Central nervous system tumors

Inhibition of STAT3: A promising approach to enhancing the efficacy of chemotherapy in medulloblastoma

Medulloblastoma is a type of brain cancer that primarily affects children. While chemotherapy has been shown to be effective in treating medulloblastoma, the development of chemotherapy resistance remains a challenge. One potential therapeutic approach is to selectively inhibit the inducible transcription factor called STAT3, which is known to play a crucial role in the survival and growth of tumor cells. The activation of STAT3 has been linked to the growth and progression of various cancers, including medulloblastoma. Inhibition of STAT3 has been shown to sensitize medulloblastoma cells to chemotherapy, leading to improved treatment outcomes. Different approaches to STAT3 inhibition have been developed, including small-molecule inhibitors and RNA interference. Preclinical studies have shown the efficacy of STAT3 inhibitors in medulloblastoma, and clinical trials are currently ongoing to evaluate their safety and effectiveness in patients with various solid tumors, including medulloblastoma. In addition, researchers are also exploring ways to optimize the use of STAT3 inhibitors in combination with chemotherapy and identify biomarkers that can predict treatment that will help to develop personalized treatment strategies. This review highlights the potential of selective inhibition of STAT3 as a novel approach for the treatment of medulloblastoma and suggests that further research into the development of STAT3 inhibitors could lead to improved outcomes for patients with aggressive cancer.

Pesticide exposure and risk of Central Nervous System tumors in children: a systematic review with meta-analysis

Central Nervous System (CNS) tumors represent more than half of all childhood malignant neoplasms. The aim of this study was to determine the relationship between environmental exposure to pesticides and the development of CNS tumors in children. We conducted a systematic review of the literature in the PubMed/MEDILINE, Embase, Web of Science, Scopus, and CINAHL databases. The inclusion criteria were cohort and case-control studies investigating the association between exposure to pesticides and CNS tumors (all histological types included in group III of the WHO Classification of Childhood Cancer) in children aged 0-14 years. The meta-analysis was performed using a random effects model and the Mantel-Haenszel method. Strength of association was measured using odds ratios (OR). The review was registered in the International Prospective Register of Systematic Reviews (PROSPERO) under identification number CRD42021209354. The search identified 1,158 studies, 14 of which were included in the review. There was evidence of an association between the development of astrocytomas and exposure to all classes of pesticides (OR 1.50; 95%CI 1.15-1.96; p=0.03). The synthesis of the evidence pointed to a relationship between exposure to pesticides and some histological types of CNS tumors in childhood.

A Preliminary Study Indicating Improvement in the Median Survival Time of Glioblastoma Multiforme Patients by the Application of Deuterium Depletion in Combination with Conventional Therapy

Glioblastoma multiforme (GBM) and malignant gliomas are the most common primary malignant brain tumors. Temozolomide (TMZ) chemotherapy plus radiation therapy (RT), admi-mistered after debulking surgery, increased the median survival time (MST) from 12.1 months with RT alone merely to 14.6 months, respectively. In this study, the actions of deuterium-depleted water (DDW) on the survival of GBM patients who also received conventional therapies was investigated. Without changing the conventional treatment, the daily fluid intake of the patients was wholly replaced with DDW in 1.5-2 L per day volume to reduce the D concentration in their bodies. The primary endpoint was the MST. The 55 patients involved in this study, who received conventional treatment and consumed DDW, showed a longer MST (30 months) compared to the historical control (12.1-14.6 months). There was a massive difference between the two genders in the calculated MST values; it was 25 months in the male subgroup (n = 33) and 42 months in the female subgroup (n = 22), respectively. The MST was 27 months without TMZ treatment (38 patients) and 42 months in the TMZ-treated group (17 patients), respectively. For the selected 31 patients, who consumed DDW in the correct way in addition to their conventional treatments, their MST was calculated as 30 months. Within this group, the 20 subjects who had relapsed before DDW treatment had 30 months of MST, but in those 10 subjects who were in remission when DDW treatment started, their MST was 47 months. In the subgroup of patients who began their DDW treatment parallel with radiotherapy, their MST was again 47 months, and it was 25 months when their DDW treatment was started at 8 weeks or later after the completion of radiotherapy. Altogether, these survival times were substantially prolonged compared to the prospective clinical data of patients with primary GBM. Consequently, if conventional therapies are supplemented with D depletion, better survival can be achieved in the advanced stage of GBM than with the known targeted or combination therapies. Application of DDW is recommended in all stages of the disease before surgery and in parallel with radiotherapy, and repeated DDW courses are advised when remission has been achieved.

Evaluation of total oxidative stress and antioxidant capacity of brain tumour patients attending referral hospitals in Addis Ababa, 2020: a comparative cross-sectional study

Background

The exact cause of brain tumours is still unknown, but disruptions of redox balance are thought to play a significant role in all stages of brain tumour development. However, the roles of free radical imbalance at different grades of brain tumour and degree of oxidative stress before and after surgery have not been addressed in prior studies.

Aim

A comparative cross-sectional study was conducted to assess the redox imbalance among confirmed brain tumour patients.

Methods and results

An institution-based comparative cross-sectional study was conducted on a total of 100 participants (50 brain tumour patients and 50 controls) at referral hospitals in Addis Ababa, Ethiopia. Descriptive statistics, t-test and analysis of variance (ANOVA) (post-hoc) analysis were used and statistical significance was declared at p ≤ 0.05. The serum oxidised glutathione and total oxidative stress were significantly higher in the serum of brain tumour patients (0.72 ± 0.03 μM/μg and 9.66 ± 1.76 μmol H2O2 Eq/L, respectively) compared to the control group (0.21 ± 0.07 μM/μg and 6.59 ± 0.81 μmol H2O2 Eq/L, respectively) (p ≤ 0.05). The serum total oxidant status gradually increased as the tumour grade increased, being higher in grade four (11.96 ± 0.72) and lower in grade one (8.43 ± 1.56), and the mean differences were statistically significant (p ≤ 0 05). A statistically significantly higher total antioxidant capacity (116.78 ± 5.03 Trolox Eq/L) was obtained in the post-surgery than pre-surgery level (79.65 ± 17.914 Trolox Eq/L) (p ≤ 0 05).

Conclusion

Higher oxidant and lower antioxidant levels were found in the serum of brain tumour patients than in the control group. The post-surgery oxidant level was lower than the pre-surgery state. The findings of this study could suggest that redox imbalance may have a role in the pathophysiology of brain tumours, but further experimental studies are needed.

Epidemiologic and histologic characteristics of CNS lesions: a 20-year experience of a tertiary center in Lebanon

Aim:

Report the epidemiologic and histologic characteristics of CNS lesions in the Lebanese population.

Methods:

We conducted a retrospective study evaluating 2025 CNS lesions diagnosed between 1998 and 2017 in the pathology laboratory of a Lebanese tertiary center.

Results:

52.2% of patients were men with a median age of 50 years. The most frequent symptoms were epilepsy (22.5%), headache (20.6%) and motor impairment (19.9%). 90.7% of tumors were primary. Lung (35.6%) and breast (16.5%) were the most frequent primaries of metastases. 46.2% of primary CNS tumors were glial, predominantly astrocytic (56.4%), and (42.5%) were nonglial, predominantly meningeal tumors (58%).

Conclusion:

Compared with Western literature, the Lebanese population is characterized by a younger age of onset of brain tumors, a lower rate of meningiomas and a higher rate of gliomas.

Immunohistochemical Expression of Epidermal Growth Factor Receptor in Astrocytic Tumors in Iraqi Patients

BACKGROUND

Diffuse astrocytomas constitute the largest group of primary malignant human intracranial tumours. They are classified by the World Health Organization (WHO) into three histological malignancy grades: diffuse astrocytomas (grade II), anaplastic astrocytomas (grade III) and glioblastoma (grade IV) based on histopathological features such as cellular atypia, mitotic activity, necrosis and microvascular proliferation. Epidermal growth factor receptor (EGFR) is a 170-kDa transmembrane tyrosine kinase receptor expressed in a variety of normal and malignant cells regulating critical cellular processes. When activated, epidermal growth factor receptor (EGFR) triggers several signalling cascades leading to increased proliferation and angiogenesis and decreased apoptosis and hence associated with aggressive progression of the tumour. Epidermal growth factor receptor (EGFR) level is known to be a strong indicator associated with the aggressive behaviour of the tumour and acts as a prognostic factor for evaluating the survival rate.

AIM

To evaluate the expression of epidermal growth factor receptor (EGFR) in different grades of astrocytoma.

MATERIAL AND METHODS

formalin-fixed paraffin-embedded astrocytic tumours of 44 patients were collected from the archival material of pathology department of Ghazi Al Hariri Teaching Hospital during the period from June to December 2018. Hematoxylin and eosin-stained sections were used to characterise the tumours histologically based on cellularity, nuclear hyperchromasia, polymorphism, mitotic activity, vascular proliferation and necrosis with or without pseudopallisading of tumour cells. Diagnosis and grading of astrocytic tumours in this study were made according to WHO criteria (2016). Using a monoclonal antibody to the epidermal growth factor receptor (EGFR) and immunohistochemical analysis, the expression and distribution of epidermal growth factor receptor in astrocytic tumours were examined.

RESULTS

The study included 1 case pilocytic astrocytoma (grade I), 20 cases diffuse astrocytoma (grade II), 5 cases anaplastic astrocytoma (grade III) and 18 cases of glioblastoma (grade IV). Expression of EGFR was found in 38.88% of the glioblastoma samples (grade IV). However, none of the astrocytomas of WHO grades I, II and III showed immunoreactivity for EGFR protein. Different patterns of immunoreactive cells and significant intratumor heterogeneity of EGFR expression were observed in glioblastomas.

CONCLUSION

The immunohistochemical expression of Epidermal growth factor receptor (EGFR) was restricted only to high-grade astrocytic tumours, namely glioblastoma, thus may use to predict glioblastoma.

Pyrosequencing versus methylation-specific PCR for assessment of MGMT methylation in tumor and blood samples of glioblastoma patients

Circulating biomarkers in blood may provide an interesting alternative to risky tissue biopsies in the diagnosis and follow-up of glioblastoma patients. We have assessed MGMT methylation status in blood and tissue samples from unresected glioblastoma patients who had been included in the randomized GENOM-009 trial. Paired blood and tissue samples were assessed by methylation-specific PCR (MSP) and pyrosequencing (PYR). After establishing the minimum PYR cut-off that could yield a significant difference in overall survival, we assessed the sensitivity, specificity, positive predictive value and negative predictive value (NPV) of the analyses. Methylation could be detected in cfDNA by both MSP and PYR but with low concordance with results in tissue. Sensitivity was low for both methods (31% and 38%, respectively), while specificity was higher for MSP in blood than for PYR in plasma (96% vs 76%) and NPV was similar (56 vs 57%). Concordance of results in tissue by MSP and PYR was 84.3% (P < 0.001) and correlated with outcome. We conclude that detection of cfDNA in the blood of glioblastoma patients can be an alternative when tumor tissue is not available but methods for the detection of cfDNA in blood must improve before it can replace analysis in tumor tissue.

The cancer incidence and mortality among children and adolescents during the period of 2010-2014 in Henan Province, China

OBJECTIVE

The cancer etiology in children and adolescents is largely different with that in adults, and the description in epidemiology still remains deficiency. Therefore, we described the cancer incidence and related epidemiological features in children and adolescents to provide clues for etiological studies.

METHODS

Cancer incidence stratified by age, gender, and areas was calculated using data extracted from population-based cancer registries in Henan Province, China. All cancer among children aged 0-19 years were reclassified according to category criteria of the International Classification of Childhood Cancer, 3rd Edition (ICCC-3). Age-standardized rate (WSR) was calculated using Segi's world standardized population by the direct method, and it was expressed per million person-years.

RESULTS

The crude cancer incidence and mortality were 87.56 and 36.32 per million person-years among children aged 0-19 years, and the WSRs slightly changed compared with crude incidence and mortality, and they were 87.36 and 35.46 per million person-years. Leukemia and central nervous system neoplasms (CNS) were the most common cancer categories both in children aged 0-14 years and in adolescents aged 15-19 years in regardless of gender and areas. Tiny difference of incidence and mortality existed in different age groups across 0-14 years; however, they were higher in adolescents aged 15-19 years than that in children aged 0-14 years. Among children aged 0-19 years, the cancer incidence and mortality were predominant in boys, and the sex ratio was 1.19; however, it was varied by diagnostic categories.

CONCLUSION

This is the first study that described the cancer incidence and mortality among children aged 0-19 in Henan Province, and it would help researchers to understand the burden and epidemiological characteristics of childhood cancer, and hence suggested clues for the etiological studies.

Risk factors for central nervous system tumors in children: New findings from a case-control study

Background

Central nervous system tumors (CNS) are the most frequent solid tumor in children. Causes of CNS tumors are mainly unknown and only 5% of the cases can be explained by genetic predisposition. We studied the effects of environmental exposure on the incidence of CNS tumors in children by subtype, according to exposure to industrial and/or urban environment, exposure to crops and according to socio-economic status of the child.

Methods

We carried out a population-based case-control study of CNS tumors in Spain, covering 714 incident cases collected from the Spanish Registry of Childhood Tumors (period 1996–2011) and 4284 controls, individually matched by year of birth, sex, and autonomous region of residence. We built a covariate to approximate the exposure to industrial and/or urban environment and a covariate for the exposure to crops (GCI) using the coordinates of the home addresses of the children. We used the 2001 Census to obtain information about socio-economic status (SES). We fitted logistic regression models to estimate odds ratios (ORs) and 95% confidence intervals (95%CIs).

Results

The results for all CNS tumors showed an excess risk (OR = 1.37; 95%CI = 1.09–1.73) for SES, i.e., children living in the least deprived areas had 37% more risk of CNS tumor than children living in the most deprived areas. For GCI, an increase of 10% in crop surface in the 1-km buffer around the residence implied an increase of 22% in the OR (OR = 1.22; 95%CI = 1.15–1.29). Children living in the intersection of industrial and urban areas could have a greater risk of CNS tumors than children who live outside these areas (OR = 1.20; 95%CI = 0.82–1.77). Living in urban areas (OR = 0.90; 95%CI = 0.65–1.24) or industrial areas (OR = 0.96; 95%CI = 0.81–1.77) did not seem to increase the risk for all CNS tumors together. By subtype, Astrocytomas, Intracranial and intraspinal embryonal tumors, and other gliomas showed similar results.

Conclusion

Our results suggest that higher socioeconomic status and exposure to crops could increase the risk of CNS tumors in children.

Application of Nanomedicine to the CNS Diseases

Drug delivery to the brain is a challenge because of the many mechanisms that protect the brain from the entry of foreign substances. Numerous molecules which could be active against brain disorders are not clinically useful due to the presence of the blood-brain barrier. Nanoparticles can be used to deliver these drugs to the brain. Encapsulation within colloidal systems can allow the passage of nontransportable drugs across this barrier by masking their physicochemical properties. It should be noted that the status of the blood-brain barrier is different depending on the brain disease. In fact, in some pathological situations such as tumors or inflammatory disorders, its permeability is increased allowing very easy translocation of carriers. This chapter gathers the promising results obtained by using nanoparticles as drug delivery systems with the aim to improve the therapy of some CNS diseases such as brain tumor, Alzheimer's disease, and stroke. The data show that several approaches can be investigated: (1) carrying drug through a permeabilized barrier, (2) crossing the barrier thanks to receptor-mediated transcytosis pathway in order to deliver drug into the brain parenchyma, and also (3) targeting and treating the endothelial cells themselves to preserve locally the brain tissue. The examples given in this chapter contribute to demonstrate that delivering drugs into the brain is one of the most promising applications of nanotechnology in clinical neuroscience.

Complete Intestinal Obstruction and Necrosis as a Complication of a Ventriculoperitoneal Shunt in Children: A Report of 2 Cases and Systematic Literature Review

Ventriculoperitoneal (VP) shunt complications are common, but abdominal complications are rare. The objective of this report is to present 2 cases of intestinal obstruction due to a VP shunt and review the literature for data on this rare occurrence.A 4-month-old boy received surgical resection of a medulloblastoma and a VP shunt was inserted to manage progressive hydrocephalus. Two months later, he was admitted with intermittent vomiting, and plain abdominal radiography showed complete intestinal obstruction. Emergency laparotomy revealed an adhesive intestinal obstruction around the catheter, and approximately 5 cm of necrotic ileum was resected. His recovery was uneventful. In the second case, a 6-year-old boy was diagnosed with a primary nongerminomatous malignant germ cell tumor and a VP shunt was place to treat hydrocephalus. Two weeks after the first course of chemotherapy, he went into a coma; computed tomography demonstrated enlargement of the tumor and gross total resection was performed. Two weeks later, he developed abdominal distention; plain radiography showed intestinal obstruction and laparotomy revealed adhesive intestinal obstruction around the catheter with 15 cm of necrotic ileum. The necrotic bowel was resected. Unfortunately, the patient developed sepsis and despite treatment remained in a vegetative state.Medline, Central, Embase, and Google Scholar databases were searched up to May 9, 2014, using the terms VP shunt, shunting, and/or intestinal obstruction. Only cases involving children or adolescents were included. Eleven reports involving patients with abdominal complications resulting from a VP shunt for hydrocephalus were identified. The dates of the reports spanned from 1971 to 2014. Volvulus was the most common cause of VP shunt-related obstruction, and mechanical obstruction due to twisting of the catheter the second most common. Only 1 case in the literature review was related to intestinal adhesions. Treatment in most cases was laparotomy.Although intestinal obstruction is a rare complication of a VP shunt, it should be considered in the presence of abdominal symptoms and prompt treatment provided to have a good outcome.

The worldwide incidence and prevalence of primary brain tumors: a systematic review and meta-analysis

BACKGROUND

Primary brain tumors are a heterogeneous group of benign and malignant tumors arising from the brain parenchyma and its surrounding structures. The epidemiology of these tumors is poorly understood. The aim of our study is to systematically review the latest literature on the incidence and prevalence of primary brain tumors.

METHODS

The systematic review and meta-analysis were conducted according to a predetermined protocol and established guidelines. Only studies reporting on data from 1985 onward were included. Articles were included if they met the following criteria: (i) original research, (ii) population based, (iii) reported an incidence or prevalence estimate of primary brain tumors.

RESULTS

From the 53 eligible studies overall, 38 were included in the meta-analysis. A random-effects model found the overall incidence rate of all brain tumors to be 10.82 (95% CI: 8.63-13.56) per 100 000 person-years. The incidence proportion estimates were heterogeneous, even among the same tumor subtypes, and ranged from 0.051 per 100 000 (germ cell tumors) to 25.48 per 100 000 (all brain tumors). There were insufficient data to conduct a meta-analysis of the prevalence of primary brain tumors.

CONCLUSIONS

There is a need for more accurate and comparable incidence and prevalence estimates of primary brain tumors across the world. A standardized approach to the study of the epidemiology of these tumors is needed to better understand the burden of brain tumors and the possible geographical variations in their incidence.