Less common mechanisms of acquired resistance include MET amplification, ERBB2 amplification, transformation to small-cell lung cancer, and others. Here, we present a condensed overview of the literature on EGFR-mutant NSCLC, paying particular attention to mechanisms of drug resistance, recent clinical trial results, and novel strategies for identifying and confronting drug resistance, while also striving to identify gaps in current knowledge. These advances are rapidly altering the treatment landscape for EGFR-mutant NSCLC, expanding the armamentarium of available therapies to maximize patient benefit.

Clinical factors associated with treatment outcomes in EGFR mutant non-small cell lung cancer patients with brain metastases: a case-control observational study

Background

Non-small cell lung cancer (NSCLC) patients harboring epidermal growth factor receptor (EGFR) mutations often develop brain metastases. Treatment with EGFR-tyrosine kinase inhibitors (TKIs) has shown the effectiveness; however, knowledge of the clinical factors associated with outcomes in NSCLC patients with EGFR mutations remains limited.

Methods

Treatment-naive patients diagnosed with advanced non-squamous NSCLC with brain metastases harboring EGFR mutations and treated with an EGFR-TKI as first-line therapy were enrolled with analysis of their medical records.

Results

A total of 134 advanced NSCLC patients with brain metastases harboring EGFR mutations received an EGFR-TKI (gefitinib: 62, erlotinib: 49, and afatinib: 23) as the first-line therapy. Sixty-nine had exon 19 deletions (51.5%), and 56 (41.8%) had L858R mutations. There was no statistically significant difference in progression-free survival (PFS) and overall survival (OS) among the EGFR-TKIs. Significantly shorter OS was noted in patients with multiple brain metastases (hazard ratio [HR]: 2.43, p = 0.007), uncommon EGFR mutations (HR: 3.75, p = 0.009), and liver metastases. Thirty-eight patients (29.1%) received brain radiotherapy for brain metastases before disease progression, and had a significantly longer time until intracranial progression. However, the brain radiotherapy had no statistically significant impact on PFS or OS.

Conclusions

Patients with uncommon mutations, multiple brain metastases, and concomitant liver metastases tended to have shorter OS. Brain radiotherapy could delay the time to intracranial disease progression but had no impact on survival. The different first-line EGFR-TKIs achieved similar treatment responses in terms of PFS and OS in the EGFR-mutated NSCLC patients with brain metastases.

Great efficacy of afatinib on a patient with lung adenocarcinoma harboring uncommon EGFR delE709_T710insD mutations: a case report

EGFR)-targeted drugs have been the first-line treatment for patients with EGFR-mutant non-small cell lung cancer (NSCLC), especially exon 19 deletions and L858R mutation in exon 21. However, there is insufficient evidence for other less common types of EGFR mutations, such as delE709_T710insD (del 18). Recent studies have revealed that these rare genotypes could be targetable if appropriate mutations, such as delE709_T710insD (del 18). Recent studies have revealed that these rare genotypes could be targetable if appropriate EGFR tyrosine kinase inhibitors are selected. Here we reported a stage Ⅳ NSCLC patient with delE709_T710insD mutation who responded well to afatinib, a second-generation TKI. Afatinib had taken good control of the patient’s brain metastasis with a progression-free survival of 11 months and an overall survival exceeded 21 months, although he had received multi-line therapy. This case demonstrates EGFR delE709_T710insD is a rare but potentially afatinib responsive mutation in NSCLC, which may contribute to changes in clinical practice and further research into the precise detection and treatment of rare mutations in EGFR.

Patterns of brain metastasis in anaplastic lymphoma kinase - rearranged and epidermal growth factor receptor-mutated lung cancer patients in magnetic resonance imaging

Introduction:

The optimal management of neuroparenchymal lesions in cases of lung cancer is exigent as this frequent yet notorious complication negatively impacts the morbidity and mortality index.

Aims:

This study is aimed at recognizing various patterns of neuroparenchymal metastasis in patients of lung cancer with epidermal growth factor receptor (EGFR)- and anaplastic lymphoma kinase (ALK)-positive mutations.

Material and Methods:

The radiological findings of the neuroparenchymal lesions were analyzed and the statistical data were charted. We identified two groups of patients with neuroparenchymal lesions among a cohort of 340 patients having EGFR-positive (68) and ALK-positive (24) mutations (total: 24 + 68 = 92).

Results:

We observed that among the ALK group, leptomeningeal spread was less compared to EGFR group (2/24 as opposed to 18/68). Morphological heterogeneity and central necrosis in the parenchymal lesion which were associated with unfavorable outcomes were predominant in ALK group (8/24) as opposed to EGFR group (2/68). Ancillary findings but pertinent to survival and morbidity such as presence of perilesional edema, hemorrhage, and hydrocephalus on magnetic resonance imaging were also analyzed. The mutation-specific differential imaging spectrum could be attributed to biological differences between these cancers.

Brain MRI imaging characteristics predict treatment response and outcome in patients with de novo brain metastasis of EGFR-mutated NSCLC

Patients with non-small cell lung cancer (NSCLC) and de novo brain metastasis (BM) have poor prognosis. We aim to investigate the characteristic of brain magnetic resonance (MR) imaging and the association with the treatment response of epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) for lung cancer with BM.EGFR-mutated NSCLC patients with BM from October 2013 to December 2017 in a tertiary referral center were retrospectively analyzed. Patient's age, sex, cell type, EGFR mutation status, treatment, and characteristics of BM were collected. Survival analysis was performed using Kaplan-Meier method. The efficacy of different EGFR-TKIs were also analyzed.Among the 257 eligible patients, 144 patients with Exon 19 deletion or Exon 21 L858R were included for analysis. The erlotinib group had the best progression free survival (PFS) (median PFS 13 months, P = .04). The overall survival (OS) revealed no significant difference between three EGFR-TKI groups. Brain MR imaging features including tumor necrosis, rim enhancement and specific tumor locations (frontal lobe, putamen or cerebellum) were factors associated with poor prognosis. Patients with poor prognostic imaging features, the high-risk group, who received erlotinib had the best PFS (median PFS 12 months, P < .001). However, the OS revealed no significant difference between 3 EGFR-TKI groups. The low risk group patients had similar PFS and OS treated with three different EGFR-TKIs.In NSCLC patients with common EGFR mutation and de novo BM, those with poor prognostic brain MR characteristics, erlotinib provided better PFS than afatinib or gefitinib.

Real-World Data on Prognostic Factors for Overall Survival in EGFR-Mutant Non-Small-Cell Lung Cancer Patients with Brain Metastases

Background: With the wide application of epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs), the survival of EGFR-mutant non-small-cell lung cancer (NSCLC) patients with brain metastasis (BM) has been significantly improved. However, prognosis analysis for patients with EGFR mutation and BM is still lacking, and the prognostic factors remain to be determined. Materials and methods: A total of 746 NSCLC patients with BM were identified between January 2013 and December 2016 at our institution. Overall, 261 patients harboring EGFR mutation and meeting the inclusion criteria for the study were enrolled. Exclusion criteria included KPS<50, diagnosed with BM during treatment with EGFR-TKIs, or insufficient follow-up. Overall survival (OS) was measured from the date of brain metastases. Independent prognostic factors were confirmed using a Cox regression model. Results: The median follow-up time for these patients was 32.7 months (95% CI, 23.5-41.9). The median OS after development of brain metastases was 23.0 months (95% CI, 20.01-25.99). By univariate analysis, significantly shorter OS was noted in patients older than 65 years (p=0.025), KPS <70 (p=0.003), presence of extracranial metastases (ECM) (p=0.00), without intracranial local treatment (p=0.000), and without chemotherapy (p=0.001). There was no difference in OS with respect to EGFR mutation type and number of BM (p=0.343, p=0.729, respectively). The Cox proportional hazards regression model revealed that performance status (KPS<70, p=0.010), ECM (p=0.001), receiving intracranial local treatment (p=0.005) and chemotherapy (p=0.005) were independent prognostic factors for OS, while age was not (p=0.087). Patients with higher diagnosis-specific graded prognostic assessment (DS-GPA) and Lung-molGPA scores corresponded to better prognosis (p=0.000). Conclusion: This retrospective analysis demonstrated that performance status (KPS≥70), absence of ECM metastases, administration of local treatment and chemotherapy were associated with superior OS in patients with EGFR-mutant NSCLC who developed BM. The DS-GPA and Lung-molGPA indexes still applied to NSCLC patients with mutant genotypes and BM.

[Prognostic Analysis of EGFR-TKIs Combined with Gamma Knife in EGFR-mutant Lung Adenocarcinoma with Brain Metastasis]

背景与目的

晚期表皮生长因子受体（epidermal growth factor receptor, EGFR）基因突变的肺腺癌在初诊或治疗过程中脑转移的总发生率高，局部治疗联合系统性靶向治疗可能是更佳策略。本研究拟探讨分析EGFR酪氨酸激酶抑制剂（tyrosine kinase inhibitors, TKIs）联合头颅伽玛刀治疗EGFR突变的肺腺癌伴脑转移患者的疗效及预后因素。

方法

回顾性收集EGFR基因突变的肺腺癌、在初诊即存在脑转移或在EGFR-TKIs治疗过程中肺部病灶稳定而出现脑转移、接受一线口服EGFR-TKIs靶向治疗联合脑部伽玛刀局部治疗的患者，评价EGFR-TKIs联合头颅伽马刀治疗对颅内病灶的疗效，随访并分析颅内无进展生存时间（intracranial progression free survival, i-PFS），探索EGFR突变肺腺癌伴脑转移的预后因素。

结果

共纳入74例患者，其中位i-PFS为14.7个月，1年无颅内进展率为58.5%，2年无颅内进展率为22.2%。颅内病灶与肺部病灶具有相近的进展时间。单因素生存分析显示，初诊癌胚抗原（carcinoembryonic antigen, CEA）水平 < 10 ng/mL（16.9个月vs 12.6个月，P=0.012）、颅内病灶长径 < 2 cm（15.4个月vs 10.8个月，P=0.021）、肺癌脑转移分级预后系统（lung graded prognostic assessment, Lung-molGPA）评分 > 3（15个月vs 12.6个月，P=0.041）的患者具有更长的i-PFS。多因素分析显示初诊时CEA≥10 ng/mL和颅内病灶≥2 cm是i-PFS的不良预后因素。

结论

EGFR-TKIs联合伽玛刀局部治疗对EGFR突变肺腺癌伴脑转移患者的颅内病灶具有良好的疗效。初诊时CEA水平≥10 ng/mL、颅内病灶≥2 cm是接受EGFR-TKIs联合伽马刀治疗的脑转移肺腺癌患者的不良预后因素。

Precision Medical Approaches to the Diagnoses and Management of Brain Metastases

OPINION STATEMENT

Brain metastases represent a common and devastating complication of cancer with survival on the order of a few months in most patients. Melanoma, breast cancer, and lung cancer remain the primary disease histologies with the highest rates of metastatic spread to the brain. The incidence of brain metastases has continued to rise, likely explained by multiple factors. Improvement in progression-free survival in systemic cancer is likely attributable to advances in medical therapy, earlier supportive and symptomatic care, and improved precision around diagnosis and detection. In this context, longer survival and improved extracranial control disease has likely contributed to the increased development of metastatic spread intracranially. The foundation of management remains systemic therapy, as well as a combination of surgery and radiation therapy. In the era of targeted therapies, specific agents have demonstrated improved CNS penetration, however with varying degrees of durable responses. Most patients develop resistance to targeted agents, limiting their duration of use for patients. In this era of personalized medicine, the role of genomic characterization in cancer has been critical in the field of brain metastases, as alterations unique to both the brain metastases and its systemic predecessor have been identified, potentially offering new avenues for therapy.