Current standards in the management of cerebral metastases

Immunotherapy and brain metastasis in lung cancer: connecting bench side science to the clinic

Brain metastases (BMs) are the most common form of intracranial malignant neoplasms in adults, with a profound impact on quality of life and traditionally associated with a dismal prognosis. Lung cancer accounts for approximately 40%-50% of BM across different tumors. The process leading to BMs is complex and includes local invasion, intravasation, tumor cells circulation into the bloodstream, disruption of the blood-brain barrier, extravasation of tumor cells into the brain parenchyma, and interaction with cells of the brain microenvironment, among others. Once the tumor cells have seeded in the brain parenchyma, they encounter different glial cells of the brain, as well as immune cells. The interaction between these cells and tumor cells is complex and is associated with both antitumoral and protumoral effects. To overcome the lethal prognosis associated with BMs, different treatment strategies have been developed, such as immunotherapy with immune checkpoint inhibitors, particularly inhibitors of the PD-1/PD-L1 axis, which have demonstrated to be an effective treatment in both non-small cell lung cancer and small cell lung cancer. These antibodies have shown to be effective in the treatment of BM, alone or in combination with chemotherapy or radiotherapy. However, many unsolved questions remain to be answered, such as the sequencing of immunotherapy and radiotherapy, the optimal management in symptomatic BMs, the role of the addition of anti-CTLA-4 antibodies, and so forth. The complexity in the management of BMs in the era of immunotherapy requires a multidisciplinary approach to adequately treat this devastating event. The aim of this review is to summarize evidence regarding epidemiology of BM, its pathophysiology, current approach to treatment strategies, as well as future perspectives.

Application of C-Terminal Clostridium Perfringens Enterotoxin in Treatment of Brain Metastasis from Breast Cancer

Simple Summary

Brain metastasis occurs in primary cancers, such as breast cancer, and is correlated with mortality. There are limited options available for treatment, but Clostridium perfringens Enterotoxin (CPE) and its interaction with Claudin-4, a possible diagnostic biomarker for breast cancer, can provide a molecular pathway basis for the development of treatment options for metastatic brain cancer. Analysis of the literature reveals that Claudin-4 plays an important role as a receptor for CPE, allowing for the disruption of cell membrane permeability, an influx of calcium ions, and subsequent cell death. The negligible presence of Claudin-4 in normal brain cancer cells and the high abundance of Claudin-4 in breast cancer cells metastasized to the brain, allow for the targeted binding of CPE to tumor cells in the brain. We show that the C-terminal of CPE conjugated to nanoparticles that cross the blood–brain barrier could serve as a drug delivery tool to treat metastatic cells in the brain.

Abstract

Claudin-4 is part of the Claudin family of transmembrane tight junction (TJ) proteins found in almost all tissues and, together with adherens junctions and desmosomes, forms epithelial and endothelial junctional complexes. Although the distribution of Claudin-4 occurs in many cell types, the level of expression is cell-specific. Claudin proteins regulate cell proliferation and differentiation by binding cell-signaling ligands, and its expression is upregulated in several cancers. As a result, alterations in Claudin expression patterns or distribution are vital in the pathology of cancer. Profiling the genetic expression of Claudin-4 showed that Claudin-4 is also a receptor for the clostridium perfringens enterotoxin (CPE) and that Claudin-4 has a high sequence similarity with CPE’s high-affinity receptor. CPE is cytolytic due to its ability to form pores in cellular membranes, and CPE treatment in breast cancer cells have shown promising results due to the high expression of Claudin-4. The C-terminal fragment of CPE (c-CPE) provides a less toxic alternative for drug delivery into breast cancer cells, particularly metastatic tumors in the brain, especially as Claudin-4 expression in the central nervous system (CNS) is low. Therefore, c-CPE provides a unique avenue for the treatment of breast–brain metastatic tumors.

Outcomes in patients with brain metastasis from esophageal carcinoma

BACKGROUND

Brain metastases from esophageal carcinoma have historically been rare and associated with poor prognosis. With improvements in systemic disease control, the incidence of brain metastases is expected to rise. To better inform management decisions, we sought to identify factors associated with survival in patients with brain metastasis from esophageal cancer.

METHODS

We retrospectively identified 49 patients with brain metastasis from stage I-IV primary esophageal cancer treated with surgery, radiation, or a combination of modalities at our tertiary referral center between 1998 and 2015. Medical records were reviewed to collect demographic and clinical information.

RESULTS

Median age at diagnosis of the primary esophageal cancer was 60 years. Forty-one (84%) patients were male and forty patients (82%) had adenocarcinoma. Median overall survival (MS) following esophageal cancer diagnosis was 24 months (range, 3-71 months), and median survival after the identification of brain metastases was 5 months (range, 1-52 months). On univariate analysis, only patients with poor Karnofsky performance status (KPS <70), recursive partitioning analysis (RPA) classification (III), or 3 or more brain metastases were found to have worsened survival after the diagnosis of brain metastases (all P<0.01). Factors not associated with survival were age, gender, histology (adenocarcinoma vs. other), palliative-intent treatment of the primary tumor, time to diagnosis of brain metastases from initial diagnosis, uncontrolled primary tumor at time of brain metastasis diagnosis, or extracranial metastases. On multivariate analysis (MVA, KPS excluded), patients with RPA class I (MS, 14.6 months) or II (MS, 5.0 months) disease had significantly improved overall survival compared to class III disease (MS, 1.6 months, P<0.01). Also on MVA, patients with 1 (MS, 10.7 months) or 2 (MS, 4.7 months) brain metastases had significantly improved overall survival compared to patients with 3 or more brain metastases (MS, 0.3 months, P<0.01). For the 36 patients with 1-2 brain metastases and KPS ≥70, MS was 11.1 months.

CONCLUSIONS

While the prognosis for esophageal cancer metastatic to brain remains poor overall, we found that patients with good performance status and limited number of brain lesions have superior survival. Aggressive management may further improve outcomes in these patients.

Quality of life and radiotherapy in brain metastasis patients

AIM

The primary objective of this study was to assess whether there was an improvement in QoL for patients with brain metastases after radiotherapy treatments.

BACKGROUND

Assessment of quality of life (QoL) in brain metastasis patients has become increasingly recognized as an important outcome.

MATERIALS AND METHODS

Patients treated for brain metastasis in our department during 2010 were included in our prospective study. QoL assessments were conducted at baseline, 1 month, and 3 months after completion of whole-brain radiotherapy (WBRT). Wilcoxon test for multiple comparisons was calculated to detect significant differences in global QoL scores.

RESULTS

Thirty-nine patients with brain metastases completed the EORTC QLQ-C30/BN-20 questionnaire independently. Median age was 59.9 years (from 37 to 81 years). Our results report differences between the baseline and 3 months in worsening of a global health status (p = 0.034) and cognitive function (p = 0.004), as well as drowsiness (p = 0.001), appetite loss (p = 0.031) and hair loss (p = 0.005). There is a tendency for deterioration of physical function (p = 0.004), communication deficit (p = 0.012), and weakness of legs (p = 0.024), between the baseline and 1 month evaluation. There was no difference in a global cognitive status between different evaluations. Median survival time was 3 months (CI 95% 1.85; 4.15).

CONCLUSIONS

Our findings indicate a small deterioration for a global QoL status, and large deterioration for cognitive function after radiation treatments, as well as worsening of brain metastasis related symptom items. Further research is necessary to refine treatment selection for patients with brain metastases, since it may at least contribute to the stabilization of their QoL status.