Systemic therapy of brain metastases: non-small cell lung cancer, breast cancer, and melanoma

Involvement of platelet-derived VWF in metastatic growth of melanoma in the brain

Background

The prognosis of patients with brain metastases (BM) is poor despite advances in our understanding of the underlying pathophysiology. The high incidence of thrombotic complications defines tumor progression and the high mortality rate. We, therefore, postulated that von Willebrand factor (VWF) promotes BM via its ability to induce platelet aggregation and thrombosis.

Methods

We measured the abundance of VWF in the blood and intravascular platelet aggregates of patients with BM, and determined the specific contribution of endothelial and platelet-derived VWF using in vitro models and microfluidics. The relevance for the brain metastatic cascade in vivo was demonstrated in ret transgenic mice, which spontaneously develop BM, and by the intracardiac injection of melanoma cells.

Results

Higher levels of plasma VWF in patients with BM were associated with enhanced intraluminal VWF fiber formation and platelet aggregation in the metastatic tissue and peritumoral regions. Platelet activation triggered the formation of VWF multimers, promoting platelet aggregation and activation, in turn enhancing tumor invasiveness. The absence of VWF in platelets, or the blocking of platelet activation, abolished platelet aggregation, and reduced tumor cell transmigration. Anticoagulation and platelet inhibition consistently reduced the number of BM in preclinical animal models.

Conclusions

Our data indicate that platelet-derived VWF is involved in cerebral clot formation and in metastatic growth of melanoma in the brain. Targeting platelet activation with low-molecular-weight heparins represents a promising therapeutic approach to prevent melanoma BM.

A Retrospective Study of Intrathecal Pemetrexed Combined With Systemic Therapy for Leptomeningeal Metastasis of Lung Cancer

Objective This retrospective study aimed to investigate the clinical features of lung cancer patients with leptomeningeal metastasis (LM) and explore the clinical efficacy and tolerance of intrathecal pemetrexed (IP) combined with systemic antitumor therapy. Methods Thirty-four lung cancer patients (11 men, 23 women) with LM receiving IP at our hospital were retrospectively reviewed between August 2018 and December 2019. Identified cases showed either positive cerebrospinal fluid cytology or typical findings (leptomeningeal enhancement or ventricle broadening) upon imaging examination. Results Before the diagnosis of LM, 24 (70.6%) patients received EGFR-TKI therapy with or without other agents (antivascular therapy, or chemotherapy), 5 (14.7%) patients received chemotherapy, 1 (2.9%) patient received antivascular therapy, and 3 (8.8%) patients received ALK inhibitors. Fourteen (41.2%) patients did not change the systematic regimen at the beginning of IP, while 20 (58.8%) patients changed to antitumor agents. IP was administered for a median of 3 times (range, 1-12 times). The IP dose was 15, 20, 25, 30, and 40 mg in 8 (23.5%), 21 (58.8%), 2 (5.9%), 2 (5.9%), and 1 (5.9%) patient, respectively. In all IP dose levels, the major adverse events were myelosuppression and elevation of hepatic aminotransferases (EHA). Grade 1/2 myelosuppression occurred in 4 (11.8%) patients. Grade 1/2 EHA also occurred in 4 (11.8%) patients. Grades 3/4 adverse events were not observed. After IP and systematic therapy, the clinical manifestations related to LM in 26 (76.5%) patients improved. In the whole cohort, the median overall survival was 20 months. The median time from the initial IP administration until death or the last follow-up was 3.5 months. Conclusions IP showed controllable toxicity and good efficacy, prolonged the survival time, and improved the quality of life when combined with tailored systemic antitumor therapy in lung cancer patients.

Brain penetration and efficacy of tepotinib in orthotopic patient-derived xenograft models of MET-driven non-small cell lung cancer brain metastases

Central nervous system-penetrant therapies with intracranial efficacy against non-small cell lung cancer (NSCLC) brain metastases are urgently needed. We report preclinical studies investigating brain penetration and intracranial activity of the MET inhibitor tepotinib. After intravenous infusion of tepotinib in Wistar rats (n = 3), mean (±standard deviation) total tepotinib concentration was 2.87-fold higher in brain (505 ± 22 ng/g) than plasma (177 ± 20 ng/mL). In equilibrium dialysis experiments performed in triplicate, mean tepotinib unbound fraction was 0.35% at 0.3 and 3.0 µM tepotinib in rat brain tissue, and 4.0% at 0.3 and 1.0 µM tepotinib in rat plasma. The calculated unbound brain-to-plasma ratio was 0.25, indicating brain penetration sufficient for intracranial target inhibition. Of 20 screened subcutaneous patient-derived xenograft (PDX) models from lung cancer brain metastases (n = 1), two NSCLC brain metastases models (LU5349 and LU5406) were sensitive to the suboptimal dose of tepotinib of 30 mg/kg/qd (tumor volume change [%TV]: -12% and -88%, respectively). Molecular profiling (nCounter®; NanoString) revealed high-level MET amplification in both tumors (mean MET gene copy number: 11.2 and 24.2, respectively). Tepotinib sensitivity was confirmed for both subcutaneous models at a clinically relevant dose (125 mg/kg/qd; n = 5). LU5349 and LU5406 were orthotopically implanted into brains of mice and monitored by magnetic resonance imaging (MRI). Tepotinib 125 mg/kg/qd induced pronounced tumor regression, including complete or near-complete regressions, compared with vehicle in both orthotopic models (n = 10; median %TV: LU5349, -84%; LU5406, -63%). Intracranial antitumor activity of tepotinib did not appear to correlate with blood-brain barrier leakiness assessed in T1-weighted gadolinium contrast-enhanced MRI.

Harnessing nanomedicine for enhanced immunotherapy for breast cancer brain metastases

Brain metastases (BMs) are the most common type of brain tumor, and the incidence among breast cancer (BC) patients has been steadily increasing over the past two decades. Indeed, ~ 30% of all patients with metastatic BC will develop BMs, and due to few effective treatments, many will succumb to the disease within a year. Historically, patients with BMs have been largely excluded from clinical trials investigating systemic therapies including immunotherapies (ITs) due to limited brain penetration of systemically administered drugs combined with previous assumptions that BMs are poorly immunogenic. It is now understood that the central nervous system (CNS) is an immunologically distinct site and there is increasing evidence that enhancing immune responses to BCBMs will improve patient outcomes and the efficacy of current treatment regimens. Progress in IT for BCBMs, however, has been slow due to several intrinsic limitations to drug delivery within the brain, substantial safety concerns, and few known targets for BCBM IT. Emerging studies demonstrate that nanomedicine may be a powerful approach to overcome such limitations, and has the potential to greatly improve IT strategies for BMs specifically. This review summarizes the evidence for IT as an effective strategy for BCBM treatment and focuses on the nanotherapeutic strategies currently being explored for BCBMs including targeting the blood-brain/tumor barrier (BBB/BTB), tumor cells, and tumor-supporting immune cells for concentrated drug release within BCBMs, as well as use of nanoparticles (NPs) for delivering immunomodulatory agents, for inducing immunogenic cell death, or for potentiating anti-tumor T cell responses.

Factors Associated with Cranial Nerve Injury after Radiotherapy for Large Brain Metastases

This paper mainly studied the correlation factors of cranial nerve injury after radiotherapy for large brain metastases by investigating the influencing factors and predictors of cranial nerve injury, which can provide a good reference and idea for radiotherapy. Through a large number of experiments, it is proved that the research idea proposed in this paper is reasonable and correct.

Mutational profiles of primary pulmonary adenocarcinoma and paired brain metastases disclose the importance of KRAS mutations

BACKGROUND

Brain metastases present a significant complication in lung cancer with an unmet therapeutic need.

METHODS

In this single-centre, retrospective study, we genotyped a clinico-pathologically well-annotated cohort of consecutively resected brain metastases of lung adenocarcinomas and paired primary tumours, diagnosed from 2000 to 2015, using the Ion Torrent Oncomine Comprehensive Cancer Panel v3.

RESULTS

Among 444 consecutive brain metastases, 210 (49%) originated from lung cancer. Analysis was successful in 111 samples, including 54 pairs of brain metastasis and primary tumour. Most driver alterations were preserved in brain metastases. Private alterations exclusive to primary tumours, brain metastases or both sites (intersecting cases) were present in 22%, 26% and 26% of cases, respectively. Seven percent had no shared mutations. KRAS mutations were more frequent in primary tumours metastasised to the brain (32/55, 58%) compared to TCGA (33%, p < 0.005) and own data from routine diagnostics, independent from clinical or pathological characteristics. Fourteen cases showed alterations in the EGFR signalling pathway including additional KRAS alterations that were private to brain metastases. KRAS G12C was detected most frequently (26% of patients) and KRAS G12C and G13C variants were significantly enriched in brain metastases. Synchronous and metachronous cases had a similar mutation profile.

CONCLUSIONS

Our results suggest an important role of KRAS alterations in the pathobiology of brain metastases from lung adenocarcinomas. This has direct therapeutic implications as inhibitors selectively targeting KRAS G12C are entering the clinics.

Unique Genomic Alterations of Cerebrospinal Fluid Cell-Free DNA Are Critical for Targeted Therapy of Non-Small Cell Lung Cancer With Leptomeningeal Metastasis

We reported unique molecular features of cerebrospinal fluid (CSF) of nonsmall cell lung cancer (NSCLC) patients with leptomeningeal metastasis (LM), suggesting establishing CSF as a better liquid biopsy in clinical practices. We performed next-generation panel sequencing of primary tumor tissue, plasma, and CSF from 131 NSCLC patients with LM and observed high somatic copy number variations (CNV) in CSF of NSCLC patients with LM. The status of EGFR-activating mutations was highly concordant between CSF, plasma, and primary tumors. ALK translocation was detected in 8.3% of tumor tissues but only 2.4% in CSF and 2.7% in plasma. Others such as ROS1 rearrangement, RET fusion, HER2 mutation, NTRK1 fusion, and BRAF V600E mutation were detected in 7.9% of CSF and 11.1% of tumor tissues but only 4% in plasma. Our study has shed light on the unique genomic variations of CSF and demonstrated that CSF might represent better liquid biopsy for NSCLC patients with LM.

Optimization of treatment isocenter location in single-isocenter LINAC-based stereotactic radiosurgery for management of multiple brain metastases

PURPOSE

Single-isocenter linear accelerator (LINAC)-based stereotactic radiosurgery (SRS) has become a promising treatment technique for the management of multiple brain metastases. Because of the high prescription dose and steep dose gradient, SRS plans are sensitive to geometric errors, resulting in loss of target coverage and suboptimal local tumor control. Current planning techniques rely on adding a uniform and isotropic setup margin to all gross tumor volumes (GTVs) to account for rotational uncertainties. However, this setup margin may be insufficient, since the magnitude of rotational uncertainties varies and is dependent upon the distance between a GTV and the isocenter. In this study, we designed a framework to determine the optimal isocenter of a single-isocenter SRS plan for multiple brain metastases using stochastic optimization to mitigate potential errors resulting from rotational uncertainties.

METHODS

Planning target volumes (PTVs), defined as GTVs plus a 1-mm margin following common SRS planning convention, were assumed to be originally treated with a prescription dose and therefore covered by the prescription isodose cloud. The dose distribution, including the prescription isodose, was considered invariant assuming small rotations throughout the study. A stochastic optimization scheme was developed to determine the location of the optimal isocenter, so that the prescription dose coverage of rotated GTVs, equivalent to the intersecting volumes between the rotated GTVs and original PTVs, was maximized for any random small rotations about the isocenter. To evaluate the coverage of GTVs, the expected V 100 % undergoing random rotations was approximated as the sample average V 100 % undergoing a predetermined number of rotations. The expected V 100 % of each individual GTV and total GTVs was then compared between the plans using the optimal isocenter and the center-of-mass (CoM), respectively.

RESULTS

Twenty-two patients previously treated for multiple brain metastases in a single institute were included in this retrospective study. Each patient was initially treated for more than three brain metastases (mean: 7.6; range: 3-15) with the average GTV volume of 0.89 cc (range: 0.03-11.78 cc). The optimal isocenter found for each patient was significantly different from the CoM, with the average Euclidean distance between the optimal isocenter and the CoM being 4.36 ± 2.59 cm. The dose coverage to GTVs was also significantly improved (paired t-test; p < 0.001) when the optimal isocenter was used, with the average V 100 % of total GTVs increasing from 87.1% (standard deviation as std: 11.7%; range: 39.9-98.2%) to 94.2% (std: 5.4%; range: 77.7-99.4%). The volume of a GTV was positively correlated with the expected V 100 % regardless of the isocenter used (Spearman coefficient: ρ = 0.66 ; p < 0.001). The distance between a GTV and the isocenter was negatively correlated with the expected V 100 % when the CoM was used ( ρ = - 0.21 ; p = 0.004), however no significant correlation was found when the optimal isocenter was used ( ρ = - 0.11 ; p = 0.137).

CONCLUSION

The proposed framework provides an effective approach to determine the optimal isocenter of single-isocenter LINAC-based SRS plans for multiple brain metastases. The implementation of the optimal isocenter results in SRS plans with consistently higher target coverage despite potential rotational uncertainties, and therefore significantly improves SRS plan robustness against random rotational uncertainties.

Experimental Study of Almonertinib Crossing the Blood-Brain Barrier in EGFR-Mutant NSCLC Brain Metastasis and Spinal Cord Metastasis Models

Roughly one third of non-small cell lung cancer (NSCLC) patients with epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI)-sensitive mutated (EGFRm) tumors experience disease progression through central nervous system (CNS) metastases during treatment. Although EGFR-TKIs have been reported to be favored in some patients with EGFRm NSCLC CNS metastases, novel EGFR-TKIs with proven efficacy in CNS pathologies are clinically needed.To investigate whether almonertinib, a novel third-generation EGFR-TKI for NSCLC, can cross the blood-brain barrier (BBB) and deliver treatment for EGFR-mutant NSCLC brain metastases and spinal cord metastases, we constructed NSCLC brain metastasis and spinal cord metastasis models in vivo to observe the anti-tumor effects of almonertinib. Using ABCB1-MDCK and BCRP-MDCK monolayer cells as the in vitro study model, the effects of transport time and drug concentration on the apparent permeability coefficient of almonertinib and its active metabolite, HAS-719, were investigated. The results of this study show that almonertinib can significantly inhibit PC9 brain and spinal cord metastases. Pharmacokinetic studies in mice revealed that almonertinib has good BBB penetration ability, whereas the metabolite HAS-719 does not easily penetrate the BBB. Early clinical evidence of almonertinib activity in patients with EGFRm-advanced NSCLC and brain metastases has also been reported. In conclusion, almonertinib easily penetrates the BBB and inhibits advanced NSCLC brain and spinal cord metastases.

Whole-Brain Radiotherapy vs. Localized Radiotherapy after Resection of Brain Metastases in the Era of Targeted Therapy: A Retrospective Study

Simple Summary

The paradigm shift from cytotoxic chemotherapy to molecular targeted therapy dramatically improved the survival and quality of life of cancer patients. In radio-oncological aspects, there also was a paradigm shift from whole-brain radiotherapy to localized radiotherapy including stereotactic radiosurgery. This retrospective study analyzed 124 consecutive patients who had undergone surgical resection of brain metastases. We found targeted therapies to improve overall survival and distant control with decreased incidence of leptomeningeal metastasis. Our data suggest that localized radiotherapy is sufficient after resection of brain metastases when systemic targeted therapy is available.

Abstract

Whether targeted therapy (TT) and radiotherapy impact survival after resection of brain metastases (BM) is unknown. The purpose of this study was to analyze the factors affecting overall survival (OS), local control (LC), distant control (DC), and leptomeningeal metastases (LMM) in patients who had undergone resection of BM. We retrospectively analyzed 124 consecutive patients who had undergone resection of BM between 2004 and 2020. Patient information about age, sex, Karnofsky Performance Scale (KPS), origin of cancer, synchronicity, tumor size, status of primary cancer, use of TT, extent of resection, and postoperative radiotherapy was collected. Radiation therapy was categorized into whole-brain radiotherapy (WBRT), localized radiotherapy (local brain radiotherapy or stereotactic radiosurgery (LBRT/SRS)), and no radiation. We identified factors that affect OS, LC, DC, and LMM. In multivariable analysis, significant factors for OS were higher KPS score (≥90) (HR 0.53, p = 0.011), use of TT (HR 0.43, p = 0.001), controlled primary disease (HR 0.63, p = 0.047), and single BM (HR 0.55, p = 0.016). Significant factors for LC were gross total resection (HR 0.29, p = 0.014) and origin of cancer (p = 0.041). Both WBRT and LBRT/SRS showed superior LC than no radiation (HR 0.32, p = 0.034 and HR 0.38, p = 0.018, respectively). Significant factors for DC were use of TT (HR 0.54, p = 0.022) and single BM (HR 0.47, p = 0.004). Reduced incidence of LMM was associated with use of TT (HR 0.42, p = 0.038), synchronicity (HR 0.25, p = 0.028), and controlled primary cancer (HR 0.44, p = 0.047). TT was associated with prolonged OS, improved DC, and reduced LMM in resected BM patients. WBRT and LBRT/SRS showed similar benefits on LC. Considering the extended survival of cancer patients and the long-term effect of WBRT on cognitive function, LBRT/SRS appears to be a good option after resection of BM.

CD74 and CD44 Expression on CTCs in Cancer Patients with Brain Metastasis

Up to 40% of advance lung, melanoma and breast cancer patients suffer from brain metastases (BM) with increasing incidence. Here, we assessed whether circulating tumor cells (CTCs) in peripheral blood can serve as a disease surrogate, focusing on CD44 and CD74 expression as prognostic markers for BM. We show that a size-based microfluidic approach in combination with a semi-automated cell recognition system are well suited for CTC detection in BM patients and allow further characterization of tumor cells potentially derived from BM. CTCs were found in 50% (7/14) of breast cancer, 50% (9/18) of non-small cell lung cancer (NSCLC) and 36% (4/11) of melanoma patients. The next-generation sequencing (NGS) analysis of nine single CTCs from one breast cancer patient revealed three different CNV profile groups as well as a resistance causing ERS1 mutation. CD44 and CD74 were expressed on most CTCs and their expression was strongly correlated, whereas matched breast cancer BM tissues were much less frequently expressing CD44 and CD74 (negative in 46% and 54%, respectively). Thus, plasticity of CD44 and CD74 expression during trafficking of CTCs in the circulation might be the result of adaptation strategies.

Brain Metastases in HER2-Positive Breast Cancer: Current and Novel Treatment Strategies

Development of brain metastases can occur in up to 30-50% of patients with breast cancer, representing a significant impact on an individual patient in terms of survival and quality of life. Patients with HER2-positive breast cancer have an increased risk of developing brain metastases; however, screening for brain metastases is not currently recommended due to the lack of robust evidence to support survival benefit. In recent years, several novel anti-HER2 agents have led to significant improvements in the outcomes of HER2-positive metastatic breast cancer. Despite these advances, brain and leptomeningeal metastases from HER2-positive breast cancer remain a significant cause of morbidity and mortality, and their optimal management remains an unmet need. This review presents an update on the current and novel treatment strategies for patients with brain metastases from HER2-positive breast cancer and discusses the open questions in the field.

Primary Analysis and 4-Year Follow-Up of the Phase III NIBIT-M2 Trial in Melanoma Patients With Brain Metastases

PURPOSE

Phase II trials have shown encouraging activity with ipilimumab plus fotemustine and ipilimumab plus nivolumab in melanoma brain metastases. We report the primary analysis and 4-year follow-up of the NIBIT-M2 study, the first phase III trial comparing these regimens with fotemustine in patients with melanoma with brain metastases.

PATIENTS AND METHODS

This phase III study recruited patients 18 years of age and older with BRAF wild-type or mutant melanoma, and active, untreated, asymptomatic brain metastases from nine centers, randomized (1:1:1) to fotemustine, ipilimumab plus fotemustine, or ipilimumab plus nivolumab. The primary endpoint was overall survival (OS).

RESULTS

From January, 2013 to September, 2018, 27, 26, and 27 patients received fotemustine, ipilimumab plus fotemustine, and ipilimumab plus nivolumab. Median OS was 8.5 months [95% confidence interval (CI), 4.8-12.2] in the fotemustine arm, 8.2 months (95% CI, 2.2-14.3) in the ipilimumab plus fotemustine arm (HR vs. fotemustine, 1.09; 95% CI, 0.59-1.99; P = 0.78), and 29.2 months (95% CI, 0-65.1) in the ipilimumab plus nivolumab arm (HR vs. fotemustine, 0.44; 95% CI, 0.22-0.87; P = 0.017). Four-year survival rate was significantly higher for ipilimumab plus nivolumab than fotemustine [(41.0%; 95% CI, 20.6-61.4) vs. 10.9% (95% CI, 0-24.4; P = 0.015)], and was 10.3% (95% CI, 0-22.6) for ipilimumab plus fotemustine. In the fotemustine, ipilimumab plus fotemustine, and ipilimumab plus nivolumab arms, respectively, 11 (48%), 18 (69%), and eight (30%) patients had treatment-related grade 3 or 4 adverse events, without treatment-related deaths.

CONCLUSIONS

Compared with fotemustine, ipilimumab plus nivolumab significantly improved overall and long-term survival of patients with melanoma with asymptomatic brain metastases.

Eribulin in brain metastases of breast cancer: outcomes of the EBRAIM prospective observational trial

Background: Eribulin shows some activity in controlling brain metastasis in breast cancer. Methods: This observational, multicenter study evaluated brain disease control rates, survival and safety in patients with brain metastatic breast cancer treated with eribulin in clinical practice. Results: A total of 34 patients were enrolled (mean age 49 years, 91% with visceral metastases) and 29 were evaluable for brain disease. Fourteen achieved disease control and showed a longer time without progression: 10 months (95% CI: 2.3-17.7) versus 4 months (95% CI: 3.3-4.7) in the control group (p = 0.029). Patients with clinical benefits at 6 months had longer survival. Leukopenia and neutropenia were the most frequent grade 3-4 toxicities. Conclusion: Eribulin confirms its effectiveness in patients with brain metastatic breast cancer. Further studies on larger cohorts are needed to confirm the results.

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

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

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.

Fractionated Stereotactic Radiation Therapy Using Volumetric Modulated Arc Therapy in Patients with Solitary Brain Metastases

Purpose

To analyze retrospectively the clinical efficacy and safety for patients treated with fractionated stereotactic radiation therapy (FSRT) using volumetric modulated arc therapy.

Methods

Between 2016 and 2017, 46 patients with solitary brain metastasis who underwent FSRT consisting of 25-40 Gy/5 fractions were recruited in this study. All targets within the same course received different prescriptions according to size. Toxicities were graded according to the Common Terminology Criteria for Adverse Events version 4.0.

Results

The median follow-up was 11 months (3-53 months). The 6-month and 12-month local control rate calculated by Kaplan-Meier estimate was, respectively, 95% and 86%. Tumor diameter < 2.5 cm obtained 100% improved 12-month local control rate compared with 66% in those with ≥2.5 cm (P < 0.001). The 12-month local control calculated by Kaplan-Meier estimate was 95% in tumors with >30 Gy treatment and only 60% in tumors with ≤30 Gy treatment (P = 0.001). Multivariate analysis revealed that the prescription dose ≤ 30 Gy resulted in increased local failure (hazard ratio (HR), 0.14 (range, 0.019-0.95; P = .046)). Grade 3 or worse toxic effects were found in 5 (11%) patients, and no patient experienced surgical resection for symptomatic radioactive necrosis.

Conclusions

FSRT for solid brain metastasis appears to have the advantages of a high rate of local control with a minimal risk of severe toxicity and deserves application in the clinical practice.

Bile acids as novel enhancers of CNS targeting antitumor drugs: a comprehensive review

Despite a relatively low prevalence of primary brain tumors, they continuously attract scientific interest because of the complexity of their treatment due to their location behind the blood-brain barrier. The main challenge in treatment of brain tumors is not the efficacy of the drugs, per se, but the low efficiency of drug delivery to malignant cells. At the core of the problem is the complex structure of the blood-brain barrier. Nowadays, there is evidence supporting the claim that bile acids have the ability to cross the blood-brain barrier. That ability can be exploited by taking a part in novel drug carrier designs. Bile acids represent a drug carrier system as a part of a mixed micelle composition, bilosomes and conjugates with various drugs. This review discusses the current knowledge related to bile acid molecules as drug penetration modifying agents, with the focus on central nervous system antitumor drug delivery.

Micropapillary Predominance Is a Risk Factor for Brain Metastasis in Resected Lung Adenocarcinoma

BACKGROUND

Histologic subtyping offers some prognostic value in lung adenocarcinoma. We thus hypothesized that histologic subtypes may be useful for risk stratification of brain metastasis (BM). In this study, we aimed to investigate the impact of histologic subtypes on the risk for BM in patients with resected lung adenocarcinoma.

PATIENTS AND METHODS

Of 1099 consecutive patients who had undergone curative-intent surgery (2000-2014), 448 patients who had undergone complete resection for lung adenocarcinoma were included in this study. Correlated clinical variables and BM-free survival were analyzed.

RESULTS

Micropapillary predominance was significantly associated with higher risk of BM after complete resection in univariate analyses (P < .001). In addition, multivariate analyses showed that micropapillary predominance was an independent risk factor for BM (hazard ratio = 2.727; 95% confidence interval, 1.260-5.900; P = .011), along with younger age and advanced pathologic stage. Unlike the other subtypes, an increase in the percentage of the micropapillary subtype was positively correlated with an increase in BM frequency. Patients with micropapillary adenocarcinoma showed significantly poorer brain metastasis-free survival compared with those with non-micropapillary adenocarcinoma (3 years, 78.2% vs. 95.6%; 5 years, 67.3% vs. 94.3%; P < .001).

CONCLUSION

The current study demonstrated a significant correlation between micropapillary subtype and higher risk of BM in patients with resected lung adenocarcinoma. This routine histologic evaluation of resected adenocarcinoma may provide useful information for the clinician when considering postoperative management in patients with lung adenocarcinoma. Histologic subtyping offer some prognostic value in lung adenocarcinoma. Because brain metastasis is critical and often refractory to systemic chemotherapy, early detection is clinically important to achieve effective local treatment. We retrospectively analyzed the association between histologic subtypes and occurrence of brain metastasis and found a significant association between micropapillary predominance and higher risk for brain metastasis. Our findings may be relevant when considering postoperative management.

ALCAM contributes to brain metastasis formation in non-small-cell lung cancer through interaction with the vascular endothelium

Background

Brain metastasis (BM) in non-small-cell lung cancer (NSCLC) has a very poor prognosis. Recent studies have demonstrated the importance of cell adhesion molecules in tumor metastasis. The aim of our study was to investigate the role of activated leukocyte cell adhesion molecule (ALCAM) in BM formation in NSCLC.

Methods

Immunohistochemical analysis was performed on 143 NSCLC primary tumors and BM. A correlation between clinicopathological parameters and survival was developed. Biological properties of ALCAM were assessed in vitro by gene ablation using CRISPR/Cas9 technology in the NCI-H460 NSCLC cell line and in vivo by intracranial and intracardial cell injection of NCI-H460 cells in NMRI-Foxn1^nu/nu mice.

Results

ALCAM expression was significantly upregulated in NSCLC brain metastasis (P = 0.023) with a de novo expression of ALCAM in 31.2% of BM. Moderate/strong ALCAM expression in both primary NSCLC and brain metastasis was associated with shortened survival. Functional analysis of an ALCAM knock-out (KO) cell line showed a significantly decreased cell adhesion capacity to human brain endothelial cells by 38% (P = 0.045). In vivo studies showed significantly lower tumor cell dissemination in mice injected with ALCAM-KO cells in both mouse models, and both the number and size of BM were significantly diminished in ALCAM depleted tumors.

Conclusions

Our findings suggest that elevated levels of ALCAM expression promote BM formation in NSCLC through increased tumor cell dissemination and interaction with the brain endothelial cells. Therefore, ALCAM could be targeted to reduce the occurrence of BM.

Key Points

1. ALCAM expression associates with poor prognosis and brain metastasis in NSCLC.

2. ALCAM mediates interaction of NSCLC tumor cells with brain vascular endothelium.

3. ALCAM might represent a novel preventive target to reduce the occurrence of BM in NSCLC.

Perilesional edema in brain metastases as predictive factor of response to systemic therapy in non-small cell lung cancer patients: a preliminary study

BACKGROUND

The significance of upfront systemic therapies as an alternative to whole brain radiotherapy (WBRT) for multiple brain metastases (BM) is debatable. Our purpose is to investigate if peritumoral edema could predict the intracranial response to systemic chemotherapy (chemo) in patients with advanced non-squamous non-small cell lung cancer (non-SQ-NSCLC) and synchronous multiple BM.

METHODS

In this observational cohort study, we evaluated the outcome of 28 patients with multiple BM (≥3) treated with chemo based on cisplatin/carboplatin plus pemetrexed (chemo, group A, n=17) or WBRT plus subsequent chemo (group B, n=11). The intracranial response, assessed by the response assessment neuro-oncology (RANO) BM criteria, was correlated with the degree of BM-associated edema estimated by the maximum diameter ratio among fluid attenuated inversion recovery (FLAIR) and gadolinium-enhanced T1WI (T1Gd) per each BM at the baseline brain magnetic resonance imaging (MRI).

RESULTS

No differences were observed in baseline characteristics between both groups, except for the number of patients under steroid treatment that was clearly superior in group B (P=0.007). Median OS was similar between groups. Regarding FLAIR/T1Gd ratio (F/Gd), patients treated with chemo alone exhibited significantly higher values (P=0.001) in those who developed intracranial progression disease (PD) (2.80±0.32 mm), compared with those who achieved partial response (PR) (1.30±0.11 mm) or stable disease (SD) (1.35±0.09 mm). In patients treated with WBRT, F/Gd ratio was not predictive of response.

CONCLUSIONS

Peritumoral edema estimated by F/Gd ratio appears a promising predictive tool to identify oligosymptomatic patients with multiple BM in whom WBRT can be postponed.

Next-generation immunotherapies for brain metastatic cancers

Patients with extracranial tumors, like lung, breast, and skin cancers, often develop brain metastases (BM) during the course of their diseases and BM commonly represent the terminal stage of cancer progression. Recent insights in the immune biology of BM and the increasing focus of immunotherapy as a therapeutic option for cancer has prompted testing of promising biological immunotherapies, including immune cell-targeting, virotherapy, vaccines, and different cell-based therapies. Here, we review the pathobiology of BM progression and evaluate the potential of next-generation immunotherapies for BM tumors. We also provide future perspectives on the development and implementation of such therapies for brain metastatic cancer patients.

Cost-effectiveness analysis of different sequences of osimertinib administration for epidermal growth factor receptor-mutated non-small-cell lung cancer

Osimertinib is a third-generation epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) that is clinically effective in patients with EGFR-mutated non-small-cell lung cancer (NSCLC). However, the use of this treatment is limited by its high cost. A cost-effectiveness analysis of different sequences of osimertinib administration in China and the United States was conducted in the present study. Markov models were established based on data from the FLAURA and AURA3 trials. First-line osimertinib was compared with both first-generation EGFR-TKIs and second-line osimertinib after the failure of first-generation EGFR-TKIs. The analysis also considered different payment modalities available in China. Additionally, one-way and probability sensitivity analyses, with a willingness-to-pay threshold (WTP) of three times the per capita gross domestic product [$27,783/quality-adjusted life year (QALY) for China and $100,000/QALY for the United States], were performed. The first-line osimertinib group displayed higher QALYs and costs than those of the first-generation EGFR-TKI group. The first generation EGFR-TKI group displayed an incremental cost-effectiveness ratio (ICER) of $212,252/QALY in China and $151,922/QALY in the United States. In addition, the ICERs were negative in the second-line osimertinib group, with higher QALYs and lower costs compared with those in the first-line osimertinib group. Furthermore, osimertinib company donation was of benefit in China, with an average cost-effectiveness of $836/QALY. The one-way sensitivity analysis highlighted the influence of utilities in different states. First-line osimertinib could be cost-effective either with higher WTP or a price reduction of 68% in China and 9% in the United States. Although first-line osimertinib therapy could have health benefits, it was not cost-effective compared with first-line first-generation EGFR-TKIs and second-line osimertinib therapy. However, paying via company donation may be a good choice in China.

Use of radiotherapy in breast cancer patients with brain metastases: a retrospective 11-year single center study

AIM

To analyse the use of radiotherapy (RT) and factors affecting overall survival (OS) after RT in breast cancer patients with brain metastases.

METHODS

Breast cancer patients treated from 2008 to 2018 with whole brain RT (WBRT) or stereotactic radiosurgery (SRS) at a large regional cancer referral center were identified from the hospital's RT register. Clinical variables were extracted from medical records. OS was calculated from date of first RT until death or last follow up. Potential factors affecting OS were analyzed.

RESULTS

255 females with WBRT (n = 206) or SRS (n = 49) as first RT were included. An increased use of initial SRS was observed in the second half of the study period. The most common WBRT fractionation regimen was 3 Gy × 10. SRS was most often single fractions; 18 or 25 Gy between 2009 and 2016, while fractionated SRS was mostly used in 2017 and 2018. Median OS in the WBRT group was 6 months (CI 1-73) relative to 23 (CI 0-78) in the SRS group. Age, performance status, initial RT technique, extracranial disease, brain metastasis surgery, number of brain metastases and DS-GPA score had significant impact on OS. Only ECOG 0 and brain metastasis surgery were associated with superior OS in multivariate analysis.

CONCLUSION

WBRT was the most frequent primary RT. An increased use of initial SRS was observed in the second half of the study period. Only ECOG 0 and brain metastasis surgery were associated with superior OS in multivariate analysis.

Mean apparent diffusion coefficient in a single slice may predict tumor response to whole-brain radiation therapy in non-small-cell lung cancer patients with brain metastases

OBJECTIVES

This study aimed to access the performance of apparent diffusion coefficient (ADC) as a predictor for treatment response to whole-brain radiotherapy (WBRT) in patients with brain metastases (BMs) from non-small-cell lung cancer (NSCLC).

METHODS

A retrospective analysis was conducted of 102 NSCLC patients with BMs who underwent WBRT between 2012 and 2016. Diffusion-weighted MRI were performed pre-WBRT and within 12 weeks after WBRT started. Mean single-plane ADC value of ROIs was evaluated by two radiologists blinded to results of each other. The treatment response rate, intracranial progression-free survival (PFS), and overall survival (OS) were analyzed based on the ADC value and ΔADC respectively. At last, we used COX and logistic regression to do the multivariate analysis.

RESULTS

There was good inter-observer agreement of mean ADC value pre-WBRT, post-WBRT, and ΔADC between the 2 radiologists (Pearson correlation 0.915 [pre-WBRT], 0.950 [post-WBRT], 0.937 [ΔADC], p < 0.001, for each one). High mean ADC value were related with better response rate (72.2% vs 37.5%, p = 0.001) and iPFS (7.6 vs 6.4 months, p = 0.031). High ΔADC were related with better response rate (73.6% vs 36.7%, p < 0.001). Multivariate analysis shows that histopathology, BMs number, high ADC value pre-WBRT, and high ΔADC post-WBRT were related to better treatment response of WBRT, and KPS, BMs number, and low ADC value pre-WBRT increased the risk of developing intracranial relapse.

CONCLUSIONS

The mean single-plane ADC value pre-WBRT and ΔADC post-WBRT were potential predictor for intracranial tumor response to WBRT in NSCLC patients with brain metastases.

KEY POINTS

• ADC value is a potential predictor of intracranial treatment response to WBRT in NSCLC patients with brain metastases. • Higher mean ADC value pre-WBRT and ΔADC post-WBRT of brain metastases were related to better intracranial tumor response. • Prediction of response before WBRT using ADC value can help oncologists to make better therapy plans and avoid missing opportunities for rescue therapy.

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

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

FLAIR hyperintensity along the brainstem surface in leptomeningeal metastases: a case series and literature review

Background

The incidence of leptomeningeal metastasis (LM) is underestimated because of its non-specific signs and the low sensitivity of clinical diagnostic modalities. Cerebrospinal magnetic resonance (MR) imaging with and without contrast enhancement (CE) is a gold standard for the neuroradiological assessment of patients with suspected LM. Previous studies suggested that some LM cases show changes of the brainstem surface on non-contrast MR images without or before the appearance of abnormalities on CE images. We assessed the features of this non-contrast MR finding in a cohort of LM patients in this retrospective single-institution study.

Methods

We reviewed head MR images and clinical data of 142 consecutive patients in whom the final diagnosis was LM.

Results

We found that 11 of these 142 patients (7.7%) with LM had band-like hyperintensity on the brainstem surface on non-enhanced FLAIR images, which looked like bloomy rind on cheese. Three of seven patients who were examined using diffusion-weighted imaging showed restricted diffusion in the corresponding lesion site. The above-mentioned 11 patients included 10 women and 1 man, with a median age of 61 years. All 11 patients had primary lung adenocarcinoma. Seven patients had symptomatic hydrocephalus. Ten patients had EGFR-mutated and one had ALK-rearrangement adenocarcinomas. Before the diagnosis of LM, 10 patients had undergone systemic therapy with EGFR-TKI or pemetrexed, and 1 patient with ALK inhibitor and bevacizumab.

Conclusions

We present a series of patients with bloomy rind sign that is non-enhancing LM reliably detected by FLAIR hyperintensity on the brainstem surface. This finding is rare, but may reflect the spread of cancer cells in both the leptomeningeal membrane and the surface of the brain parenchyma specifically in patients with lung adenocarcinomas. Further study is needed to determine the clinical significance of this sign, and the pathophysiological factors associated with it may be clarified by analyzing serial MR images in a larger cohort of patients treated for LM.

Development and Validation of a Seven-Gene Signature for Predicting the Prognosis of Lung Adenocarcinoma

Background

Prognosis is a main factor affecting the survival of patients with lung adenocarcinoma (LUAD), yet no robust prognostic model of high effectiveness has been developed. This study is aimed at constructing a stable and practicable gene signature-based model via bioinformatics methods for predicting the prognosis of LUAD sufferers.

Methods

The mRNA expression data were accessed from the TCGA-LUAD dataset, and paired clinical information was collected from the GDC website. R package “edgeR” was employed to select the differentially expressed genes (DEGs), which were then used for the construction of a gene signature-based model via univariate COX, Lasso, and multivariate COX regression analyses. Kaplan-Meier and ROC survival analyses were conducted to comprehensively evaluate the performance of the model in predicting LUAD prognosis, and an independent dataset GSE26939 was accessed for further validation.

Results

Totally, 1,655 DEGs were obtained, and a 7-gene signature-based risk score was developed and formulated as risk_score = 0.000245∗NTSR1 + (7.13E − 05)∗RHOV + 0.000505∗KLK8 + (7.01E − 05)∗TNS4 + 0.000288∗C1QTNF6 + 0.00044∗IVL + 0.000161∗B4GALNT2. Kaplan-Meier survival curves revealed that the survival rate of patients in the high-risk group was lower in both the TCGA-LUAD dataset and GSE26939 relative to that of patients in the low-risk group. The relationship between the risk score and clinical characteristics was further investigated, finding that the model was effective in prognosis prediction in the patients with different age (age > 65, age < 65) and TNM stage (N0&N1, T1&T2, and tumor stage I/II). In sum, our study provides a robust predictive model for LUAD prognosis, which boosts the clinical research on LUAD and helps to explore the mechanism underlying the occurrence and progression of LUAD.

Efficacy of pembrolizumab in patients with brain metastasis caused by previously untreated non-small cell lung cancer with high tumor PD-L1 expression

OBJECTIVES

Pembrolizumab is recommended for patients with previously untreated non-small cell lung cancer (NSCLC) with a programmed death ligand 1 (PD-L1) tumor proportion score (TPS) of ≥1%. The KEYNOTE-024 study described the efficacy of pembrolizumab in patients with previously untreated NSCLC who had a PD-L1 TPS of at least 50 %. However, patients with untreated brain metastasis (BM) were excluded from many clinical trials. Therefore, we assessed the efficacy of pembrolizumab against BM of NSCLC with high tumor PD-L1 expression.

MATERIALS AND METHODS

We retrospectively reviewed patients who received pembrolizumab as first-line treatment against NSCLC with PD-L1 TPS ≥ 50 % between March 2017 and September 2019. Treatment efficacy was compared between patients with (BM group) and without BM (non-BM group). In addition, the BM group was divided into patients who previously received treatment for BM before pembrolizumab (BM-T group) and those with no prior treatment for BM (BM-not T group).

RESULTS

Eighty-seven patients (23 BM group and 64 non-BM group) were assessable for efficacy. No significant differences in patient characteristics were found between the BM and non-BM groups, but proportion of patients with stage IV at diagnosis was significantly higher in the BM group. Median progression-free survival (PFS) (6.5 months vs. 7.0 months) and overall survival (OS) (21.6 months vs. 24.6 months) did not significantly differ between the two groups. The response rate of BM was 70 %. The BM group was subdivided into 13 patients in the BM-T group and 10 patients in the BM-not T group. No significant differences in patient characteristics were found between the two groups, but maximum diameter of BM and proportion of patients with symptomatic BM were significantly greater in the BM-T group. PFS and OS did not significantly differ between the two groups. The median PFS of BM was 13.6 months in the BM-T group and 18.6 months in the BM-not T group.

CONCLUSION

Pembrolizumab may be effective for BM caused by previously untreated NSCLC with high PD-L1 tumor expression.

Brain metastases-derived extracellular vesicles induce binding and aggregation of low-density lipoprotein

BACKGROUND

Cancer cell-derived extracellular vesicles (EVs) have previously been shown to contribute to pre-metastatic niche formation. Specifically, aggressive tumors secrete pro-metastatic EVs that travel in the circulation to distant organs to modulate the microenvironment for future metastatic spread. Previous studies have focused on the interface between pro-metastatic EVs and epithelial/endothelial cells in the pre-metastatic niche. However, EV interactions with circulating components such as low-density lipoprotein (LDL) have been overlooked.

RESULTS

This study demonstrates that EVs derived from brain metastases cells (Br-EVs) and corresponding regular cancer cells (Reg-EVs) display different interactions with LDL. Specifically, Br-EVs trigger LDL aggregation, and the presence of LDL accelerates Br-EV uptake by monocytes, which are key components in the brain metastatic niche.

CONCLUSIONS

Collectively, these data are the first to demonstrate that pro-metastatic EVs display distinct interactions with LDL, which impacts monocyte internalization of EVs.

Emerging and investigational targeted chemotherapy and immunotherapy agents for metastatic brain tumors

INTRODUCTION

Metastases to the central nervous system are the most common cause of malignant intracranial tumors in adults. Current standard of care includes surgery and radiation, but overall survival remains poor. A range of systemic therapies are emerging as promising treatment options for these patients.

AREAS COVERED

This study reviews novel drug regimens that are under investigation in phase 1 and 2 clinical trials. To identify relevant therapies under clinical investigation, a search was performed on http://clinicaltrials.gov and Pubmed with the keywords brain metastasis, Phase I clinical trial, and Phase II clinical trial from 2016 to 2020. The authors detail the mechanisms of action of all trial agents, outline evidence for their utility, and summarize the current state of the field.

EXPERT OPINION

Current advancements in the medical management of brain metastases can be categorized into targeted therapies, methods of overcoming treatment resistance, novel combinations of therapies, and modulation of the tumor microenvironment with a specific focus on immunotherapy. Each of these realms holds great promise for the field going forward. A more streamlined structure for enrollment into clinical trials will be a crucial step in accelerating progress in this area.

Modeling the Interaction between the Microenvironment and Tumor Cells in Brain Tumors

Despite considerable recent advances in understanding and treating many other cancers, malignant brain tumors remain associated with low survival or severe long-term sequelae. Limited progress, including development of immunotherapies, relates in part to difficulties in accurately reproducing brain microenvironment with current preclinical models. The cellular interactions among resident microglia, recruited tumor-associated macrophages, stromal cells, glial cells, neurons, and cancer cells and how they affect tumor growth or behavior are emerging, yet many questions remain. The role of the blood-brain barrier, extracellular matrix components, and heterogeneity among tumor types and within different regions of a single tumor further complicate the matter. Here, we focus on brain microenvironment features impacted by tumor biology. We also discuss limits of current preclinical models and how complementary models, such as humanized animals and organoids, will allow deeper mechanistic insights on cancer biology, allowing for more efficient testing of therapeutic strategies, including immunotherapy, for brain cancers.

Radial basis function-generated finite difference scheme for simulating the brain cancer growth model under radiotherapy in various types of computational domains

BACKGROUND AND OBJECTIVES

We extend the original mathematical model, i.e., Swanson's reaction-diffusion equation to the surfaces with no boundary, and we find a new numerical method based on a meshless approach for solving numerically Swanson's reaction-diffusion model in the square and on the sphere.

METHODS

To solve numerically the Swanson's reaction-diffusion model and its extension version, a collocation meshless technique, namely radial basis function-generated finite difference (RBF-FD) scheme is employed for approximating the spatial variables in the square domain and on the sphere, respectively. Also, to approximate the time variable of the studied models, a first-order semi-implicit backward Euler scheme is used. The resulting fully discrete scheme is a linear system of algebraic equations per time step that is solved via the biconjugate gradient stabilized (BiCGSTAB) iterative algorithm with a zero-fill incomplete lower-upper (ILU) preconditioner.

RESULTS

The numerical simulations show the growth of untreated and treated brain tumors with radiotherapy using estimated and clinical data (given from magnetic resonance imaging (MRI) scans of patients). Moreover, the results reported here can be used for improving the treatment strategies of the invasive brain tumor.

CONCLUSIONS

Using the developed numerical scheme in this paper, we can simulate the behavior of the invasive form of brain tumor response to radiotherapy. Also, we can see the effects of radiation response on the brain tumor cell concentration of individual patients. The proposed meshless technique, which is applied for solving numerically the studied model, does not depend on any background mesh or triangulation for approximation in comparison with mesh-dependent methods. Moreover, we apply this technique to the sphere via any set of distributed points easily.

Characteristics and Clinical Outcome of Breast Cancer Patients with Asymptomatic Brain Metastases

Background: Brain metastases (BM) have become a major challenge in patients with metastatic breast cancer. Methods: The aim of this analysis was to characterize patients with asymptomatic BM (n = 580) in the overall cohort of 2589 patients with BM from our Brain Metastases in Breast Cancer Network Germany (BMBC) registry. Results: Compared to symptomatic patients, asymptomatic patients were slightly younger at diagnosis (median age: 55.5 vs. 57.0 years, p = 0.01), had a better performance status at diagnosis (Karnofsky index 80-100%: 68.4% vs. 57%, p < 0.001), a lower number of BM (>1 BM: 56% vs. 70%, p = 0.027), and a slightly smaller diameter of BM (median: 1.5 vs. 2.2 cm, p < 0.001). Asymptomatic patients were more likely to have extracranial metastases (86.7% vs. 81.5%, p = 0.003) but were less likely to have leptomeningeal metastasis (6.3% vs. 10.9%, p < 0.001). Asymptomatic patients underwent less intensive BM therapy but had a longer median overall survival (statistically significant for a cohort of HER2-positive patients) compared to symptomatic patients (10.4 vs. 6.9 months, p < 0.001). Conclusions: These analyses show a trend that asymptomatic patients have less severe metastatic brain disease and despite less intensive local BM therapy still have a better outcome (statistically significant for a cohort of HER2-positive patients) than patients who present with symptomatic BM, although a lead time bias of the earlier diagnosis cannot be ruled out. Our analysis is of clinical relevance in the context of potential trials examining the benefit of early detection and treatment of BM.

Validation of Nine Different Prognostic Grading Indexes for Radiosurgery of Brain Metastases in Breast Cancer Patients and Development of an All-Encompassing Prognostic Tool

Purpose: Several prognostic indexes for overall survival (OS) after radiotherapy of brain metastases in breast cancer patients exist but are mainly validated for whole-brain radiotherapy or not specifically for breast cancer patients. To date, no such index provides information beyond mere OS.

Methods: We retrospectively analyzed 95 breast cancer patients treated with stereotactic radiosurgery for 203 brain metastases. The Kaplan–Meier method with log-rank test was used to assess OS, local control (LC), distant cranial control (DCC), and extracranial control (EC). Cox regression was applied to detect prognostic outcome factors. A point scoring system was designed to stratify patients based on outcome. Nine established prognostic indexes were analyzed using the concordance index (c-index).

Results: Two out of nine analyzed prognostic indexes for OS showed a significant c-index, the breast graded prognostic assessment (bGPA; 0.631; 95% CI, 0.514–0.748; p = 0.037) and the modified bGPA (mod-bGPA; 0.662; 95% CI, 0.547–0.777; p = 0.010). Significant results from multivariate analysis (Karnofsky Performance Score, Her2/neu receptor status, extracranial control) were used to generate a new point system: the breast cancer stereotactic radiotherapy score (bSRS), which discriminated three significantly different prognostic groups, for LC, DCC, EC, and OS, respectively. However, the c-index was only significant for OS (0.689; 95% CI, 0.577–0.802; p = 0.003).

Conclusions: The new bSRS score was superior to the bGPA and mod-bGPA scores for prognosis of OS. The bSRS is easy to use and the first tool, which might also provide outcome assessment beyond mere OS. Future studies need to validate these findings.

Docetaxel-Loaded Cholesterol-PEG Co-Modified Poly (n-Butyl) Cyanoacrylate Nanoparticles for Antitumor Drug Pulmonary Delivery: Preparation, Characterization, and in vivo Evaluation

BACKGROUND AND AIM

Polymeric nanoparticles (NPs) have received much attention as promising carrier systems in lung cancer and brain metastases.

METHODS

Here, for the first time, we investigated the feasibility of using inhaled cholesterol-PEG co-modified poly (n-butyl) cyanoacrylate NPs (CLS-PEG NPs) of docetaxel (DTX) for sustained pulmonary drug delivery in cancer metastasis.

RESULTS

Spray-dried or freeze-dried NPs yielded sustained drug release in vitro. In vitro inhalation evaluation data indicated that the inhalation formulation had better inhalability. Compared with intravenous (IV) administration, pharmacokinetic data suggested that the inhalation formulation prolonged plasma concentration of DTX for greater than 24 h and is more quickly and completely absorbed into the rat lung after intratracheal (IT) administration. Furthermore, freeze-dried powders were found to increase the t1/2 and area under curve (AUC) by 2.3 and 6.5 fold compared to the free drug after IT administration, and spray-dried powders were found to increase the t1/2 and AUC by 3.4 and 8.8 fold, respectively. After pulmonary administration of the inhalation formulation, DTX appeared to prolong the pulmonary absorption time. In addition, the inhalation formulation was distributed to the brain in a sustained release manner.

CONCLUSION

These experimental results demonstrated that freeze- and spray-dried powders have the potential for pulmonary sustained release, and they also have the potential to be used as a novel treatment for the delivery of drugs that pass through the air-blood barrier and enter the brain and are efficient carriers for the treatment of brain metastasis.

Intrathecal pemetrexed combined with involved-field radiotherapy as a first-line intra-CSF therapy for leptomeningeal metastases from solid tumors: a phase I/II study

Purpose:

A phase I/II study of intrathecal pemetrexed (IP) combined with involved-field radiotherapy (IFRT) was performed to determine feasibility, safety, and antitumor activity for leptomeningeal metastases (LM) from solid tumors.

Methods:

Participants first received induction IP administration, followed by concomitant radiotherapy within 3 days. The concomitant regimen consisted of IP (pemetrexed 10 mg, dexamethasone 5 mg, once per week, 4 times in 4 weeks) and IFRT (40 Gy in 20 fractions). Six participants were recruited to assess feasibility in phase I, and then 28 patients were recruited further. All patients were assessed to investigate safety, efficacy, and outcomes.

Results:

Between April 2018 and December 2018, 34 patients (male: 15; female: 19; median age: 56 years) were enrolled, including non-small-cell lung cancer (21), small-cell lung cancer (5), breast cancer (4), and others (4). Thirty-two patients received concurrent therapy and 25 (74%) patients completed the treatment. Major adverse events (AEs) consisted of myelosuppression, the elevation of hepatic aminotransferases, and radiculitis. Total AEs rate was 53% (18/34), including 6 (18%) patients with grade 3 and 1 (3%) with grade 4 AEs. The response rate was 68% (23/34). The median overall survival was 5.5 (0.3–16.6) months. Median neurological progression-free survival (NPFS) was 3.5 (0.3–15.2) months. Six-month NPFS rate was 47%. One-year survival rate was 21.6%.

Conclusion:

IP at a 10 mg dose on a schedule of 1–2 times per week presented good efficacy and safety in CSF. The concomitant regimen is an efficacious therapeutic option for LM patients with solid tumors.

Trial Registration:

This study (IPLM) was registered at https://register.clinicaltrials.gov [ClinicalTrials.gov identifier: NCT03507244].

Efficacy of Immune Checkpoint Inhibitors in Non-small-cell Lung Cancer Patients With Different Metastatic Sites: A Systematic Review and Meta-Analysis

Background: Organ-specific response patterns reported in previous studies indicate different response toward immune checkpoint inhibitors (ICIs) in non-small-cell lung cancer (NSCLC) patients with different metastatic sites. This study aims to compare the efficacy of ICIs with conventional therapy in NSCLC patients with bone, brain or liver metastases. Materials and Methods: MEDLINE, Embase, and CENTRAL were searched for studies comparing ICIs with conventional therapy in NSCLC patients with bone, brain or liver metastases. The pooled hazard ratio (HR) of overall survival (OS) and progression-free survival (PFS) among included studies was analyzed using the random effects model. Results: Eight studies consisting of 988 NSCLC patients were included, 259 with brain metastases and 729 with liver metastases. No available study with bone metastases information was identified. For patients with brain metastases, ICIs significantly improved their OS (HR, 0.57; P = 0.007). For patients with liver metastases, both OS (HR, 0.72; P = 0.006), and PFS (HR, 0.72; P = 0.004) improvements were observed in the ICI treatment arm. Subgroup analysis was conducted based on target of ICIs and treatment regimen. PD-1 inhibitors could benefit patients with liver or brain metastases on OS and PFS (brain metastases: OS, HR, 0.43; P < 0.001; liver metastases: PFS, HR, 0.52; P = 0.003; OS, HR, 0.66; P = 0.001), while PD-L1 inhibitors could not. Patients with brain metastases could only gain OS improvement from ICIs combined with chemotherapy (HR, 0.41; P = 0.001), but for patients with liver metastases, the benefit was detected using ICIs single agent (HR, 0.68; P = 0.012) or ICIs combined with chemotherapy plus anti-VEGF therapy (HR, 0.52; P = 0.005). Conclusion: ICIs could significantly improve OS in NSCLC patients with brain or liver metastases compared with conventional therapy. Patients with brain metastases could only gain OS benefit from ICIs combined with chemotherapy, while those with liver metastases obtained superior OS from ICIs single agent or ICIs combined with chemotherapy plus anti-VEGF therapy.

Brain metastases treated with hypofractionated stereotactic radiotherapy: 8 years experience after Cyberknife installation

BACKGROUND

Hypofractionated stereotactic radiotherapy (HFSRT) is indicated for large brain metastases (BM) or proximity to critical organs (brainstem, chiasm, optic nerves, hippocampus). The primary aim of this study was to assess factors influencing BM local control after HFSRT. Then the effect of surgery plus HFSRT was compared with exclusive HFSRT on oncologic outcomes, including overall survival.

MATERIALS AND METHODS

Retrospective study conducted in Léon Bérard Cancer Center, included patients over 18 years-old with BM, secondary to a tumor proven by histology and treated by HFSRT alone or after surgery. Three different dose-fractionation schedules were compared: 27 Gy (3 × 9 Gy), 30 Gy (5 × 6 Gy) and 35 Gy (5 × 7 Gy), prescribed on isodose 80%. Primary endpoint were local control (LC). Secondary endpoints were overall survival (OS) and radionecrosis (RN) rate.

RESULTS

A total of 389 patients and 400 BM with regular MRI follow-up were analyzed. There was no statistical difference between the different dose-fractionations. On multivariate analysis, surgery (p = 0.049) and size (< 2.5 cm) (p = 0.01) were independent factors improving LC. The 12 months LC was 87.02% in the group Surgery plus HFSRT group vs 73.53% at 12 months in the group HFSRT. OS was 61.43% at 12 months in the group Surgery plus HFSRT group vs 50.13% at 12 months in the group HFSRT (p < 0.0085). Prior surgery (OR = 1.86; p = 0.0028) and sex (OR = 1.4; p = 0.0139) control of primary tumor (OR = 0.671, p = 0.0069) and KPS < 70 (OR = 0.769, p = 0.0094) were independently predictive of OS. The RN rate was 5% and all patients concerned were symptomatic.

CONCLUSIONS

This study suggests that HFSRT is an efficient and well-tolerated treatment. The optimal dose-fractionation remains difficult to determine. Smaller size and surgery are correlated to LC. These results evidence the importance of surgery for larger BM (> 2.5 cm) with a poorer prognosis. Multidisciplinary committees and prospective studies are necessary to validate these observations.

Utility of whole brain radiation therapy for leptomeningeal carcinomatosis

BACKGROUND

Although whole brain radiation therapy (WBRT) is commonly used as first-line treatment for leptomeningeal carcinomatosis, the prognosis is uncertain despite treatment. Moreover, the benefit of WBRT for leptomeningeal carcinomatosis has not been adequately evaluated. Therefore, this study aimed to clarify the utility of WBRT for leptomeningeal carcinomatosis.

METHODS

Consecutive patients who received WBRT for leptomeningeal carcinomatosis or brain metastasis from solid tumors between January 2008 and July 2017 were retrospectively evaluated. The overall survival, symptom relief, and adverse events were compared between patients with leptomeningeal carcinomatosis and those with brain metastasis after WBRT.

RESULTS

Of the 277 treated patients, 204 patients (22 with leptomeningeal carcinomatosis and 182 with brain metastasis) were included in the study. The median overall survival was 440 days (95% confidence interval [CI] 0-931 days) for patients with leptomeningeal carcinomatosis and 322 days (95% CI 196-448 days) for those with brain metastasis (p = 0.972 on the log-rank test). On evaluating the overall survival of patients with leptomeningeal carcinomatosis, the prognostic factors of performance status 0-1, no extracranial metastasis, and no symptoms at the time of WBRT showed a significant survival advantage on univariate analysis. Among patients with leptomeningeal carcinomatosis, those with headache and nausea often showed improvement while those with depressed levels of consciousness and seizures did not. On comparing all-grade adverse events, vomiting and seizures were more frequent in patients with leptomeningeal carcinomatosis than in those with brain metastasis.

CONCLUSIONS

WBRT was generally well tolerated and effective for treating patients with leptomeningeal carcinomatosis.

Nivolumab efficacy in leptomeningeal metastasis of renal cell carcinoma: a case report

BACKGROUND

Meningeal carcinomatosis is rare in patients with kidney cancer and treatment options are limited. Few patients treated with systemic approaches have been reported. We describe a case of complete remission of leptomeningeal metastasis in a patient with renal cell carcinoma treated with nivolumab. To our knowledge, this is the first report of nivolumab safety and efficacy in this particular site of metastasis.

CASE PRESENTATION

Our patient was a 60-year-old Caucasian man with bone and lung metastases from renal cell carcinoma. He developed leptomeningeal metastasis and progression of bone and lung lesions after only 2 months of his first-line treatment. He was then treated with nivolumab in second-line setting and experienced a rapid improvement of cancer-related symptoms, complete remission of leptomeningeal and lung lesions, and increased bone mineral density in bone metastasis. The patient did not experience any drug-related toxicity.

CONCLUSIONS

Meningeal carcinomatosis metastasis from renal cancer is a rare condition. Diagnosis is often challenging: the onset of nonspecific presenting symptoms could be initially attributed to bone involvement, side effects of oncologic therapy, or paraneoplastic syndromes. Our case suggests that nivolumab could be an effective and safe treatment option in patients with pretreated renal cancer with leptomeningeal metastasis.

Fluorescence-guided stereotactic biopsy: a proof-of-concept study

OBJECTIVE

Accurate histopathological diagnoses are often necessary for treating neuro-oncology patients. However, stereotactic biopsy (STB), a common method for obtaining suspicious tissue from deep or eloquent brain regions, fails to yield diagnostic tissue in some cases. Failure to obtain diagnostic tissue can delay initiation of treatment and may result in further invasive procedures for patients. In this study, the authors sought to determine if the coupling of in vivo optical imaging with an STB system is an effective method for identification of diagnostic tissue at the time of biopsy.

METHODS

A minimally invasive fiber optic imaging system was developed by coupling a 0.65-mm-diameter coherent fiber optic fluorescence microendoscope to an STB system. Human U251 glioma cells were transduced for stable expression of blue fluorescent protein (BFP) to produce U251-BFP cells that were utilized for in vitro and in vivo experiments. In vitro, blue fluorescence was confirmed, and tumor cell delineation by fluorescein sodium (FNa) was quantified with fluorescence microscopy. In vivo, transgenic athymic rats implanted with U251-BFP cells (n = 4) were utilized for experiments. Five weeks postimplantation, the rats received 5–10 mg/kg intravenous FNa and underwent craniotomies overlying the tumor implantation site and contralateral normal brain. A clinical STB needle containing our 0.65-mm imaging fiber was passed through each craniotomy and images were collected. Fluorescence images from regions of interest ipsilateral and contralateral to tumor implantation were obtained and quantified.

RESULTS

Live-cell fluorescence imaging confirmed blue fluorescence from transduced tumor cells and revealed a strong correlation between tumor cells quantified by blue fluorescence and FNa contrast (R2 = 0.91, p < 0.001). Normalized to background, in vivo FNa-mediated fluorescence intensity was significantly greater from tumor regions, verified by blue fluorescence, compared to contralateral brain in all animals (301.7 ± 34.18 relative fluorescence units, p < 0.001). Fluorescence intensity measured from the tumor margin was not significantly greater than that from normal brain (p = 0.89). Biopsies obtained from regions of strong fluorescein contrast were histologically consistent with tumor.

CONCLUSIONS

The authors found that in vivo fluorescence imaging with an STB needle containing a submillimeter-diameter fiber optic fluorescence microendoscope provided direct visualization of neoplastic tissue in an animal brain tumor model prior to biopsy. These results were confirmed in vivo with positive control cells and by post hoc histological assessment. In vivo fluorescence guidance may improve the diagnostic yield of stereotactic biopsies.

Bevacizumab treatment of meningeal melanoma metastases

Background

Melanoma patients with metastatic growth in the meninges have poor prognosis and few treatment options. Although treatment with BRAF inhibitors or immune checkpoint inhibitors has provided promising results, most patients with advanced melanoma are resistant to these treatments and develop severe side effects. Novel treatment strategies are needed for patients with meningeal melanoma metastases, and the potential of antiangiogenic therapy was investigated in this preclinical study.

Methods

Two GFP-transfected melanoma models (A-07 and D-12) differing substantially in VEGF-A expression were included in the study, and the anti-VEGF-A antibody bevacizumab was used as therapeutic agent. Meningeal metastases were initiated in BALB/c nu/nu mice by intracranial inoculation of melanoma cells, and bevacizumab treatment was given twice a week in i.p. doses of 10 mg/kg until the mice became moribund. Therapeutic effects were evaluated by determining tumor host survival time, assessing tumor growth and angiogenic activity by quantitative analyses of histological preparations, and measuring the expression of angiogenesis-related genes by quantitative PCR.

Results

Meningeal A-07 melanomas showed higher expression of VEGF-A than meningeal D-12 melanomas, whereas the expression of ANGPT2 and IL8, two important angiogenesis drivers in melanoma, was much higher in D-12 than in A-07 tumors. Bevacizumab treatment inhibited tumor angiogenesis and prolonged host survival in mice with A-07 tumors but not in mice with D-12 tumors. Meningeal A-07 tumors in bevacizumab-treated mice compensated for the reduced VEGF-A activity by up-regulating a large number of angiogenesis-related genes, including ANGPT2 and its receptors TIE1 and TIE2. Melanoma cells migrated from meningeal tumors into the cerebrum, where they initiated metastatic growth by vessel co-option. In the A-07 model, the density of cerebral micrometastases was higher in bevacizumab-treated than in untreated mice, either because bevacizumab treatment increased mouse survival or induced increased tumor gene expression.

Conclusions

The development of antiangiogenic strategies for the treatment of meningeal melanoma metastases is a challenging task because the outcome of treatment will depend on the angiogenic signature of the tumor tissue, treatment-induced alterations of the angiogenic signature, and the treatment sensitivity of metastatic lesions in other intracranial sites.

Palliative care access in the elderly metastatic breast cancer population: obstacles and opportunities

Metastatic breast cancer in the elderly encompasses a group of patients with worse cancer-specific survival and more barriers to care than their non-elderly counterparts. Metastatic breast cancer has a longer natural history than many other common metastatic solid tumors. Palliative care access in this group is thus affected by increased need from (I) more aggressive disease status with more severe symptoms, (II) increased barriers to care, (III) more patients living with the disease than other metastatic solid tumors, and (IV) increased incidence of breast cancer as compared to other solid tumors. This review outlines the rationale for outpatient palliative care, the needs for this specific population of cancer patients, and the barriers that the medical community faces in providing palliative care access for these patients.

The impact of EGFR mutation status and single brain metastasis on the survival of non-small-cell lung cancer patients with brain metastases

BACKGROUND

Molecular and genetic alterations of non-small-cell lung cancer (NSCLC) now play a vital role in patient care of this neoplasm. The authors focused on the impact of epidermal growth factor receptor mutation (EGFR-mt) status on the survival of patients after brain metastases (BMs) from NSCLC. The purpose of the study was to understand the most desirable management of BMs from NSCLC.

METHODS

This was a retrospective observational study analyzing 647 patients with NSCLC, including 266 patients with BMs, diagnosed at our institute between January 2008 and December 2015. EGFR mutation status, overall survival (OS) following diagnosis, OS following BMs, duration from diagnosis to BMs, and other factors related to OS and survival after BMs were measured.

RESULTS

Among 647 patients, 252 (38.8%) had EGFR mutations. The rate and frequency of developing BMs were higher in EGFR-mt patients compared with EGFR wildtype (EGFR-wt) patients. EGFR-mt patients showed longer median OS (22 vs 11 months, P < .001) and a higher frequency of BMs. Univariate and multivariate analyses revealed that good performance status, presence of EGFR-mt, single BM, and receiving local therapies were significantly associated with favorable prognosis following BM diagnosis. Single metastasis, compared with multiple metastases, exhibited a positive impact on patient survival after BMs in EGFR-mt patients, but not in EGFR-wt NSCLC patients.

CONCLUSIONS

Single BM with EGFR-mt performed better than other groups. Furthermore, effective local therapies were recommended to achieve better outcomes.

Osimertinib in Patients With Epidermal Growth Factor Receptor Mutation-Positive Non-Small-Cell Lung Cancer and Leptomeningeal Metastases: The BLOOM Study

PURPOSE

In this phase I study (BLOOM), osimertinib, a third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI), was evaluated in patients with leptomeningeal metastases (LMs) from EGFR-mutated (EGFRm) advanced non-small-cell lung cancer (NSCLC) whose disease had progressed on previous EGFR-TKI therapy.

PATIENTS AND METHODS

Patients with cytologically confirmed LM received osimertinib 160 mg once daily. Objectives were to assess confirmed objective response rate (ORR), duration of response (DoR), progression-free survival (PFS), overall survival (OS), pharmacokinetics (PK), and safety. Additional efficacy evaluations included changes from baseline in CSF cytology and neurologic examination. Measurable lesions were assessed by investigator according to RECIST version 1.1. LMs were assessed by neuroradiologic blinded central independent review (BICR) according to Response Assessment in Neuro-Oncology LM radiologic criteria and by investigator.

RESULTS

Forty-one patients were enrolled. LM ORR and DoR by neuroradiologic BICR were 62% (95% CI, 45% to 78%) and 15.2 months (95% CI, 7.5 to 17.5 months), respectively. Overall, ORR by investigator was 41% (95% CI, 26% to 58%), and median DoR was 8.3 months (95% CI, 5.6 to 16.5 months). Median investigator-assessed PFS was 8.6 months (95% CI, 5.4 to 13.7 months) with 78% maturity; median OS was 11.0 months (95% CI, 8.0 to 18.0 months) with 68% maturity. CSF tumor cell clearance was confirmed in 11 (28%; 95% CI, 15% to 44%) of 40 patients. Neurologic function was improved in 12 (57%) of 21 patients with an abnormal assessment at baseline. The adverse event and PK profiles were consistent with previous reports for osimertinib.

CONCLUSION

Osimertinib showed meaningful therapeutic efficacy in the CNS and a manageable safety profile at 160 mg once daily in patients with EGFRm NSCLC and LM.

[Targeted Therapies for Driver Gene Mutation-positive Lung Cancer Patients with Brain Metastasis]

脑是晚期肺癌转移最常见的部位，驱动基因阳性者脑转移发病率更高，肺癌脑转移患者预后较差，且不同治疗方式的选择影响肺癌脑转移患者的病程转归及预后。近年来，随着精准医学的发展，针对肺癌脑转移，尤其是具有特殊靶点的驱动基因阳性患者治疗方式的选择越来越成为人们的研究热点，并逐步取得进展。本文主要阐述了肺癌脑转移治疗存在的挑战，系统综述了驱动基因阳性肺癌脑转移的靶向治疗进展，以期在精准医学时代下，指导此类患者临床实践中个体化精准治疗方案的抉择。

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 Metastases as a First Site of Recurrence in Patients Receiving Chemotherapy with Controlled Systemic Cancer: a Critical but Under-Recognized Clinical Scenario

PURPOSE OF REVIEW

As the treatment of many malignancies has improved, brain metastases (BM) have been observed as a site of the first recurrence in patients with controlled systemic cancers. This suggests that while the administered chemotherapy is effective against systemic cancer, drug concentrations in the central nervous system (CNS) are likely too low to be effective. These findings are in accord with data suggesting that more than 98% of FDA-approved drugs on the market today are unable to cross the blood-brain barrier (BBB).

RECENT FINDINGS

This retrospective literature review was conducted to estimate the proportion of patients with non-small lung cancer, breast cancer, and melanoma who develop BM as their initial site of recurrence while their systemic cancers are well controlled. Of 267 studies screened, 12 studies fit criteria for inclusion. These 12 studies reported on 923 patients. According to compiled data across these studies, 16% of patients on chemotherapy with stable or responding systemic cancer developed isolated BM as their initial site of relapse. These findings strongly suggest that while chemotherapy controlled systemic cancer, drug concentrations within the CNS were low enough to allow disease progression. Ultimately, reducing the incidence of BM in these patients will require novel therapeutic approaches that facilitate drug entry through an intact BBB early in their treatment.