Prevention of Brain Metastases

Prognostic Value of Baseline 18F-FDG PET/CT to Predict Brain Metastasis Development in Melanoma Patients

To investigate the value of 18F-FDG-PET/CT in predicting the occurrence of brain metastases in melanoma patients, in this retrospective study 201 consecutive patients with pathology-proven melanoma, between 2008 and 2021, were reviewed. Those who underwent 18F-FDG-PET/CT for initial staging were considered eligible. Baseline assessment included histopathology, 18F-FDG-PET/CT, and brain MRI. Also, all patients had serial follow-ups for diagnosing brain metastasis development. Baseline 18F-FDG-PET/CT parameters were analysed using competing risk regression models to analyze their correlation with the occurrence of brain metastases. Overall, 159 patients entered the study. The median follow-up was six years. Among clinical variables, the initial M-stage and TNM-stage were significantly correlated with brain metastasis. Regarding 18F-FDG-PET/CT parameters, regional metastatic lymph node uptake values, as well as prominent SULmax (pSULmax) and prominent SUVmean (pSUVmean), were significantly correlated with the outcome. Cumulative incidences were 10% (6.3-16%), 31% (24.4-38.9%), and 35.2% (28.5-43.5%) after 1, 5, and 10 years. There were significant correlations between pSULmax (p-value < 0.001) and pSULpeak (p-value < 0.001) and the occurrence of brain metastases. The higher these values, the sooner the patient developed brain metastases. Thus, baseline 18F-FDG-PET/CT may have the potential to predict brain metastasis in melanoma patients. Those with high total metabolic activity should undergo follow-up/complementary evaluations, such as brain MRI.

The origin of brain malignancies at the blood-brain barrier

Despite improvements in extracranial therapy, survival rate for patients suffering from brain metastases remains very poor. This is coupled with the incidence of brain metastases continuing to rise. In this review, we focus on core contributions of the blood-brain barrier to the origin of brain metastases. We first provide an overview of the structure and function of the blood-brain barrier under physiological conditions. Next, we discuss the emerging idea of a pre-metastatic niche, namely that secreted factors and extracellular vesicles from a primary tumor site are able to travel through the circulation and prime the neurovasculature for metastatic invasion. We then consider the neurotropic mechanisms that circulating tumor cells possess or develop that facilitate disruption of the blood-brain barrier and survival in the brain's parenchyma. Finally, we compare and contrast brain metastases at the blood-brain barrier to the primary brain tumor, glioma, examining the process of vessel co-option that favors the survival and outgrowth of brain malignancies.

Genomic and Transcriptomic Profiling of Brain Metastases

Simple Summary

Brain metastases (BM) are the most common brain tumors in adults and are the main cause of cancer-associated death. Omics analysis of BM will allow for a better understanding of metastatic progression, prognosis and therapeutic targeting. In this study, BM samples underwent comprehensive molecular profiling with genomics and transcriptomics. Mutational signatures suggested that most mutations were gained prior to metastasis. A novel copy number event centered around the MCL1 gene was found in 75% of all samples. Transcriptomics revealed that melanoma BM formed a distinct cluster in comparison to other subtypes. Poor survival correlated to self-identified black race and absence of radiation treatment but not molecular profiles. These data identify potential new drivers of brain metastatic progression, implicate that melanoma BM are distinctive and likely responsive to unique therapies, and further investigation of sociodemographic and clinical features are needed in BM cohorts.

Abstract

Brain metastases (BM) are the most common brain tumors in adults occurring in up to 40% of all cancer patients. Multi-omics approaches allow for understanding molecular mechanisms and identification of markers with prognostic significance. In this study, we profile 130 BM using genomics and transcriptomics and correlate molecular characteristics to clinical parameters. The most common tumor origins for BM were lung (40%) followed by melanoma (21%) and breast (15%). Melanoma and lung BMs contained more deleterious mutations than other subtypes (p < 0.001). Mutational signatures suggested that the bulk of the mutations were gained before metastasis. A novel copy number event centered around the MCL1 gene was found in 75% of all samples, suggesting a broader role in promoting metastasis. Unsupervised hierarchical cluster analysis of transcriptional signatures available in 65 samples based on the hallmarks of cancer revealed four distinct clusters. Melanoma samples formed a distinctive cluster in comparison to other BM subtypes. Characteristics of molecular profiles did not correlate with survival. However, patients with self-identified black race or those who did not receive radiation correlated with poor survival. These data identify potential new drivers of brain metastatic progression. Our data also suggest further investigation of sociodemographic and clinical features is needed in BM cohorts.

Comprehensive Characterization of Stage IIIA Non-Small Cell Lung Carcinoma

Introduction

Heterogeneity of non-small cell lung carcinoma (NSCLC) among patients is currently not well studied. Pathologic markers and staging systems have not been a precise predictor of the prognosis of an individual patient. Hence, we hypothesize to develop a transcript-based signature to categorize stage IIIA-NSCLC in lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC), plus identify markers that could indicate the prognosis of the disease.

Methods

Human Transcriptome Array 2.0 (HTA) and NanoString nCounter® platform were used for high-throughput gene-expression profiling. Initially, we profiled stage IIIA-NSCLC through HTA and validated through NanoString. Additionally, two metastatic markers SPP1 and CDH2 were validated in 47 NSCLC stage IIIA samples through real-time PCR.

Results

We observed distinct gene clusters in LUAD and LUSC with down-regulation of six genes and up-regulation of 57 genes through HTA. Ninety-six transcripts were randomly selected after analyzing HTA data and validated on the NanoString platform. We found 40 differentially expressed transcripts that categorized NSCLC into LUAD and LUSC. SPP1 is significantly overexpressed (4.311±1.27 fold in LUAD and 13.41±3.82 fold in LUSC compared to control), and the CDH2 transcript was significantly overexpressed (11.53 ± 4.027-fold compared to control) only in LUSC.

Discussion

These markers enable us to categorize stage IIIA NSCLC into LUAD and LUSC plus these markers may be helpful to understand the pathophysiology of NSCLC. However, more data required to make these findings useful in general clinical practice.

Mental disorder or conscious disturbance in epidermal growth factor receptor-tyrosine kinase inhibitor treatment of advanced lung adenocarcinoma

Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) are currently recommended by international guidelines as first-line treatment in patients with advanced EGFR-mutant non-small-cell lung cancer. With the availability of drugs, more and more patients choose EGFR-TKI treatment. However, pharmaceutical drugs used in clinical practice have side effects, such as diarrhea, paronychia, and hepatotoxicity. Mental or conscious disturbance has never been reported before. In our clinical center, we found that several patients with advanced lung adenocarcinoma developed a mental disorder or conscious disturbance after EGFR-TKI treatment. This situation has not previously been reported. We conducted a retrospective study of patients with advanced lung adenocarcinoma treated with EGFR-TKI who showed a mental disorder or conscious disturbance. We reported five cases of lung adenocarcinoma who developed a mental disorder or conscious disturbance after treatment with EGFR-TKI. The main clinical symptoms of these patients were sluggishness, memory deterioration, cognitive disorder, and even hallucination. Brain magnetic resonance imaging showed increased ischemic foci and lacunar infarction, worse encephalatrophy, and demyelination after EGFR-TKI therapy. These psychiatric symptoms did not improve but worsened after taking antipsychotic drugs, suggesting that they were irreversible. The neuropsychiatric symptoms in EGFR-TKI treatment must be considered, and the underlying reason warrants further study.

Metastases to the central nervous system: Molecular basis and clinical considerations

BACKGROUND

Metastatic tumors are the most common malignancies of the central nervous system (CNS) in adults. CNS metastases are associated with unfavorable prognosis, high morbidity and mortality. Lung cancer is the most common source of brain metastases, followed by breast cancer and melanoma. Rising incidence is primarily due to improvements in systemic control of primary malignancies, prolonged survival and advances in cancer detection.

PURPOSE

To provide an overview of the metastatic cascade and the role of angiogenesis, neuroinflammation, metabolic adaptations, and clinical details about brain metastases from different primary tumors.

METHODS

A review of the literature on brain metastases was conducted, focusing on the pathophysiology and clinical aspects of the disease. PubMed was used to search for relevant articles published from January 1975 through December 2019 using the keywords brain metabolism, brain metastasis, metastatic cascade, molecular mechanisms, incidence, risk factors, and prognosis. 146 articles met the criteria and were included in this review.

DISCUSSION

Some primary tumors have a higher tendency to metastasize to the CNS. Establishing a suitable metastatic microenvironment is important in maintaining tumor cell growth and survival. Magnetic resonance imaging (MRI) is a widely used tool for diagnosis and treatment monitoring. Available treatments include surgery, radiotherapy, stereotactic radiosurgery, chemotherapy, immunotherapy, and systemic targeted therapies.

CONCLUSIONS

Prevention of metastases to the CNS remains a difficult challenge. Advances in screening of high-risk patients and future development of novel treatments may improve patient outcomes.