Targeted therapy of brain metastases: latest evidence and clinical implications

Perfusion-MRI for differentiating cerebral metastatic lesions and gliomas: An evidence-based review

BACKGROUND

Lesions affecting the brain are variable and have multiple pathologies. Brain metastasis is a common entity of lesions that can be misleading in diagnosis. Brain metastasis affects the patient's life and survival in about 40% of cases; all patients with metastatic brain lesions are indicated for surgery, so proper diagnosis is crucial for each patient. Non-invasive diagnosis is a promising way to confirm the diagnosis of cerebral metastatic lesions for patients who are not indicated for surgery for medical reasons. To our knowledge, this is the first evidence-based review article regarding utilizing perfusion-MRI for approaching cerebral metastatic lesions.

METHODS

A comprehensive database search on PubMed/Medline, Scopus and Google Scholar was done by the relevant keywords. Eligibility of articles was done by following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Cochrane risk of bias assessment tool was used to determine the risk of bias among the included studies.

RESULTS

From 2989 articles, only 31 studies were eligible for the qualitative synthesis. A comprehensive summary of the included study was made according to population, intervention, comparator and outcomes (PICO) method.

CONCLUSIONS

Diagnosing cerebral metastases, categorizing subtypes, and monitoring their response to treatment is a challenging endeavor for neurosurgeons, neuroradiologists, and oncologists. Technological advances in MRI software as perfusion-based MRIs are designated to facilitate diagnosis and follow-up for patients with cerebral metastases.

Emerging Therapies for Brain Metastases in NSCLC, Breast Cancer, and Melanoma: A Critical Review

PURPOSE OF REVIEW

Advancements in precision medicine have shifted the treatment paradigm of brain metastases (BM) from non-small cell lung cancer (NSCLC), breast cancer, and melanoma, especially through targeted therapies focused on specific molecular drivers. These novel agents have improved outcomes by overcoming challenges posed by the blood-brain barrier (BBB) and resistance mechanisms, enabling more effective treatment of BM.

RECENT FINDINGS

In NSCLC, therapies such as osimertinib have improved efficacy in treating EGFR-mutant BM, with emerging combinations such as amivantamab and lazertinib offering promising alternatives for patients resistant to frontline therapies. In HER2-positive breast cancer, significant advancements with tucatinib and trastuzumab deruxtecan (T-DXd) have transformed the treatment landscape, achieving improved survival and intracranial control in patients with BM. Similarly, in triple-negative breast cancer (TNBC), novel therapies such as sacituzumab govitecan (SG) and datopotamab deruxtecan (Dato-DXd) offer new hope for managing BM. For melanoma, the combination of immune checkpoint inhibitors such as nivolumab and ipilimumab has proven effective in enhancing survival for patients with BM, both in BRAF-mutant and wild-type cases. Developing targeted therapies penetrating the BBB has revolutionized BM treatment by targeting key drivers like EGFR, ALK, HER2, and BRAF. Despite improved survival, challenges persist, particularly for patients with resistant genetic alterations. Future research should optimise combination therapies, overcome resistance, and refine treatment sequencing. Continued emphasis on personalized, biomarker-driven approaches offers the potential to further improve outcomes, even for complex cases.

Immunotherapeutic and Targeted Strategies for Managing Brain Metastases from Common Cancer Origins: A State-of-the-Art Review

PURPOSE OF REVIEW

This review examines contemporary strategies for managing brain metastases (BM) from common cancers such as lung, breast, and melanoma. We evaluate the efficacy and applicability of targeted therapies and immunotherapies, exploring their potential to cross the blood-brain barrier and improve patient outcomes.

RECENT FINDINGS

Recent studies have shown that tyrosine kinase inhibitors, immune checkpoint inhibitors, and ADCs effectively treat BM. These treatments can overcome the challenges posed by the blood-brain barrier and improve therapeutic outcomes. ADCs are promising because they can deliver cytotoxic agents directly to tumor cells, which reduces systemic toxicity and increases drug delivery efficiency to the brain. Personalized medicine is becoming increasingly significant in treatment decisions, with biomarkers playing an essential role. Advances in molecular genetics and drug development have led to more refined treatments, emphasizing the precision medicine framework. The management of BM is evolving, driven by drug efficacy, resistance mechanisms, and the need for personalized medicine. Integrating ADCs into treatment regimens represents a significant advancement in targeting metastatic brain tumors. Despite these advances, BM management still presents considerable challenges, requiring ongoing research and multi-institutional trials to optimize therapeutic strategies. This review outlines the current state and future directions in treating BM, highlighting the critical need for continued innovation and comprehensive clinical evaluations to improve survival rates and quality of life for affected patients.

Local control and toxicity after stereotactic radiotherapy in brain metastases patients and the impact of novel systemic treatments

BACKGROUND AND PURPOSE

Treatment modalities for patients with brain metastases consist of surgery, radiotherapy, and systemic treatments such as immunotherapy and targeted therapy. Although much is known about local control of brain metastases after radiotherapy and surgery alone, more understanding is needed of the additional effect of new systemic treatments. Our study presents real-world data about the combined effects of different local and systemic treatment strategies on local response of irradiated brain metastases.

MATERIALS AND METHODS

We performed a retrospective consecutive cohort study of patients that presented with brain metastases in our institution between June 2018 and May 2020, reporting the impact of radiotherapy alone versus radiotherapy combined with systemic treatment on local control of irradiated brain metastases and toxicity. Chemotherapy and targeted therapy were temporarily discontinued around irradiation.

RESULTS

262 consecutively treated patients were included in the study. Median time to local failure of irradiated brain metastases was 18 months (IQR 9-34), median overall survival was 20 months (IQR 10-36). 211 (81 %) patients received systemic treatment. Patients with breast cancer had a worse local control (HR 2.3, 95 % CI 1.0-5.0, p = 0.038), as did patients without any systemic treatment (HR 2.1, 95 % CI 1.1-4.3, p = 0.034). Symptomatic radiation necrosis occurred in 36 (14 %) patients. A diameter > 2.5 cm was associated with a higher risk of radiation necrosis. No association was found between systemic treatment in combination with local radiotherapy and symptomatic radiation necrosis.

CONCLUSION

Patients who received any form of systemic treatment had better local control after stereotactic radiosurgery for brain metastases. We did not find an association between systemic treatment and the incidence of radiation necrosis.

Sex Difference in Disease-Related Adverse Events Post-Diagnosis of Lung Cancer Brain Metastases in Medicare Individuals ≥ 66 Years of Age

Sex differences are evident in adverse events (AEs) related to brain tumors, yet sex differences in AEs specific to brain metastases (BrMs) are underexplored. Lung cancer BrMs dominate among BrM, comprising over half of cases. This study examined sex differences in AEs associated with lung cancer BrMs in individuals aged 66 or older using the SEER-Medicare dataset. Multivariable logistic regression, adjusted for demographic factors and comorbidities, stratified by histological subtype, treatment, age, and year of diagnosis were used to analyze AEs among those with BrMs from primary lung tumors. Year of diagnosis was grouped into prior/post-2013, to account for shifts in treatment paradigms. The results showed nuanced sex-specific AEs. Females diagnosed post-2013 with small-cell, squamous-cell, or other non-small-cell carcinoma BrMs had a higher headache likelihood than males. Males with adenocarcinoma post-2013 were more likely to experience brain herniation. Females aged 76 and older with small-cell BrM exhibited increased vision difficulty risk compared to males of the same age, with no significant difference in other age groups. Males treated for adenocarcinoma faced heightened hemorrhagic stroke risk. This study reveals sex-specific disparities in AEs among older individuals with lung cancer BrMs, varying by histological subtype, age, diagnosis year, and treatment.

Accuracy of machine learning in preoperative identification of genetic mutation status in lung cancer: A systematic review and meta-analysis

BACKGROUND AND PURPOSE

We performed this systematic review and meta-analysis to investigate the performance of ML in detecting genetic mutation status in NSCLC patients.

MATERIALS AND METHODS

We conducted a systematic search of PubMed, Cochrane, Embase, and Web of Science up until July 2023. We discussed the genetic mutation status of EGFR, ALK, KRAS, and BRAF, as well as the mutation status at different sites of EGFR.

RESULTS

We included a total of 128 original studies, of which 114 constructed ML models based on radiomic features mainly extracted from CT, MRI, and PET-CT data. From a genetic mutation perspective, 121 studies focused on EGFR mutation status analysis. In the validation set, for the detection of EGFR mutation status, the aggregated c-index was 0.760 (95%CI: 0.706-0.814) for clinical feature-based models, 0.772 (95%CI: 0.753-0.791) for CT-based radiomics models, 0.816 (95%CI: 0.776-0.856) for MRI-based radiomics models, and 0.750 (95%CI: 0.712-0.789) for PET-CT-based radiomics models. When combined with clinical features, the aggregated c-index was 0.807 (95%CI: 0.781-0.832) for CT-based radiomics models, 0.806 (95%CI: 0.773-0.839) for MRI-based radiomics models, and 0.822 (95%CI: 0.789-0.854) for PET-CT-based radiomics models. In the validation set, the aggregated c-indexes for radiomics-based models to detect mutation status of ALK and KRAS, as well as the mutation status at different sites of EGFR were all greater than 0.7.

CONCLUSION

The use of radiomics-based methods for early discrimination of EGFR mutation status in NSCLC demonstrates relatively high accuracy. However, the influence of clinical variables cannot be overlooked in this process. In addition, future studies should also pay attention to the accuracy of radiomics in identifying mutation status of other genes in EGFR.

Surgical Management of Brain Metastasis from Esophageal Cancer: A Systematic Review and Single-Center Experience

BACKGROUND

Brain metastases from esophageal cancer (BMEC) are rare and aggressive, with limited literature on optimal treatment modalities and a standard of care yet to be established. The objective of this study was to systematically review existing literature and perform a retrospective analysis of our institution's patients to evaluate the influence of different treatment modalities on patient outcomes.

METHODS

A systematic review of the literature following Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines and a retrospective review of our institutional experience with BMEC were both conducted. Data based on mean survival,histology, metastasis location, and treatment modality were abstracted.

RESULTS

A total of 48 studies representing 136 patients with BMEC were identified, in addition to the 11 patients treated at our institution. There were a total of 100 males (12 unreported), with a median age of 62.2 at diagnosis in our systematic review, along with 8 males with a median age of 62 in our institutional review. Collectively, survival rates observed based on histology were not similar (squamous cell carcinoma: 9.2 months, adenocarcinoma: 13.4 months), however, based on treatment modalities (surgery: 11.6 months, radiation: 10.4 months, chemotherapy: 12.3 months), and metastasis location (supratentorial: 10.5 months, infratentorial: 9.9 months), the survival times were comparable.

CONCLUSIONS

Our review suggests that causes of death were often independent of brain metastases highlighting the need for further studies on early detection and prevention of primary esophageal cancer, as well as improved treatment modalities for BMECs.

From pre-clinical to translational brain metastasis research: current challenges and emerging opportunities

Brain metastasis, characterized by poor clinical outcomes, is a devastating disease. Despite significant mechanistic and therapeutic advances in recent years, pivotal improvements in clinical interventions have remained elusive. The heterogeneous nature of the primary tumor of origin, complications in drug delivery across the blood-brain barrier, and the distinct microenvironment collectively pose formidable clinical challenges in developing new treatments for patients with brain metastasis. Although current preclinical models have deepened our basic understanding of the disease, much of the existing research on brain metastasis has employed a reductionist approach. This approach, which often relies on either in vitro systems or in vivo injection models in young and treatment-naive mouse models, does not give sufficient consideration to the clinical context. Given the translational importance of brain metastasis research, we advocate for the design of preclinical experimental models that take into account these unique clinical challenges and align more closely with current clinical practices. We anticipate that aligning and simulating real-world patient conditions will facilitate the development of more translatable treatment regimens. This brief review outlines the most pressing clinical challenges, the current state of research in addressing them, and offers perspectives on innovative metastasis models and tools aimed at identifying novel strategies for more effective management of clinical brain metastasis.

Concomitant radiosurgical and targeted oncological treatment improves the outcome of patients with brain metastases from gastrointestinal cancer

BACKGROUND

So far, only limited studies exist that evaluate patients with brain metastases (BM) from GI cancer and associated primary cancers who were treated by Gamma Knife Radiosurgery (GKRS) and concomitant immunotherapy (IT) or targeted therapy (TT).

METHODS

Survival after GKRS was compared to the general and specific Graded Prognostic Assessment (GPA) and Score Index for Radiosurgery (SIR). Further, the influence of age, sex, Karnofsky Performance Status Scale (KPS), extracranial metastases (ECM) status at BM diagnosis, number of BM, the Recursive Partitioning Analysis (RPA) classes, GKRS1 treatment mode and concomitant treatment with IT or TT on the survival after GKRS was analyzed. Moreover, complication rates after concomitant GKRS and mainly TT treatment are reported.

RESULTS

Multivariate Cox regression analysis revealed IT or TT at or after the first Gamma Knife Radiosurgery (GKRS1) treatment as the only significant predictor for overall survival after GKRS1, even after adjusting for sex, KPS group, age group, number of BM at GKRS1, RPA class, ECM status at BM diagnosis and GKRS treatment mode. Concomitant treatment with IT or TT did not increase the rate of adverse radiation effects. There was no significant difference in local BM progression after GKRS between patients who received IT or TT and patients without IT or TT.

CONCLUSION

Good local tumor control rates and low rates of side effects demonstrate the safety and efficacy of GKRS in patients with BM from GI cancers. The concomitant radiosurgical and targeted oncological treatment significantly improves the survival after GKRS without increasing the rate of adverse radiation effects. To provide local tumor control, radiosurgery remains of utmost importance in modern GI BM management.

Cytoreduction of Residual Tumor Burden Is Decisive for Prolonged Survival in Patients with Recurrent Brain Metastases-Retrospective Analysis of 219 Patients

BACKGROUND

Despite advances in treatment for brain metastases (BMs), the prognosis for recurrent BMs remains poor and requires further research to advance clinical management and improve patient outcomes. In particular, data addressing the impact of tumor volume and surgical resection with regard to survival remain scarce.

METHODS

Adult patients with recurrent BMs between December 2007 and December 2022 were analyzed. A distinction was made between operated and non-operated patients, and the residual tumor burden (RTB) was determined by using (postoperative) MRI. Survival analysis was performed and RTB cutoff values were calculated using maximally selected log-rank statistics. In addition, further analyses on systemic tumor progression and (postoperative) tumor therapy were conducted.

RESULTS

In total, 219 patients were included in the analysis. Median age was 60 years (IQR 52-69). Median preoperative tumor burden was 2.4 cm3 (IQR 0.8-8.3), and postoperative tumor burden was 0.5 cm3 (IQR 0.0-2.9). A total of 95 patients (43.4%) underwent surgery, and complete cytoreduction was achieved in 55 (25.1%) patients. Median overall survival was 6 months (IQR 2-10). Cutoff RTB in all patients was 0.12 cm3, showing a significant difference (p = 0.00029) in overall survival (OS). Multivariate analysis showed preoperative KPSS (HR 0.983, 95% CI, 0.967-0.997, p = 0.015), postoperative tumor burden (HR 1.03, 95% CI 1.008-1.053, p = 0.007), and complete vs. incomplete resection (HR 0.629, 95% CI 0.420-0.941, p = 0.024) as significant. Longer survival was significantly associated with surgery for recurrent BMs (p = 0.00097), and additional analysis demonstrated the significant effect of complete resection on survival (p = 0.0027). In the subgroup of patients with systemic progression, a cutoff RTB of 0.97 cm3 (p = 0.00068) was found; patients who had received surgery also showed prolonged OS (p = 0.036). Single systemic therapy (p = 0.048) and the combination of radiotherapy and systemic therapy had a significant influence on survival (p = 0.036).

CONCLUSIONS

RTB is a strong prognostic factor for survival in patients with recurrent BMs. Operated patients with recurrent BMs showed longer survival independent of systemic progression. Maximal cytoreduction should be targeted to achieve better long-term outcomes.

Intracranial Efficacy of Adagrasib in Patients From the KRYSTAL-1 Trial With KRASG12C-Mutated Non-Small-Cell Lung Cancer Who Have Untreated CNS Metastases

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.Patients with Kirsten rat sarcoma viral oncogene homolog (KRAS)-mutated non-small-cell lung cancer (NSCLC) and untreated CNS metastases have a worse prognosis than similar patients without KRAS mutations. Adagrasib has previously demonstrated CNS penetration preclinically and cerebral spinal fluid penetration clinically. We evaluated adagrasib in patients with KRASG12C-mutated NSCLC and untreated CNS metastases from the KRYSTAL-1 trial (ClinicalTrials.gov identifier: NCT03785249; phase Ib cohort), in which adagrasib 600 mg was administered orally, twice daily. Study outcomes included the safety and clinical activity (intracranial [IC] and systemic) by blinded independent central review. Twenty-five patients with KRASG12C-mutated NSCLC and untreated CNS metastases were enrolled and evaluated (median follow-up, 13.7 months); 19 patients were radiographically evaluable for IC activity. Safety was consistent with previous reports of adagrasib, with grade 3 treatment-related adverse events (TRAEs) in 10 patients (40%) and one grade 4 (4%) and no grade 5 TRAEs. The most common CNS-specific TRAEs included dysgeusia (24%) and dizziness (20%). Adagrasib demonstrated an IC objective response rate of 42%, disease control rate of 90%, progression-free survival of 5.4 months, and median overall survival of 11.4 months. Adagrasib is the first KRASG12C inhibitor to prospectively demonstrate IC activity in patients with KRASG12C-mutated NSCLC and untreated CNS metastases, supporting further investigation in this population.

Identifying New Contributors to Brain Metastasis in Lung Adenocarcinoma: A Transcriptomic Meta-Analysis

Lung tumors frequently metastasize to the brain. Brain metastasis (BM) is common in advanced cases, and a major cause of patient morbidity and mortality. The precise molecular mechanisms governing BM are still unclear, in part attributed to the rarity of BM specimens. In this work, we compile a unique transcriptomic dataset encompassing RNA-seq, microarray, and single-cell analyses from BM samples obtained from patients with lung adenocarcinoma (LUAD). By integrating this comprehensive dataset, we aimed to enhance understanding of the molecular landscape of BM, thereby facilitating the identification of novel and efficient treatment strategies. We identified 102 genes with significantly deregulated expression levels in BM tissues, and discovered transcriptional alterations affecting the key driver 'hub' genes CD69 (a type II C-lectin receptor) and GZMA (Granzyme A), indicating an important role of the immune system in the development of BM from primary LUAD. Our study demonstrated a BM-specific gene expression pattern and revealed the presence of dendritic cells and neutrophils in BM, suggesting an immunosuppressive tumor microenvironment. These findings highlight key drivers of LUAD-BM that may yield therapeutic targets to improve patient outcomes.

Improved Brain Tumor Conspicuity at 3 T Using Dark Blood, Fat-Suppressed, Dixon Unbalanced T1 Relaxation-Enhanced Steady-State MRI

OBJECTIVES

Contrast-enhanced magnetic resonance imaging (MRI) is the cornerstone for brain tumor diagnosis and treatment planning. We have developed a novel dual-echo volumetric dark blood pulse sequence called Dixon unbalanced T1 relaxation-enhanced steady-state (uT 1 RESS) that improves the visibility of contrast-enhancing lesions while suppressing the tissue signals from blood vessels and fat. The purpose of this study was to test the hypothesis that Dixon uT 1 RESS would significantly improve the conspicuity of brain tumors compared with magnetization-prepared rapid gradient echo (MPRAGE), as well as to determine potential limitations of the technique.

MATERIALS AND METHODS

This retrospective study was approved by the hospital institutional review board. Forty-seven adult patients undergoing an MRI scan for a brain tumor indication were included. Contrast-enhanced MRI of the brain was performed at 3 T using both MPRAGE and Dixon uT 1 RESS. To control for any impact of contrast agent washout during the scan procedure, Dixon uT 1 RESS was acquired in approximately half the subjects immediately after MPRAGE, and in the other half immediately before MPRAGE. Image quality, artifacts, and lesion detection were scored by 3 readers, whereas lesion apparent signal-to-noise ratio and lesion-to-background Weber contrast were calculated from region-of-interest measurements.

RESULTS

Image quality was not rated significantly different between MPRAGE and Dixon uT 1 RESS, whereas motion artifacts were slightly worse with Dixon uT 1 RESS. Comparing Dixon uT 1 RESS with MPRAGE, the respective values for mean lesion apparent signal-to-noise ratio were not significantly different (199.31 ± 99.05 vs 203.81 ± 110.23). Compared with MPRAGE, Dixon uT 1 RESS significantly increased the tumor-to-brain contrast (1.60 ± 1.18 vs 0.61 ± 0.47 when Dixon uT1RESS was acquired before MPRAGE and 1.94 ± 0.97 vs 0.82 ± 0.55 when Dixon uT 1 RESS was acquired after MPRAGE). In patients with metastatic disease, Dixon uT 1 RESS detected at least 1 enhancing brain lesion that was missed by MPRAGE on average in 24.7% of patients, whereas Dixon uT 1 RESS did not miss any lesions that were demonstrated by MPRAGE. Dixon uT 1 RESS better detected vascular and dural invasion in a small number of patients.

CONCLUSIONS

In conclusion, brain tumors were significantly more conspicuous at 3 T using Dixon uT 1 RESS compared with MPRAGE, with an approximately 2.5-fold improvement in lesion-to-background contrast irrespective of sequence order. It outperformed MPRAGE for the detection of brain metastases, dural or vascular involvement. These results suggest that Dixon uT 1 RESS could prove to be a useful adjunct or alternative to existing neuroimaging techniques for the postcontrast evaluation of intracranial tumors.

Increased risk for ex-vacuo ventriculomegaly with leukoencephalopathy (EVL) in whole brain radiation therapy and repeat radiosurgery treated brain metastasis patients

INTRODUCTION

Cerebral atrophy with leukoencephalopathy is a known morbidity after whole brain radiation therapy (WBRT), resulting in ex-vacuo ventriculomegaly with leukoencephalopathy (EVL). Here we studied the correlation between WBRT, stereotactic radiosurgery (SRS), and risk for EVL in brain metastases patients.

METHODS

In a retrospective study, we identified 195 patients (with 1,018 BM) who underwent SRS for BM (2007-2017) and had > 3 months of MRI follow-up. All patients who underwent ventriculoperitoneal shunting were excluded. Cerebral atrophy was measured by ex-vacuo-ventriculomegaly, defined based on Evans' criteria. Demographic and clinical variables were analyzed using logistic regression models.

RESULTS

Ex-vacuo ventriculomegaly was observed on pre-radiosurgery imaging in 29.7% (58/195) of the study cohort. On multivariate analysis, older age was the only variable associated with pre-radiosurgery ventriculomegaly. Of the 137 patients with normal ventricular size before radiosurgery, 27 (19.7 %) developed ex-vacuo ventriculomegaly and leukoencephalopathy (EVL) post-SRS. In univariate analysis, previous whole brain radiation therapy was the main factor associated with increased risk for developing EVL (OR = 5.08, p < 0.001). In bivariate models that included prior receipt of WBRT, both the number of SRS treatments (OR = 1.499, p = 0.025) and WBRT (OR = 11.321, p = 0.003 were independently associated with increased EVL risk.

CONCLUSIONS

While repeat radiosurgery contributes to the risk of EVL in BM patients, this risk is ∼20-fold lower than that associated with WBRT.

A 3-month survival model after Gamma Knife surgery in patients with brain metastasis from lung cancer with Karnofsky performance status ≤ 70

Gamma Knife surgery (GKS) for brain metastasis (BM) has been generally advocated for patients with a Karnofsky performance status (KPS) scale of ≥ 70. However, some patients with a poor KPS scale of < 70 are recoverable after GKS and show durable survival. A purpose of this study is to devise a 3-month survival prediction model to screen patients with BM with a KPS of ≤ 70 in whom GKS is needed. A retrospective analysis of 67 patients with a KPS scale of 60-70 undergoing GKS for BM of non-small cell lung cancer (NSCLC) from 2016 to 2020 in our institute was performed. Univariate and multivariate logistic regression analyses were performed to investigate factors related to survival for more than 3 months after GKS. The probability (P) prediction model was designed by giving a weight corresponding to the odds ratio of the variables. The overall survival was 9.9 ± 12.7 months (range 0.2-53.2), with a 3-month survival rate of 59.7% (n = 40). In multivariate logistic regression analysis, extracranial disease (ECD) control (p = .033), focal neurological deficit (FND) (p = .014), and cumulative tumor volume (∑ TV) (p = .005) were associated with 3-month survival. The prediction model of 3-month survival (Harrell's C index = 0.767) was devised based on associated factors. In conclusion, GKS for BMs is recommended in selected patients, even if the KPS scale is ≤ 70.

Brain Metastasis Growth Kinetics: A Novel Prognosticator for Stereotactic Radiotherapy

AIMS

The rate of size change in brain metastasis may have clinical implications on tumour biology and prognosis for patients who receive stereotactic radiotherapy (SRT). We analysed the prognostic value of brain metastasis size kinetics and propose a model for patients with brain metastases treated with linac-based SRT in predicting overall survival.

MATERIALS AND METHODS

We analysed the patients receiving linac-based SRT between 2010 and 2020. Patient and oncological factors, including the changes in sizes of brain metastasis between the diagnostic and stereotactic magnetic resonance imaging, were collected. The associations between prognostic factors and overall survival were assessed using Cox regression with least absolute selection and shrinkage operator (LASSO) checked by 500 bootstrap replications. Our prognostic score was calculated by evaluating the most statistically significant factors. Patients were grouped and compared according to our proposed score, Score Index for Radiosurgery in Brain Metastases (SIR) and Basic Score for Brain Metastases (BS-BM).

RESULTS

In total, 85 patients were included. We developed the prognostic model based on the most important predictors of overall survival: growth kinetics, i.e. percentage change in brain metastasis size per day between the diagnostic and stereotactic magnetic resonance imaging (hazard ratio per 1% increase, 1.32; 95% confidence interval 1.06-1.65), extracranial oligometastatic diseases (≤5 involvements) (hazard ratio 0.28; 95% confidence interval 0.16-0.52) and the presence of neurological symptoms (hazard ratio 2.99; 95% confidence interval 1.54-5.81). Patients with scores 0, 1, 2 and 3 had a median overall survival of 44.4 (95% confidence interval 9.6-not reached), 20.4 (95% confidence interval 15.6-40.8), 12.0 (95% confidence interval 7.2-22.8) and 2.4 (95% confidence interval 1.2-not reached) years, respectively. The optimism-corrected c-indices for our proposed model, SIR and BS-BM were 0.65, 0.58 and 0.54, respectively.

CONCLUSIONS

Brain metastasis growth kinetics is a valuable metric for survival outcomes of SRT. Our model is useful in identifying patients with brain metastasis treated with SRT with different overall survival.

MRI-based two-stage deep learning model for automatic detection and segmentation of brain metastases

OBJECTIVES

To develop and validate a two-stage deep learning model for automatic detection and segmentation of brain metastases (BMs) in MRI images.

METHODS

In this retrospective study, T1-weighted (T1) and T1-weighted contrast-enhanced (T1ce) MRI images of 649 patients who underwent radiotherapy from August 2019 to January 2022 were included. A total of 5163 metastases were manually annotated by neuroradiologists. A two-stage deep learning model was developed for automatic detection and segmentation of BMs, which consisted of a lightweight segmentation network for generating metastases proposals and a multi-scale classification network for false-positive suppression. Its performance was evaluated by sensitivity, precision, F1-score, dice, and relative volume difference (RVD).

RESULTS

Six hundred forty-nine patients were randomly divided into training (n = 295), validation (n = 99), and testing (n = 255) sets. The proposed two-stage model achieved a sensitivity of 90% (1463/1632) and a precision of 56% (1463/2629) on the testing set, outperforming one-stage methods based on a single-shot detector, 3D U-Net, and nnU-Net, whose sensitivities were 78% (1276/1632), 79% (1290/1632), and 87% (1426/1632), and the precisions were 40% (1276/3222), 51% (1290/2507), and 53% (1426/2688), respectively. Particularly for BMs smaller than 5 mm, the proposed model achieved a sensitivity of 66% (116/177), far superior to one-stage models (21% (37/177), 36% (64/177), and 53% (93/177)). Furthermore, it also achieved high segmentation performance with an average dice of 81% and an average RVD of 20%.

CONCLUSION

A two-stage deep learning model can detect and segment BMs with high sensitivity and low volume error.

KEY POINTS

• A two-stage deep learning model based on triple-channel MRI images identified brain metastases with 90% sensitivity and 56% precision. • For brain metastases smaller than 5 mm, the proposed two-stage model achieved 66% sensitivity and 22% precision. • For segmentation of brain metastases, the proposed two-stage model achieved a dice of 81% and a relative volume difference (RVD) of 20%.

Quantitative Relaxometry Metrics for Brain Metastases Compared to Normal Tissues: A Pilot MR Fingerprinting Study

The purpose of the present pilot study was to estimate T1 and T2 metric values derived simultaneously from a new, rapid Magnetic Resonance Fingerprinting (MRF) technique, as well as to assess their ability to characterize-brain metastases (BM) and normal-appearing brain tissues. Fourteen patients with BM underwent MRI, including prototype MRF, on a 3T scanner. In total, 108 measurements were analyzed: 42 from solid parts of BM's (21 each on T1 and T2 maps) and 66 from normal-appearing brain tissue (11 ROIs each on T1 and T2 maps for gray matter [GM], white matter [WM], and cerebrospinal fluid [CSF]). The BM's mean T1 and T2 values differed significantly from normal-appearing WM (p < 0.05). The mean T1 values from normal-appearing GM, WM, and CSF regions were 1205 ms, 840 ms, and 4233 ms, respectively. The mean T2 values were 108 ms, 78 ms, and 442 ms, respectively. The mean T1 and T2 values for untreated BM (n = 4) were 2035 ms and 168 ms, respectively. For treated BM (n = 17) the T1 and T2 values were 2163 ms and 141 ms, respectively. MRF technique appears to be a promising and rapid quantitative method for the characterization of free water content and tumor morphology in BMs.

Quantum dots: The cutting-edge nanotheranostics in brain cancer management

Quantum dots (QDs) are semiconductor nanocrystals possessing unique optoelectrical properties in that they can emit light energy of specific tunable wavelengths when excited by photons. They are gaining attention nowadays owing to their all-around ability to allow high-quality bio-imaging along with targeted drug delivery. The most lethal central nervous system (CNS) disorders are brain cancers or malignant brain tumors. CNS is guarded by the blood-brain barrier which poses a selective blockade toward drug delivery into the brain. QDs have displayed strong potential to deliver therapeutic agents into the brain successfully. Their bio-imaging capability due to photoluminescence and specific targeting ability through the attachment of ligand biomolecules make them preferable clinical tools for coming times. Biocompatible QDs are emerging as nanotheranostic tools to identify/diagnose and selectively kill cancer cells. The current review focuses on QDs and associated nanoformulations as potential futuristic clinical aids in the continuous battle against brain cancer.

Differentiating EGFR from ALK mutation status using radiomics signature based on MR sequences of brain metastasis

PURPOSE

More and more small brain metastases (BMs) in asymptomatic patients can be detected even prior to their primary lung cancer with the development of MRI. The aim of this study was to develop a predictive radiomics model to identify epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK) mutation status in BM and explore the optimal MR sequence for predication.

METHODS

This retrospective study included 186 patients with proven BM of lung cancer (training cohort: 70 patients with EGFR mutations and 65 patients with ALK rearrangements; testing cohort: 26 patients with EGFR mutations and 25 patients with ALK rearrangements). Radiomics features were separately extracted from contrast-enhanced T1-weighted imaging (T1-CE), T2 fluid-attenuated inversion recovery (T2-FLAIR) and T2WI sequences. The model for three MR sequences were constructed using a random forest classifier. ROC curves were used to validate the capability of the models in the training and testing cohorts.

RESULTS

The AUCs of the T2-FLAIR model were significantly higher than those of the T1-CE model in training cohort (0.991 versus 0.954) and testing cohort (0.950 versus 0.867) and much higher than those of the T2WI model in training cohort (0.991 versus 0.880) and testing cohort (0.950 versus 0.731). Besides, the F1 scores of the T1-CE model were slightly higher than the T2-FLAIR model and much higher than the T2WI model in two cohorts.

CONCLUSION

T2-FLAIR and T1-CE radiomics models that can be used as noninvasive tools for identifying EGFR and ALK mutation status are helpful to guide therapeutic strategies.

Upfront Brain Treatments Followed by Lung Surgery Improves Survival for Stage IV Non-small Cell Lung Cancer Patients With Brain Metastases: A Large Cohort Analysis

Background: Current treatment guidelines for stage IV non-small cell lung cancer (NSCLC) with brain metastases recommend brain treatments, including surgical resection and radiotherapy (RT), in addition to resection of the primary lung tumor. Here, we investigate the less-studied impact of treatment sequence on the overall survival.

Methods: The National Cancer Database was queried for NSCLC patients with brain metastases who underwent surgical resection of the primary lung tumor (n = 776). Kaplan-Meier survival curves with log-rank test and propensity score stratified Cox regression with Wald test were used to evaluate the associations between various treatment plans and overall survival (OS).

Results: Compared to patients who did not receive any brain treatment (median OS = 6.05 months), significantly better survival was observed for those who received brain surgery plus RT (median OS = 26.25 months, p < 0.0001) and for those who received brain RT alone (median OS = 14.49 months, p < 0.001). Patients who received one upfront brain treatment (surgery or RT) before lung surgery were associated with better survival than those who received lung surgery first (p < 0.05). The best survival outcome (median OS 27.1 months) was associated with the sequence of brain surgery plus postoperative brain RT followed by lung surgery.

Conclusions: This study shows the value of performing upfront brain treatments followed by primary lung tumor resection for NSCLC patients with brain metastases, especially the procedure of brain surgery plus postoperative brain RT followed by lung surgery.

Frequency of actionable molecular drivers in lung cancer patients with precocious brain metastases

Brain metastases frequently occur during the course of disease in patients suffering from lung cancer. Occasionally, neurological symptoms caused by brain metastases (BM) might represent the first sign of systemic tumor disease (so called precocious metastases), leading to the detection of the primary lung tumor. The biological basis of precocious BM is largely unknown, and treatment options are not well established for this subgroup of patients. Therefore, we retrospectively analyzed 33 patients (24 non-small cell lung cancer (NSCLC)), 9 small cell lung cancer (SCLC)) presenting with precocious BM focusing on molecular alterations potentially relevant for the tumor's biology and treatment. We found five FGFR1 amplifications (4 adenocarcinoma, 1 SCLC) among 31 analyzed patients (16.1%), eight MET amplifications among 30 analyzed tumors (7 NSCLC, 1 SCLC; 26.7%), three EGFR mutations within 33 patients (all adenocarcinomas, 9.1%), and five KRAS mutations among 32 patients (all adenocarcinomas; 15.6%). No ALK, ROS1 or RET gene rearrangements were detected. Our findings suggest that patients with precocious BM of lung cancer harbor EGFR mutations, MET amplifications or FGFR1 amplifications as potential targeted treatment options.

Osimertinib alone as second-line treatment for brain metastases (BM) control may be more limited than for non-BM in advanced NSCLC patients with an acquired EGFR T790M mutation

BACKGROUND

This study was designed to investigate the difference between brain metastases (BM) and non-brain metastases (non-BM) treated by osimertinib in advanced patients with an acquired EGFR T790M mutation after obtaining first-generation EGFR-TKI resistance.

METHODS

A total number of 135 first-generation EGFR-TKI-resistant patients with an acquired EGFR T790M mutation were retrospectively analyzed. The patients were divided into BM and non-BM groups. According to the type of treatment (whether brain radiotherapy), the BM patients were divided into an osimertinib combined with brain radiotherapy group and an osimertinib without brain radiotherapy group. In addition, according to the type of BM (the sequence between BM and osimertinib), the BM patients were subdivided into an osimertinib after BM group (initial BM developed after obtaining first-generation EGFR-TKI resistance) and an osimertinib before BM group (first-generation EGFR-TKI resistance then osimertinib administration performed; initial BM was not developed until osimertinib resistance). The progression-free survival (PFS) and overall survival (OS) were evaluated. The primary endpoint was OS between BM and no-BM patients. The secondary endpoints were PFS of osimertinib, and OS between brain radiotherapy and non-brain radiotherapy patients.

RESULTS

A total of 135 patients were eligible and the median follow-up time of all patients was 50 months. The patients with BM (n = 54) had inferior OS than those without BM (n = 81) (45 months vs. 55 months, P = 0.004). And in BM group, the OS was longer in patients that received osimertinib combined with brain radiotherapy than in those without brain radiotherapy (53 months vs. 40 months, P = 0.014). In addition, the PFS was analysed according to whether developed BM after osimertinib resistance. The PFS of the patients that developed BM after acquiring osimertinib resistance was shorter than that without BM development, whether patients developed initial BM after first-generation EGFR-TKI resistance (7 months vs. 13 months, P = 0.003), or developed non-BM after first-generation EGFR-TKI resistance (13 months vs. 17 months, P < 0.001).

CONCLUSIONS

In advanced patients with an acquired EGFR T790M mutation after obtaining first-generation EGFR-TKI resistance, osimertinib may be more limited in its control in BM than in non-BM. Also, osimertinib combined with brain radiotherapy may improve the survival time of BM patients.

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.

Tumor DNA Mutations From Intraparenchymal Brain Metastases Are Detectable in CSF

Discordant responses between brain metastases and extracranial tumors can arise from branched tumor evolution, underscoring the importance of profiling mutations to optimize therapy. However, the morbidity of brain biopsies limits their use. We investigated whether cell-free DNA (cfDNA) in CSF could serve as an effective surrogate marker for genomic profiling of intraparenchymal (IP) brain metastases.

METHODS

CSF and blood were collected simultaneously from patients with progressive brain metastases undergoing a craniotomy or lumbar puncture. Mutations in both biofluids were measured using an error-suppressed deep sequencing method previously published by our group. Forty-three regions of 24 cancer-associated genes were assayed.

RESULTS

This study enrolled 14 patients with either IP brain metastases (n = 12) or cytology-positive leptomeningeal disease (LMD, n = 2) and two controls with normal pressure hydrocephalus. Primary cancer types were lung, melanoma, renal cell, and colorectal. cfDNA was measurable in all sixteen samples of CSF. Cancer-associated mutations were found in the CSF of ten patients (eight with IP [67%] and two with LMD [100%]) and plasma of five patients (five with IP [42%] and none with LMD). All patients with plasma cfDNA had extracranial tumors. Among the five patients in the cohort who also had mutation data from time-matched brain metastasis tissue, four patients (80%) had matching mutations detected in CSF and brain, whereas only one patient (20%) had matching mutations detected in plasma and brain.

CONCLUSION

The detection of mutational DNA in CSF is not restricted to LMD and was found in two thirds of patients with IP brain metastases in our cohort. Analysis of CSF can be a viable alternative to biopsy for detection of somatic mutations in brain metastases.

Gamma Knife Radiosurgery for Brain Metastases in Non-Small Cell Lung Cancer Patients Treated with Immunotherapy or Targeted Therapy

Simple Summary

In non-small cell lung cancer patients with brain metastases, combined Gamma Knife radiosurgery and immunotherapy or targeted therapy showed an increase in overall survival. The combination of Gamma Knife radiosurgery and immunotherapy or targeted therapy did not increase complications related to radiosurgery. Therefore, the combined treatment seems to be a safe and powerful treatment option for non-small cell lung cancer patients with brain metastases.

Abstract

The combination of Gamma Knife radiosurgery (GKRS) and systemic immunotherapy (IT) or targeted therapy (TT) is a novel treatment method for brain metastases (BMs) in non-small cell lung cancer (NSCLC). To elucidate the safety and efficacy of concomitant IT or TT on the outcome after GKRS, 496 NSCLC patients with BMs, who were treated with GKRS were retrospectively reviewed. The median time between the initial lung cancer diagnosis and the diagnosis of brain metastases was one month. The survival after the initial BM diagnosis was significantly longer than the survival predicted by prognostic BM scores. After the first Gamma Knife radiosurgery treatment (GKRS1), the estimated median survival was 9.9 months (95% CI = 8.3–11.4). Patients with concurrent IT or TT presented with a significantly longer survival after GKRS1 than patients without IT or TT (p < 0.001). These significant differences in the survival were also apparent among the four treatment groups and remained significant after adjustment for Karnofsky performance status scale (KPS), recursive partitioning analysis (RPA) class, sex, and multiple BMs. About half of all our patients (46%) developed new distant BMs after GKRS1. Of note, no statistically significant differences in the occurrence of radiation reaction, radiation necrosis, or intralesional hemorrhage in association with IT or TT at or after GKRS1 were observed. In NSCLC-BM patients, the concomitant use of GKRS and IT or TT showed an increase in overall survival without increased complications related to GKRS. Therefore, the combined treatment with GKRS and IT or TT seems to be a safe and powerful treatment option and emphasizes the role of radiosurgery in modern BM treatment.

Importance of the Role of ω-3 and ω-6 Polyunsaturated Fatty Acids in the Progression of Brain Cancer

Brain cancer is one of the most malignant types of cancer in both children and adults. Brain cancer patients tend to have a poor prognosis and a high rate of mortality. Additionally, 20-40% of all other types of cancer can develop brain metastasis. Numerous pieces of evidence suggest that omega-3-polyunsaturated fatty acids (ω-PUFAs) could potentially be used in the prevention and therapy of several types of cancer. PUFAs and oxylipins are fundamental in preserving physiological events in the nervous system; it is, therefore, necessary to maintain a certain ratio of ω-3 to ω-6 for normal nervous system function. Alterations in PUFAs signaling are involved in the development of various pathologies of the nervous system, including cancer. It is well established that an omega-6-polyunsaturated fatty acid (ω-6 PUFA)-rich diet has a pro-tumoral effect, whereas the consumption of an ω-3 rich diet has an anti-tumoral effect. This review aims to offer a better understanding of brain cancer and PUFAs and to discuss the role and impact of PUFAs on the development of different types of brain cancer. Considering the difficulty of antitumor drugs in crossing the blood-brain barrier, the therapeutic role of ω-3/ω-6 PUFAs against brain cancer would be a good alternative to consider. We highlight our current understanding of the role of PUFAs and its metabolites (oxylipins) in different brain tumors, proliferation, apoptosis, invasion, angiogenesis, and immunosuppression by focusing on recent research in vitro and in vivo.

Clinical effects of apatinib mesylate for treatment of multiple brain micrometastases: Two case reports

BACKGROUND

Apatinib is a small-molecule multitargeted tyrosine kinase inhibitor. Apatinib has demonstrated encouraging antitumor activities. This study aimed to observe the efficacy and safety of apatinib for the treatment of multiple brain micrometastases.

CASE SUMMARY

We report two patients with multiple brain micrometastases after failure of second-line treatment. Both patients had extracerebral metastases. When the patients took 250 mg/d apatinib orally, the intracerebral lesions disappeared. The extracerebral lesions were partially alleviated. Both patients had a progression-free survival of more than 12 mo and were still stable. The safety was good. The main adverse events (AEs) were mild hypertension and proteinuria, which could be controlled.

CONCLUSION

Apatinib has clear efficacy and good tolerance in patients with multiple brain micrometastases after failure of second-line treatment.

Exosomes Derived from Brain Metastatic Breast Cancer Cells Destroy the Blood-Brain Barrier by Carrying lncRNA GS1-600G8.5

Brain metastasis is a major cause of death in breast cancer patients. The greatest event for brain metastasis is the breaching of the blood-brain barrier (BBB) by cancer cells. The role of exosomes in cancer metastasis is clear, whereas the role of exosomes in the integrity of the BBB is unknown. Here, we established a highly brain metastatic breast cancer cell line by three cycles of in vivo selection. The effect of exosomes on the BBB was evaluated in vitro by tracking, transepithelial/transendothelial electrical resistance (TEER), and permeability assays. BBB-associated exosomal long noncoding RNA (lncRNA) was selected from the GEO dataset and verified by real-time PCR, TEER, permeability, and Transwell assays. The cells obtained by the in vivo selection showed higher brain metastatic capacity in vivo and higher migration and invasion in vitro compared to the parental cells. Exosomes from the highly brain metastatic cells were internalized by brain microvascular endothelial cells (BMECs), which reduced TEER and increased permeability of BBB. The exosomes derived from the highly metastatic cells promoted invasion of the breast cancer cells in the BBB model. lncRNA GS1-600G8.5 was highly expressed in the highly brain metastatic cells and their exosomes, as compared to the samples with reduced metastatic behavior. Silencing of GS1-600G8.5 significantly abrogated the BBB destructive effect of exosomes. GS1-600G8.5-deficient exosomes failed to promote the infiltration of cancer cells through the BBB. Furthermore, BMECs treated with GS1-600G8.5-deprived exosomes expressed higher tight junction proteins than those treated with the control exosomes. These data suggest the exosomes derived from highly brain metastatic breast cancer cells might destroy the BBB system and promote the passage of cancer cells across the BBB, by transferring lncRNA GS1-600G8.5.

Radiomic prediction of mutation status based on MR imaging of lung cancer brain metastases

Lung cancer metastases comprise most of all brain metastases in adults and most brain metastases are diagnosed by magnetic resonance (MR) scans. The purpose of this study was to conduct an MR imaging-based radiomic analysis of brain metastatic lesions from patients with primary lung cancer to classify mutational status of the metastatic disease. We retrospectively identified lung cancer patients with brain metastases treated at our institution between 2009 and 2017 who underwent genotype testing of their primary lung cancer. Brain MR Images were used for segmentation of enhancing tumors and peritumoral edema, and for radiomic feature extraction. The most relevant radiomic features were identified and used with clinical data to train random forest classifiers to classify the mutation status. Of 110 patients in the study cohort (mean age 57.51 ± 12.32 years; M: F = 37:73), 75 had an EGFR mutation, 21 had an ALK translocation, and 15 had a KRAS mutation. One patient had both ALK translocation and EGFR mutation. Majority of radiomic features most relevant for mutation classification were textural. Model building using both radiomic features and clinical data yielded more accurate classifications than using either alone. For classification of EGFR, ALK, and KRAS mutation status, the model built with both radiomic features and clinical data resulted in area-under-the-curve (AUC) values based on cross-validation of 0.912, 0.915, and 0.985, respectively. Our study demonstrated that MR imaging-based radiomic analysis of brain metastases in patients with primary lung cancer may be used to classify mutation status. This approach may be useful for devising treatment strategies and informing prognosis.

Antibodies for the Treatment of Brain Metastases, a Dream or a Reality?

The incidence of brain metastases (BM) in cancer patients is increasing. After diagnosis, overall survival (OS) is poor, elicited by the lack of an effective treatment. Monoclonal antibody (mAb)-based therapy has achieved remarkable success in treating both hematologic and non-central-nervous system (CNS) tumors due to their inherent targeting specificity. However, the use of mAbs in the treatment of CNS tumors is restricted by the blood-brain barrier (BBB) that hinders the delivery of either small-molecules drugs (sMDs) or therapeutic proteins (TPs). To overcome this limitation, active research is focused on the development of strategies to deliver TPs and increase their concentration in the brain. Yet, their molecular weight and hydrophilic nature turn this task into a challenge. The use of BBB peptide shuttles is an elegant strategy. They explore either receptor-mediated transcytosis (RMT) or adsorptive-mediated transcytosis (AMT) to cross the BBB. The latter is preferable since it avoids enzymatic degradation, receptor saturation, and competition with natural receptor substrates, which reduces adverse events. Therefore, the combination of mAbs properties (e.g., selectivity and long half-life) with BBB peptide shuttles (e.g., BBB translocation and delivery into the brain) turns the therapeutic conjugate in a valid approach to safely overcome the BBB and efficiently eliminate metastatic brain cells.

Advances in covalent kinase inhibitors

This comprehensive review details recent advances, challenges and innovations in covalent kinase inhibition within a 10 year period (2007–2018).

The impact of systemic precision medicine and immunotherapy treatments on brain metastases

Metastases from melanoma, lung and breast cancer are among the most common causes of intracranial malignancy. Standard of care for brain metastases include a combination of surgical resection, stereotactic radiosurgery, and whole-brain radiation. However, evidence continues to accumulate regarding the efficacy of molecularly-targeted systemic treatments and immunotherapy. For non-small cell lung cancer (NSCLC), numerous clinical trials have demonstrated intracranial activity for inhibitors of EGFR and ALK. Patients with melanoma brain metastases may benefit from systemic therapy using BRAF-inhibitors with and without trametinib. Several targeted options are available for breast cancer brain metastases that overexpress HER2, although agents with intracranial activity are still needed for other molecular subtypes. Immune checkpoint inhibitors including anti-CTLA-4 and anti-PD-1/PD-L1 antibodies are yielding impressive responses in intracranial manifestations of metastatic melanoma and NSCLC. Given the promising early results with these emerging therapies, management of eligible patients will require increased multidisciplinary discussion incorporating novel systemic treatment approaches prior or in addition to local therapy.

Brain surgery in combination with tyrosine kinase inhibitor and whole brain radiotherapy for epidermal growth factor receptor-mutant non-small-cell lung cancer with brain metastases

The role of brain surgery (BS) on the survival of patients with non-small-cell lung cancer (NSCLC) and brain metastases (BM), particularly those with epidermal growth factor receptor (EGFR) mutations under tyrosine kinase inhibitors (TKIs) is yet to be defined. We aimed to investigate whether BS could improve the survival of patients in addition to the combination of TKIs and whole brain radiotherapy (WBRT). A cohort of 1394 NSCLC patients between 2011 and 2016 was retrospectively studied. One hundred patients with BM receiving TKI + RT were enrolled. Forty patients (40%) received TKI + BS + RT, and 60 patients (60%) received TKI + RT. Survival time was calculated from the date of BM diagnoses to the date of death or last follow-up. With a median follow-up of 25.6 months (95% CI, 18.6–35.7), the median survival after BM was 18.2 months (95% CI, 10.8 to 27.4) in the TKI + BS + RT group and 11.8 months (95% CI, 5.2 to18) in the TKI + RT group. Cox proportional hazards regression model for the patients with the largest BM over 1 cm showed that TKI + BS + RT group was associated with improved survival relative to TKI + RT group (HR, 0.49; 95% CI, 0.29 to 0.83; P = 0.008). BS adds significant survival benefits in addition to TKIs and WBRT, especially for patients with EGFR-mutant NSCLC and the largest BM over 1 cm.

Advances in the management of brain metastases from cancer of unknown primary

Cancer of unknown primary accounts for 3-5% of all cancers for which an adequate investigation does not identify the primary tumor. The particular subset of brain metastasis in cancer of unknown primary (BMCUP) is a clinical challenge that lacks standardized diagnostic and therapeutic options. It is diagnosed predominantly in male patients in the sixth decade of age with complaints of headache, neurological dysfunction, cognitive and behavioral disturbances and seizures. The therapeutic approach to patients with BMCUP relies on local control and systemic treatment. Surgery or stereotactic radiosurgery and/or whole brain radiation therapy seems to be the cornerstone of the treatment approach to BMCUP. Systemic therapy remains essential as cancers of unknown primary are conceptually metastatic tumors. The benefits of chemotherapy were disappointing whereas those of targeted therapies and immune checkpoint inhibitors remain to be evaluated. In this Review, we address the advances in the diagnosis and treatment of BMCUP.

LncRNA FOXC2 antisense transcript accelerates non-small-cell lung cancer tumorigenesis via silencing p15

Non-coding RNAs (ncRNAs) have been demonstrated to modulate the oncogenesis of non-small cell lung cancer (NSCLC), especially the long non-coding RNAs (lncRNAs). However, the role of lncRNA FOXC2-AS1 in the NSCLC is still unclear. In this research, we find that lncRNA FOXC2-AS1 is involved to NSCLC oncogenesis. The ectopic high-expression level of FOXC2-AS1 is closely correlated with the limited NSCLC patients' survival. In the functional experiments, the knockdown of FOXC2-AS1 dramatically suppressed the NSCLC cells' (A549, H460) proliferation, accelerated the apoptosis and induced the cycle arrest at G0/G1 phase. Mechanistic experiments revealed that FOXC2-AS1 repressed the p15 expression via recruiting the polycomb repressive complex 2 (PRC2) to the promoter of p15. The interaction within FOXC2-AS1 and p15 was validated using the rescue experiments. In conclusion, the results in this work confirmed that FOXC2-AS1 could aggravate NSCLC oncogenesis through repressing p15 expression via interacting EZH2, which provide new idea for the NSCLC therapeutic strategy.

Advanced Magnetic Resonance Imaging Techniques in Management of Brain Metastases

Brain metastases are the most common intracranial tumors and occur in 20–40% of all cancer patients. Lung cancer, breast cancer, and melanoma are the most frequent primary cancers to develop brain metastases. Treatment options include surgical resection, whole brain radiotherapy, stereotactic radiosurgery, and systemic treatment such as targeted or immune therapy. Anatomical magnetic resonance imaging (MRI) of the tumor (in particular post-Gadolinium T₁-weighted and T₂-weighted FLAIR) provide information about lesion morphology and structure, and are routinely used in clinical practice for both detection and treatment response evaluation for brain metastases. Advanced MRI biomarkers that characterize the cellular, biophysical, micro-structural and metabolic features of tumors have the potential to improve the management of brain metastases from early detection and diagnosis, to evaluating treatment response. Magnetic resonance spectroscopy (MRS), chemical exchange saturation transfer (CEST), quantitative magnetization transfer (qMT), diffusion-based tissue microstructure imaging, trans-membrane water exchange mapping, and magnetic susceptibility weighted imaging (SWI) are advanced MRI techniques that will be reviewed in this article as they pertain to brain metastases.

Developments in the Space of New MAPK Pathway Inhibitors for BRAF-Mutant Melanoma

The characterization of the MAPK signaling pathway has led to the development of multiple promising targeted therapy options for a subset of patients with metastatic melanoma. The combination of BRAF and MEK inhibitors represents an FDA-approved standard of care in patients with metastatic and resected BRAF-mutated melanoma. There are currently three FDA-approved BRAF/MEK inhibitor combinations for the treatment of patients with BRAF-mutated melanoma. Although there have been significant advances in the field of targeted therapy, further exploration of new targets within the MAPK pathway will strengthen therapeutic options for patients. Important clinical and translational research focuses on mechanisms of resistance, predictive biomarkers, and challenging patient populations such as those with brain metastases or resected melanoma.

Upfront Cranial Radiotherapy vs. EGFR Tyrosine Kinase Inhibitors Alone for the Treatment of Brain Metastases From Non-small-cell Lung Cancer: A Meta-Analysis of 1465 Patients

Background: Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) is revolutionizing the management of brain metastases (BMs). This study was to explore the value of upfront cranial radiotherapy (RT) in EGFR-mutated non-small cell lung cancer (NSCLC) with BMs compared with EGFR-TKIs alone. Methods: We searched all topic-related comparative articles in public databases (MEDLINE, EMBASE, Cochrane Library, and Web of Science) and conference proceedings. Outcomes of interest were intracranial objective response rate (ORR), overall survival (OS), and intracranial progression-free survival (PFS). Statistical analyses were calculated using Review Manager 5.3 software. Results: Thirteen comparative studies that included a total of 1,456 patients were eligible. Upfront brain RT had significantly higher OS (HR = 0.78, 95% CI = 0.65-0.93, P = 0.005) than EGFR-TKI alone. Upfront RT plus TKI had superior OS (HR = 0.71, 95% CI = 0.58-0.86, P = 0.0005) and intracranial PFS (HR = 0.69, 95% CI = 0.49-0.99, P = 0.04). The pooled data favored upfront whole brain RT (WBRT) plus TKI in terms of intracranial PFS (HR = 0.64, 95% CI = 0.48-0.85, P = 0.002) and OS (HR = 0.75, 95% CI = 0.57-1, P = 0.05). Upfront stereotactic radiosurgery (SRS) was associated with better OS (HR = 0.37, 95% CI = 0.26-0.54, P < 0.00001). Similar results were observed when analysis was restricted to the use of erlotinib or geftinib. Conclusions: The upfront use of brain RT seemed critical, especially for SRS. Upfront administration of upfront WBRT plus EGFR-TKI had better survival outcomes and seemed superior to EGFR-TKI alone.

Clinical presentation, risk factors and outcome of central nervous system metastasis vs stroke in cancer patients

BACKGROUND AND PURPOSE

Cancer and stroke are the second and third causes of death worldwide; brain metastases (BM) occur in one third of patients with cancer, any neurologic deficit in these population always prompts the clinician to discard metastases for their presence carries a bad outcome. Both might share clinical presentation and differences in their outcome are not entirely known. The aim was to compare risk factors, clinical presentation, and outcome of cancer patients with BM vs stroke.

METHODS

A descriptive study with prospectively acquired data from a cancer referral center included patients seen at the neuro-oncologic unit from March 2011 to February 2018 with confirmed cancer who had BM or stroke.

RESULTS

Six hundred and thirteen BM patients were compared with 268 with stroke and cancer. Demographic factors, cancer type, risk factors, clinical presentation, and outcome are presented. Median overall survival in months for those with any stroke was 15 (95%confidence interval [CI] 8.6-21.4)-5 (95%CI 0.12.4) for hemorrhagic stroke and 22 (95%CI 13.4-30.6) in the ischemic group-and for those with BM 12 (95%CI 10.4-13.6). Hemorrhagic stroke commonly found in stroke patients as well as focal motor weakness, aphasia, and altered mental status. BM was more common in breast and lung cancer with headache, visual complaint, and/or vertigo.

CONCLUSION

Survival in cancer patients with BM is not that different than those with stroke, but clinical presentation and risk factors were found different.

Radiological Kinetics of Brain Metastases and Clinical Implications for Patients Treated With Stereotactic Radiosurgery

AIMS

Select patients with brain metastases receive stereotactic radiosurgery (SRS) with the objective of improving survival and intracranial disease control. Brain metastases number and volume are prognostic factors used to inform patient selection. The aim of this study was to assess the rate of change of brain metastases size and number (growth kinetics) between the diagnostic and day of SRS magnetic resonance imaging (MRI) scans.

MATERIALS AND METHODS

All patients treated with Gamma Knife SRS between October 2015 and April 2017 were included in this single-centre retrospective analysis. Brain metastases number and diameter were recorded at diagnosis and treatment. For patients with multiple brain metastases, the largest lesion was the index lesion. Distant intracranial control and overall survival were reported from the date of SRS.

RESULTS

In total, 146 patients received 156 episodes of SRS. The median interval between diagnostic and SRS MRI was 20 days (range 1-68). Interval growth in the index lesion of at least 3 mm or the development of a new brain metastasis was noted in 60.2% of patients. This was associated with age less than 60 years (P = 0.001), Eastern Cooperative Oncology Group (ECOG) performance status 2 or above (P = 0.04), non-small cell lung carcinoma (NSCLC) (P = 0.03) or melanoma histologies (P = 0.05) and uncontrolled extracranial disease (P = 0.05). These patients were also more likely to develop distant intracranial recurrence (P = 0.046). Clinically significant growth was not associated with scan interval or differences in overall survival. The Kaplan-Meier estimate of probability of survival at 12 months was 59.3% (95% confidence interval 46.7-75.2%) for all patients.

CONCLUSION

Intracranial progression between diagnosis and day of SRS is common. Risk factors are uncontrolled extracranial disease, poorer performance status, NSCLC or melanoma histologies and age less than 60 years. These patients would benefit from an MRI closer to treatment to inform patient selection and target delineation for SRS planning.

Factors associated with long-term survival in central nervous system metastases

BACKGROUND

Cancer is a leading cause of death worldwide; central nervous system metastases (CNSm) are amongst the most common complications of cancer and are associated with high morbidity and mortality. The aim of the study was to associate clinic and oncologic characteristics with the possibility of survival for ≥ 1 year.

MATERIALS AND METHODS

A prospective cohort in two referral centers recollected clinical and oncologic data from patients diagnosed with CNSm. Chronic metastases were defined as those patients that survived for ≥ 12 months after the diagnosis of CNSm.

RESULTS

Of 613 patients with CNSm, 554 had solid tumors as the primary cancer and were included; 405 (73%) were women, the most common primary cancer site were breast, lung and urologic. Chronic CNSm were found in 260 (47%) and were compared to those who did not. After multivariate logistic regression analysis, variables associated with good prognosis (living > 12 months) were: female sex (HR 0.55), single CNSm (HR 0.39), diagnosis of CNSm during initial extension studies or during presentation of cancer (HR 0.43), and occipital location (HR 0.62).

CONCLUSIONS

Long-term survival in patients with CNSm remains a topic of debate; their bad prognosis could be changing towards improvement. Clinical findings are typically overlooked in CNSm reports and prognostic scales. After our findings, we propose to include them in forthcoming studies to aid prognostic considerations. Factors associated with prolonged survival found in our study include female gender, timing of CNSm diagnosis, occipital lobe location, and single CNSm.