Occupational and environmental risk factors for brain cancer: a pilot case-control study in France

Recent Advances in the Use of Lipid-Based Nanoparticles Against Glioblastoma Multiforme

Glioblastoma (GBM) is the most common and aggressive malignant brain tumor in adults. Although the overall incidence is less than 10 per 100,000 individuals, its poor prognosis and low survival rate make GBM a crucial public health issue. The main challenges for GBM treatment are related to tumor location and its complex and heterogeneous biology. In this sense, a broad range of nanoparticles with different sizes, architectures, and surface properties, have been engineered as brain drug delivery systems. Among them, lipid-based nanoparticles, such as liposomes, have been pointed out as promising materials to deliver antitumoral drugs to the central nervous system and thus, to improve brain drug targeting and therapeutic efficiency. Here, we describe the synthesis and general characteristics of lipid-based nanoparticles, as well as evidence in the past 5 years regarding their potential use to treat GBM.

Molecular biological investigation of temozolomide and KC7F2 combination in U87MG glioma cell line

Glioblastom Multiforme (GBM) is the most invasive and malignant member of the IV grade of the subclass Astrocytoma according to the last assessment of the 2016 WHO report. Due to the resistance to treatment and weak response, as well as the topographical structure of the blood brain barrier, the treatment is also difficult due to the severe clinical manifestation, and new treatment methods and new therapeutic agents are needed. Temozolomide (TMZ) is widely used in the treatment of glioblastoma and is considered as the primary treatment modality. TMZ, a member of the class of cognitive agents, is currently considered the most effective drug because it can easily pass through the blood brain barrier. Glucose metabolism is a complex energy producing machine that, a glucose molecule produces 38 molecules of ATP after full glycolytic catabolism. According to Otto Warburg's numerous studies cancer cells perform the first glycolytic step without entering the mitochondrial step. These cells produce lactic acid and make the micro-media more acidic even in aerobic conditions. This phenomenon is attributed to the Warburg hypothesis and either as aerobic glycolysis. Although glycolysis enzymes are the primary actors of this phenotypic expression, some genetic and epigenetic factors are no exception. We experimentally used KC7F2 active ingredient to target cancer metabolism. In our study, we evaluated cancer metabolism in combination with the effect of TMZ chemotherapeutic agent, examining the effect of two different agents separately and in combination to observe the effects of cancer cell proliferation, survival, apoptosis and expression of metabolism genes on expression. We observed that the combined effect of reduced the effective dose of the TMZ alkylating agent and that the effect was increased and the effect of the combined teraphy is assessed from a metabolic point of view and that it suppresses aerobic glycolysis.

Cellular Phone Use and Risk of Tumors: Systematic Review and Meta-Analysis

We investigated whether cellular phone use was associated with increased risk of tumors using a meta-analysis of case-control studies. PubMed and EMBASE were searched from inception to July 2018. The primary outcome was the risk of tumors by cellular phone use, which was measured by pooling each odds ratio (OR) and its 95% confidence interval (CI). In a meta-analysis of 46 case-control studies, compared with never or rarely having used a cellular phone, regular use was not associated with tumor risk in the random-effects meta-analysis. However, in the subgroup meta-analysis by research group, there was a statistically significant positive association (harmful effect) in the Hardell et al. studies (OR, 1.15-95% CI, 1.00 to 1.33- n = 10), a statistically significant negative association (beneficial effect) in the INTERPHONE-related studies (case-control studies from 13 countries coordinated by the International Agency for Research on Cancer (IARC); (OR, 0.81-95% CI, 0.75 to 0.89-n = 9), and no statistically significant association in other research groups' studies. Further, cellular phone use with cumulative call time more than 1000 h statistically significantly increased the risk of tumors. This comprehensive meta-analysis of case-control studies found evidence that linked cellular phone use to increased tumor risk.

Incidence of Primary Central Nervous System Tumors Among the Hispanic Population in Texas 1995-2013

INTRODUCTION

Primary central nervous system (CNS) tumors constitute a group of rare and heterogeneous tumors. A rising incidence rate in the United States has been linked to modern changes in early diagnosis and reporting. This study aims to examine temporal incidence trends, geographic variation, and the average annual age-adjusted rates among Hispanic populations in Texas from 1995 to 2013.

METHODS

SEER*STAT (Surveillance Research Program, National Cancer Institute (seer.cancer.gov/seerstat) version 8.3.2) and Joinpoint Regression 4.4.0.0 (Statistical Methodology and Applications Branch, Surveillance Research Program, National Cancer Institute) software were used to analyze incidence of primary brain and CNS tumors among Texas residents. Data were obtained from the Texas Cancer Registry of the Texas Department of State Health Services.

RESULTS

From the 30,122 cases of primary CNS tumors diagnosed throughout the state of Texas from 2008 to 2012, the overall average annual age-adjusted incidence rate for Hispanics and non-Hispanics combined was 25.35 per 100,000 persons. Among Hispanics, West Texas had the highest incidence trends and the highest average age-adjusted incidence rate of 27.17, followed by North Texas at 26.01 and the Panhandle at 23.63. East Texas had the lowest incidence rate of 16.23. The incidence trend among Hispanics has decreased consistently at a rate of 0.83 % from 1995 to 2013.

CONCLUSIONS

The incidence of tumors was more pronounced in the Hispanic population in northern Texas compared with southern Texas. The presence of oil and gas production industries with farming and construction could play a role in the observed incidence of disease. Further studies with a focus on occupational health among Hispanics in Texas will be needed to elucidate the cause of such distribution.

Brain and Salivary Gland Tumors and Mobile Phone Use: Evaluating the Evidence from Various Epidemiological Study Designs

Mobile phones (MPs) are the most relevant source of radiofrequency electromagnetic field (RF-EMF) exposure to the brain and the salivary gland. Whether this exposure implies a cancer risk has been addressed in several case-control and few cohort studies. A meta-analysis of these studies does not show increased risks for meningioma, pituitary, and salivary gland tumors. For glioma and acoustic neuroma, the results are heterogeneous, with few case-control studies reporting substantially increased risks. However, these elevated risks are not coherent with observed incidence time trends, which are considered informative for this specific topic owing to the steep increase in MP use, the availability of virtually complete cancer registry data from many countries, and the limited number of known competing environmental risk factors. In conclusion, epidemiological studies do not suggest increased brain or salivary gland tumor risk with MP use, although some uncertainty remains regarding long latency periods (>15 years), rare brain tumor subtypes, and MP usage during childhood.

A systematic review of the risk factors associated with the onset and progression of primary brain tumours

The overall aim of this systematic review was to identify risk factors for onset and natural progression, which were shown to increase, decrease, or have a null association with risk of primary brain tumour. For onset, the project was separated into two phases. The first phase consisted of a systematic search of existing systematic reviews and meta-analyses. Moderate to high methodological quality reviews were incorporated and summarized with relevant observational studies published since 2010, identified from a systematic search performed in phase 2. For natural progression, only the first phase was conducted. Standard systematic review methodology was utilized. Based on this review, various genetic variants, pesticide exposures, occupational farming/hairdressing, cured meat consumption and personal hair dye use appear to be associated with increased risk of onset amongst adults. The specific EGF polymorphsm 61-A allele within Caucasian populations and having a history of allergy was associated with a decreased risk. For progression, M1B-1 antigen was shown to increase the risk. High birth weight, pesticide exposure (childhood exposure, and parental occupational exposure) and maternal consumption of cured meat during pregnancy may also increase the risk of onset of childhood brain tumours. Conversely, maternal intake of pre-natal supplements (folic acid) appeared to decrease risk. Children with neurofibromatosis 2 were considered to have worse overall and relapse free survival compared to neurofibromatosis 1, as were those children who had grade III tumours compared to lesser grades.

Glioblastoma multiforme - an overview

Glioblastoma multiforme is a central nervous system tumor of grade IV histological malignancy according to the WHO classification. Over 90% of diagnosed glioblastomas multiforme cases are primary gliomas, arising from normal glial cells through multistep oncogenesis. The remaining 10% are secondary gliomas originating from tumors of lower grade. These tumors expand distinctly more slowly. Although genetic alterations and deregulations of molecular pathways leading to both primary and secondary glioblastomas formation differ, morphologically they do not reveal any significant differences. Glioblastoma is a neoplasm that occurs spontaneously, although familial gliomas have also been noted. Caucasians, especially those living in industrial areas, have a higher incidence of glioblastoma. Cases of glioblastoma in infants and children are also reported. The participation of sex hormones and viruses in its oncogenesis was also suggested. Progression of glioblastoma multiforme is associated with deregulation of checkpoint G1/S of a cell cycle and occurrence of multiple genetic abnormalities of tumor cells. Metastases of glioblastoma multiforme are rarely described. Treatment of glioblastoma multiforme includes tumor resection, as well as radiotherapy and chemotherapy. Drugs inhibiting integrin signaling pathways and immunotherapy are also employed. Treatment modalities and prognosis depend on the tumor localization, degree of its malignancy, genetic profile, proliferation activity, patient's age and the Karnofsky performance scale score. Although the biology of glioblastoma multiforme has recently been widely investigated, the studies summarizing the knowledge of its development and treatment are still not sufficient in terms of comprehensive brain tumor analysis.

Links between private habits, psychological stress and brain cancer: a case-control pilot study in France

Numerous studies have increasingly suggested that medical history and lifestyle factors could be involved in the increase of cancer risk in adults. The issue whether psychological factors can influence the development of cancer has been discussed for many years. In the field of brain cancer, psychological stress has not so far been investigated. We conducted a French case-control pilot study with 122 adult incident cases and 122 controls free of any cancer diagnosis, matched for age and gender, to investigate links between malignant primitive brain tumours (MPBT) and medical history, private habits and psychological stress. Data were collected through self-administered questionnaires, and person-to-person interviews. To complete the psychological stress assessment, 100-mm visual analog scales were used. After adjustment for confounders, we found no significant effect of head trauma, aspartame, tobacco or alcohol consumption, place (rural or urban) of residence, sociodemographic data, and experience of psychological stress at work/home. Our results showed a significant association between MPBT risk and major life events over the past 5 years before diagnosis (OR = 1.90, 95% CI 1.13-3.20), family histories of cancer (OR = 1.90, 95% CI 1.12-3.22), fresh vegetable and fruit intake (OR = 0.29, 95% CI 0.09-0.95), and skipped meals several times per week (OR = 0.35, 95% CI 0.16-0.77). The present study suggests the role of genetic factors in glioma risk, and also suggests that an acute and sudden psychological stress might influence MPBT appearance. Additional large clinical studies are needed to confirm these findings.