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

[Progress and Discussion of Perioperative Targeted Therapy in Patients with EGFR-mutated Resectable Non-small Cell Lung Cancer]

Lung cancer is still the leading cause of cancer death worldwide. Non-small cell lung cancer (NSCLC) is the main pathological type of lung cancer, accounting for about 80%. Approximately 30% of all patients with NSCLC have resectable early and middle stage disease at the time of diagnosis. Recently, the epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) have made a major breakthrough in the adjuvant targeted therapy of EGFR-mutated resectable NSCLC, and are recommended by the guidelines for clinical use. In this review, we summarize the clinical research progress of perioperative adjuvant targeted therapy for EGFR-mutated resectable NSCLC, and discuss the key issues in the clinical researches.
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[Brain metastases]

Cerebral metastases in patients with metastatic lung cancer are found in more than 30% of patients at baseline and manifest themselves in two out of three patients during disease evolution. For a long time, the cerebral manifestation of the disease was classified as prognostically unfavorable and hence such patients were regularly excluded from therapy studies. In the context of targeted molecular therapy strategies and established immuno-oncological systemic therapies, the blood-brain barrier no longer represents an insurmountable barrier. However, the treatment of brain metastases requires decision making in a multidisciplinary team within dedicated lung cancer and/or oncology centers. The differentiated treatment decision is based on the number, size and location of the brain metastases, neurology and general condition, comorbidities, potential life expectancy and the patient's wishes, but also tumor biology including molecular targets, extra-cranial tumor burden and availability of a CNS-effective therapy. Systemic therapies as well as neurosurgical and radiotherapeutic concepts are now often combined for optimized and prognosis-improving therapeutic strategies.

Efficacy and safety of dacomitinib in treatment-naïve patients with advanced NSCLC harboring uncommon EGFR mutation: an ambispective cohort study

BACKGROUND

About 10% of non-small cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) mutations are harbored as uncommon mutations. This study aimed to explore the efficacy and safety of dacomitinib, a second-generation EGFR tyrosine kinase inhibitor (EGFR-TKIs), in treating uncommon EGFR-mutated advanced NSCLC.

METHODS

Treatment-naïve advanced NSCLC patients treated with dacomitinib at Hunan Cancer Hospital with uncommon EGFR mutations were evaluated. The primary endpoint was progression-free survival (PFS). Secondary end points included overall survival (OS), objective response rate (ORR), disease control rate (DCR) and safety.

RESULT

Between December 2019 and December 2021, a total of 16 patients was included. Median PFS was 14.0 (95% CI 4.32-23.7) months, and median OS was not reached. ORR was 68.8% (95% CI 41.3 to 89.0%) and DCR was 93.8% (95%CI 69.8 to 99.8%), including three achieving complete remission (CR) and eight achieving partial remission (PR). Median PFS for patients with brain metastasis was 9.0 (95%CI 6.9 to 11.1) months. Intracranial ORR was 100%, including 2 CR and 4 PR. Major treatment-related adverse events (TRAEs) included rash (87.5%), paronychia (62.5%), oral ulcers (50.0%), and diarrhea (50.0%), none of which were ≥ grade 3 TRAEs.

CONCLUSIONS

Dacomitinib showed good activity and manageable toxicity in NSCLC patients with uncommon EGFR mutations.

Distinct metastatic spread and progression patterns in patients treated with crizotinib for ROS1- and ALK-rearranged non-small cell lung cancer: a single-center retrospective study

Background

Crizotinib has been approved for C-ros oncogene 1 (ROS1)- and anaplastic lymphoma kinase (ALK)-rearranged non-small cell lung cancer (NSCLC) patients. Few studies have examined the differences in crizotinib treatment outcomes between these patients and the progression sites during treatment. We investigated the metastatic spread, crizotinib efficacy, and progression patterns during crizotinib treatment in ROS1- and ALK-rearranged NSCLC patients.

Methods

We retrospectively reviewed crizotinib-treated ROS1- and ALK-rearranged NSCLC patients between January 2011 and March 2021. Patient characteristics, clinical outcomes, and progression patterns during treatment were collected from medical records. The metastasis extent, crizotinib response, and progression patterns between the groups were compared.

Results

We identified 26 patients with ROS1- and 42 with ALK-positive NSCLC. The baseline proportion of central nervous system (CNS) metastases did not differ between the groups (12% vs. 29%, P=0.10), but the proportion of extrathoracic metastases, including CNS metastases, was significantly higher in ALK-positive than in ROS1-positive NSCLC patients (35% vs. 71%, P=0.003). Regarding the response to crizotinib, the objective response rate (ORR), progression-free survival (PFS), or overall survival (OS) did not significantly differ between the groups (ROS1 vs. ALK, ORR: 69% vs. 69%, P=0.987; PFS: median 10.9 vs. 10.7 months, P=0.232; median OS: not reached vs. 67.7 months, P=0.495). The CNS was the most common metastasis site in both groups [ROS1 vs. ALK, 69% (11/16) vs. 46% (17/37), P=0.127], and the cumulative incidence of CNS metastasis did not differ between the groups (P=0.914).

Conclusions

Crizotinib treatment outcomes, including progression patterns, were similar between ROS1- and ALK-positive NSCLC patients.

Adjuvant therapies in stages I-III epidermal growth factor receptor-mutated lung cancer: current and future perspectives

Surgical resection followed by adjuvant cisplatin-based chemotherapy is the recommended treatment for patients with completely resected stage IB-IIIA non-small cell lung cancer (NSCLC). Even with the best management, recurrence is common and increases with disease stage (stage I: 26-45%; stage II: 42-62%; stage III: 70-77%). For patients with metastatic lung cancer and tumours that harbour epidermal growth factor receptor (EGFR) mutations, EGFR-tyrosine kinase inhibitors (TKIs) have improved survival. Their effectiveness in advanced stages of NSCLC raises the possibility that these agents may improve outcomes for patients with resectable EGFR-mutated lung cancer. In the ADAURA study, adjuvant osimertinib provided a significant improvement in disease-free survival (DFS) and reduced central nervous system (CNS) disease recurrence in patients with resected stage IB-IIIA EGFR-mutated NSCLC, with or without prior adjuvant chemotherapy. To reap the maximum benefits of EGFR-TKIs for patients with lung cancer, the early and rapid identification of EGFR mutations [and other oncogenic drivers, such as programmed cell death-ligand 1 (PD-L1), with matched targeted therapies] in diagnostic pathologic specimens has become essential. To ensure patients receive the most appropriate treatment, routine, comprehensive histological, immunohistochemical, and molecular analyses (with multiplex next generation sequencing) should be undertaken at the time of diagnosis. The potential for personalised treatments to cure more patients with early-stage lung cancer can only be realised if all therapies are considered when the care plan is formulated, by the multi-specialty experts managing patients. In this review, we discuss the progress and prospects for adjuvant treatments as part of a comprehensive plan of care for patients with resected stages I-III EGFR-mutated lung cancer, and explore how the field could go beyond DFS and overall survival to make cure a more frequent outcome of treatment in patients with resected EGFR-mutated lung cancer.

Adjuvant Osimertinib for Resected EGFR-Mutated Stage IB-IIIA Non-Small-Cell Lung Cancer: Updated Results From the Phase III Randomized ADAURA Trial

PURPOSE

The phase III ADAURA (ClinicalTrials.gov identifier: NCT02511106) primary analysis demonstrated a clinically significant disease-free survival (DFS) benefit with adjuvant osimertinib versus placebo in EGFR-mutated stage IB-IIIA non-small-cell lung cancer (NSCLC) after complete tumor resection (DFS hazard ratio [HR], 0.20 [99.12% CI, 0.14 to 0.30]; P < .001). We report an updated exploratory analysis of final DFS data.

METHODS

Overall, 682 patients with stage IB-IIIA (American Joint Committee on Cancer/Union for International Cancer Control, seventh edition) EGFR-mutated (exon 19 deletion/L858R) NSCLC were randomly assigned 1:1 (stratified by stage, mutational status, and race) to receive osimertinib 80 mg once-daily or placebo for 3 years. The primary end point was DFS by investigator assessment in stage II-IIIA disease analyzed by stratified log-rank test; following early reporting of statistical significance in DFS, no further formal statistical testing was planned. Secondary end points included DFS in stage IB-IIIA, overall survival, and safety. Patterns of recurrence and CNS DFS were prespecified exploratory end points.

RESULTS

At data cutoff (April 11, 2022), in stage II-IIIA disease, median follow-up was 44.2 months (osimertinib) and 19.6 months (placebo); the DFS HR was 0.23 (95% CI, 0.18 to 0.30); 4-year DFS rate was 70% (osimertinib) and 29% (placebo). In the overall population, DFS HR was 0.27 (95% CI, 0.21 to 0.34); 4-year DFS rate was 73% (osimertinib) and 38% (placebo). Fewer patients treated with osimertinib had local/regional and distant recurrence versus placebo. CNS DFS HR in stage II-IIIA was 0.24 (95% CI, 0.14 to 0.42). The long-term safety profile of osimertinib was consistent with the primary analysis.

CONCLUSION

These updated data demonstrate prolonged DFS benefit over placebo, reduced risk of local and distant recurrence, improved CNS DFS, and a consistent safety profile, supporting the efficacy of adjuvant osimertinib in resected EGFR-mutated NSCLC.

Advances in the Molecular Landscape of Lung Cancer Brain Metastasis

Lung cancer is one of the most frequent tumors that metastasize to the brain. Brain metastasis (BM) is common in advanced cases, being the major cause of patient morbidity and mortality. BMs are thought to arise via the seeding of circulating tumor cells into the brain microvasculature. In brain tissue, the interaction with immune cells promotes a microenvironment favorable to the growth of cancer cells. Despite multimodal treatments and advances in systemic therapies, lung cancer patients still have poor prognoses. Therefore, there is an urgent need to identify the molecular drivers of BM and clinically applicable biomarkers in order to improve disease outcomes and patient survival. The goal of this review is to summarize the current state of knowledge on the mechanisms of the metastatic spread of lung cancer to the brain and how the metastatic spread is influenced by the brain microenvironment, and to elucidate the molecular determinants of brain metastasis regarding the role of genomic and transcriptomic changes, including coding and non-coding RNAs. We also present an overview of the current therapeutics and novel treatment strategies for patients diagnosed with BM from NSCLC.

Correlation of EGFR mutation subtypes and survival in surgically treated brain metastasis from non-small-cell lung cancer

OBJECTIVE

Epidermal growth factor receptor (EGFR) mutation is a positive prognostic factor for survival in patients with non-small-cell lung cancer (NSCLC). In such patients, brain metastasis signifies negative outcomes. Patients with NSCLC brain metastasis that may benefit from neurosurgery is under investigation. We aim to investigate the impact of different mutation loci in surgically treated NSCLC brain metastasis patients.

METHODS

This retrospective cohort study included patients with NSCLC brain metastasis who underwent brain lesionectomy, followed by radiotherapy and chemotherapy or targeted therapy. Demographics and tumor characteristics were compared between the EGFR mutant type and wild type groups. Postoperative survival and risk factors were analyzed using log rank and Cox regression methods.

RESULTS

Overall, 101 patients were included, with 57 belonging to the EGFR mutant type group and 44 to the EGFR wild type group. The median postoperative survival was 17 months for the entire cohort, with the duration being 19 and 14 months for EGFR mutant type and wild type patients (p = 0.013), respectively. Multivariate analysis revealed that exon 19 del (p = 0.02) and a high Karnofsky Performance Scale score (p < 0.01) were independent positive prognostic factors to predict survival. The timing of development of the brain metastasis or the location of the intracranial metastasis was not associated with EGFR mutations.

CONCLUSION

EGFR mutations are associated with better survival outcomes in patients with NSCLC brain metastasis suitable for surgical treatment. This advantage was attributed to patients having a specific mutation of exon 19 deletion.

Brain metastasis screening in the molecular age

The incidence of brain metastases (BM) amongst cancer patients has been increasing due to improvements in therapeutic options and an increase in overall survival. Molecular characterization of tumors has provided insights into the biology and oncogenic drivers of BM and molecular subtype-based screening. Though there are currently some screening and surveillance guidelines for BM, they remain limited. In this comprehensive review, we review and present epidemiological data on BM, their molecular characterization, and current screening guidelines. The molecular subtypes with the highest BM incidence are epithelial growth factor receptor-mutated non-small cell lung cancer (NSCLC), BRCA1, triple-negative (TN), and HER2+ breast cancers, and BRAF-mutated melanoma. Furthermore, BMs are more likely to present asymptomatically at diagnosis in oncogene-addicted NSCLC and BRAF-mutated melanoma. European screening standards recommend more frequent screening for oncogene-addicted NSCLC patients, and clinical trials are investigating screening for BM in hormone receptor+, HER2+, and TN breast cancers. However, more work is needed to determine optimal screening guidelines for other primary cancer molecular subtypes. With the advent of personalized medicine, molecular characterization of tumors has revolutionized the landscape of cancer treatment and prognostication. Incorporating molecular characterization into BM screening guidelines may allow physicians to better identify patients at high risk for BM development and improve patient outcomes.

Dynamic monitoring of cerebrospinal fluid circulating tumor DNA to identify unique genetic profiles of brain metastatic tumors and better predict intracranial tumor responses in non-small cell lung cancer patients with brain metastases: a prospective cohort study (GASTO 1028)

BACKGROUND

Due to the blood-brain barrier, plasma is not an ideal source to evaluate the genetic characteristics of central nervous system tumors. Thus, cerebrospinal fluid (CSF) is becoming an alternative biopsy type to evaluate the genetic landscape of intracranial tumors. We aimed to explore the genetic profiles of CSF-derived circulating tumor DNA (ctDNA) to predict intracranial tumor responses and monitor mutational evolution during the treatment of non-small cell lung cancer (NSCLC) patients with brain metastases.

METHODS

We conducted a prospective study of 92 newly diagnosed NSCLC patients with brain metastases. Paired CSF and plasma samples were collected at baseline, 8 weeks after treatment initiation, and disease progression. All samples underwent next-generation sequencing of 425 cancer-related genes.

RESULTS

At baseline, the positive detection rates of ctDNA in CSF, plasma, and extracranial tumors were 63.7% (58/91), 91.1% (82/90), and 100% (58/58), respectively. A high level of genetic heterogeneity was observed between paired CSF and plasma, while concordance in driver mutations was also observed. A higher number of unique copy number variations was detected in CSF-ctDNA than in plasma. ctDNA positivity of CSF samples at baseline was associated with poor outcomes (HR=2.565, P=0.003). Moreover, patients with ≥ 50% reductions in the concentrations of CSF ctDNA after 8 weeks of treatment had significantly longer intracranial progression-free survivals (PFS) than patients with &lt; 50% reductions in CSF ctDNA concentrations (13.27 months vs 6.13 months, HR=0.308, P=0.017). A ≥ 50% reduction in CSF ctDNA concentrations had better concordance with radiographic intracranial tumor responses than plasma. A ≥ 50% reduction in plasma ctDNA concentrations was also associated with longer extracranial PFS (11.57 months vs 6.20 months, HR=0.406, P=0.033). Based on clonal evolution analyses, the accumulation of subclonal mutations in CSF ctDNA was observed after 8 weeks of treatment. The clonal mutations that remained in more than 80% in CSF after 8 weeks also predicted shorter intracranial PFS (HR=3.785, P=0.039).

CONCLUSIONS

CSF ctDNA exhibited unique genetic profiles of brain metastases, and dynamic changes in CSF ctDNA could better predict intracranial tumor responses and track clonal evolution during treatment in NSCLC patients with brain metastases.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03257735.

The cost-effectiveness of brigatinib in adult patients with ALK inhibitor–naive ALK-positive non–small cell lung cancer from a US perspective

BACKGROUND: The discovery of specific oncogenic drivers in non-small cell lung cancer (NSCLC) has led to the development of highly targeted anaplastic lymphoma kinase tyrosine kinase inhibitors (ALKis). Brigatinib is a next-generation ALKi associated with prolonged progression-free survival in patients with ALKi-naive ALK+ NSCLC. OBJECTIVE: To estimate the cost-effectiveness of brigatinib compared with crizotinib and alectinib in patients with ALKi-naive ALK+ NSCLC, from a US payer perspective. METHODS: A lifetime area under the curve-partitioned survival model with 4 health states was used to evaluate the relative cost-effectiveness of brigatinib in the ALKi-naive ALK+ NSCLC setting. Brigatinib was compared with crizotinib within a cost-effectiveness framework and compared with alectinib in a cost-comparison framework, where all efficacy outcomes were assumed equal. The efficacy of brigatinib and crizotinib was informed by the ALTA-1L trial, and an indirect treatment comparison was performed to inform the efficacy of brigatinib vs alectinib owing to a lack of head-to-head data. Costs were derived from public sources. The main outcomes of the model were total costs, quality-adjusted life-years (QALYs), life-years, and incremental cost-effectiveness ratios. Univariate and probabilistic sensitivity analyses, in addition to multiple scenario analyses, were conducted to assess the robustness of the model outcomes. RESULTS: The improved outcomes observed in ALTA-1L translated into QALY gains (+0.97) in the comparison of brigatinib vs crizotinib. The superior efficacy profile was associated with increased time on treatment with brigatinib, which drove the increase in costs vs crizotinib (+$210,519). The resulting base-case incremental cost-effectiveness ratio was $217,607/QALY gained. Compared with alectinib, brigatinib was associated with a cost difference of -$8,546. Sensitivity analysis suggested that extrapolation of overall survival, the assumptions relating to time on treatment, and subsequent therapy costs were the most influential determinants of results. Probabilistic sensitivity analysis suggested brigatinib had the highest probability of being cost-effective beyond willingness-to-pay thresholds of $236,000 per QALY vs crizotinib and alectinib. CONCLUSIONS: At list prices and under base-case assumptions in the current analysis, brigatinib was associated with cost-savings vs alectinib, and QALY gains but at higher costs vs crizotinib. Additional research into the real-world efficacy of ALKis is warranted to further understand the comparative cost-effectiveness of these therapies. DISCLOSURES: Ms Cranmer and Ms Kearns are employees of Takeda UK Ltd. Dr Young is a former employee of Takeda Pharmaceuticals America, Inc. Dr Humphries is an employee of Takeda Pharmaceuticals U.S.A., Inc. Mr Trueman is an employee of Source Health Economics, the consultancy company that provided health economic and writing services. This work was funded by ARIAD Pharmaceuticals, Inc., a wholly owned subsidiary of Takeda Pharmaceutical Company Limited. Work by Source Health Economics was funded by ARIAD Pharmaceuticals, Inc. Professional medical writing assistance was provided by Phillipa White, of Source Health Economics, and funded by ARIAD Pharmaceuticals, Inc.

Precision medicine biomarkers in brain metastases: applications, discordances, and obstacles

Brain metastases (BM) present a common cause of mortality and morbidity in several metastatic cancer entities. New therapeutic developments during the last decades, including targeted and immune-related therapies, have shown considerable extra- and intracranial response rates in specific subgroups of BM patients. However, differences in the molecular alteration in the BM tumor tissue compared to extracranial tumors leads to heterogeneous therapeutic responses. Therefore, an accurate molecular analyzation of BM tissue, if possible, has become an essential part in therapeutic decision making in BM patients. The concordance of predictive molecular biomarkers between multiple sites including extracranial and intracranial tumor tissue have been analyzed for some but not all biomarkers routinely applied in modern precision medicine approaches. In the present review, we summarize the current evidence of predictive biomarkers for personalized therapy approaches in the treatment of parenchymal BM.

Impact of Low-Dose Computed Tomography Screening for Primary Lung Cancer on Subsequent Risk of Brain Metastasis

INTRODUCTION

Brain metastasis (BM) is one of the most common metastases from primary lung cancer (PLC). Recently, the National Lung Screening Trial revealed the efficacy of low-dose computed tomography (LDCT) screening on LC mortality reduction. Nevertheless, it remains unknown if early detection of PLC through LDCT may be potentially beneficial in reducing the risk of subsequent metastases. Our study aimed to investigate the impact of LDCT screening for PLC on the risk of developing BM after PLC diagnosis.

METHODS

We used the National Lung Screening Trial data to identify 1502 participants who were diagnosed with PLC in 2002 to 2009 and have follow-up data for BM. Cause-specific competing risk regression was applied to evaluate an association between BM risk and the mode of PLC detection-that is, LDCT screen-detected versus non-LDCT screen-detected. Subgroup analyses were conducted in patients with early stage PLC and those who underwent surgery for PLC.

RESULTS

Of 1502 participants, 41.4% had PLC detected through LDCT screening versus 58.6% detected through other methods, for example, chest radiograph or incidental detection. Patients whose PLC was detected with LDCT screening had a significantly lower 3-year incidence of BM (6.5%) versus those without (11.9%), with a cause-specific hazard ratio (HR) of 0.53 (p = 0.001), adjusting for age at PLC diagnosis, PLC stage, PLC histology, and smoking status. This significant reduction in BM risk among PLCs detected through LDCT screening persisted in subgroups of participants with early stage PLC (HR = 0.47, p = 0.002) and those who underwent surgery (HR = 0.37, p = 0.001).

CONCLUSIONS

Early detection of PLC using LDCT screening is associated with lower risk of BM after PLC diagnosis on the basis of a large population-based study.

Effect of timing, technique and molecular features on brain control with local therapies in oncogene-driven lung cancer

BACKGROUND

The improved efficacy of tyrosine kinase inhibitors (TKI) mandates reappraisal of local therapy (LT) for brain metastases (BM) of oncogene-driven non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

This study included all epidermal growth factor receptor-mutated (EGFR⁺, n = 108) and anaplastic lymphoma kinase-rearranged (ALK⁺, n = 33) TKI-naive NSCLC patients diagnosed with BM in the Thoraxklinik Heidelberg between 2009 and 2019. Eighty-seven patients (62%) received early LT, while 54 (38%) received delayed (n = 34; 24%) or no LT (n = 20; 14%). LT comprised stereotactic (SRT; n = 40; 34%) or whole-brain radiotherapy (WBRT; n = 77; 66%), while neurosurgical resection was carried out in 19 cases.

RESULTS

Median overall survival (OS) was 49.1 months for ALK⁺ and 19.5 months for EGFR⁺ patients (P = 0.001), with similar median intracranial progression-free survival (icPFS) (15.7 versus 14.0 months, respectively; P = 0.80). Despite the larger and more symptomatic BM (P < 0.001) of patients undergoing early LT, these experienced longer icPFS [hazard ratio (HR) 0.52; P = 0.024], but not OS (HR 1.63; P = 0.12), regardless of the radiotherapy technique (SRT versus WBRT) and number of lesions. High-risk oncogene variants, i.e. non-del19 EGFR mutations and 'short' EML4-ALK fusions (mainly variant 3, E6:A20), were associated with earlier intracranial progression (HR 2.97; P = 0.001). The longer icPFS with early LT was also evident in separate analyses of the EGFR⁺ and ALK⁺ subsets.

CONCLUSIONS

Despite preferential use for cases with poor prognostic factors, early LT prolongs the icPFS, but not OS, in TKI-treated EGFR⁺/ALK⁺ NSCLC. Considering the lack of survival benefit, and the neurocognitive effects of WBRT, patients presenting with polytopic BM may benefit from delaying radiotherapy, or from radiosurgery of multiple or selected lesions. For SRT candidates, the improved tumor control with earlier radiotherapy should be weighed against the potential toxicity and the enhanced intracranial activity of newer TKI. High-risk EGFR/ALK variants are associated with earlier intracranial failure and identify patients who could benefit from more aggressive management.

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.

Durability of CNS disease control in NSCLC patients with brain metastases treated with immune checkpoint inhibitors plus cranial radiotherapy

BACKGROUND

Immune checkpoint inhibitors (ICIs) have excellent systemic activity and are standard first line treatment in EGFR/ALK wild type metastatic non-small cell lung cancer (NSCLC). However, their role in patients with brain metastases, which affects over 20% of patients and cause significant morbidity, is less clear.

METHODS

We reviewed patients with EGFR/ALK wild-type mNSCLC with CNS metastases. Serial MRIs were reviewed to determine the time to intracranial progression (iPFS). Multivariate regression was performed to adjust for the disease-specific graded prognostic score (ds-GPA).

RESULTS

We identified 36 ICI- and 33 chemotherapy-treated patients with baseline CNS metastases and available serial MRIs (average frequency:3.5 months). Baseline radiation was given except for 2 chemotherapy-treated patients with asymptomatic solitary metastasis. The CNS burden of disease was higher in the ICI-treated group (ICI:22% vs. chemotherapy:0% had >10 lesions; p = 0.02), but the utilization of WBRT was not (ICI:31% vs. chemotherapy:45%; p = 0.09). At the time of progression, CNS involvement was identified in 30 % of ICI-treated patients compared to 64 % of chemotherapy controls (p = 0.02). ICI-treated patients had superior iPFS (13.5 vs 8.4 months) that remained significant in multivariate analysis (HR 1.9; 95%CI 1.1--3.4). Superior CNS outcomes in ICI-treated patients were driven by the PD-L1 high subgroup where the 12-month cumulative incidence rate of CNS progression was 19% in ICI-treated PD-L1 ≥ 50%, 50% in ICI-treated PD-L1 < 50% and 58% in chemotherapy-treated patients (p = 0.03).

CONCLUSIONS

Remarkable CNS disease control is seen with baseline RT plus ICIs in patients with PD-L1 ≥ 50%. Strategies for delaying WBRT should be investigated in this subgroup of patients.

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.

Alisertib inhibits migration and invasion of EGFR-TKI resistant cells by partially reversing the epithelial-mesenchymal transition

Epithelial growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) have been widely used in the clinical treatment of non-small cell lung cancer (NSCLC) patients with EGFR mutations. Previous studies have shown that Aurora kinase A (AURKA) is overexpressed in a broad spectrum of cancer cells, which can induce epithelial-mesenchymal transition (EMT) and contribute to the occurrence of acquired EGFR-TKI resistance. However, whether the inhibition of AURKA could overcome EGFR-TKI resistance or reverse the EMT in TKI-resistant NSCLC cells remains unclear. In the current study, we established three EGFR-TKI-resistant cell lines and analyzed their expression profiles by RNA sequencing. The results revealed that the EMT pathway is significantly upregulated in the three cell lines with EGFR-TKI resistance. The phosphorylation of AURKA at Thr 288 was also upregulated, suggesting that the activation of AURKA plays an important role in the occurrence of EGFR-TKI resistance. Interestingly, the AURKA inhibitor, alisertib treatment restored the susceptibility of resistant cells to EGFR-TKIs and partially reversed the EMT process, thereby reducing migration and invasion in EGFR-TKI-resistant cells. This study provides evidence that targeting AURKA signaling pathway by alisertib may be a novel approach for overcoming EGFR-TKI resistance and for the treatment of metastatic EGFR-TKIs in NSCLC patients.

Evaluating Infectious, Neoplastic, Immunological, and Degenerative Diseases of the Central Nervous System with Cerebrospinal Fluid-Based Next-Generation Sequencing

Cerebrospinal fluid (CSF) is a clear and paucicellular fluid that circulates within the ventricular system and the subarachnoid space of the central nervous system (CNS), and diverse CNS disorders can impact its composition, volume, and flow. As conventional CSF testing suffers from suboptimal sensitivity, this review aimed to evaluate the role of next-generation sequencing (NGS) in the work-up of infectious, neoplastic, neuroimmunological, and neurodegenerative CNS diseases. Metagenomic NGS showed improved sensitivity—compared to traditional methods—to detect bacterial, viral, parasitic, and fungal infections, while the overall performance was maximized in some studies when all diagnostic modalities were used. In patients with primary CNS cancer, NGS findings in the CSF were largely concordant with the molecular signatures derived from tissue-based molecular analysis; of interest, additional mutations were identified in the CSF in some glioma studies, reflecting intratumoral heterogeneity. In patients with metastasis to the CNS, NGS facilitated diagnosis, prognosis, therapeutic management, and monitoring, exhibiting higher sensitivity than neuroimaging, cytology, and plasma-based molecular analysis. Although evidence is still rudimentary, NGS could enhance the diagnosis and pathogenetic understanding of multiple sclerosis in addition to Alzheimer and Parkinson disease. To conclude, NGS has shown potential to aid the research, facilitate the diagnostic approach, and improve the management outcomes of all the aforementioned CNS diseases. However, to establish its role in clinical practice, the clinical validity and utility of each NGS protocol should be determined. Lastly, as most evidence has been derived from small and retrospective studies, results from randomized control trials could be of significant value.

Evaluation of Computationally Designed Peptides against TWEAK, a Cytokine of the Tumour Necrosis Factor Ligand Family

The tumour necrosis factor-like weak inducer of apoptosis (TWEAK) is a member of the tumour necrosis factor ligand family and has been shown to be overexpressed in tumoral cells together with the fibroblast growth factor–inducible 14 (Fn14) receptor. TWEAK-Fn14 interaction triggers a set of intracellular pathways responsible for tumour cell invasion and migration, as well as proliferation and angiogenesis. Hence, modulation of the TWEAK-Fn14 interaction is an important therapeutic goal. The targeting of protein-protein interactions by external agents, e.g., drugs, remains a substantial challenge. Given their intrinsic features, as well as recent advances that improve their pharmacological profiles, peptides have arisen as promising agents in this regard. Here, we report, by in silico structural design validated by cell-based and in vitro assays, the discovery of four peptides able to target TWEAK. Our results show that, when added to TWEAK-dependent cellular cultures, peptides cause a down-regulation of genes that are part of TWEAK-Fn14 signalling pathway. The direct, physical interaction between the peptides and TWEAK was further elucidated in an in vitro assay which confirmed that the bioactivity shown in cell-based assays was due to the targeting of TWEAK. The results presented here are framed within early pre-clinical drug development and therefore these peptide hits represent a starting point for the development of novel therapeutic agents. Our approach exemplifies the powerful combination of in silico and experimental efforts to quickly identify peptides with desirable traits.

Autophagy-mediated tumor cell survival and progression of breast cancer metastasis to the brain

Brain metastases represent a substantial amount of morbidity and mortality in breast cancer (BC). Metastatic breast tumor cells committed to brain metastases are unique because they escape immune surveillance, can penetrate the blood-brain barrier, and also adapt to the brain tissue microenvironment (TME) for colonization and outgrowth. In addition, dynamic intracellular interactions between metastatic cancer cells and neighboring astrocytes in the brain are thought to play essential roles in brain tumor progression. A better understanding of the above mechanisms will lead to developing more effective therapies for brain metastases. Growing literature suggests autophagy, a conserved lysosomal degradation pathway involved in cellular homeostasis under stressful conditions, plays essential roles in breast tumor metastatic transformation and brain metastases. Cancer cells must adapt under various microenvironmental stresses, such as hypoxia, and nutrient (glucose) deprivation, in order to survive and progress. Clinical studies reveal that tumoral expression of autophagy-related proteins is higher in brain metastasis compared to primary breast tumors. In this review, we outline the molecular mechanisms underlying autophagy-mediated BC cell survival and metastasis to the brain.

Real-world impact of brain metastases on healthcare utilization and costs in patients with non-small cell lung cancer treated with EGFR-TKIs in the US

BACKGROUND

Non-small cell lung cancer (NSCLC) with brain metastases (BM) is difficult to treat and associated with poor survival. This study assessed the impact of BM on healthcare-related utilization and costs (HRUC) among patients receiving epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs).

PATIENTS AND METHODS

Adults newly-diagnosed with metastatic NSCLC, initiating first-/second-generation EGFR-TKI treatment, with BM or no BM (NBM), were identified retrospectively from IBM MarketScan healthcare claims databases (2013-2017). HRUC were measured during the variable-length follow-up period. Generalized linear models assessed the impact of BM on total healthcare costs, standardized to 2017 US$.

RESULTS

Overall, 222 BM and 280 NBM patients were included, with a mean duration of follow-up of 14 months. Adjusted NSCLC-related and all-cause costs over average follow-up were 1.2 times higher among BM patients (Δ$5,640 and Δ$6,366, respectively; p <0.05); differences were driven primarily by radiation treatment and radiology. More than two times more BM than NBM patients received NSCLC-related radiation treatment, in both inpatient (15.3% vs 6.8%; p <0.05) and outpatient settings (87.8% vs 37.5%; p <0.05). Per-patient per-month (PPPM) radiation costs were also higher among BM patients, both inpatient ($796 vs $464, p =0.172) and outpatient ($2,443 vs $747, p <0.05). All-cause PPPM radiology visits (2.0 vs 1.3) and associated costs ($3,824 vs $1,621) were higher among BM patients (both p <0.05).

CONCLUSION

NSCLC-related HRUC, especially those attributable to radiation treatment, were higher among patients with BM. Future research should compare the potential for CNS-active EGFR-TKIs vs first-/second-generation EGFR-TKIs combined with radiotherapy to reduce HRUC.

Brain metastases in metastatic cancer: a review of recent advances in systemic therapies

Introduction: Brain metastases (BM) are a frequent complication of metastatic cancer. Due to the wider availability and application of screening procedures, an increasing fraction of patients are diagnosed at the asymptomatic stage. The introduction of immune checkpoint inhibitors and targeted therapies has revolutionized treatment in several frequently BM-causing entities like metastatic lung cancer, melanoma and breast cancer. However, registered trials of new targeted and immunotherapy mostly excluded patients with BM resulting in limited knowledge of the intracranial efficacy of new systemic agents.Areas covered: The present review highlights recent advances in systemic therapies for the treatment and prophylaxis of the three leading BM causing tumors: NSCLC, melanoma and breast cancer.Expert opinion: High intracranial efficacy was observed for several next-generation tyrosine kinase inhibitors as well as immune checkpoint inhibitors, especially in patients with asymptomatic disease. Ongoing discussions addressed the need for local therapies in patients with asymptomatic BM and the availability of systemic therapy with high intracranial efficacy. Further BM-specific studies as well as BM-specific endpoints in registered trials are needed to define the role of systemic monotherapies in patients with BM.

Oxidative stress associated metabolic adaptations regulate radioresistance in human lung cancer cells

Differential inherent and acquired radioresistance of human lung cancer cells contribute to poor therapeutic outcome and tumor recurrence after radiotherapy. Inherent radioresistance of lung cancer cells is known to be associated with ROS^Low cancer stem cells (CSCs). However, mechanism of acquired radioresistance in lung cancer cells is poorly understood. Here, we exposed human lung cancer cells (A549) to a cumulative dose of 40Gy and allowed the radioresistant (RR) survivors to divide and form macroscopic colonies after each fraction of 5Gy dose. The RR subline exhibited enrichment of cytosolic ROS^High cells without specific increase in mitochondrial ROS levels. We found a concomitant increase in the expression of redox regulatory transcription factor Nrf2 and its dependent antioxidant genes in RR cells and cell cycle delay as compared to parental cells. The treatment of RR cells with Nrf2 inhibitor resulted in decreased clonogenic survival indicating their addiction to Nrf2 for metabolic adaptations under high levels of cytosolic ROS. A causal role of inherent ROS levels in conferring radioresistance was established by sorting ROS^High and ROS^Low populations from parental and RR cells. It was observed that ROS^High population from both parental and RR cells exhibited radioresistance as observed by clonogenic assay. Interestingly, ROS^High population of cells exhibited higher levels of cellular thiols in both parental and RR cells. Thus, our observations highlight presence of a novel subpopulation in lung cancer cells, which exhibits radioresistance by maintaining 'oxidative stress' and Nrf2 dependent metabolic adaptations. We also posit Nrf2 pathway as a druggable target for radiosensitization of RR A549 cells.

Neurofilament Light Chain as A Biomarker for Brain Metastases

Simple Summary

Early detection of brain metastases is warranted to allow timely intervention that can improve local control and survival time. Neurofilament light chain (NfL) is a neuron-specific protein released after neuronal decay, and we evaluated blood-borne NfL as a biomarker in 43 lung cancer patients with brain metastases and 25 without brain metastasis. NfL was elevated in patients with brain metastasis and serial measurements uncovered increasing NfL levels with a median of three months before a brain metastasis was found on a brain scan. Our findings imply that measuring chances of NfL in the blood could be a potential biomarker for early detection of brain metastases.

Abstract

Background: Brain metastases are feared complications in cancer. Treatment by neurosurgical resection and stereotactic radiosurgery are only available when metastatic lesions are limited and early detection is warranted. The neurofilament light chain (NfL) is a sensitive neuron-specific biomarker released following neuronal decay. We explored serum NfL as a biomarker of brain metastases. Methods: Serum was collected from 43 stage IV lung cancer patients with brain metastases and 25 stage I lung cancer patients. Serum was collected at time of cancer diagnosis and at time of brain metastasis diagnosis. In nine patients with brain metastases, additional samples were available between the two time points. NfL was quantified by Single Molecule Array (Simoa)™. Results: The median NfL level was significantly higher in patients with brain metastases than in patients without (35 versus 16 pg/mL, p = 0.001) and separated patients with an area under the curve of 0.77 (0.66–0.89). An increase in NfL could be measured median 3 months (range: 1–5) before the brain metastasis diagnosis. Further, a high level of NfL at time of brain metastasis diagnosis correlated with an inferior survival (hazard ratio: 2.10 (95% confidence interval: 1.11–3.98)). Conclusions: This study implies that NfL could be a potential biomarker of brain metastases.

Neurological symptom burden impacts survival prognosis in patients with newly diagnosed non-small cell lung cancer brain metastases

BACKGROUND

Brain metastases (BM) are a frequent complication of advanced cancer and are characterized by a variety of neurological symptoms. Although the presence of neurological symptoms is included in the response assessment in patients with primary brain tumors, to the authors' knowledge little is known regarding the prognostic impact of neurological symptoms in patients with BM.

METHODS

Patients with newly diagnosed BM from non-small cell lung cancer were identified from the Vienna Brain Metastasis Registry and were evaluated according to the incidence, distribution, and prognostic impact of neurological symptoms at the time of diagnosis of BM.

RESULTS

A total of 1608 patients (57.3% male and 42.7% female; median age, 62 years) were available for further analyses. Neurological symptoms including focal deficits (985 patients; 61.3%), signs of increased intracranial pressure (483 patients; 30.0%), epileptic seizures (224 patients; 13.9%), and neuropsychological symptoms (233 patients; 14.5%) were documented in 1186 of the 1608 patients (73.8%). Patients with asymptomatic BM presented with a longer median overall survival after the diagnosis of BM compared with patients with symptomatic BM (11 months vs 7 months; P < .001). In multivariate analysis with a diagnosis-specific graded prognostic assessment (hazard ratio, 1.41; 95% CI, 1.33-1.50 [P < .001]), the presence of neurological symptoms (hazard ratio, 1.39; 95% CI, 1.23-1.57 [P < .001]) was found to be independently associated with survival prognosis from the time of diagnosis of BM.

CONCLUSIONS

Neurological symptoms at the time of BM diagnosis demonstrated a strong and independent association with survival prognosis. The results of the current study have highlighted the need for the integration of the presence of neurological symptoms into the prognostic assessment of patients with BM from non-small cell lung cancer.

LAY SUMMARY

Neurological symptom evaluation is included regularly in the assessment of patients with primary brain tumors. However, to the authors' knowledge, little is known regarding the prognostic impact in patients with newly diagnosed brain metastases (BM). The current study has provided a detailed clinical characterization of the incidence, distribution, and prognostic impact of neurological symptoms in a large, real-life cohort of patients with BM from non-small cell lung cancer. In this cohort, neurological symptoms at the time of diagnosis of BM demonstrated a strong, independent prognostic impact on the survival prognosis. The results of the current study have highlighted the need for the integration of neurological symptom burden into the prognostic assessment of patients with BM from non-small cell lung cancer.

Effective Treatment With Afatinib of Lung Adenocarcinoma With Leptomeningeal Metastasis Harboring the Exon 18 p.G719A Mutation in the EGFR Gene Was Detected in Cerebrospinal Fluid: A Case Report

Background: In patients with lung adenocarcinoma and leptomeningeal metastases, it remains unknown whether non-classical mutations in the epidermal growth factor receptor (EGFR) gene can be detected in the cerebrospinal fluid (CSF) and how it may be used to design directed therapy.

Methods: On April 18, 2018, the Interventional Department of Tianjin Huanhu Hospital admitted a 34-years-old male patient with lung adenocarcinoma and leptomeningeal metastasis. An emergency lateral ventriculoperitoneal shunt was performed to relieve the clinical symptoms of intracranial hypertension. Next-generation sequencing (NGS) of the CFS specimens revealed a mutation in EGFR exon 18 p.G719A, and afatinib was administered. Follow-up showed significantly relieved headache, with significantly reduced soft leptomeningeal abnormal enhancement as revealed by enhanced magnetic resonance imaging and significantly smaller tumors in the left lung by chest computed tomography. Carcinoembryonic antigens (CEAs) in cerebrospinal fluid and peripheral blood were significantly reduced. The patient responded well to afatinib, with mild adverse complications. The patient died on October 27, 2019 from respiratory failure as a result of lung infection unrelated to cancer progression. The overall survival (OS) using afatinib was 530 days.

Conclusion: CSF can be used as a liquid biopsy for NGS gene detection in patients with lung adenocarcinoma and leptomeningeal metastases. Afatinib exhibits a beneficial effect in patients with lung adenocarcinoma and leptomeningeal metastases harboring the EGFR exon 18 p.G719A mutation.

Brain metastases of lung cancer: comparison of survival outcomes among whole brain radiotherapy, whole brain radiotherapy with consecutive boost, and simultaneous integrated boost

PURPOSE

Radiotherapy is the mainstay for treating brain metastasis (BM). The objective of this study is to evaluate the overall survival (OS) of patients with BM of lung cancer treated with different radiotherapy modalities.

METHODS

Patients with BM of lung cancer who underwent radiotherapy between July 2007 and November 2017 were collected, and their baseline demographics, clinicopathological characteristics and treatments were recorded. Survival was estimated by the Kaplan-Meier method and compared by using the log-rank test. Univariate and multivariate analysis of the prognostic factors were performed using the Cox proportional hazard regression model.

RESULTS

A total of 144 patients were enrolled, of whom 77 underwent whole-brain radiotherapy (WBRT), 39 underwent whole brain radiotherapy with consecutive boost (WBRT + boost), and 28 underwent integrated simultaneous integrated boost intensity-modulated radiotherapy (SIB-IMRT). The OS in SIB-IMRT group was significantly longer than that in WBRT group (median OS 14 (95% confidence interval [CI] 8.8-19.1) vs.7 (95% CI 5.5-8.5) months, log-rank p < 0.001) and WBRT + boost group (median OS: 14 (95% CI 8.8-19.1) vs.11 (95% CI 8.3-13.7) months, log-rank p = 0.037). Multivariable analysis showed that mortality risk of patients treated with SIB-IMRT decrease by 56, 59, 64 and 64% in unadjusted model (hazard ratio [HR] = 0.44; 95% CI 0.28-0.70, p < 0.001), model 1 (HR = 0.41; 95% CI 0.26-0.65, p < 0.001), model 2 (HR = 0.36; 95% CI 0.21-0.61, p < 0.001), and model 3 (HR = 0.36; 95% CI 0.21-0.61, p < 0.001).

CONCLUSIONS

For patients with BM of lung cancer, SIB-IMRT seems to be associated with a more favorable prognosis.

Economic burden in patients with ALK + non-small cell lung cancer, with or without brain metastases, receiving second-line anaplastic lymphoma kinase (ALK) inhibitors

Aims: To describe the real-world economic burden of patients with anaplastic lymphoma kinase-positive (ALK+) non-small cell lung cancer (NSCLC) treated with post-crizotinib, second-line ALK inhibitor therapy.Materials and methods: Retrospective analysis using data from US Optum: Clinformatics Data Mart administrative claims database. Adult patients with ALK + NSCLC treated with ceritinib or alectinib as second-line ALK inhibitors between 1 January 2011 and 30 September 2017 were included. Healthcare costs and resource utilization for up to 1 year of therapy were calculated on a per-patient-per-month (PPPM) basis and stratified by presence or absence of brain metastases (BM). Multivariate regression analysis was performed to identify factors associated with costs. Top ten cost drivers of non-inpatient procedure costs were recorded.Results: One hundred and twelve patients received second-line ALK inhibitors. Total mean PPPM healthcare costs were $23,984 for all patients receiving up to 1 year of post-crizotinib, second-line ALK inhibitor therapy. Total mean PPPM costs for patients with BM on or prior to post-crizotinib, second-line ALK inhibitor therapy were 1.37-times as high as those for patients without BM (p = 0.0406). Mean PPPM outpatient visits and inpatient hospitalization stays were higher for patients with BM versus no BM. The main cost drivers for non-inpatient procedures were radiation therapy, medications, and diagnostic radiology.Limitations: Analyses did not include newer ALK-directed therapies. BM development after the index date (defined as the date of the first claim for a second-line ALK inhibitor) may have been misclassified as non-BM. Findings may not be generalizable to patients with no health insurance coverage.Conclusions: Treatment of patients with ALK + NSCLC with ceritinib or alectinib as post-crizotinib, second-line ALK inhibitor therapy represents a high economic burden. Healthcare costs and resource utilization were significantly higher for patients with ALK + NSCLC with BM versus no BM.

Incidence of hippocampal metastases in non-small-cell lung cancer

OBJECTIVES

Patients with locally advanced non-small-cell lung cancer (LA-NSCLC) develop brain metastases in 25-50% of cases during the course of their disease. Data on the incidence of metastases occurring in the hippocampus/perihippocampal zones are limited. This is important when considering hippocampal-sparing brain radiation (HS-BR), a method that could potentially reduce the neurocognitive impact of such treatment. The aim of this study was to assess the incidence of hippocampal/perihippocampal metastases in a cohort of patients with advanced NSCLC treated at our institution.

METHODS

This retrospective cohort study included NSCLC patients discussed at our institutional lung cancer multidisciplinary meeting between 2000 and 2016. MRI and contrast-enhanced CT (ceCT) brain images were reviewed to assess the incidence of hippocampal/perihippocampal metastases including metastases within the hippocampal subgranular zone and a 5 mm margin (hippocampal avoidance region) defined as per the RTOG 0933 study.

RESULTS

Of 2146 patients reviewed, 357 (16.6%) had brain metastases. A total of 335 patients had available MRI/ceCT brain images for review. Thirty (9%) patients had brain metastases in the hippocampal avoidance region, 8 (2.4%) with hippocampal metastases and 22 (6.6%) with perihippocampal metastases. Univariate analyses did not show an association between developing metastases in the hippocampal avoidance region and age (P = 0.75), gender (P = 0.91) and tumour type (P = 0.298).

CONCLUSION

The incidence of metastases in the hippocampal avoidance region in our large cohort of patients was 9%. With low rates of metastases in this region, HS-BR can be considered a feasible option in the management of patients with advanced NSCLC.

Can stress promote the pathophysiology of brain metastases? A critical review of biobehavioral mechanisms

Chronic stress can promote tumor growth and progression through immunosuppressive effects and bi-directional interactions between tumor cells and their microenvironment. β-Adrenergic receptor signaling plays a critical role in mediating stress-related effects on tumor progression. Stress-related mechanisms that modulate the dissemination of tumor cells to the brain have received scant attention. Brain metastases are highly resistant to chemotherapy and contribute considerably to morbidity and mortality in various cancers, occurring in up to 20% of patients in some cancer types. Understanding the mechanisms promoting brain metastasis could help to identify interventions that improve disease outcomes. In this review, we discuss biobehavioral, sympathetic, neuroendocrine, and immunological mechanisms by which chronic stress can impact tumor progression and metastatic dissemination to the brain. The critical role of the inflammatory tumor microenvironment in tumor progression and metastatic dissemination to the brain, and its association with stress pathways are delineated. We also discuss translational implications for biobehavioral and pharmacological interventions.

Management of CNS metastases in patients with EGFR mutation-positive NSCLC

Central nervous system (CNS) metastases are a frequent and severe complication associated with epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC). The first- and second-generation EGFR tyrosine kinase inhibitors (TKIs) have shown considerable efficacy in EGFR-mutated NSCLC. However, their limited potential to cross the blood-brain barrier (BBB) renders them less effective in the management of CNS metastases in NSCLC. Osimertinib, a third-generation irreversible EGFR-TKI with good potential to cross the BBB, has shown significant clinical activity and acceptable safety profile in patients with EGFR-positive NSCLC brain and leptomeningeal metastases. The progression-free survival (PFS) of up to 15.2 months in CNS metastases patients in the FLAURA trial and the CNS objective response rates (ORRs) of 54% and 43% in the AURA/AURA2 and BLOOM trials, respectively, have established the role of osimertinib in patients with NSCLC with CNS metastases. The AURA3 trial also reported a PFS of 8.5 months and overall ORR of 71%. These data have supported osimertinib to be recognized as a "preferred" first-line treatment for EGFR-positive metastatic NSCLC by the National Comprehensive Cancer Network (NCCN). With limited treatment options available, upfront administration of osimertinib in patients with NSCLC irrespective of EGFR T790M and CNS metastases may improve the overall response rate and potentially reduce the adverse effects of radiotherapy. Our review focuses on the management of EGFR-mutated NSCLC CNS metastases in the context of recent NCCN guidelines.

High Biologically Effective Dose Radiotherapy for Brain Metastases May Improve Survival and Decrease Risk for Local Relapse Among Patients With Small-Cell Lung Cancer: A Propensity-Matching Analysis

To evaluate whether high biologically effective dose (BED) radiotherapy improves local control and survival outcomes for patients with brain metastases (BMs) from small-cell lung cancer (SCLC) and to determine possible prognostic factors. From January 1998 to June 2018, 250 patients with BM from SCLC were retrospectively analyzed. The Cutoff Finder program was used to classify patients by BED. Overall survival (OS) and BM progression-free survival (BM-PFS) were analyzed using the Kaplan-Meier method and log-rank test. A Cox regression model was used to calculate the hazard ratio and 95% CI for prognostic factors for OS among the study population and propensity score (PS)-matched patients. A BED of 47.4 was taken as the optimal cutoff value. Both OS and BM-PFS were significantly improved in the high-BED (>47.4 Gy) than in the low-BED (≤47.4 Gy) group (median OS: 17.5 months vs 9.5 months, P < .001, median BM-PFS: 14.4 months vs 8.3 months, P < .001). Biologically effective dose (P < .001), Eastern Cooperative Oncology Group performance status (P = .047), smoking (P = .005), and pleural effusion (P = .004) were independent prognostic factors for OS. Propensity score matching with a ratio of 1:2 resulted in 57 patients in the high-BED group and 106 patients in the low-BED group. In the PS-matched cohort, OS and BM-PFS were significantly prolonged in the high-BED group compared with the low-BED group (P < .001). Biologically effective dose >47.4 Gy improves survival among patients with BM from SCLC. Eastern Cooperative Oncology Group score, smoking, and pleural effusion independently affect OS of SCLC patients with BM.

S100B as a biomarker for brain metastases in patients with non-small cell lung cancer

Brain metastases are frequent in patients with lung cancer and a major cause of morbidity and mortality. Finding a biomarker predicting brain metastases could facilitate early start of treatment and thereby reduce morbidity and possibly improve overall survival. Previous studies suggest S100B as a possible biomarker for this purpose. This prospective study enrolled 185 patients with newly diagnosed stage IV non-small cell lung cancer (NSCLC). A total of 22 patients had brain metastases verified by magnetic resonance imaging or computed tomography at the time of enrollment. Serum S100B levels were measured in blood samples collected prior to any treatment from 22 patients who had brain metastases at enrollment and from 50 patients randomly selected from the remaining 163 patients without brain metastases at enrollment. No statistically significant difference was found in the levels of serum S100B between patients with and without brain metastases [range 0.018-0.209 µg/l, mean 0.049 µg/l, 95% confidence interval (CI), 0.032-0.061 µg/l] and (range 0.016-0.130 µg/i, mean 0.044 µg/l, 95% CI, 0.037-0.051 µg/l), respectively, (P=0.852). Univariate analysis of prognostic factors for S100B indicated a correlation (P<0.2) with sex (P=0.088) and histology (adenocarcinoma vs. squamous cell carcinoma/others) (P=0.028). In the multivariate analysis only histology (P=0.029) remained statistically significant. Conclusion: The present study found no significant correlation between the level of serum S100B and the presence of brain metastases in patients with advanced NSCLC. The clear cut-off of S100B in patients with and without brain metastases reported in other studies could not be verified in this study. Further studies investigating the role of S100B as a biomarker for brain metastases in non-small cell lung cancer are warranted.

Tyrosine Kinase Inhibitors Could Be Effective Against Non-small Cell Lung Cancer Brain Metastases Harboring Uncommon EGFR Mutations

Background: The significance of uncommon epidermal growth factor receptor (EGFR) mutations in patients with non-small cell lung cancer (NSCLC) and brain metastasis (BM) remains unclear. Cerebrospinal fluid (CSF) liquid biopsy is a novel tool for assessing EGFR mutations in BM. This study aimed to evaluate the EGFR mutations in patients with NSCLC and newly diagnosed BM and to examine the effect of EGFR tyrosine kinase inhibitors (TKI) on BM harboring CSF-tested uncommon EGFR mutations.

Methods: This was a prospective study of 21 patients with NSCLC and BM diagnosed between 04/2018 and 01/2019. CSF was obtained to detect the BM EGFR mutations by next-generation sequencing. BM characteristics at magnetic resonance imaging (MRI) and EGFR-TKI response were examined.

Results: Of 21 patients with NSCLC, 10 (47.6%) had leptomeningeal metastasis (LM), while 11 (52.4%) had brain parenchymal metastasis (BPM); 13 (61.9%) had confirmed EGFR mutation-positive primary tumors. The uncommon mutation rate in CSF ctDNA was 33.3% (7/21). Among those with EGFR mutation-positive primary tumors, the rate of uncommon EGFR mutations in CSF was 53.8% (7/13). Uncommon EGFR mutations were more common in patients with LM than in patients with PBM (6/11, 54.5% vs. 1/10, 10%), and included G719A, L861Q, L703P, and G575R. TKI was effective for four patients with BMs harboring uncommon EGFR mutations.

Conclusion: In patients with NSCLC and LM, the rate of uncommon EGFR mutation was high. The BMs with uncommon EGFR mutations seem to respond to EGFR-TKI treatment. CSF liquid biopsy could reveal the EGFR genetic profile of the BM and help guide treatment using small-molecule TKI.

Brain Metastases in Lung Cancers with Emerging Targetable Fusion Drivers

The management of non-small cell lung cancer (NSCLC) has transformed with the discovery of therapeutically tractable oncogenic drivers. In addition to activating driver mutations, gene fusions or rearrangements form a unique sub-class, with anaplastic lymphoma kinase (ALK) and c-ros oncogene 1 (ROS1) targeted agents approved as the standard of care in the first-line setting for advanced disease. There are a number of emerging fusion drivers, however, including neurotrophin kinase (NTRK), rearrangement during transfection (RET), and neuregulin 1 (NRG1) for which there are evolving high-impact systemic treatment options. Brain metastases are highly prevalent in NSCLC patients, with molecularly selected populations such as epidermal growth factor receptor (EGFR) mutant and ALK-rearranged tumors particularly brain tropic. Accordingly, there exists a substantial body of research pertaining to the understanding of brain metastases in such populations. Little is known, however, on the molecular mechanisms of brain metastases in those with other targetable fusion drivers in NSCLC. This review encompasses key areas including the biological underpinnings of brain metastases in fusion-driven lung cancers, the intracranial efficacy of novel systemic therapies, and future directions required to optimize the control and prevention of brain metastases.

Beyond the Blood: CSF-Derived cfDNA for Diagnosis and Characterization of CNS Tumors

Genetic data are rapidly becoming part of tumor classification and are integral to prognosis and predicting response to therapy. Current molecular tumor profiling relies heavily on tissue resection or biopsy. Tissue profiling has several disadvantages in tumors of the central nervous system, including the challenge associated with invasive biopsy, the heterogeneous nature of many malignancies where a small biopsy can underrepresent the mutational profile, and the frequent lack of obtaining a repeat biopsy, which limits routine monitoring to assess therapy response and/or tumor evolution. Circulating tumor, cell-free DNA (cfDNA), has been proposed as a liquid biopsy to address some limitations of tissue-based genetics. In cancer patients, a portion of cfDNA is tumor-derived and may contain somatic genetic alterations. In central nervous system (CNS) neoplasia, plasma tumor-derived cfDNA is very low or absent, likely due to the blood brain barrier. Interrogating cfDNA in cerebrospinal fluid (CSF) has several advantages. Compared to blood, CSF is paucicellular and therefore predominantly lacks non-tumor cfDNA; however, patients with CNS-limited tumors have significantly enriched tumor-derived cfDNA in CSF. In patients with metastatic CNS disease, mutations in CSF cfDNA are most concordant with the intracranial process. CSF cfDNA can also occasionally uncover additional genetic alterations absent in concurrent biopsy specimens, reflecting tumor heterogeneity. Although CSF is enriched for tumor-derived cfDNA, absolute quantities are low. Highly sensitive, targeted methods including next-generation sequencing and digital PCR are required to detect mutations in CSF cfDNA. Additional technical and bioinformatic approaches also facilitate enhanced ability to detect tumor mutations in CSF cfDNA.

Evaluation of radiotherapy combined with targeted therapy and concurrent radiotherapy, chemotherapy in the treatment of Non-Small Cell Lung Cancer with brain metastasis

Objective:

To compare and analyze the clinical efficacy of brain radiotherapy combined with targeted therapy and concurrent radiotherapy and chemotherapy in the treatment of non-small cell lung cancer (NSCLC) with brain metastasis.

Methods:

Fifty-eight patients with NSCLC with brain metastasis who were admitted to our hospital between October 2016 and October 2017 were randomly divided into a control group and an observation group, 29 cases in each group. The control group was treated with concurrent radiotherapy and chemotherapy, while the observation group was treated with whole brain radiotherapy plus targeted therapy. The disease control rate, adverse reactions and survival condition were compared between the two groups.

Results:

The disease control rate of the observation group was 68.97%, significantly higher than 41.38% of the control group (P<0.05); the total incidence of adverse reactions in the observation group was 6.90%, significantly lower than 24.14% of the control group (P<0.05); the median survival time of the observation group was (16.81±5.32) months, significantly longer than that of the control group ((9.76±3.25) months). The one-year and two-year survival rates in the observation group were significantly higher than those in the control group (P<0.05).

Conclusion:

Whole brain radiotherapy combined with targeted therapy is superior to concurrent radiotherapy and chemotherapy in the treatment of NSCLC with brain metastasis and has high safety. It can effectively prolong the life span of patients and is worth clinical promotion and application.

Detection of circulating tumor DNA from non-small cell lung cancer brain metastasis in cerebrospinal fluid samples

Background

Evaluating the molecular characteristics of brain metastases is limited by difficult access and by the blood–brain barrier, which prevents circulating tumor DNA (ctDNA) from entering the blood. In this study, we aimed to compare the sequencing results from cerebrospinal fluid (CSF) ctDNA versus plasma ctDNA, plasma circulating tumor cells (CTCs), and brain tissue specimens from patients with brain metastasis from non‐small cell lung cancer (NSCLC).

Methods

This was a prospective study of 21 consecutive patients with NSCLC and brain metastasis diagnosed between April 2018 and January 2019. Samples of CSF and peripheral blood were obtained from all 21 patients. Brain tissues were obtained from five patients after surgical resection. Next‐generation sequencing was performed using the Ion system. Single nucleotide variants (SNVs) and small insertions or deletions (indels) were searched.

Results

Mutations were detected in the CSF ctDNA of 20 (95.2%) patients. The detection rate of epidermal growth factor receptor (EGFR) mutations in CSF ctDNA was 57.1% (12/21) whereas this rate was only 23.8% (5/21) in peripheral blood ctDNA and in CTCs. EGFR mutations were found in the CSF of 9 of 11 (81.8%) patients with leptomeningeal metastases, as compared with three of 10 (30%) patients with brain parenchymal metastases. Mutations were also detected in KIT, PIK3CA, TP53, SMAD4, ATM, SMARCB1, PTEN, FLT3, GNAS, STK11, MET, CTNNB1, APC, FBXW7, ERBB4, and KDR (all >10%). The status of EGFR and TP53 mutations was consistent between CSF ctDNA and brain lesion tissue in all five patients.

Conclusion

Sequencing of CSF ctDNA revealed specific mutation patterns in driver genes among patients with NSCLC and brain metastasis.

Key points

In some small‐sample studies, the importance of cerebrospinal fluid in guiding the treatment of cancerous brain lesions has been verified in that it may reflect genomic mutations of brain tumors relatively accurately.

Cerebrospinal fluid is a new form of liquid biopsy that can be helpful in improving the management of patients with brain metastasis from non‐small cell lung cancer by detecting genetic abnormalities specific to brain metastases.

Successful osimertinib rechallenge following drug-induced pneumonitis after previous anti-PDL1 exposure

Osimertinib is a first-line treatment option for patients with metastatic non-small cell lung cancer (NSCLC) harbouring EGFR mutations. Pneumonitis is a severe adverse event (AE) related to osimertinib treatment which appears to be more frequent when associated with concurrent or previous anti-PD(L)1 exposure. Data regarding the efficacy and safety of osimertinib rechallenge, especially in the setting of central nervous system (CNS) metastases, are scarce. We herein describe a case of a 53-year-old patient with metastatic EGFR-mutated NSCLC, who developed pneumonitis after osimertinib treatment and was successfully rechallenged with 40 mg daily osimertinib, with CNS response. This dose reduction strategy may be an option for selected patients with brain metastases after tyrosine kinase inhibitors-induced AEs.

Bevacizumab suppresses the growth of established non-small-cell lung cancer brain metastases in a hematogenous brain metastasis model

Brain metastases are common in patients with non-small-cell lung cancer (NSCLC). The efficacy of bevacizumab, an anti-vascular endothelial growth factor (VEGF) humanized antibody, has been demonstrated in patients with nonsquamous NSCLC. We established a transplantable NSCLC cell line (Nluc-H1915) that stably expresses NanoLuc® reporter and confirmed the correlation between total Nluc activity in tumor and tumor volume in vivo. SCID mice inoculated with these cells through the internal carotid artery formed reproducible brain metastases, in which human VEGF was detected. Next, after metastases were established in the model mice (15-17 days), they were intraperitoneally administered weekly doses of human immunoglobulin G (HuIgG) or bevacizumab. Nluc activity in the brain was significantly lower in bevacizumab-treated mice than in HuIgG-treated mice. Additionally, bevacizumab concentration in the brain was higher in mice with brain metastasis than in normal mice, and bevacizumab was primarily observed in brain metastasis lesions. The microvessel density in brain metastasis was lower in bevacizumab-treated mice than in HuIgG-treated mice. We believe bevacizumab's anti-proliferative effect on brain metastasis is due to anti-angiogenic activity achieved by its penetration into brain metastases; this suggests that a bevacizumab-containing regimen may be a promising treatment option for patients with NSCLC brain metastasis.

Demographic and Socioeconomic Factors for Renouncing Further Active Therapy for Patients with Brain Metastasis of Non-Small Cell Lung Cancer

Background

As patients with brain metastasis (BM) of non-small cell lung cancer (NSCLC) have dismal prognosis, some of them decide to discontinue further treatment for BM. The objective of this study was to determine factors for renouncing further active therapy in patients with BM of NSCLC, focusing on their demographic and socioeconomic status.

Methods

Medical records of 105 patients with radiological diagnosis of BM of NSCLC for the recent 11 years at authors' institution were retrospectively reviewed. Clinical features as well as demographic and socioeconomic characteristics such as marriage status, cohabiting family members, religious affiliations, educational background, and economic responsibility were reviewed.

Results

Median overall survival (OS) was 13.84 (95% CI: 10.26–17.42) years in 67 patients (group A) who underwent active treatment (radiotherapy and/or chemotherapy) and 4.76 (95% CI: 3.12–6.41) years in 38 patients (group B) who renounced active treatment. Less patients were unmarried (p=0.046), more cohabitating family members (p=0.008), and economically independent (p=0.014) in group A than those in group B. Similarly, the unmarried, and none cohabitating family members had short OS (5.17 and 7.38 years, respectively). In multivariate analysis for predisposing factors of OS in these patients, the following demographic and socioeconomic factors had independent significance: marriage status and cohabitating family members.

Conclusion

This study suggests that demographic and socioeconomic status as well as clinical factors could influence the decision of further active treatment and prognosis of patients with BM of NSCLC.

Changing equipoise in the landscape of radiation for oligometastatic lung cancer

There is growing interest in exploring use of local therapies in the management of oligometastatic non-small cell lung cancer (NSCLC) to provide durable local and distant disease control. Prospective phase II studies have incorporated local therapy (predominantly stereotactic ablative radiotherapy or SABR) to both primary and metastatic sites. For patients who received these treatments, median progression-free survival (PFS) and overall survival (OS) exceeded that of historical controls treated with systemic therapy alone (9.7-23.5 and 13.5-41.2 months, respectively). Additionally, three trials randomized oligometastatic NSCLC patients to standard of care systemic therapy regimens vs. local consolidative therapy (LCT) plus standard of care systemic therapy (or observation) and all demonstrated a significant improvement in PFS, with two showing OS benefits to date. Notably, a majority of these trials selected patients with at least stable disease after completion of systemic therapy for local therapy and defined the oligometastatic state as one with no more than five metastatic sites spread across three organs. For patients with oligometastatic NSCLC, there are many important factors that should drive use and timing of local therapy, including metastatic presentation sequence (synchronous vs. metachronous), extent of disease (number and distribution of sites), and quality of life goals. The referenced clinical trials accrued patients prior to the approval of immunotherapy for metastatic NSCLC, so the benefits of any local therapy in this setting remain uncertain. To ultimately clarify the role of local therapy in oligometastatic NSCLC in the era of improving systemic therapy efficacy (i.e., immunotherapy and targeted therapy combinations with cytotoxics), we recommend enrollment in in phase III studies with OS endpoints (i.e., NRG LU 002 and SARON) whenever possible. These and other important issues associated with local therapy for oligometastatic NSCLC are reviewed in this paper.

Dynamic transition of the blood-brain barrier in the development of non-small cell lung cancer brain metastases

Invasion of the brain by non-small cell lung cancer (NSCLC) results in a shift of the blood-brain barrier (BBB) to the insufficiently characterized blood-tumor barrier (BTB). Effective drug delivery through the BTB is one of the greatest therapeutic obstacles in treating brain metastases. Using an experimental model, we defined key changes within the BTB and the BBB in the brain around the tumor (BAT) region over time. Brain-seeking NSCLC cells were delivered into the circulation of athymic-nude mice via intracardiac injection and developing brain metastases were evaluated over six-weeks. Components of the BBB and BTB were analyzed using immunofluorescence microscopy and compared using a mixed model of regression. Our results demonstrate a dynamic time-dependent BTB phenotype. Capillaries of the BAT and BTB were dilated with increased CD31 expression compared to controls. Expression of collagen IV, a pan-basement membrane component, was significantly decreased in the BTB compared to the BBB. There was also a significant increase in the desmin-positive pericyte subpopulation in the BTB compared to the BBB. The most striking changes were identified in astrocyte water channels with a 12.18-fold (p < 0.001) decrease in aquaporin-4 in the BTB; the BAT was unchanged. Analysis of NSCLC brain metastases from patient samples similarly demonstrated dilated capillaries and loss of both collagen IV and aquaporin-4. These data provide a comprehensive analysis of the BTB in NSCLC brain metastasis. Astrocytic endfeet, pericytes, and the basement membrane are potential therapeutic targets to improve efficacy of chemotherapeutic delivery into NSCLC brain metastases.

Detailed analysis of 5-aminolevulinic acid induced fluorescence in different brain metastases at two specialized neurosurgical centers: experience in 157 cases

OBJECTIVE

Incomplete neurosurgical resection of brain metastases (BM) due to insufficient intraoperative visualization of tumor tissue is a major clinical challenge and might result in local recurrence. Recently, visible 5-aminolevulinic acid (5-ALA) induced fluorescence was first reported in patients with BM. The aim of this study was thus to investigate, for the first time systematically, the value of 5-ALA fluorescence for intraoperative visualization of BM in a large patient cohort.

METHODS

Adult patients (≥ 18 years) with resection of suspected BM after preoperative 5-ALA administration were prospectively recruited at two specialized neurosurgical centers. During surgery, the fluorescence status (visible or no fluorescence); fluorescence quality (strong, vague, or none); and fluorescence homogeneity (homogeneous or heterogeneous) of each BM was investigated. Additionally, these specific fluorescence characteristics of BM were correlated with the primary tumor type and the histopathological subtype. Tumor diagnosis was established according to the current WHO 2016 criteria.

RESULTS

Altogether, 157 BM were surgically treated in 154 patients. Visible fluorescence was observed in 104 BM (66%), whereas fluorescence was absent in the remaining 53 cases (34%). In detail, 53 tumors (34%) showed strong fluorescence, 51 tumors (32%) showed vague fluorescence, and 53 tumors (34%) had no fluorescence. The majority of BM (84% of cases) demonstrated a heterogeneous fluorescence pattern. According to primary tumor, visible fluorescence was less frequent in BM of melanomas compared to all other tumors (p = 0.037). According to histopathological subtype, visible fluorescence was more common in BM of ductal breast cancer than all other subtypes (p = 0.008). It is of note that visible fluorescence was observed in the surrounding brain tissue after the resection of BM in 74 (67%) of 111 investigated cases as well.

CONCLUSIONS

In this largest series to date, visible 5-ALA fluorescence was detected in two-thirds of BM. However, the characteristic heterogeneous fluorescence pattern and frequent lack of strong fluorescence limits the use of 5-ALA in BM and thus this technique needs further improvements.

Candidate genes and pathways associated with brain metastasis from lung cancer compared with lymph node metastasis

Brain metastasis from lung cancer (BMLC) is one of the common types of metastasis associated with poor prognosis. The aim of the present study was to elucidate the underlying molecular mechanisms of BMLC. The mRNA microarray dataset GSE18549 was downloaded from the Gene Expression Omnibus database. The Limma package of R was used to screen the differentially expressed genes (DEGs). Based on the DAVID database, functional and pathway enrichment analyses of DEGs were performed. Furthermore, the protein-protein interaction (PPI) network was predicted using the STRING database and visualized with Cytoscape software. In addition, hub genes and significant modules were selected based on the network. A total of 190 DEGs with log₂|(fold change)|>1, including 129 significantly downregulated DEGs and 61 upregulated DEGs, were obtained. Gene Ontology functional enrichment analysis indicated that downregulated DEGs were mainly associated with ‘immune response’, ‘cell activation’ and ‘leukocyte activation’, while the upregulated DEGs were involved in ‘DNA repair’ and ‘viral process’. Kyoto Encyclopedia of Genes and Genomes pathway analysis indicated that the downregulated DEGs were mainly enriched in ‘chemokine signaling pathway’, whereas the upregulated DEGs were associated with ‘oocyte meiosis’. Based on the PPI network, 9 hub genes were selected, namely tumor necrosis factor, C-C motif chemokine ligand (CCL) 2, CD34, vascular cell adhesion molecule 1, CD48, CD27, CCL19, C-X-C motif chemokine receptor 6 and C-C motif chemokine receptor 2. The present study sheds light on the molecular mechanisms of BMLC and may provide molecular targets and diagnostic biomarkers for BMLC.

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

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

Review: Peering through a keyhole: liquid biopsy in primary and metastatic central nervous system tumours

Tumour molecular profiling by liquid biopsy is being investigated for a wide range of research and clinical purposes. The possibility of repeatedly interrogating the tumour profile using minimally invasive procedures is helping to understand spatial and temporal tumour heterogeneity, and to shed a light on mechanisms of resistance to targeted therapies. Moreover, this approach has been already implemented in clinical practice to address specific decisions regarding patients’ follow‐up and therapeutic management. For central nervous system (CNS) tumours, molecular profiling is particularly relevant for the proper characterization of primary neoplasms, while CNS metastases can significantly diverge from primary disease or extra‐CNS metastases, thus compelling a dedicated assessment. Based on these considerations, effective liquid biopsy tools for CNS tumours are highly warranted and a significant amount of data have been accrued over the last few years. These results have shown that liquid biopsy can provide clinically meaningful information about both primary and metastatic CNS tumours, but specific considerations must be taken into account, for example, when choosing the source of liquid biopsy. Nevertheless, this approach is especially attractive for CNS tumours, as repeated tumour sampling is not feasible. The aim of our review was to thoroughly report the state‐of‐the‐art regarding the opportunities and challenges posed by liquid biopsy in both primary and secondary CNS tumours.

Survival and intracranial control outcomes of whole-brain radiotherapy (WBRT) alone versus WBRT plus a radiotherapy boost in non-small-cell lung cancer with brain metastases: a single-institution retrospective analysis

Purpose: To compare the differences in survival and intracranial local control between patients treated with whole-brain radiotherapy (WBRT) and WBRT plus a radiotherapy boost (RTB) in non-small-cell lung cancer (NSCLC) patients with brain metastases (BMs).

Patients and methods: Between May 2010 and October 2017, 206 NSCLC patients with BMs were treated with brain radiotherapy; among these patients, 140 patients underwent WBRT alone (group A) and 66 patients underwent WBRT plus RTB (group B). The endpoints included intracranial local progression-free survival and regional progression-free survival time (iLPFS and iRPFS, respectively) and overall survival (OS).

Results: Between the two groups, not all baseline clinical factors were well-balanced. The median iLPFS was 17.9 months in group A and 22.3 months in group B. The 2-year iLPFS rates were significantly lower in group A than in group B (34.5% vs 49.3%, P=0.041); however, no significant differences were observed in OS or iRPFS. Multivariate analyses revealed that epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) therapy was significantly associated with good OS, iLPFS, and iRPFS. Among the patients treated with TKIs (n=62), there were no differences in OS (P=0.190), iLPFS (P=0.334), or iRPFS (P=0.338) between groups A and B. In the patients without TKI treatment (n=102), the median iLPFS was significantly longer in group B than in group A (16.7 vs 12.0 months, P=0.032), but no significant differences were found in OS (p=0.182) or iRPFS (P=0.837) between the two groups.

Conclusion: WBRT plus RTB significantly improved iLPFS compared with WBRT alone, especially in patients without EGFR-TKI treatment. However,there were no significant differences in iRPFS or OS between the two groups. Patients treated with EGFR-TKIs may not benefit from WBRT plus RTB.