Brain metastases

Tumor-derived extracellular vesicles disrupt the blood-brain barrier endothelium following high-frequency irreversible electroporation

High-frequency irreversible electroporation (H-FIRE), a nonthermal brain tumor ablation therapeutic, generates a central tumor ablation zone while transiently disrupting the peritumoral blood-brain barrier (BBB). We hypothesized that bystander effects of H-FIRE tumor cell ablation, mediated by small tumor-derived extracellular vesicles (sTDEV), disrupt the BBB endothelium. Monolayers of bEnd.3 cerebral endothelial cells were exposed to supernatants of H-FIRE or radiation (RT)-treated LL/2 and F98 cancer cells. Endothelial cell response was evaluated microscopically and via flow cytometry for apoptosis. sTDEV were isolated following H-FIRE and RT, characterized via nanoparticle tracking analysis (NTA) and transmission electron microscopy, and applied to a Transwell BBB endothelium model to quantify permeability changes. Supernatants of H-FIRE-treated tumor cells, but not supernatants of sham- or RT-treated cells, disrupted endothelial cell monolayer integrity while maintaining viability. sTDEV released by glioma cells treated with 3000 V/cm H-FIRE increased permeability of the BBB endothelium model compared to sTDEV released after lower H-FIRE doses and RT. NTA revealed significantly decreased sTDEV release after the 3000 V/cm H-FIRE dose. Our results demonstrate that sTDEV increase permeability of the BBB endothelium after H-FIRE ablation in vitro. sTDEV-mediated mechanisms of BBB disruption may be exploited for drug delivery to infiltrative margins following H-FIRE ablation.

Novel models by machine learning to predict prognosis of breast cancer brain metastases

BACKGROUND

Breast cancer brain metastases (BCBM) are the most fatal, with limited survival in all breast cancer distant metastases. These patients are deemed to be incurable. Thus, survival time is their foremost concern. However, there is a lack of accurate prediction models in the clinic. What's more, primary surgery for BCBM patients is still controversial.

METHODS

The data used for analysis in this study was obtained from the SEER database (2010-2019). We made a COX regression analysis to identify prognostic factors of BCBM patients. Through cross-validation, we constructed XGBoost models to predict survival in patients with BCBM. Meanwhile, a BCBM cohort from our hospital was used to validate our models. We also investigated the prognosis of patients treated with surgery or not, using propensity score matching and K-M survival analysis. Our results were further validated by subgroup COX analysis in patients with different molecular subtypes.

RESULTS

The XGBoost models we created had high precision and correctness, and they were the most accurate models to predict the survival of BCBM patients (6-month AUC = 0.824, 1-year AUC = 0.813, 2-year AUC = 0.800 and 3-year survival AUC = 0.803). Moreover, the models still exhibited good performance in an externally independent dataset (6-month: AUC = 0.820; 1-year: AUC = 0.732; 2-year: AUC = 0.795; 3-year: AUC = 0.936). Then we used Shiny-Web tool to make our models be easily used from website. Interestingly, we found that the BCBM patients with an annual income of over USD$70,000 had better BCSS (HR = 0.523, 95%CI 0.273-0.999, P < 0.05) than those with less than USD$40,000. The results showed that in all distant metastasis sites, only lung metastasis was an independent poor prognostic factor for patients with BCBM (OS: HR = 1.606, 95%CI 1.157-2.230, P < 0.01; BCSS: HR = 1.698, 95%CI 1.219-2.365, P < 0.01), while bone, liver, distant lymph nodes and other metastases were not. We also found that surgical treatment significantly improved both OS and BCSS in BCBM patients with the HER2 + molecular subtypes and was beneficial to OS of the HR-/HER2- subtype. In contrast, surgery could not help BCBM patients with HR + /HER2- subtype improve their prognosis (OS: HR = 0.887, 95%CI 0.608-1.293, P = 0.510; BCSS: HR = 0.909, 95%CI 0.604-1.368, P = 0.630).

CONCLUSION

We analyzed the clinical features of BCBM patients and constructed 4 machine-learning prognostic models to predict their survival. Our validation results indicate that these models should be highly reproducible in patients with BCBM. We also identified potential prognostic factors for BCBM patients and suggested that primary surgery might improve the survival of BCBM patients with HER2 + and triple-negative subtypes.

Multiphasic modelling and computation of metastatic lung-cancer cell proliferation and atrophy in brain tissue based on experimental data

Cancer is one of the most serious diseases for human beings, especially when metastases come into play. In the present article, the example of lung-cancer metastases in the brain is used to discuss the basic problem of cancer growth and atrophy as a result of both nutrients and medication. As the brain itself is a soft tissue that is saturated by blood and interstitial fluid, the biomechanical description of the problem is based on the Theory of Porous Media enhanced by the results of medication tests carried out in in-vitro experiments on cancer-cell cultures. Based on theoretical and experimental results, the consideration of proliferation, necrosis and apoptosis of metastatic cancer cells is included in the description by so-called mass-production terms added to the mass balances of the brain skeleton and the interstitial fluid. Furthermore, the mass interaction of nutrients and medical drugs between the solid and the interstitial fluid and its influence on proliferation, necrosis and apoptosis of cancer cells are considered. As a result, the overall model is appropriate for the description of brain tumour treatment combined with stress and deformation induced by cancer growth in the skull.

A method for the efficient iron-labeling of patient-derived xenograft cells and cellular imaging validation

There is momentum towards implementing patient-derived xenograft models (PDX) in cancer research to reflect the histopathology, tumor behavior, and metastatic properties observed in the original tumor. To study PDX cells preclinically, we used both bioluminescence imaging (BLI) to evaluate cell viability and magnetic particle imaging (MPI), an emerging imaging technology to allow for detection and quantification of iron nanoparticles. The goal of this study was to develop the first successful iron labeling method of breast cancer cells derived from patient brain metsastases and validate this method with imaging during tumor development. The overall workflow of this labeling method is as follows: adherent and non-adherent luciferase expressing human breast cancer PDX cells (F2-7) are dissociated and concurrently labeled after incubation with micron-sized iron oxide particles (MPIO; 25 μg Fe/ml), with labeling validated by cellular imaging with MPI and BLI. In this study, NOD/SCID/ILIIrg^-/- (n = 5) mice Received injections of 1 × 10⁶ iron-labeled F2-7 cells into the fourth mammary fat pad (MFP). BLI was performed longitudinally to day 49 and MPI was performed up to day 28. In vivo BLI revealed that signal increased over time with tumor development. MPI revealed decreasing signal in the tumors over time. Here, we demonstrate the first application of MPI to monitor the growth of a PDX MFP tumor and the first successful labeling of PDX cells with iron oxide particles. Imaging of PDX cells provides a powerful system to better develop personalized therapies targeting breast cancer brain metastasis.

Seizures in cancer patients: a vast spectrum of etiologies

Aim: This study aims to recognize the distribution of different seizures etiologies in cancer patients, the most common primary tumors responsible for brain metastases, the most epileptogenic primary tumors and the therapeutic modalities. Methods: A retrospective study was conducted at Hotel-Dieu de France Hospital targeting patients admitted to hematology–oncology department between 2005 and 2016 who presented a seizure. Results: Of the 153 included patients, mean age was 57 years (standard deviation = 16 years) and a male predominance (66%). The majority of seizures were due to a primary tumor (49%) or brain metastases (32%). Other reversible (metabolic and drug) or nonreversible causes (carcinomatous meningitis, radiation and cardiovascular complications) formed the remaining causes. Regarding antiepileptic treatments, sodium valproate was mostly used, followed by levetiracetam and phenytoin. Conclusion: Numerous reversible causes are involved in the onset of epileptic seizures, including metabolic disorders, antibiotics and chemotherapies.

Neural Stem Cells

Neural stem cell (NSC) transplantation has provided the basis for the development of potentially powerful new therapeutic cell-based strategies for a broad spectrum of clinical diseases, including stroke, psychiatric illnesses such as fetal alcohol spectrum disorders, and cancer. Here, we discuss pertinent preclinical investigations involving NSCs, including how NSCs can ameliorate these diseases, the current barriers hindering NSC-based treatments, and future directions for NSC research. There are still many translational requirements to overcome before clinical therapeutic applications, such as establishing optimal dosing, route of delivery, and timing regimens and understanding the exact mechanism by which transplanted NSCs lead to enhanced recovery. Such critical lab-to-clinic investigations will be necessary in order to refine NSC-based therapies for debilitating human disorders.

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.

Retrospective dosimetric analysis of brain lesions planned in Pinnacle 9.8 via a HDMLC linac

The University of Toledo Medical Center's Eleanor N. Dana Cancer Center located in northwest Ohio currently utilizes the Edge Radiosurgery System (Varian Medical Systems Inc., Palo Alto, CA) to deliver stereotactic radiosurgery for the treatment of brain lesions. The purpose of this study is to determine the quality of conformal arc radiotherapy in treating patients with brain lesions at The University of Toledo Medical Center and to provide more data for conformity and gradient indices (due to a lack of current data) to hopefully improve national standards by allowing centers to compare among each other. Treatment plans were assessed using the Pinnacle³ v9.8 Radiation Therapy Planning System (Philips Healthcare, Amsterdam, Netherlands). For patients (n = 41) presenting with small brain lesions (n = 82) and treated with conformal arc radiotherapy via the Edge Radiosurgery System, the RTOG conformity index, Paddick conformity index, conformity gradient index, gradient index, and dose gradient index were determined for each plan. This study additionally provides data to suggest the more accurate method of volume derivation provided by the Pinnacle³ v9.8 software. Using this method, average values for each of the following indices were calculated: RTOG conformity index = 1.36 ± 0.29; Paddick conformity index = 0.72 ± 0.12; conformity gradient index = 214.67 ± 12.35; gradient index = 3.64 ± 1.09; dose gradient index = -0.11 ± 0.16. Thus, The University of Toledo Medical Center provides favorable conformity of dose to intracranial target lesions.

Pre- and early postoperative GFAP serum levels in glioma and brain metastases

SUBJECT

To date there is no established tumor marker for the clinical follow-up of glioblastoma, WHO grade IV, (GBM) which constitutes the most frequent and malignant primary brain tumor. However, since there is promising data that the serum glial fibrillary acidic protein (sGFAP) may serve as a biomarker for glial brain tumors, this prospective study aimed at evaluating the diagnostic relevance of perioperative changes in sGFAP levels for the assessment of residual glial tumor tissue in patients undergoing surgery of intracerebral tumors.

METHODS

Serum GFAP was measured using an electrochemiluminometric immunoassay (ElecsysR GFAP prototype test, Roche Diagnostics, Penzberg/Germany) in 32 prospectively recruited patients between September 2009 and August 2010. Twenty-five were diagnosed with glioma and seven with brain metastases (BM). We assessed sGFAP levels prior to and at different time points during the early postoperative phase until patient discharge.

RESULTS

There were only significant differences in the pre-operative sGFAP levels of patients with gliomas compared to BM (0.18 vs. 0.08 µg/l; p = 0.0198, Welch's t-Test). Even though there was an increase of sGFAP after surgery, there were no significant differences between glioma and BM patients at any other time point. Peak sGFAP levels where reached on postoperative day 1 followed by a slight decrease, but not reaching pre-operative levels until postop day 7. There was no significant correlation between postoperative glioma tumor volume and sGFAP levels in univariate analyses.

CONCLUSION

According to our data sGFAP does not appear to be suitable to detect residual glioma tissue in the acute postoperative phase.

Cystic brain metastasis is associated with poor prognosis in patients with advanced breast cancer

Purpose

Brain metastasis (BM) with a cystic component from breast cancer is rare and largely uncharacterized. The purpose of this study was to identify the characteristics of cystic BM in a large cohort of breast cancer patients.

Results

A total of 35 eligible patients with cystic BM and 255 patients with solid BM were analyzed. Three factors were significantly associated with an increased probability of developing cystic lesions: age at diagnosis ≤ 40 years, age at BM ≤ 45 years, and poor histological grade (p < 0.05). Patients with cystic metastasis were also characterized by a larger metastasis volume, a shorter progression-free survival (PFS) following their first treatment for BM, and poor overall survival after BM (p < 0.05). Multivariate analysis further demonstrated that local control of cystic BM was only potentially achieved for HER2-negative primary tumors (p = 0.084).

Methods

Breast cancer patients with parenchymal BM were reviewed from consecutive cases treated at our institution. Cystic BM was defined when the volume of a cystic lesion was greater than 50% of the aggregated volume of all lesions present. Clinicopathologic and radiographic variables were correlated with development of cystic lesions and with prognosis of cystic BM.

Conclusions

This study shows that cystic BM from breast cancer, a special morphological type of BM, had worse prognosis than the more commonly observed solid BM. Younger age and low tumor grade were associated with the development of cystic lesions. Further comprehensive research and management of cystic BM are warranted to improve its poor prognosis.

Methods and results of local treatment of brain metastases in patients with breast cancer

This article presents methods and results of surgical treatment and radiation therapy of brain metastases in breast cancer patients (brain metastases from breast cancer BMF-BC). Based on the literature data, it was shown that patients with single BMF-BC, aged less than 65 years, with Karnofsky score (KPS) of 70 or more and with cured or controlled extracranial disease are the best candidates to surgical treatment. Irrespective of the extracranial disease control status, there are indications for surgery in patients with symptomatic mass effect (tumour diameter larger than 3 cm) and patients with obstructive hydrocephalus from their BMF-BC. Stereotactic radiosurgery (SRS) has some advantages over surgery, with similar effectiveness: it may be used in the treatment of lesions inaccessible to surgery, the number of lesion is not a limiting factor if each lesion is small (< 3) and adequate doses can be delivered, it is not contraindicated in patients with active extracranial disease, it does not interfere with ongoing systemic treatment, and it does not require general anaesthesia or hospitalisation. A disadvantage of SRS, as compared to whole brain radiotherapy (WBRT), in patients with BMF-BC is the possibility of subsequent development of new lesion in the non-irradiated field. Thus the majority of the BMF-BC patients are not good candidates to surgery or SRS; WBRT alone or combined with a systemic treatment still plays a major role in the treatment of these patients.

Macrophages promote matrix protrusive and invasive function of breast cancer cells via MIP-1β dependent upregulation of MYO3A gene in breast cancer cells

The potential of a tumor cell to metastasize profoundly depends on its microenvironment, or "niche" interactions with local components. Tumor-associated-macrophages (TAMs) are the most abundant subpopulation of tumor stroma and represent a key component of tumor microenvironment. The dynamic interaction of cancer cells with neighboring TAMs actively drive cancer progression and metastatic transformation through intercellular signaling networks that need better elucidation. Thus, current study was planned for discerning paracrine communication networks operational between TAMs, and breast cancer cells with special reference to cancer cell invasion and dissemination to distant sites. Here, we report role of MIP-1β in enhancing invasive potential of metastatic breast cancer MDA-MB-231 and MDA-MB-468 cells. In addition, the poorly metastatic MCF-7 cells were also rendered invasive by MIP-1β. The MIP-1β-driven cancer cell invasion was dependent on upregulated expression levels of MYO3A gene, which encodes an unconventional myosin super-family protein harboring a kinase domain. Ex ovo study employing Chick-embryo-model and in vivo Syngenic 4T1/BALB/c mice-model further corroborated aforementioned in vitro findings, thereby substantiating their physiological relevance. Concordantly, human breast cancer specimen exhibited significant association between mRNA expression levels of MIP-1β and MYO3A. Both, MIP-1β and MYO3A exhibited positive correlation with MMP9, an established molecular determinant of cancer cell invasion. Higher expression of these genes correlated with poor survival of breast cancer patients. Collectively, these results point toward so far undisclosed MIP-1β/MYO3A axis being operational during metastasis, wherein macrophage-derived MIP-1β potentiated cancer cell invasion and metastasis via up regulation of MYO3A gene within cancer cells. Our study exposes opportunities for devising potential anti-metastatic strategies for efficient clinical management of breast cancer.

Spine Stereotactic Body Radiotherapy Outcomes in Patients with Concurrent Brain Metastases

Objectives: Stereotactic body radiotherapy (SBRT) is an emerging technique for maximizing tumor and pain control in selected patients with spinal metastases. Outcomes for those with concurrent brain metastases (CBM) have not been well-described previously. The goal of this study was to compare outcomes for patients with or without CBM treated with spine SBRT.

Methods: Records of all patients treated with SBRT for spine metastases at our institution from January 2008 to January 2014 were reviewed. Chi-square analyses and the Mann-Whitney test were used to assess the association of CBM (defined as brain metastasis present prior to or at the time of spinal SBRT) with potential covariates. The log-rank test and Cox proportional hazards regression were used to evaluate the impact of CBM on overall survival and local control from the time of the first course of spine SBRT.

Results: Seventy-eight patients and a total of 86 SBRT lesions were treated. Median patient age was 60 years (range: 38-84 years); 28.2% had radioresistant histologies. A single fraction was used in 91.0% of treatments. One-year local control was 89.4%, and one-year overall survival was 45.8%. A total of 19 patients (24.4%) had CBM. Among these CBM patients, 18 (94.7%) underwent intracranial radiosurgery and nine (47.4%) were diagnosed synchronously with their spine metastases. Local control was not significantly different between patients with or without CBM on univariable (median: 58 months vs. not reached, p = 0.53) or multivariable analyses (HR 0.52, 95% CI 0.06-4.33). Overall survival was also not significantly different between patients with or without CBM on univariable (median: 7 vs. 11 months, log-rank p = 0.12) or multivariable analyses (HR 1.62, 95% CI 0.87-3.03).

Conclusions: Patients with CBM do not appear to have a statistically significant detriment in clinical outcomes, suggesting that CBM should not necessarily be considered a contraindication for spine SBRT. Although our study is limited by significant heterogeneity in tumor type within our series, future work should focus on the development of reliable survival prognosticators for patients undergoing spinal radiosurgery. Nearly half of the patients with CBM were diagnosed synchronously with their spine metastases, emphasizing the usefulness of obtaining a brain MRI for complete staging prior to spine SBRT.

Incidence and relapse risk of intracranial metastases within the perihippocampal region in 314 patients with breast cancer

PURPOSE

The safe prerequisite of hippocampal-sparing whole brain radiotherapy (HS-WBRT) for patients with breast cancer is unclear. This study investigated the risk and relapse of perihippocampal (PH) metastases in breast cancer.

METHODS

Consecutive breast cancer patients with brain metastasis (BM) were reviewed. Metastases and hippocampi were contoured in cranial magnetic resonance imaging (MRI). The closest distance from metastasis to hippocampus was calculated. Clinical and radiographic variables were correlated with PH (in or within 5mm around the hippocampus) metastasis. The risk of post-treatment PH recurrence was estimated.

RESULTS

Three hundred and fourteen patients with 1678 metastases exhibited a median breast cancer-specific overall survival (OS) and OS after BM (BMOS) of 75.4 and 14.3 months, respectively. Hippocampal metastases were identified in 1.2% of metastases and 4.1% of patients. PH lesions comprised 3.5% of lesions in 11.1% of patients. The number and aggregated volume of BM were associated with PH disease probability (univariate). Only the number of BM significantly correlated with PH disease in the multivariate analysis. The patients with PH lesions exhibited more non-oligometastatic disease, increased tumor volume, and poor BMOS. One hundred and eleven patients without original PH lesions developed intracranial progression post-treatment. The risks of PH metastasis recurrence were 4.6% for WBRT and 6.8% for sub-therapeutic irradiation in the PH region. The increase in the absolute risk of PH recurrence with hippocampal-sparing irradiation was approximately 2%.

CONCLUSIONS

These novel findings indicate that BM from breast cancer exhibits low risks of metastases and relapse within the hippocampal avoidance region. Non-oligometastatic disease is associated with PH metastasis. Thus, HS-WBRT is considered safe and suitable for breast cancer.

Control of the blood-brain barrier function in cancer cell metastasis

Cerebral metastases are the most common brain neoplasms seen clinically in the adults and comprise more than half of all brain tumours. Actual treatment options for brain metastases that include surgical resection, radiotherapy and chemotherapy are rarely curative, although palliative treatment improves survival and life quality of patients carrying brain-metastatic tumours. Chemotherapy in particular has also shown limited or no activity in brain metastasis of most tumour types. Many chemotherapeutic agents used systemically do not cross the blood-brain barrier (BBB), whereas others may transiently weaken the BBB and allow extravasation of tumour cells from the circulation into the brain parenchyma. Increasing evidence points out that the interaction between the BBB and tumour cells plays a key role for implantation and growth of brain metastases in the central nervous system. The BBB, as the tightest endothelial barrier, prevents both early detection and treatment by creating a privileged microenvironment. Therefore, as observed in several in vivo studies, precise targetting the BBB by a specific transient opening of the structure making it permeable for therapeutic compounds, might potentially help to overcome this difficult clinical problem. Moreover, a better understanding of the molecular features of the BBB, its interrelation with metastatic tumour cells and the elucidation of cellular mechanisms responsible for establishing cerebral metastasis must be clearly outlined in order to promote treatment modalities that particularly involve chemotherapy. This in turn would substantially expand the survival and quality of life of patients with brain metastasis, and potentially increase the remission rate. Therefore, the focus of this review is to summarise the current knowledge on the role and function of the BBB in cancer metastasis.

In-line phase-contrast and grating-based phase-contrast synchrotron imaging study of brain micrometastasis of breast cancer

Current bio-medical imaging researches aim to detect brain micrometastasis in early stage for its increasing incidence and high mortality rates. Synchrotron phase-contrast imaging techniques, such as in-line phase-contrast (IPC) and grating-based phase-contrast (GPC) imaging, could provide a high spatial and density imaging study of biological specimens' 3D structures. In this study, we demonstrated the detection efficiencies of these two imaging tools on breast cancer micrometastasis in an ex vivo mouse brain. We found that both IPC and GPC can differentiate abnormal brain structures induced by micrometastasis from the surrounding normal tissues. We also found that GPC was more sensitive in detecting the small metastasis as compared to IPC.

A novel preclinical method to quantitatively evaluate early-stage metastatic events at the murine blood-brain barrier

The observation that approximately 15% of women with disseminated breast cancer will develop symptomatic brain metastases combined with treatment guidelines discouraging single-agent chemotherapeutic strategies facilitates the desire for novel strategies aimed at outright brain metastasis prevention. Effective and robust preclinical methods to evaluate early-stage metastatic processes, brain metastases burden, and overall mean survival are lacking. Here, we develop a novel method to quantitate early metastatic events (arresting and extravasation) in addition to traditional end time-point parameters such as tumor burden and survival in an experimental mouse model of brain metastases of breast cancer. Using this method, a reduced number of viable brain-seeking metastatic cells (from 3,331 ± 263 cells/brain to 1,079 ± 495 cells/brain) were arrested in brain one week postinjection after TGFβ knockdown. Treatment with a TGFβ receptor inhibitor, galunisertib, reduced the number of arrested cells in brain to 808 ± 82 cells/brain. Furthermore, we observed a reduction in the percentage of extravasated cells (from 63% to 30%) compared with cells remaining intralumenal when TGFβ is knocked down or inhibited with galunisertib (40%). The observed reduction of extravasated metastatic cells in brain translated to smaller and fewer brain metastases and resulted in prolonged mean survival (from 36 days to 62 days). This method opens up potentially new avenues of metastases prevention research by providing critical data important to early brain metastasis of breast cancer events.

Pharmacologic inhibition of MLK3 kinase activity blocks the in vitro migratory capacity of breast cancer cells but has no effect on breast cancer brain metastasis in a mouse xenograft model

Brain metastasis of breast cancer is an important clinical problem, with few therapeutic options and a poor prognosis. Recent data have implicated mixed lineage kinase 3 (MLK3) in controlling the in vitro migratory capacity of breast cancer cells, as well as the metastasis of MDA-MB-231 breast cancer cells from the mammary fat pad to distant lymph nodes in a mouse xenograft model. We therefore set out to test whether MLK3 plays a role in brain metastasis of breast cancer cells. To address this question, we used a novel, brain penetrant, MLK3 inhibitor, URMC099. URMC099 efficiently inhibited the migration of breast cancer cells in an in vitro cell monolayer wounding assay, and an in vitro transwell migration assay, but had no effect on in vitro cell growth. We also tested the effect of URMC099 on tumor formation in a mouse xenograft model of breast cancer brain metastasis. This analysis showed that URMC099 had no effect on the either the frequency or size of breast cancer brain metastases. We conclude that pharmacologic inhibition of MLK3 by URMC099 can reduce the in vitro migratory capacity of breast cancer cells, but that it has no effect on either the frequency or size of breast cancer brain metastases, in a mouse xenograft model.

Brain metastasis from gastrointestinal cancers: a systematic review

BACKGROUND

Brain metastases (BM) from the gastrointestinal tract (GIT) cancers are relatively rare. Despite those advances in diagnostic and treatment options, life expectancy and quality of life in these patients are still poor. In this review, we present an overview of the studies which have been previously performed as well as a comprehensive strategy for the assessment and treatment of BM from the GIT cancers.

METHOD

To obtain information on brain metastases from GIT, we performed a systematic review of Medline, EMBASE and the Cochrane Central Register of Controlled Trials (CENTRAL). The collected data included patient characteristics, primary tumor data and brain metastases data.

RESULT

In our search of the literature, we found 74 studies between 1980 and 2011, which included 2538 patients with brain metastases originated from gastrointestinal cancer. Analysis of available data showed that among 2538 patients who had brain metastases from GIT, a total of 116 patients (4.57%) had esophageal cancer, 148 patients (5.83%) had gastric cancer, 233 patients (9.18%) had liver cancer, 13 patients had pancreas cancer (0.52%) and 2028 patients (79.90%) had colorectal cancer. The total median age of the patients was 58.9 years.

CONCLUSION

Brain metastases have been considered the most common structural neurological complication of systemic cancer. Due to poor prognosis they influence the survival rate as well as the quality of life of the patients. The treatment of cerebral metastasis depends on the patients' situation and the decisions of the treating physicians. The early awareness of a probable metastasis from GI to the brain will have a great influence on treatment outcomes as well as the survival rate and the quality-of-life of the patients.

Novel treatments for melanoma brain metastases

BACKGROUND

The development of brain metastases is common in patients with melanoma and is associated with a poor prognosis. Treating patients with melanoma brain metastases (MBMs) is a major therapeutic challenge. Standard approaches with conventional chemotherapy are disappointing, while surgery and radiotherapy have improved outcomes.

METHODS

In this article, we discuss the biology of MBMs, briefly outline current treatment approaches, and emphasize novel and emerging therapies for MBMs.

RESULTS

The mechanisms that underlie the metastases of melanoma to the brain are unknown; therefore, it is necessary to identify pathways to target MBMs. Most patients with MBMs have short survival times. Recent use of immune-based and targeted therapies has changed the natural history of metastatic melanoma and may be effective for the treatment of patients with MBMs.

CONCLUSIONS

Developing a better understanding of the factors responsible for MBMs will lead to improved management of this disease. In addition, determining the optimal treatments for MBMs and how they can be optimized or combined with other therapies, along with appropriate patient selection, are challenges for the management of this disease.

Frequent genetic alterations in EGFR- and HER2-driven pathways in breast cancer brain metastases

Current standard systemic therapies for treating breast cancer patients with brain metastases are inefficient. Targeted therapies against human epidermal growth factor receptors are of clinical interest because of their alteration in a subset of breast cancers (BCs). We analyzed copy number, mutation status, and protein expression of epidermal growth factor receptor (EGFR), human epidermal growth factor 2 (HER2), phosphatase and tensin homologue (PTEN), and PI3K catalytic subunit (PIK3CA) in 110 ductal carcinoma in situ, primary tumor, and metastatic BC samples. Alterations in EGFR, HER2, and PTEN, alone or in combination, were found in a significantly larger fraction of breast cancer brain metastases tumor tissue compared with samples from primary tumors with good prognosis, bone relapse, or other distant metastases (all P < 0.05). Primary tumor patients with a subsequent brain relapse showed almost equally high frequencies of especially EGFR and PTEN alteration as the breast cancer brain metastases patients. PIK3CA was not associated with an increased risk of brain metastases. Genetic alterations in both EGFR and PTEN were especially common in triple-negative breast cancer patients and rarely were seen among HER2-positive patients. In conclusion, we identified two independent high-risk primary BC subgroups for developing brain metastases, represented by genetic alterations in either HER2 or EGFR/PTEN-driven pathways. In contrast, none of these pathways was associated with an increased risk of bone metastasis. These findings highlight the importance of both pathways as possible targets in the treatment of brain metastases in breast cancer.

The tumour is not enough or is it? Problems and new concepts in the surgery of cerebral metastases

Cerebral metastases are the most frequent cerebral tumours. Surgery of cerebral metastases plays an indispensible role in a multimodal therapy concept. Conventional white-light, microscopy assisted microsurgical and circumferential stripping of cerebral metastases is neurosurgical standard therapy, but is associated with an extraordinarily high recurrence rate of more than 50% without subsequent whole-brain radiotherapy. Therefore, neurosurgical standard therapy fails to achieve local tumour control in many patients. The present conceptual paper focuses on this issue and discusses the possible causes of the high recurrence rates such as intraoperative dissemination of tumour cells or the lack of sharp delimitation of metastases from the surrounding brain tissue resulting in incomplete resections. Adjuvant whole-brain radiotherapy reduces the risk of local and distant recurrences, but is associated with a well-documented impairment of neurocognitive function. New surgical strategies, such as supramarginal or fluorescence-guided resection, address the possibility of infiltrating tumour parts to achieve more complete resection of cerebral metastases. Supramarginal resection was shown to significantly reduce the risk of a local recurrence and prolongs two-year survival rates. Furthermore, radiosurgery in combination with surgery represents a promising approach.

The role of surgical resection in the management of brain metastasis: a 17-year longitudinal study

BACKGROUND

Advancements over the past generation have yielded several new treatment options for the management of brain metastases. However, surgical resection (SR) still remains the mainstay of treatment and is performed especially if decompression is required. The goal of this study was to evaluate the role of surgical resection for patients with brain metastases and to find the best indications for SR.

METHODS

SR as an initial treatment was performed in 157 patients. Among the 157 patients, 109 (69.4 %) and 17 (10.8 %) underwent adjuvant whole-brain radiotherapy and radiosurgery, respectively. Thirty-one (19.7 %) patients did not undergo adjuvant treatment. Overall survival, tumour recurrence, and clinical outcomes were evaluated. The clinical situation was classified based on the recursive partitioning analysis (RPA) class and Karnofsky performance scale (KPS).

RESULTS

The overall median survival was 19.3 months. Median survival according to the extent of surgical resection was 20.4 months after gross total resection (GTR) and 15.1 months after subtotal resection (STR) (P = 0.016). The patients with stable primary extracranial cancer survived longer than patients with synchronous detection of extracranial cancer (P = 0.032). The RPA I class patients showed longer survival than the RPA II class patients (P = 0.047). This difference was more prominent in the GTR group than in the STR group (GTR, P = 0.022; STR, P = 0.075). The KPS score of the GTR group changed from 82.3 to 87.0 and that of the STR group changed from 79.2 to 77.1 (P = 0.001). Adjuvant treatment did not lead to a significant improvement in the survival and clinical outcome.

CONCLUSIONS

Surgical resection may accomplish satisfactory outcomes with technical advancement. The best indications for SR for brain metastasis are RPA I class, stable extracranial cancer, and a planned GTR of the tumour. Even with the advancements in adjuvant therapy, surgical resection plays a major role in the management of brain metastasis.

Radiosensitization of brain metastasis by targeting c-MET

Radiotherapy is the most widely used therapeutic modality in brain metastasis; however, it only provides palliation due to inevitable tumor recurrence. Resistance of tumor cells to ionizing radiation is a major cause of treatment failure. A critical unmet need in oncology is to develop rationale driven approaches that can enhance the efficacy of radiotherapy against metastatic tumor. Utilizing in vivo orthotopic primary tumor and brain metastasis models that recapitulate clinical situation of the patients with metastatic breast cancer, we investigated a molecular mechanism through which metastatic tumor cells acquire resistance to radiation. Recent studies have demonstrated that the hepatocyte growth factor (HGF)-c-Met pathway is essential for the pathologic development and progression of many human cancers such as proliferation, invasion and resistance to anticancer therapies. In this study, c-Met signaling activity as well as total c-Met expression was significantly upregulated in both breast cancer cell lines irradiated in vitro and ex vivo radio-resistant cells derived from breast cancer brain metastatic xenografts. To interrogate the role of c-Met signaling in radioresistance of brain metastasis, we evaluated the effects on tumor cell viability, clonogenicity, sensitivity to radiation, and in vitro/in vivo tumor growth after targeting c-Met by small-hairpin RNA (shRNA) or small-molecule kinase inhibitor (PF-2341066). Although c-Met silencing or radiation alone demonstrated a modest decrease in clonogenic growth of parental breast cancers and brain metastatic derivatives, combination of two modalities showed synergistic antitumor effects resulting in significant prolongation of overall survival in tumor-bearing mice. Taken together, optimizing c-Met targeting in combination with radiation is critical to enhance the effectiveness of radiotherapy in the treatments of brain metastasis.

Predictive factors of brain metastasis in patients with breast cancer

The aim of this study is to determine the risk factors associated with metastasis to the brain of primary breast cancer patients and evaluate a predictive model. The clinicopathological characteristics of 206 patients with primary breast cancer were analyzed retrospectively with a univariate and multivariate logistic regression model. A predictive model was generated, and its validity evaluated with a receiver operating characteristic (ROC) curve. Independent risk factors for brain metastasis in patients with primary breast cancer were: being younger than 35 years old at the time of diagnosis, having four or more metastatic axillary nodes, being estrogen receptor-negative, and with 24 months of metastasis-free survival. The predictive value of the brain metastasis risk model, measured as the area under the ROC curve, was 0.765 ± 0.040 (95 % CI 0.688-0.842). When 0.8 was considered the cutoff point of probability calculated by the model, the sensitivity and specificity for predicting the occurrence of brain metastases in these patients were 0.769 and 0.713, respectively. The predictive model constructed in this study can be used to forecast brain metastasis in breast cancer. Patients with a predictive level ≥0.8 could be treated preventively for brain metastases.

Preclinical evaluation of oncolytic δγ(1)34.5 herpes simplex virus expressing interleukin-12 for therapy of breast cancer brain metastases

The metastasis of breast cancer to the brain and central nervous system (CNS) is a problem of increasing importance. As improving treatments continue to extend patient survival, the incidence of CNS metastases from breast cancer is on the rise. New treatments are needed, as current treatments are limited by deleterious side effects and are generally palliative. We have previously described an oncolytic herpes simplex virus (HSV), designated M002, which lacks both copies of the γ₁34.5 neurovirulence gene and carries a murine interleukin 12 (IL-12) expression cassette, and have validated its antitumor efficacy in a variety of preclinical models of primary brain tumors. However, M002 has not been yet evaluated for use against metastatic brain tumors. Here, we demonstrate the following: both human breast cancer and murine mammary carcinoma cells support viral replication and IL-12 expression from M002; M002 replicates in and destroys breast cancer cells from a variety of histological subtypes, including “triple-negative” and HER2 overexpressing; M002 improves survival in an immunocompetent model more effectively than does a non-cytokine control virus. Thus, we conclude from this proof-of-principle study that a γ₁34.5-deleted IL-12 expressing oncolytic HSV may be a potential new therapy for breast cancer brain metastases.

Management of brain metastasis: past lessons, modern management, and future considerations

Brain metastasis is a major challenge for patients, physicians, and the broader health care system, with approximately 170,000 new cases per year. After a diagnosis of brain metastasis, patients have a poor prognosis, but modern management has made significant advances in the past two decades to improve palliative efficacy and patient survival through a multidisciplinary approach. A number of factors must be taken into consideration in the treatment approach, including the number of intracranial lesions, the control of extracranial disease, and the patient's overall health, while weighing the benefits of treatment against the toxicities, both acute and chronic. With quality of life as an emphasis, emerging concepts for modern management of brain metastasis have sought to minimize long-term toxicities. The economic impact of such strategies for patients and the health care system has been demonstrated in some studies, but has not been a consistent area of focus. Each of these strategies, as well as novel therapeutics, has embraced the concept of personalized treatment. This review will discuss the current knowledge of modern multidisciplinary management of brain metastasis and look forward to emerging concepts.

Radiographic response of brain metastasis after linear accelerator radiosurgery

BACKGROUND

Radiographic response of brain metastasis to stereotactic radiosurgery (SRS) over time has not been well characterized. Being able to predict SRS-induced changes in tumor size over time may allow improved counseling of patients and potentially earlier recognition of poor response to SRS.

OBJECTIVE

To quantify the rate of change in size of metastatic brain tumors after treatment with a linear accelerator (LINAC) SRS.

METHODS

We performed a retrospective analysis of patients with single metastatic brain tumors treated with LINAC SRS at the University of Florida between 1992 and 2009 who had at least one MRI after treatment. A total of 218 patients with 406 follow-up MRI scans were included in the study. Tumor area was calculated by measuring the largest tumor area on axial imaging and using the equation for area of an ellipse. Primary outcome was percent change in tumor size. The contribution of several factors including gender, primary tumor histology, synchronous or asynchronous presentation, prior treatment, primary tumor control, and SRS dose were examined using multivariate analysis.

RESULTS

Mean patient age was 58.3 years (range 4-86), and 48.6% of patients were female. Sixty-three percent of patients had primary tumor control and 70.6% had asynchronous presentation of their brain metastases. SRS peripheral dose range was 1,000-2,250 cGy with a median of 1,750 cGy. The mean percent size change was -22.6% with a mean rate of change of -7.0% per month. The median percent change was -49.7% with a median rate of change of -8.8% per month. The median follow-up was 4.8 months (range 0.3-52.5). Female gender and melanoma histology were found to be significant predictors of an increase in tumor size. Lack of previous surgical resection was a significant predictor of a decrease in tumor size after SRS. Other factors tested with multivariate analysis, including age, synchronicity of presentation, dose, dose volume, Karnofsky performance score, and primary tumor control, were not significant in predicting tumor size change after SRS.

CONCLUSION

In this study, brain metastases decreased in size by a median of 50% for a median follow-up of 4.8 months after SRS. The overall rate of decrease was 9% per month after treatment with SRS. Melanoma histology was a predictor of poor tumor control.

Temozolomide and/or Erlotinib in the Treatment of Lung Cancer Patients With Progressive Central Nervous System Metastases

BACKGROUND

Patients with lung cancer who develop brain metastases have a poor prognosis. Those patients with progressive brain metastases tend to have a dismal prognosis. Currently, there is no standard of care for the treatment of these patients.

METHODS

In this manuscript, we present a retrospective evaluation of 10 patients treated at our institution with a combination of temozolomide and/or erlotinib after disease progression in the central nervous system following radiation therapy.

RESULTS

Median overall survival was 28 weeks. Median time to progression in the central nervous system was 14 weeks. Median time to progression systemically was 7.5 weeks. Some patients demonstrated prolonged stability of disease.

CONCLUSIONS

A palliative regimen of temozolomide and/or erlotinib could be considered in progressive central nervous system metastases from lung cancer.

Surgical management of brain metastases

In the past 20 years, surgical resection has found an established role in the management of metastatic brain tumors. Several factors, however, make strong evidence-based medicine impossible to provide for all possible patient presentations. These important factors, such as patient variables (eg, age, medical comorbidities, preoperative performance), tumor variables (eg, number, size, location, histology), and primary disease status must be taken into account on a case-by-case basis to guide patient selection and treatment strategy. Although progress has been made to answer some of the major questions in the management of metastatic brain tumors, several important questions remain. Future studies comparing surgery with stereotactic radiosurgery, for example, are needed to delineate patient selection, complications, and outcome for both of these important modalities.

Investigational therapies for brain metastases

Contrary to the incidence of primary cancers, the incidence of brain metastasis has been increasing. This increase is likely because of the effects of an aging population, improved neuroimaging surveillance, and better control of systemic cancer, allowing time for brain metastasis to occur. Unlike systemic cancers, for which chemotherapy is the mainstay of treatment, the therapeutic strategies available to treat brain metastasis have traditionally been limited to surgical resection, whole brain radiation therapy, or stereotactic radiosurgery, either individually or in combination. It is important to put the treatment in the context of the prognosis for patients with brain metastases.

Modern multidisciplinary management of brain metastases

Ideal management of brain metastases (BMs) requires simultaneous control of the existing brain metastasis (local brain control), prevention of future BMs (distant brain control), and control of the systemic cancer (systemic control). Available tools include whole brain radiation therapy (WBRT), surgery, stereotactic radiosurgery (SRS), and systemic therapies, such as chemotherapies, biologic agents, and radiosensitizing agents. Selecting the combination of these tools is highly individualized and is impacted by numerous factors involving the tumor, patient, provider, and evolving evidence. Historically, patients received WBRT, either alone or with local treatments (surgery or SRS). However, concern about the effects of WBRT, coupled with improvements in local control and survival in select patients, with the combination treatment, has led to a reconsideration of the role of WBRT. Additionally, there have been advancements in the efficacy and tolerance of systemic therapies and clarification regarding the relative risks and symptoms of tumor recurrence versus treatment complications. Thankfully, individualizing modern multidisciplinary management for patients with BMs is being aided by numerous recently completed, ongoing, and planned prospective series.

Immunohistochemical assessment of primary breast tumors and metachronous brain metastases, with particular regard to differences in the expression of biological markers and prognosis

In this study, we conducted an immunohistochemical analysis of primary breast tumors and metachronous brain metastases to compare the differences in the expression of biological markers between the two. Carcinoma tissues from primary breast tumors and metachronous brain metastases collected from 21 patients were examined immunohistochemically for the expression status of the estrogen receptor (ER), progesterone receptor (PgR), human epidermal growth factor receptor (HER)-2, Ki-67, bcl-2 and p53, and the results were compared. In addition, the relationships between the expression of these factors and prognosis were evaluated. There were no significant differences in the frequencies of ER-, PgR-, HER-2-, bcl-2- or p53-positivity between the primary breast tumors and metachronous brain metastases. While the Ki-67 labeling index (LI) was high in both the primary breast tumors and brain metastases, it was significantly higher in the brain metastases than in the corresponding primary breast tumors (P=0.003). With regard to the prognosis, breast cancer patients who showed ER-positivity in the primary tumors showed significantly longer survival after primary diagnosis (P=0.0076). Furthermore, breast cancer patients who exhibited ER-positivity, bcl-2-positivity or p53-negativity in the primary tumors showed significantly longer intervals from primary diagnosis to the detection of the brain metastases. Of all the markers, only the Ki-67 LI was significantly higher in the brain metastases than in the primary breast tumors. We confirmed that the tumor characteristics were worse in the metachronous brain metastases.

Computer-aided detection of metastatic brain tumors using automated three-dimensional template matching

PURPOSE

To demonstrate the efficacy of an automated three-dimensional (3D) template matching-based algorithm in detecting brain metastases on conventional MR scans and the potential of our algorithm to be developed into a computer-aided detection tool that will allow radiologists to maintain a high level of detection sensitivity while reducing image reading time.

MATERIALS AND METHODS

Spherical tumor appearance models were created to match the expected geometry of brain metastases while accounting for partial volume effects and offsets due to the cut of MRI sampling planes. A 3D normalized cross-correlation coefficient was calculated between the brain volume and spherical templates of varying radii using a fast frequency domain algorithm to identify likely positions of brain metastases.

RESULTS

Algorithm parameters were optimized on training datasets, and then data were collected on 22 patient datasets containing 79 total brain metastases producing a sensitivity of 89.9% with a false positive rate of 0.22 per image slice when restricted to the brain mass.

CONCLUSION

Study results demonstrate that the 3D template matching-based method can be an effective, fast, and accurate approach that could serve as a useful tool for assisting radiologists in providing earlier and more definitive diagnoses of metastases within the brain.

Brain metastasis of non-small cell lung cancer presenting as sensorineural hearing loss and vertigo

We report a case of lung cancer with multiple metastases to the brain and internal auditory canal. A 59-year-old man complained about persistent and progressive vertigo for 3 weeks with rapidly developing left-sided hearing loss and tinnitus. Bilateral intact eardrums and unsteady gait were noted on physical examination. There was no nystagmus. Pure tone audiometry showed left-sided sensorineural hearing loss. Magnetic resonance imaging of the brain revealed multiple intracranial tumors, including of the left-side internal auditory canal, which were interpreted as seeding of metastatic malignancy. Computed tomographic and bronchoscopic biopsy identified an asymptomatic primary pulmonary adenocarcinoma in the right upper lobe of the lungs. This was a rare case of asymptomatic primary pulmonary adenocarcinoma with brain metastases presenting with sudden hearing loss and vertigo.

Management of brain metastases: the indispensable role of surgery

Brain metastases are the most common neurological complication of systemic cancer and carry a very poor prognosis. The management of patients with brain metastases has become more important recently because of the increased incidence of these tumors and the prolonged patient survival times that have accompanied increased control of systemic cancer. In this article, we review the current perspectives on surgical treatment of brain metastases in terms of patient selection criteria, intraoperative adjuncts, whole-brain radiation therapy (WBRT) as a postoperative adjuvant, reoperation for tumor recurrence, and resection of multiple and single metastases. Achieving the best outcome in treatment of brain metastasis requires the judicious and complementary use of surgical resection along with modalities such as whole-brain radiation therapy and stereotactic radiosurgery.

Sagopilone crosses the blood-brain barrier in vivo to inhibit brain tumor growth and metastases

The aim of this study was to determine the efficacy of sagopilone (ZK-EPO), a novel epothilone, compared with other anticancer agents in orthotopic models of human primary and secondary brain tumors. Autoradiography and pharmacokinetic analyses were performed on rats and mice to determine passage across the blood-brain barrier and organ distribution of sagopilone. Mice bearing intracerebral human tumors (U373 or U87 glioblastoma, MDA-MB-435 melanoma, or patient-derived non-small-cell lung cancer [NSCLC]) were treated with sagopilone 5-10 mg/kg, paclitaxel 8-12.5 mg/kg (or temozolomide, 100 mg/kg) or control (vehicle only). Tumor volume was measured to assess antitumor activity. Sagopilone crossed the blood-brain barrier in both rat and mouse models, leading to therapeutically relevant concentrations in the brain with a long half-life. Sagopilone exhibited significant antitumor activity in both the U373 and U87 models of human glioblastoma, while paclitaxel showed a limited effect in the U373 model. Sagopilone significantly inhibited the growth of tumors from CNS metastasis models (MDA-MB-435 melanoma and patient-derived Lu7187 and Lu7466 NSCLC) implanted in the brains of nude mice, in contrast to paclitaxel or temozolomide. Sagopilone has free access to the brain. Sagopilone demonstrated significant antitumor activity in orthotopic models of both glioblastoma and CNS metastases compared with paclitaxel or temozolomide, underlining the value of further research evaluating sagopilone in the treatment of brain tumors. Sagopilone is currently being investigated in a broad phase II clinical trial program, including patients with glioblastoma, NSCLC, breast cancer, and melanoma.

Central nervous system metastases in a cohort of metastatic breast cancer patients treated with trastuzumab

BACKGROUND

Several analyses suggest an increase of brain metastases in HER2 over-expressing breast cancers treated with trastuzumab as compared to historical series of unselected patients.

PATIENTS AND METHODS

We analyzed the incidence of central nervous system (CNS) metastases in 78 patients with HER2 over-expressing breast cancer treated with trastuzumab between July 2000 and June 2006 at the Oncology Department of University Federico II in Naples. We also characterized and compared patients with and without CNS involvement.

RESULTS

The median follow-up was 35.3 months (95%CI 26.3-44); median overall survival was 56 months (95%CIs 46-nr); 5 patients showed CNS involvement before trastuzumab therapy while 31 developed CNS metastases during trastuzumab treatment. The median overall survival after CNS metastases was 25.4 months (95%CIs 15.2-nr); patients with CNS lesions showed worse overall survival than patients without CNS lesions (39.1 vs. 75 months, p = 0.005).

CONCLUSION

CNS metastases are common events in patients with metastatic HER2 over-expressing breast cancer treated with trastuzumab; the impact on survival is detrimental even if survival after CNS metastases is longer than historical reports. Appropriate investigation of the role of CNS imaging screening and the prophylactic treatment strategies for CNS represents a priority research in this setting.

Cellular and in vivo activity of JNJ-28871063, a nonquinazoline pan-ErbB kinase inhibitor that crosses the blood-brain barrier and displays efficacy against intracranial tumors

JNJ-28871063 is a potent and highly selective pan-ErbB kinase inhibitor from a novel aminopyrimidine oxime structural class that blocks the proliferation of epidermal growth factor receptor (EGFR; ErbB1)- and ErbB2-overexpressing cells but does not affect the growth of non-ErbB-overexpressing cells. Treatment of human cancer cells with JNJ-28871063 inhibited phosphorylation of functionally important tyrosine residues in both EGFR and ErbB2 and blocked downstream signal transduction pathways responsible for proliferation and survival. A single dose of compound reduced phosphorylation of ErbB2 receptors in tumor-bearing mice, demonstrating target suppression in vivo. Tissue distribution studies show that JNJ-28871063 crosses the blood-brain barrier and penetrates into tumors, where it is able to accumulate to higher levels than those found in the plasma. JNJ-28871063 showed oral antitumor activity in human tumor xenograft models that overexpress EGFR and ErbB2. In an intracranial ErbB2-overexpressing tumor model, JNJ-28871063 extended survival relative to untreated animals. The brain is a primary site of metastasis for EGFR-overexpressing lung cancers and ErbB2-overexpressing breast cancers. Therefore, the ability to penetrate into the brain could be an advantage over existing therapies such as trastuzumab (Herceptin) and cetuximab (Erbitux), which are antibodies and do not cross the blood-brain barrier. These results show that JNJ-28871063 is orally bioavailable, has activity against EGFR and ErbB2-dependent tumor xenografts, and can penetrate into the brain and inhibit ErbB2-overexpressing tumor growth.

Breast cancer brain metastases

Breast cancer is the most common malignancy in woman in the USA. Metastasis is a major cause of morbidity and mortality in breast cancer patients. Total incidence of brain metastases of breast cancer is about 30%. Because of the improvements in control of systemic disease, for example the successful use of Trastuzumab, and the consequent prolonged life span, the incidence of brain metastases is increasing in breast cancer patients. The progressive neurological disabilities not only impair the quality of life, but also decrease the survival in patients. However, current treatments are of limited effectiveness. This is partially caused by the unique structure of the blood brain barrier. So far very little is known about the mechanisms how breast cancer metastizes to the brain. Some studies showed that ErbB2 overexpression is associated with the brain metastatic phenotype. Other molecules, like vascular endothelial growth factor (VEGF), matrix metalloproteinases (MMPs) and chemokine receptor CXCR4 are also involved in the metastasis of breast cancer cell to the brain. The current review will briefly overview the clinical features of brain metastasis of breast cancer and discusses the relationship of blood brain barrier and ErbB2 signal pathway to brain metastasis in breast cancer.