Factors associated with the development of brain metastases: analysis of 975 patients with early stage nonsmall cell lung cancer

A Comprehensive Meta-Analysis of Association between EGFR Mutation Status and Brain Metastases in NSCLC

Non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) mutation have different clinicopathological characteristics compared with EGFR wild type NSCLC. A growing number of studies focused on the relevance between EGFR mutation status and brain metastases (BM) in NSCLC, but it remains controversial. Therefore, this study performed a comprehensive meta-analysis to untangle this issue. Several electronic databases including Pubmed, Embase, Web of science and Cochrane database were thoroughly searched. The odds ratio (OR) with 95% confidence interval (95%CI) was pooled to evaluate the relevance. Meta-regression analysis and subgroup analysis were conducted according to the heterogeneity. A total of 26 studies were identified finally in this meta-analysis. The overall OR was 1.58 (95%CI: 1.36-1.84), which indicated that EGFR mutation had a positive association with BM of NSCLC. The subgroup analysis resulted from eleven studies with lung adenocarcinoma revealed a higher possibility of BM in NSCLC with EGFR mutation compared with EGFR wild (p < 0.05). There was no significant difference in the risk of BM between NSCLC EGFR exon 19 mutation and exon 21 point mutation (p = 0.23). This meta-analysis suggests that EGFR mutation can be a risk factor for BM in NSCLC.

Histopathologic analysis of brain metastasis in pulmonary adenocarcinoma: Necrosis is a new risk factor

BACKGROUND

Studies have shown that 30-50% of non-small cell lung cancer (NSCLC) patients develop brain metastasis (BM). Since BM shortens overall survival and decreases the quality of life, early detection and treatment of BM are vital. While data are available for clinical risk factors of NSCLC with BM, histopathological factors are not well understood. Therefore, we evaluated the histopathological related factors which will help early detection and selection of effective treatment options.

MATERIALS AND METHODS

A total of 117 surgical lung specimens diagnosed as NSCLC with BM were included as a study group. We included 237 cases without BM as a control group. One pathologist reviewed H&E slides and analyzed the histopathologic factors of all cases.

RESULTS

In pulmonary adenocarcinoma, vascular invasion, N stage, micropapillary pattern and necrosis were significantly associated with BM in multivariate analysis (vascular invasion, p = 0.009; micropapillary pattern, p = 0.024; others, p < 0.001). Tumor with extensive necrosis had higher hazard ratio and shorter time to BM (p < 0.001).

CONCLUSION

Our findings suggest that necrosis is a new predictive factor of BM in pulmonary adenocarcinoma. Short term follow-up is needed especially when extensive necrosis is present.

PSPH Mediates the Metastasis and Proliferation of Non-small Cell Lung Cancer through MAPK Signaling Pathways

Growing evidence indicates that phosphoserine phosphatase (PSPH) is up-regulated and correlates with prognosis in multiple types of cancer. However, little is known about the roles of PSPH in NSCLC. Thus, the aim of the present study was to demonstrate the expression of PSPH in human NSCLC and reveal its biological functions and the underlying mechanisms. qRT-PCR, western blot and immunohistochemistry were used to assess the expression of NSCLC patient specimens and NSCLC cell lines. The functions of PSPH in migration and invasion were determined using trans-well and wound-healing assays. Cell proliferation capacity was performed by cell counting kit-8 (CCK-8), colony formation assays and cell cycle analysis. We demonstrated that PSPH was overexpressed in NSCLC specimens compared with the adjacent non-tumorous specimens, and high expression of PSPH was associated with clinical stage, metastasis and gender in NSCLC. Decreased expression of PSPH inhibited NSCLC cells migration, invasion and proliferation. Most importantly, further experiments demonstrated that PSPH might regulate NSCLC progress through MAPK signaling pathways. Lastly, immunohistochemistry (IHC) revealed that the PSPH expression level was positively correlated with the clinical stage in NSCLC patients. These results suggest that PSPH may act as a putative oncogene and a potential therapeutic target in NSCLC.

Identification of potential biomarkers of lung adenocarcinoma brain metastases via microarray analysis of cDNA expression profiles

Brain metastases originating from lung adenocarcinoma (LAD) occur frequently. The aim of the current study was to assess potential biomarkers for the prognosis of lung adenocarcinoma brain metastasis (LAD-BM) through the analysis of gene expression microarrays. The current study downloaded two gene expression datasets, GSE14108 and GSE10245, from the Gene Expression Omnibus database. From GSE14108 and GSE10245, 19 LAD-BM samples and 40 primary LAD samples were selected for analysis. To identify the differentially expressed genes (DEGs), the current study compared the two sample groups, using the limma R package. Subsequently, pathway enrichment analysis was conducted using the Cluster Profiler R package, and the construction of the protein-protein interaction (PPI) network was executed utilizing the Search Tool for the Retrieval of Interacting Genes database. The microRNA-target network was built using the TargetScore R package. Then, these networks were established and visualized using Cytoscape software. An array of 463 DEGs was identified in the LAD-BM samples, including 256 upregulated and 207 downregulated genes. Based on functional term enrichment analysis using the Gene Ontology database and signaling pathway enrichment analysis using the Kyoto Encyclopedia of Genes and Genomes database, it was identified that the overlapping DEGs were primarily involved in chemokine-associated signal transduction, which may mediate lung cancer cell metastasis to the brain. Chemokine ligand 2, lysozyme, matrix metalloproteinase-2 (MMP-2), lysyl oxidase (LOX) and granzyme B were identified as potential biomarkers according to a topological analysis of the PPI networks. Two notable nodes, MMP-2 and LOX, appeared in the PPI network and were key points in the microRNA-target network, as they were regulated by hsa-let-7d. Many DEGs and microRNAs were regarded as prognostic biomarkers for lung adenocarcinoma metastasis in the current study. These DEGs were primarily associated with chemokine-mediated signaling pathways. In addition, MMP-2 and LOX were predicted to be targets of hsa-let-7d.

Preoperative brain MRI for clinical stage IA lung cancer: is routine scanning rational?

PURPOSE

Early detection and control of lung cancer brain metastases (BMs) are important. However, several guideline recommendations are inconsistent with regard to routine preoperative brain MRI, especially in patients with clinical stage IA lung cancer. Our study evaluated the value of preoperative brain MRI in patients with clinical stage IA lung cancer.

METHODS

A retrospective analysis of patients with lung cancer was performed using a prospectively collected database. Clinical data and the results of brain MRI were collected and analyzed.

RESULTS

Patients with pathologically proved primary lung cancer who underwent an MRI at initial diagnosis were identified (3392 patients). In total, 170 patients (5.0%) were diagnosed with BMs. The increased frequency of BMs was significantly associated with advanced clinical stage (P = 0.000) and pathological type (P = 0.011). BMs were detected in 11 out of 1595 patients with clinical stage IA lung cancer (0.7%). BMs were more common in patients with clinical stage cT1c lung cancer (1.9%) than those with clinical stage cT1a or cT1b (0.1%, odds ratio = 21.30, 95% confidence interval: 2.7-166.9, P = 0.000). All patients with stage IA lung cancer and BMs had solid lung lesions (P = 0.002).

CONCLUSIONS

Preoperative brain MRI might help identify BMs in patients with lung cancer that has progressed beyond stage IA. In patients with clinical stage IA lung cancer, we do not recommend preoperative brain MRI, but it may potentially be beneficial in those with solid T1c cancers.

Risk factors for brain metastases in patients with non-small-cell lung cancer

Brain metastases (BM) are severe incidents in patients with non-small-cell lung cancer (NSCLC). The controversial value of prophylactic cranial irradiation (PCI) in NSCLC in terms of survival benefit prompted us to explore the possible risk factors for BM in NSCLC and identify the potential population most likely to benefit from PCI. Risk factors for brain metastases in NSCLC are reviewed in this article. Identifying patients with a higher risk of BM could possibly increase the benefit of PCI while reducing the discomfort and risks caused by unnecessary invasive procedures in the NSCLC patient population. Future studies might focus on finding a solid basis for the prediction of the occurrence of brain metastases and for the therapeutic decision on the use of PCI.

Prognostic factors and outcome of surgically treated patients with brain metastases of non-small cell lung cancer

Background

Brain metastases (BM) are a common consequence of lung cancer and surgery is effective; however, the factors affecting survival after surgery are unclear. The aim of this study was to identify the outcomes and prognoses of post‐metastasectomy patients with BM from non‐small cell lung cancer (NSCLC) at a single institution over a 15‐year period.

Methods

NSCLC patients who had undergone BM surgery were retrospectively identified. Survival was analyzed using the Kaplan–Meier curve, and univariate and multivariate factors associated with survival were identified using the Cox proportional hazards model.

Results

The median overall survival was 9.8 months, 18 (14.8%) patients survived > 24 months, and 6 (4.9%) > 36 months. The one and two‐year survival rates were 41% and 18.6%, respectively. Univariate analysis revealed that recursive partitioning analysis (RPA) classification, Karnofsky Performance Scale (KPS) scores, BM number, extracranial metastasis status, different lesion locations, resection extent, postoperative treatment, and salvage therapy after recurrence significantly influenced patient survival. The different treatment modalities for primary lesions also affected postoperative survival. KPS ≥ 70, RPA class I/II, and postoperative chemotherapy were independent factors that decreased the risk of death from BM. Interestingly, the initial onset of intracranial lesions could increase the risk of death from BM.

Conclusion

A KPS score ≥ 70, RPA class I/II, and postoperative chemotherapy could benefit post‐metastasectomy patients with BM from NSCLC. Conversely, the initial onset of intracranial lesions is an unfavorable factor that increases the risk of death. These findings support the use of personalized therapy for patients with BM from NSCLC.

Brain metastases in ALK-positive NSCLC - time to adjust current treatment algorithms

The progress in molecular biology has revolutionized systemic treatment of advanced non-small-cell lung cancer (NSCLC) from conventional chemotherapy to a treatment stratified by histology and genetic aberrations. Tumors harboring a translocation of the anaplastic-lymphoma-kinase (ALK) gene constitute a distinct genetic and clinico-pathologic NSCLC subtype with patients with ALK-positive disease being at a higher risk for developing brain metastases. Due to the introduction of effective targeted therapy with ALK-inhibitors, today, patients with advanced ALK-positive NSCLC achieve high overall response rates and remain progression-free for long time intervals. Moreover, ALK-inhibitors seem to exhibit efficacy in the treatment of brain metastases. In the light of this, it needs to be discussed how treatment algorithms for managing patients with brain metastases should be modified. By integrating systemic ALK-inhibitor therapy, radiotherapy, in particular whole brain radiotherapy might be postponed deferring potential long-term impairment by neurocognitive deficits to a later time point in the course of the disease. An early treatment of asymptomatic brain metastases might offer patients a longer time without impairment of cerebral symptoms or radiotherapeutic interventions. Based on an updated extensive review of the literature this article provides an overview on the epidemiology and the treatment of patients’ brain metastases. It describes the specifics of ALK-positive disease and proposes an algorithm for the treatment of patients with advanced ALK-positive NSCLC and brain metastases.

Elemene treatment for NSCLC with multiple CNS metastases: a case report and literature review

CNS metastases are common in patients with non-small-cell lung cancer (NSCLC) and is associated with poor prognosis. In NSCLC patients with EGFR mutations, and ALK fusion oncogene, chemotherapy is ineffective; however, targeted and pulse therapies may be used as alternative treatment options. Elemene can cross the blood-brain barrier and enter the brain tissue. In this paper, treatment consisting of elemene injections in a case of NSCLC with brain metastases, spinal metastases and a possible complication of leptomeningeal metastases is reported, and the efficacy of elemene in treating NSCLC with CNS metastases was investigated.

Preventing and treating brain metastases with three first-line EGFR-tyrosine kinase inhibitors in patients with EGFR mutation-positive advanced non-small cell lung cancer

Introduction

Brain metastases (BM) are common in advanced non-small cell lung cancer (NSCLC), and the prognosis is poor with few therapeutic options. This study evaluated the efficacy of three epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) in preventing and treating BM in patients with EGFR mutation-positive advanced NSCLC.

Methods

Patients with EGFR mutation-positive advanced NSCLC who visited a tertiary referral center from 1 December 2013 to 30 November 2017 were analyzed retrospectively. They received gefitinib, erlotinib, or afatinib until disease progression, death, or intolerable adverse events. The cumulative incidence of subsequent BM of initial non-BM patients, progression-free survival (PFS), and overall survival (OS) of the BM and non-BM patients were estimated and compared using the Kaplan-Meier and log-rank tests.

Results

306 NSCLC patients were enrolled, with 116, 75, and 115 receiving first-line gefitinib, erlotinib, and afatinib, respectively. The afatinib group had a better PFS [12.7 versus 9.8 months; hazard ratio (HR) 0.59, p = 0.001] and OS (39.1 versus 22.0 months; HR 0.64, p = 0.035) than the gefitinib group. Afatinib tended to provide better BM prevention than gefitinib (BM cumulative incidence, HR 0.49; 95% confidence interval 0.34-0.71, p < 0.001) according to a Cox model adjusted for possible confounders. Patients with initial BM had a shorter PFS (p < 0.001) and OS (p = 0.015) than those without initial BM. Among the former, there were no differences in median PFS (p = 0.34) and median OS (p = 0.46) in the three EGFR-TKI groups.

Conclusions

Our data suggested that, compared with gefitinib, afatinib provided better benefits significantly in terms of PFS and OS. Both had the same effectiveness in preventing subsequent BM.

Characterization of genetic alterations in brain metastases from non-small cell lung cancer

Brain metastasis (BM) is the primary contributor to mortality in non‐small cell lung cancer (NSCLC) patients. Although the findings of NSCLC genetic sequencing studies suggest the potential for personalizing therapeutic approaches, the genetic profiles and underlying mechanisms of BM progression remain poorly understood. Here, we investigated the genetic profiles of brain metastases from NSCLC in six patients with primary tumors and corresponding BM samples via whole exome sequencing and targeted panel sequencing. We have demonstrated considerable genetic heterogeneity between primary lung cancer and corresponding brain metastases specimens. High‐frequency mutations were found in NOTCH2,NOTCH2NL,FANCD2,EGFR, and TP53. Additionally, EGFR and TP53 consistently exhibited high frequencies of mutation between primary tumors and corresponding brain metastases. The implication is that most of the genetic alterations may be acquired or lost during malignant progression, and the stable EGFR and TP53 mutational status between paired primary tumors and metastatic sites confirms that most mutations detected on analysis of the primary tumor or metastases are sufficient for clinical decision‐making, and suggest there is no need to re‐biopsy recurrent tumors or metastases for most NSCLC patients.

Brain metastases: epidemiology

Brain metastases (BM) are the most commonly diagnosed type of central nervous system tumor in the United States. Estimates of the frequency of BM vary significantly, as there is no nationwide reporting system for metastases. BM may be the first sign of a previously undiagnosed cancer, or occur years or decades after the primary cancer was diagnosed. Incidence of BM varies significantly by primary cancer site. Lung, breast, and melanoma continue to be the leading cause of BM. These tumors are increasingly more common as new therapeutics, advanced imaging, and improved screening have led to lengthened survival after primary diagnosis for cancer patients. BM are difficult to treat, and for most individuals the diagnosis of BM generally portends a poor prognosis.

Systemic Therapy of Lung Cancer CNS Metastases Using Molecularly Targeted Agents and Immune Checkpoint Inhibitors

Central nervous system (CNS) metastases most commonly arise from lung cancer, with the majority of patients affected during their disease course. The prognosis for patients with untreated brain metastases is poor, with surgical resection and/or radiotherapy as classic therapeutic options. However, the value of systemic therapy in the management of CNS metastases from lung cancer is growing. Novel targeted agents for the treatment of non-small cell lung cancer (NSCLC) have demonstrated activity in treating patients with CNS involvement, and are potential alternatives to radiation and surgery. These agents include anaplastic lymphoma kinase (ALK) inhibitors such as alectinib, crizotinib, ceritinib, lorlatinib, and others; epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors, including the recently developed third-generation inhibitor osimertinib, and even immune checkpoint inhibitors such as nivolumab, pembrolizumab, and atezolizumab. This review summarizes current activity of systemic agents in the management of CNS metastases from NSCLC, as well as potential mechanisms of action of these small and large molecules.

Targeted DNA sequencing of non-small cell lung cancer identifies mutations associated with brain metastases

Introduction

This study explores the hypothesis that dominant molecular oncogenes in non-small cell lung cancer (NSCLC) are associated with metastatic spread to the brain.

Methods

NSCLC patient groups with no evidence of metastasis, with metastatic disease to a non-CNS site, who developed brain metastasis after diagnosis, and patients with simultaneous diagnosis of NSCLC and metastatic brain lesions were studied using targeted sequencing.

Results

In patients with brain metastasis versus those without, only 2 variants (one each in BCL6 and NOTHC2) were identified that occurred in ≥ 4 NSCLC of patients with brain metastases but ≤ 1 of the NSCLC samples without brain metastases. At the gene level, 20 genes were found to have unique variants in more than 33% of the patients with brain metastases. When analyzed at the patient level, these 20 genes formed the basis of a predictive test to discriminate those with brain metastasis. Further analysis showed that PI3K/AKT signaling is altered in both the primary and metastases of NSCLC patients with brain lesions.

Conclusion

While no single variant was associated with brain metastasis, this study describes a potential gene panel for the identification of patients at risk and implicates PI3K/AKT signaling as a therapeutic target.

Potential Molecular Signatures Predictive of Lung Cancer Brain Metastasis

Brain metastases are the most common tumors of the central nervous system (CNS). Incidence rates vary according to primary tumor origin, whereas the majority of the cerebral metastases arise from primary tumors in the lung (40-50%). Brain metastases from lung cancer can occur concurrently or within months after lung cancer diagnosis. Survival rates after lung cancer brain metastasis diagnosis remain poor, to an utmost of 10 months. Therefore, prevention of brain metastasis is a critical concern in order to improve survival among cancer patients. Although several studies have been made in order to disclose the genetic and molecular mechanisms associated with CNS metastasis, the precise mechanisms that govern the CNS metastasis from lung cancer are yet to be clarified. The ability to forecast, which patients have a higher risk of brain metastasis occurrence, would aid cancer management approaches to diminish or prevent the development of brain metastasis and improve the clinical outcome for such patients. In this work, we revise genetic and molecular targets suitable for prediction of lung cancer CNS disease.

Non-small cell lung cancer brain metastasis screening in the era of positron emission tomography-CT staging: Current practice and outcomes

INTRODUCTION

Several clinical guidelines indicate that brain metastasis screening (BMS) should be guided by disease stage in non-small cell lung cancer (NSCLC). We estimate that screening is performed more broadly in practice, and patients undergo brain imaging at considerable cost with questionable benefit. Our aim was to quantify the use and detection rate of BMS in a contemporary cohort staged with ¹⁸ F-fluorodeoxyglucose positron emission tomography/computed tomography (PET-CT).

METHODS

We conducted a retrospective review of prospectively collected data from three major lung cancer referral centres in Brisbane between January 2011 and December 2015. Patients included had a new diagnosis of NSCLC and had undergone a PET-CT to stage extra-cranial disease. BMS was defined as dedicated brain imaging with contrast-enhanced computed tomography (CE-CT) or magnetic resonance (MR), in the absence of clinically apparent neurological deficits.

RESULTS

A total of 1751 eligible cases were identified and of these 718 (41%) underwent BMS. The majority had CE-CT imaging (n = 703). Asymptomatic brain metastases (BM) were detected in 18 patients (2.5%). Of these patients, 12 had concurrent non-brain metastases. Only six patients (0.8%) had BM alone. The rate of detection increased with N-stage (P = 0.02) and overall stage (P < 0.001). It was 0.5%, 1%, 1.6% and 7.3% for stage I, II, III and IV respectively. The overall screening rate increased with T-stage (P = 0.001), N-Stage (P < 0.001) and overall stage (P < 0.001).

CONCLUSIONS

Non-small cell lung cancer BMS practices remain at odds with published guidelines. The low number of occult BMs detected supports the existing international recommendations. Rationalising BMS would minimise the burden on patients and the health care system.

The impact of EGFR mutations on the incidence and survival of stages I to III NSCLC patients with subsequent brain metastasis

Previous studies have demonstrated the association between EGFR mutations and distant metastasis. However, the association for subsequent brain metastasis (BM) in stages I-III non-small cell lung cancer (NSCLC) patients remains inconclusive. We conducted a retrospective analysis to clarify the impact of EGFR mutations on the incidence of BM and associated survival in patients with stage I-III NSCLC. A total of 491 patients screened for EGFR mutations were retrospectively enrolled. Brain MRI or CT was used to detect the BM. Cumulative incidence of subsequent BM and overall survival (OS) after diagnosis of BM were estimated by the Kaplan-Meier method and compared using log-rank test. We performed Cox proportional hazard regression for predictors of subsequent BM and determinants of OS after BM. The cumulative incidence of BM seemed higher in patients harboring EGFR mutations than those without EGFR mutations although it did not reach statistical significance (hazard ratio [HR] = 1.75, 95% confidence interval [CI] = 0.73~1.81). After adjusting possible confounders, including age, smoking, stage, and tumor size, EGFR mutation became one of the predictors for subsequent BM (HR = 1.89, 95% CI = 1.12~3.17, p = 0.017). Though there was no statistical difference in survival after BM between patients with EGFR mutations and wild-type EGFR (median survival: 17.8 vs. 12.2 months, HR = 0.79, 95% CI = 0.45–1.40), patients with EGFR 19 deletion (Del) tended to have a longer survival after BM than the non-EGFR 19 Del group (median survival: 29.4 vs. 14.3 months, HR 0.58, 95% CI = 0.32–1.09, p = 0.089). In conclusion, our data suggested EGFR mutation to be one of the predictors for subsequent BM in stage I-III patients. Given the small sample size, more studies are warranted to corroborate our results.

Factors Associated With Small Aggressive Non-Small Cell Lung Cancers in the National Lung Screening Trial: A Validation Study

Background

A small proportion of non-small cell lung cancers (NSCLCs) have been observed to spread to distant lymph nodes (N3) or metastasize (M1) or both, while the primary tumor is small (≤3 cm, T1). These small aggressive NSCLCs (SA-NSLSC) are important as they are clinically significant, may identify unique biologic pathways, and warrant aggressive follow-up and treatment. This study identifies factors associated with SA-NSCLC and attempts to validate a previous finding that women with a family history of lung cancer are at particularly elevated risk of SA-NSCLC.

Methods

This study used a case-case design within the National Cancer Institute's National Lung Screening Trial (NLST) cohort. Case patients and "control" patients were selected based on TNM staging parameters. Case patients (n = 64) had T1 NSCLCs that were N3 or M1 or both, while "control" patients (n = 206) had T2 or T3, N0 to N2, and M0 NSCLCs. Univariate and multivariable logistic regression were used to identify factors associated with SA-NSCLC.

Results

In bootstrap bias-corrected multivariable logistic regression models, small aggressive adenocarcinomas were associated with a positive history of emphysema (odds ratio [OR] = 5.15, 95% confidence interval [CI] = 1.63 to 23.00) and the interaction of female sex and a positive family history of lung cancer (OR = 6.55, 95% CI = 1.06 to 50.80).

Conclusions

Emphysema may play a role in early lung cancer progression. Females with a family history of lung cancer are at increased risk of having small aggressive lung adenocarcinomas. These results validate previous findings and encourage research on the role of female hormones interacting with family history and genetic factors in lung carcinogenesis and progression.

Systemic therapy for brain metastases

Central nervous system metastases cause grave morbidity in patients with advanced malignancies. Lung cancer, breast cancer, and melanoma are the three most common causes of brain metastases. Although the exact incidence of brain metastases is unclear, there appears to be an increasing incidence which has been attributed to longer survival, better control of systemic disease, and better imaging modalities. Until recently surgical resection of solitary or symptomatic brain metastases, and radiation therapy (either whole-brain radiation therapy or stereotactic radiation) were the mainstay of treatment for patients with brain metastases. The majority of traditional chemotherapies have shown limited activity in the central nervous system, which has been attributed to the blood-brain barrier and the molecular structure of the used agents. The discovery of driver mutations and drugs targeting these mutations has changed the treatment landscape. Several of these targeted small-molecule tyrosine kinase inhibitors do cross the blood-brain barrier and/or have shown activity in the central nervous system. Another major advance in the care of brain metastases has been the advent of new immunotherapeutic agents, for which initial studies have shown intracranial activity. In this chapter, we will review the unique challenges in the treatment of brain metastases. The pertinent clinical studies of chemotherapy in brain metastases will be discussed. The currently reported clinical trials and evidence for use of targeted therapies and immunotherapeutic agents will be emphasized.

Survival time following resection of intracranial metastases from NSCLC-development and validation of a novel nomogram

Background

Brain metastases (BM) from non-small cell lung cancer (NSCLC) are the most frequent intracranial tumors. To identify patients who might benefit from intracranial surgery, we compared the six existing prognostic indexes(PIs) and built a nomogram to predict the survival for NSCLC with BM before they intended to receive total intracranial resection in China.

Methods

First, clinical data of NSCLC presenting with BM were retrospectively reviewed. All of the patients had received total intracranial resection and were randomly distributed to developing cohort and validation cohort by 2:1. Second, we stratified the cohort using a recursive partitioning analysis(RPA), a score index for radiosurgery (SIR), a basic score for BM (BS-BM), a Golden Grading System (GGS), a disease-specific graded prognostic assessment (DS-GPA) and by NSCLC-RADES. The predictive power of the six PIs was assessed using the Kaplan–Meier method and the log-rank test. Third, univariate and multivariate analysis were explored, and the nomogram predicting survival of BMs from NSCLC was constructed using R 3.2.3 software. The concordance index (C-index) was calculated to evaluate the discriminatory power of the nomogram in the developing cohort and validation cohort.

Results

BS-BM could better predict survival of patients before intracranial surgery compared with other PIs. In the final multivariate analysis, KPS at diagnosis of BM, metachronous or synchronous BM and the histology of lung cancer appeared to be the independent prognostic predictors for survival. The C-index in the developing cohort and validation cohort were 0.75 and 0.71 respectively, which was better than the C-index of the other six PIs.

Conclusions

The new nomogram is a promising tool in further choosing the candidates for intracranial surgery among NSCLC with BM and in helping physicians tailor suitable treatment options before operation in clinical practice.

Bevacizumab and gefitinib enhanced whole-brain radiation therapy for brain metastases due to non-small-cell lung cancer

Non-small-cell lung cancer (NSCLC) patients who experience brain metastases are usually associated with poor prognostic outcomes. This retrospective study proposed to assess whether bevacizumab or gefitinib can be used to improve the effectiveness of whole brain radiotherapy (WBRT) in managing patients with brain metastases. A total of 218 NSCLC patients with multiple brain metastases were retrospectively included in this study and were randomly allocated to bevacizumab-gefitinib-WBRT group (n=76), gefitinib-WBRT group (n=77) and WBRT group (n=75). Then, tumor responses were evaluated every 2 months based on Response Evaluation Criteria in Solid Tumors version 1.0. Karnofsky performance status and neurologic examination were documented every 6 months after the treatment. Compared to the standard WBRT, bevacizumab and gefitinib could significantly enhance response rate (RR) and disease control rate (DCR) of WBRT (P<0.001). At the same time, RR and DCR of patients who received bevacizumab-gefitinib-WBRT were higher than those who received gefitinib-WBRT. The overall survival (OS) rates and progression-free survival (PFS) rates also differed significantly among the bevacizumab-gefitinib-WBRT (48.6 and 29.8%), gefitinib-WBRT (36.7 and 29.6%) and WBRT (9.8 and 14.6%) groups (P<0.05). Although bevacizumab-gefitinib-WBRT was slightly more toxic than gefitinib-WBRT, the toxicity was tolerable. As suggested by prolonged PFS and OS status, bevacizumab substantially improved the overall efficacy of WBRT in the management of patients with NSCLC.

Genetic Characterization of Brain Metastases in the Era of Targeted Therapy

In the current era of molecularly targeted therapies and precision medicine, choice of cancer treatment has been increasingly tailored according to the molecular or genomic characterization of the cancer the individual has. Previously, the clinical observation of inadequate control of brain metastases was widely attributed to a lack of central nervous system (CNS) penetration of the anticancer drugs. However, more recent data have suggested that there are genetic explanations for such observations. Genomic analyses of brain metastases and matching primary tumor and other extracranial metastases have revealed that brain metastases can harbor potentially actionable driver mutations that are unique to them. Identification of genomic alterations specific to brain metastases and targeted therapies against these mutations represent an important research area to potentially improve survival outcomes for patients who develop brain metastases. Novel approaches in genomic testing such as that using cell-free circulating tumor DNA (ctDNA) in the cerebrospinal fluid (CSF) facilitate advancing our understanding of the genomics of brain metastases, which is critical for precision medicine. CSF-derived ctDNA sequencing may be particularly useful in patients who are unfit for surgical resection or have multiple brain metastases, which can harbor mutations that are distinct from their primary tumors. Compared to the traditional chemotherapeutics, novel targeted agents appear to be more effective in controlling the CNS disease with better safety profiles. Several brain metastases-dedicated trials of various targeted therapies are currently underway to address the role of these agents in the treatment of CNS disease. This review focuses on recent advances in genomic profiling of brain metastases and current knowledge of targeted therapies in the management of brain metastases from cancers of the breast, lung, colorectum, kidneys, and ovaries as well as melanoma.

Correlation between EGFR mutation status and the incidence of brain metastases in patients with non-small cell lung cancer

BACKGROUND

Lung cancer is the leading cause of cancer-related death worldwide. Numerous studies have been performed to investigate the correlation between epidermal growth factor receptor (EGFR) mutation status and the incidence of brain metastases (BMs) in patients with non-small cell lung cancer (NSCLC), however, the outcomes were inconsistent. Thus, we performed this study to establish the role of EGFR mutation status in BMs.

METHODS

Electronic databases PubMed, Embase, Cochrane Library, CBM, WanFang, CNKI were searched to identify relevant trials. The primary endpoint was the incidence of BMs in EGFR mutations or wild type NSCLC and the secondary endpoint was overall survival calculated from the BMs emerging (BMOS).

RESULTS

Twenty-two studies incorporating 8,152 participants were eligible. EGFR mutations group possessed a significantly higher risk of BMs (OR =1.99; 95% CI, 1.59-2.48; P=0.000) than EGFR wild type group. In the stratified analysis, compared with EGFR wild type group, EGFR mutations group had a significant higher incidence (OR =2.01; 95% CI, 1.56-2.59; P=0.000) of subsequent BMs while only a trend of increasing the incidence of initial BMs (OR =1.38; 95% CI, 0.98-1.94; P=0.066). Moreover, exon 19 deletion had a trend of increasing the incidence of BMs than exon 21 mutation (OR =1.44; 95% CI, 0.77-2.68; P=0.252). Compared with EGFR wild type group, EGFR mutations group possessed a prolonged overall BMOS (HR =0.68; 95% CI, 0.47-0.98; P=0.038) and a longer BMOS in initial BMs (HR =0.50; 95% CI, 0.31-0.80; P=0.004) but no significant difference in NSCLC with subsequent BMs (HR =0.95; 95% CI, 0.42-2.15; P=0.901).

CONCLUSIONS

Patients with EGFR mutations were more susceptible to develop into BMs than those with EGFR wild type, especially during the course of disease.

Prognostic model for brain metastases from lung adenocarcinoma identified with epidermal growth factor receptor mutation status

BACKGROUND

Several indices have been developed to predict survival of brain metastases (BM) based on prognostic factors. However, such models were designed for general brain metastases from different kinds of cancers, and prognostic factors vary between cancers and histological subtypes. Recently, studies have indicated that epidermal growth factor receptor (EGFR) mutation status may be a potential prognostic biological factor in BM from lung adenocarcinoma. Thus, we sought to define the role of EGFR mutation in prognoses and introduce a prognostic model specific for BM from lung adenocarcinoma.

METHODS

Data of 256 patients with BM from lung adenocarcinoma identified with EGFR mutations were collected. Independent prognostic factors were confirmed using a Cox regression model. The new prognostic model was developed based on the results of multivariable analyses. The score of each factor was calculated by six-month survival. Prognostic groups were divided into low, medium, and high risk based on the total scores. The prediction ability of the new model was compared to the three existing models.

RESULTS

EGFR mutation and Karnofsky performance status were independent prognostic factors and were thus integrated into the new prognostic model. The new model was superior to the three other scoring systems regarding the prediction of three, six, and 12-month survival by pairwise comparison of the area under the curve.

CONCLUSION

Our proposed prognostic model specific for BM from lung adenocarcinoma incorporating EGFR mutation status was valid in predicting patient survival. Further verification is warranted, with prospective testing using large sample sizes.

Prophylactic cranial irradiation for patients with lung cancer

The incidence of brain metastases in patients with lung cancer has increased as a result of improved local and systemic control and better diagnosis from advances in brain imaging. Because brain metastases are responsible for life-threatening symptoms and serious impairment of quality of life, resulting in shortened survival, prophylactic cranial irradiation has been proposed in both small-cell lung cancer (SCLC) and non-small-cell lung cancer (NSCLC) to try to improve incidence of brain metastasis, survival, and eventually quality of life. Findings from randomised controlled trials and a meta-analysis have shown that prophylactic cranial irradiation not only reduces the incidence of brain metastases in patients with SCLC and with non-metastatic NSCLC, but also improves overall survival in patients with SCLC who respond to first-line treatment. Although prophylactic cranial irradiation is potentially associated with neurocognitive decline, this risk needs to be balanced against the potential benefit in terms of brain metastases incidence and survival. Several strategies to reduce neurotoxicity are being investigated.

Correlation between status of epidermal growth factor receptor mutation and distant metastases of lung adenocarcinoma upon initial diagnosis based on 1063 patients in China

The study aimed to explore the correlations between status of epidermal growth factor receptor (EGFR) mutations and distant metastases. A total of 1063 patients with lung adenocarcinoma indentified with status of EGFR mutations from August 2010 to May 2015 at Shanxi Cancer Hospital were enrolled. 456 patients were confirmed with EGFR mutations. The associations among EGFR mutations, clinical factors, and distant metastases at initial diagnosis were evaluated. Patients harboring EGFR mutation were more likely to be female (P < 0.001), with no smoking history (P < 0.001), brain metastases (P = 0.029), and higher ECOG performance scores (P = 0.025). The correlation between EGFR mutation status and distant metastases showed statistical significance both in univariate (P = 0.022) and in multivariate analysis (OR 1.573, 95 % CI 1.202-2.059, P = 0.001) especially in brain metastases (OR 1.675, 95 % CI 1.132-2.479, P = 0.010) and lung metastases (OR 1.571, 59 % CI 1.101-2.243 P = 0.013). Furthermore, the 19del mutations showed associations with brain metastases (OR 1.586, 95 % CI 1.028-2.447, P = 0.037), and lung metastases (OR 1.587, 95 % CI 1.065-2.346, P = 0.023). The exon 21 point mutations showed statistically significant differences in liver metastases (OR 1.987, 95 % CI 1.094-3.067, P = 0.024). In conclusion, the EGFR mutations in lung adenocarcinoma patients were independently correlated with distant metastases. Subgroup analyses showed that patients harboring 19del mutations presented different distant metastases compared with those harboring 21 point mutaions.

Treatment of brain metastases in the modern genomic era

Development of brain metastasis (BM) portends a dismal prognosis for patients with cancer. Melanomas and carcinomas of the lung, breast, and kidney are the most common malignancies to metastasize to the brain. Recent advances in molecular genetics have enabled the identification of actionable, clinically relevant genetic alterations within primary tumors and their corresponding metastases. Adoption of genotype-guided treatment strategies for the management of systemic malignancy has resulted in dramatic and durable responses. Unfortunately, despite these therapeutic advances, central nervous system (CNS) relapses are not uncommon. Although these relapses have historically been attributed to limited blood brain barrier penetration of anti-neoplastic agents, recent work has demonstrated genetic heterogeneity such that metastatic sites, including BM, harbor relevant genetic alterations that are not present in primary tumor biopsies. This improved insight into molecular mechanisms underlying site specific recurrences can inform strategies for targeting these oncogenic drivers. Thus, development of rational, genomically guided CNS-penetrant therapies is crucial for ongoing therapeutic success.

A Nomogram to Predict Brain Metastases of Resected Non-Small Cell Lung Cancer Patients

PURPOSE

Brain metastasis is a major cause leading to the failure of treatment management for non-small cell lung cancer (NSCLC) patients. The goal of this study was to establish an effective nomogram for prediction of brain metastases of resected NSCLC patients.

METHODS

We retrospectively investigated 637 operable NSCLC patients who received treatment at Zhejiang Cancer Hospital, China. A Cox proportional hazards regression model was performed to identify significant risk factors, and a nomogram was developed for predicting 3- and 5-year brain metastases rates.

RESULTS

Multivariate analysis identified four independent risk factors: neuron-specific enolase, histological type, number of metastatic lymph nodes, and tumor grade, and a nomogram was developed based on these factors. The effectiveness of the nomogram was validated using an internal bootstrap resampling approach, showing that the nomogram exhibited a sufficient level of discrimination according to the C-index (0.74, 95 % confidence interval 0.67-0.82).

CONCLUSIONS

The nomogram developed in this study demonstrated its discrimination capability for predicting 3- and 5-year occurrence of brain metastases, and can be used to identify high-risk patients.

Combined action of EGFR tyrosine kinase inhibitors and whole-brain radiotherapy on EGFR-mutated non-small-cell lung cancer patients with brain metastasis

Background

Lung cancer is the most common type of cancer to spread to the brain (brain metastasis [BM]). This study assessed the effect of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in combination with whole-brain radiotherapy (WBRT) on EGFR-mutant non-small-cell lung cancer (NSCLC) patients with BM.

Patients and methods

Thirty-nine patients, who had receieved different EGFR TKIs plus 30 Gy WBRT until disease progression, were retrospectively analyzed between 2010 and 2014. Treatment response was evaluated and survival data were collected and analyzed.

Results

Among the 39 patients, 18 had an EGFR exon 19 deletion and 21 had an EGFR exon 21 point mutation. After therapy, 19 (48.7%) patients had complete remission, 12 (30.8%) had partial remission, and eight (20.5%) had stable disease in the intracranial lesions. Besides, there was no single case of complete remission, 21 (53.8%) had partial remission, and 18 (46.2%) had stable disease of the extracranial lesions. The median progression-free survival (PFS) of intracranial lesions and extracranial lesions was 18 and 12 months, respectively. The median overall survival (OS) was 26 months. The univariate analysis showed that graded prognostic assessment (P=0.006) and Karnofsky Performance Scale (P=0.045) were associated with intracranial progression-free survival (iPFS), while recursive partitioning analysis (P=0.049) was associated with OS of patients.

Conclusion

EGFR TKIs plus concomitant WBRT controlled intracranial lesions of lung cancer metastasis and significantly improved OS of patients. Further studies will be needed to confirm whether this combination treatment could be used as a standard therapy for EGFR-mutated NSCLC patients with BM.

Serum Biomarkers Associated with Clinical Outcomes Fail to Predict Brain Metastases in Patients with Stage IV Non-Small Cell Lung Cancers

Background

Lung cancers account for the majority of brain metastases which pose major therapeutic challenges. Biomarkers prognosticating for the development of brain metastases in patients with non-small cell lung cancers (NSCLC) may improve personalized care. Six serum proteomic biomarkers were previously investigated at Memorial Sloan Kettering but their associations with brain metastases were unknown.

Methods

Serum NSE, CYFRA 21–1, ProGRP, SCC-Ag, TIMP1, and HE4 by ELISA-based proteomic assays were prospectively collected from consecutive patients with stage IV NSCLC. Pre-treatment serum biomarker levels as well as age, histology, and epidermal growth factor receptor (EGFR) mutation status were evaluated for association with the baseline presence of brain metastases using logistic regression and multivariable analysis. For patients without brain metastases at baseline, the cumulative incidence of subsequent brain metastases were compared according to baseline biomarkers and clinical factors using Gray’s test.

Results

A total of 118 patients were enrolled, 31 (26%; 95% CI 0.19–0.35) had brain metastases at baseline and a further 26 (22%; 95% CI 0.15–0.30) developed brain metastases subsequently. Pre-treatment serum biomarker levels were available in 104 patients. There was no significant association between the six serum biomarkers and the baseline presence or subsequent development of brain metastases. Age younger than 65 years was the only clinical factor significantly associated with brain metastasis at baseline (OR 3.00; 95% CI 1.22–7.34, P = 0.02) by multivariable analysis. A trend toward increased cumulative incidence of subsequent brain metastases was observed in patients with EGFR mutation (p = 0.2), but this was not statistically significant possibly due to small sample size.

Conclusions

Serum NSE, CYFRA 21–1, Pro-GRP, SCC-Ag, TIMP1, and HE4 are not significantly associated with brain metastases. Our methods taking into account follow-up time may be applied to independent datasets to identify a patient cohort with a higher biologic propensity for developing brain metastases. Such information may be useful for the study of agents targeting the development of brain metastases.

EGFR and HER2 signaling in breast cancer brain metastasis

Breast cancer occurs in approximately 1 in 8 women and 1 in 37 women with breast cancer succumbed to the disease. Over the past decades, new diagnostic tools and treatments have substantially improved the prognosis of women with local diseases. However, women with metastatic disease still have a dismal prognosis without effective treatments. Among different molecular subtypes of breast cancer, the HER2-enriched and basal-like subtypes typically have higher rates of metastasis to the brain. Basal-like metastatic breast tumors frequently express EGFR. Consequently, HER2- and EGFR-targeted therapies are being used in the clinic and/or evaluated in clinical trials for treating breast cancer patients with brain metastases. In this review, we will first provide an overview of the HER2 and EGFR signaling pathways. The roles that EGFR and HER2 play in breast cancer metastasis to the brain will then be discussed. Finally, we will summarize the preclinical and clinical effects of EGFR- and HER2-targeted therapies on breast cancer metastasis.

Brain metastases in malignant pleural mesothelioma

The brain is a rare site of metastasis in malignant pleural mesothelioma (MPM), and its clinical features and prognosis remain unclear. The aim of this study was to investigate the incidence, prognosis, and risk factors for brain metastases (BM) in MPM patients. Between July 1993 and October 2014, 150 patients with histologically proven MPM were included in this retrospective study. The cumulative incidence of BM was estimated with the Kaplan-Meier method, and differences between groups were analyzed by the log-rank test. Multivariate logistic regression analysis was applied to assess risk factors for BM. The median follow-up time was 11 months (range 0-154.0 months). A total of eight patients (5.3 %) developed BM during the course of their illness. Multivariate analysis identified age <65 years (odds ratio [OR] = 5.83, p = 0.038) and International Mesothelioma Interest Group stage IV (OR = 1.69, p = 0.040) as independent factors related to increased risk of developing BM. The 1-and 2-year cumulative rates of BM were 4.0 % (95 % confidence intervals [CI] 1.4-8.5 %) and 5.3 % (95 % CI 2.3-10.2 %), respectively. Our study showed that the overall survival (OS) of patients with BM was worse than that of patients without BM (median OS 6.5 vs. 11.0 months, p = 0.037). The prognosis for BM in MPM patients is poor. Clinicians should perform careful screening for BM, especially in patients with risk factors.

Little things make big things happen: angiolymphatic invasion and tumor necrosis prognosticate the outcome of locally advanced non-small cell lung cancer treated with a prior induction therapy

OBJECTIVES

Size, invasion of thoracic structures, and ipsilateral mediastinal lymph node involvement (pN2) are well-known prognostic factors that configure the staging of resectable, locally advanced non-small cell lung cancer (LA-NSCLC). The prognostic impact of angiolymphatic invasion (ALI) and tumor necrosis (TN) has been barely explored in LA-NSCLC treated with prior induction therapies.

METHODS

We retrospectively reviewed 47 resected LA-NSCLCs treated with a prior platin-based chemotherapy or chemoradiation. The impact of ALI, TN, and other pathologic features on survival was analyzed.

RESULTS

ALI was presented in 23.4% of cases and TN in 29.8%. Disease-free and overall survival decreased when ALI, TN, or pN2 was present. The incidence of ALI was lower in LA-NSCLC with a good response to induction.

CONCLUSION

Our series is the first to report the prognostic impact of ALI and TN in induction-treated LA-NSCLC. The presence of ALI and TN should be included in the pathologic reports.

Probabilistic modeling of short survivability in patients with brain metastasis from lung cancer

The prediction of substantially short survivability in patients is extremely risky. In this study, we proposed a probabilistic model using Bayesian network (BN) to predict the short survivability of patients with brain metastasis from lung cancer. A nationwide cancer patient database from 1996 to 2010 in Taiwan was used. The cohort consisted of 438 patients with brain metastasis from lung cancer. We utilized synthetic minority over-sampling technique (SMOTE) to solve the imbalanced property embedded in the problem. The proposed BN was compared with three competitive models, namely, naive Bayes (NB), logistic regression (LR), and support vector machine (SVM). Statistical analysis showed that performances of BN, LR, NB, and SVM were statistically the same in terms of all indices with low sensitivity when these models were applied on an imbalanced data set. Results also showed that SMOTE can improve the performance of the four models in terms of sensitivity, while keeping high accuracy and specificity. Further, the proposed BN is more effective as compared with NB, LR, and SVM from two perspectives: the transparency and ability to show the relation of factors affecting brain metastasis from lung cancer; it allows decision makers to find the probability despite incomplete evidence and information; and the sensitivity of the proposed BN is the highest among all standard machine learning methods.

Outcome of surgical resection for brain metastases and radical treatment of the primary tumor in Chinese non-small-cell lung cancer patients

Purpose

Brain metastasis is the most common complication of brain cancer; nevertheless, primary lung cancer accounts for approximately 20%–40% of brain metastases cases. Surgical resection is the preferred treatment for brain metastases. However, no studies have reported the outcome of surgical resection of brain metastases from non–small-cell lung cancer (NSCLC) in the People’s Republic of China. Moreover, the optimal treatment for primary NSCLC in patients with synchronous brain metastases is hitherto controversial.

Patients and methods

We retrospectively analyzed the cases of NSCLC patients with brain metastases who underwent neurosurgical resection at the Sun Yat-sen University Cancer Center, and assessed the efficacy of surgical resection and the necessity of aggressive treatment for primary NSCLC in synchronous brain metastases patients.

Results

A total of 62 patients, including 47 men and 15 women, with brain metastases from NSCLC were enrolled in the study. The median age at the time of craniotomy was 54 years (range 29–76 years). At the final follow-up evaluation, 50 patients had died. The median OS time was 15.1 months, and the survival rates were 70% and 37% at 1 and 2 years, respectively. The median OS time of synchronous brain metastases patients was 12.5 months. Univariate analysis revealed that radical treatment of primary NSCLC was positively correlated with survival, and it was an independent prognostic factor in the multivariate analysis.

Conclusion

Surgical resection is an effective treatment for brain metastases. Besides craniotomy, radical therapy is necessary for the management of primary NSCLC in patients with synchronous brain metastases.

Molecular determinants of lung cancer metastasis to the central nervous system

Lung cancer remains the leading cause of cancer-related mortality worldwide. The propensity for metastasis to the central nervous system (CNS) is a major clinical hurdle contributing to the low five-year survival rate of advanced disease. CNS metastases significantly outnumber primary brain tumors and carry a dismal prognosis in part due to the inability of therapeutic agents to cross the blood brain barrier. Standard treatment using radiation has been largely ineffective in improving mortality, suggesting the need for new agents targeting the critical metastatic drivers. The genetic and molecular events governing CNS metastasis from the lung are poorly understood at this time. This review highlights genetic events associated with CNS dissemination from the lung and molecular mechanisms associated with CNS metastasis. In vivo model systems that faithfully recapitulate escape from the lung and colonization of the CNS are described as tools for understanding the metastatic phenotype and for testing new therapeutic agents. A deeper understanding of the mechanisms of lung cancer metastasis to the CNS is needed to elucidate novel therapeutic avenues towards the improvement of the mortality associated with advanced stage lung cancer.

Potential toxicities of prophylactic cranial irradiation

Prophylactic cranial irradiation (PCI) with total doses of 20-30 Gy reduces the incidence of brain metastasis (BM) and increases survival of patients with limited and extensive-disease small-cell lung cancer (SCLC) that showed any response to chemotherapy. PCI is currently not applied in non-small-cell lung cancer (NSCLC) since it has not proven to significantly improve OS rates in stage IIIA/B, although novel data suggest that subgroups that could benefit may exist. Here we briefly review potential toxicities of PCI which have to be considered before prescribing PCI. They are mostly difficult to delineate from pre-existing risk factors which include preceding chemotherapy, patient age, paraneoplasia, as well as smoking or atherosclerosis. On the long run, this will force radiation oncologists to evaluate each patient separately and to estimate the individual risk. Where PCI is then considered to be of benefit, novel concepts, such as intensity-modulated radiotherapy and/or neuroprotective drugs with potential to lower the rates of side effects will eventually be superior to conventional therapy. This in turn will lead to a re-evaluation whether benefits might then outweigh the (lowered) risks.

A nomogram to predict brain metastasis as the first relapse in curatively resected non-small cell lung cancer patients

OBJECTIVES

Development of brain metastasis results in a significant reduction in overall survival. However, there is no an effective tool to predict brain metastasis in non-small cell lung cancer (NSCLC) patients. We conducted this study to develop a feasible nomogram that can predict metastasis to the brain as the first relapse site in patients with curatively resected NSCLC.

MATERIAL AND METHODS

A retrospective review of NSCLC patients who had received curative surgery at National Cancer Center (Goyang, South Korea) between 2001 and 2008 was performed. We chose metastasis to the brain as the first relapse site after curative surgery as the primary endpoint of the study. A nomogram was modeled using logistic regression.

RESULTS

Among 1218 patients, brain metastasis as the first relapse developed in 87 patients (7.14%) during the median follow-up of 43.6 months. Occurrence rates of brain metastasis were higher in patients with adenocarcinoma or those with a high pT and pN stage. Younger age appeared to be associated with brain metastasis, but this result was not statistically significant. The final prediction model included histology, smoking status, pT stage, and the interaction between adenocarcinoma and pN stage. The model showed fairly good discriminatory ability with a C-statistic of 69.3% and 69.8% for predicting brain metastasis within 2 years and 5 years, respectively. Internal validation using 2000 bootstrap samples resulted in C-statistics of 67.0% and 67.4% which still indicated good discriminatory performances.

CONCLUSION

The nomogram presented here provides the individual risk estimate of developing metastasis to the brain as the first relapse site in patients with NSCLC who have undergone curative surgery. Surveillance programs or preventive treatment strategies for brain metastasis could be established based on this nomogram.

[Advances in treatment of brain metastases from primary non-small cell lung cancer]

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Modeling and predicting the occurrence of brain metastasis from lung cancer by Bayesian network: a case study of Taiwan

The Bayesian network (BN) is a promising method for modeling cancer metastasis under uncertainty. BN is graphically represented using bioinformatics variables and can be used to support an informative medical decision/observation by using probabilistic reasoning. In this study, we propose such a BN to describe and predict the occurrence of brain metastasis from lung cancer. A nationwide database containing more than 50,000 cases of cancer patients from 1996 to 2010 in Taiwan was used in this study. The BN topology for studying brain metastasis from lung cancer was rigorously examined by domain experts/doctors. We used three statistical measures, namely, the accuracy, sensitivity, and specificity, to evaluate the performances of the proposed BN model and to compare it with three competitive approaches, namely, naive Bayes (NB), logistic regression (LR) and support vector machine (SVM). Experimental results show that no significant differences are observed in accuracy or specificity among the four models, while the proposed BN outperforms the others in terms of sampled average sensitivity. Moreover the proposed BN has advantages compared with the other approaches in interpreting how brain metastasis develops from lung cancer. It is shown to be easily understood by physicians, to be efficient in modeling non-linear situations, capable of solving stochastic medical problems, and handling situations wherein information are missing in the context of the occurrence of brain metastasis from lung cancer.

Identification of subgroup patients with stage IIIB/IV non-small cell lung cancer at higher risk for brain metastases

PURPOSE

Brain metastases (BM), a common occurrence in non-small cell lung cancer (NSCLC), usually lead to a poor prognosis. Recently, the selection of treatment modalities for BM has modestly improved patient survival and quality of life. Treatment choice is largely based on the number of BM, the presence of BM-related symptoms, and performance status. Therefore, early BM detection is crucial. In this study, we aimed to elucidate the factors associated with BM and identify subgroups of patients at higher risk for BM.

METHODS AND PATIENTS

The medical records of 596 consecutive patients with stage I-IV NSCLC were reviewed between January 2006 and November 2011. A multivariate logistic regression (MLR) model was used to identify factors associated with BM.

RESULTS

Among 482 eligible stage IIIB/IV NSCLC patients, 173 (36%) experienced BM during their disease course. On MLR analysis, female gender, age < 60 years and adenocarcinoma were associated with BM (OR = 1.71, 95% CI = 1.06-2.75, P = 0.028; OR = 2.11, 95% CI = 1.38-3.22, P = 0.001; and OR = 2.39, 95% CI = 1.16-4.92, P = 0.018, respectively). The actuarial incidence of BM varied widely from 14% to 59% in different subgroups; younger patients with adenocarcinoma tended to experience BM more than older patients with squamous cell carcinoma (OR = 6.88, 95% CI = 2.97-15.94, P < 0.001). Furthermore, the incidence of BM correlated closely with survival after NSCLC diagnosis, and it was 42%, 54% and 64% in patients who survived more than 3, 12 and 24 months, respectively. Notably, the number of BM, the size of the largest BM and the proportion of multiple BM, defined as more than 4 metastatic tumors in brain, were significantly different in NSCLC patients with and without BM-related symptoms or signs (4.0 ± 2.1 vs 2.7 ± 1.9, P < 0.001; 2.6 ± 1.5 vs 1.3 ± 1.0 CM, P < 0.001, and 50% vs 21%, P < 0.001, respectively).

CONCLUSION

We found that subgroups of NSCLC patients characterized by younger age, female gender and adenocarcinoma are at higher risks for BM. These findings might be helpful to detect BM earlier and facilitate the design of clinical trials aiming at their prevention.

Clinical significance of B7-H4 expression in matched non-small cell lung cancer brain metastases and primary tumors

Background

B7-H4, a member of the inhibitory B7 family, is shown to have a profound inhibitory effect on the proliferation, activation, cytokine secretion, and development of cytotoxicity of T cells and may be involved in immune evasion in cancer patients. Although B7-H4 expression has been detected in non-small cell lung cancer (NSCLC), there are no published reports on the expression of B7-H4 in brain metastases from NSCLC.

Methods

We examined the expression of B7-H4 by immunohistochemistry in 49 cases of brain metastatic NSCLC, 18 cases of matched primary NSCLC, and 20 cases of NSCLC patients who had neither brain metastases nor other distant metastases.

Results

B7-H4 was highly expressed in 20 (40.8%) out of 49 brain metastases and two (11.1%) out of 18 matched primary tumors. The expression of B7-H4 in brain metastases appeared to be significantly higher than their matched primary tumors (P = 0.016). We also found that patients with high B7-H4 expression in their primary NSCLC have a higher risk of developing brain metastases (P = 0.022). Univariate analyses showed that median overall survival was significantly shorter in patients with high B7-H4 expression in brain metastases (P = 0.002). Multivariate analyses showed that B7-H4 was a significant independent prognostic indicator (P = 0.003).

Conclusion

NSCLC patients with high B7-H4 expression may benefit from aggressive treatment and close surveillance. Furthermore, our study suggests that B7-H4 may play an important role in the metastatic process of NSCLC and is promising to be a new immune checkpoint molecule for future antitumoral immunotherapy.

Neuropathology of brain metastases

Metastatic tumors are the most common neoplasms encountered in the central nervous system (CNS), and continue to be major cause for mortality and morbidity. Macroscopic features and corresponding radiological findings can be diagnostic in majority of the cases, however, microscopic evaluation would be necessary when the differential diagnosis includes a primary CNS tumor, unknown primary tumor site, and when the resection of the tumor is either considered therapeutic or palliative. The first step in the diagnosis of a metastatic brain lesion is to exclude a primary CNS tumor, followed by verification or identification of the primary tumor and the site. Although general approach to a metastatic lesion from an unknown primary tumor is the same everywhere else, there are slight variations for the metastatic lesions in the CNS versus other regions. When morphological features are not enough to establish a definitive diagnosis, additional studies including immunohistochemical stains are applied. With the expending immunohistochemical armamentarium for pathologists, more accurate assessments are possible even in cases of unknown primary tumor. This review summarizes the diagnostic approach to CNS metastases, immunohistochemical assessment of neoplasm of unknown primary, and primary CNS lesions entering in the differential diagnosis of metastases.

Epidemiology and prognosis of brain metastases

A substantial, but uncertain, number of patients with cancer develop brain metastases. Risk of brain metastasis is recognized to vary with type of primary cancer. Within specific types of primary cancer, prognostic factors for development of brain metastases are being recognized. Recent data suggest that molecular biomarkers that relate to cellular function can predict risk of developing brain metastases. Such information could optimize surveillance standards and/or be used to select patients for preventive interventions. Though average survival for patients with brain metastases is typically less than 6 months, it is well-recognized that subgroups of patients have significant probability of longer survival. Multiple prognostic models have been proposed, validated, and compared without clearly demonstrating superiority of one model over another. However, some factors show consistency as predictive variables across models, and performance status is almost universally significant. Application of predictive models to specific treatments has been difficult. Tumor-specific prognostic models are evolving, and combinations of biological and clinical factors may be used to optimize models for particular primary tumor types.

A case of primary lung cancer lesion demonstrated by F-18 FDG positron emission tomography/computed tomography (PET/CT) one year after the detection of metastatic brain tumor

Cancer of unknown primary origin (CUP) is an aggressive disease with a poor prognosis. Metastatic brain tumors occur in approximately 15% of all cancer patients. F-18 2'-deoxy-2fluoro-D-glucose (FDG) positron emission tomography (PET) combined with computed tomography (PET/CT) contributes to the evaluation of cancer staging, although the benefits of PET/CT for detection of CUP origins has yet to be determined. In this study, we present a 37-year-old man with a brain tumor detected by magnetic resonance imaging. Surgical biopsy indicated a metastatic undifferentiated carcinoma, while clinical examination and a CT scan did not detect any abnormalities, with the exception of brain metastases. PET/CT did not reveal abnormal FDG uptake. PET/CT revealed abnormal intense FDG uptake in a small nodular lesion in the right lung 1 year following the detection of brain metastasis, and no other abnormal FDG uptake was observed elsewhere in the body. Right upper lobectomy and dissection of mediastinal lymph nodes were performed. The pathological diagnosis was poorly differentiated adenocarcinoma, which was similar to the brain metastatic lesion, and there was no lymph node metastasis. This case revealed an extremely rare lung cancer with primary lesions demonstrated by PET/CT 1 year after the detection of brain metastasis. This case reveals that F-18 FDG PET/CT imaging of CUP origin is capable of positively impacting on the identification of small primary tumor foci.