Characterization of PD‐1 upregulation on tumor‐infiltrating lymphocytes in human and murine gliomas and preclinical therapeutic blockade

Blockade of the immune checkpoint molecule programmed‐cell‐death‐protein‐1 (PD‐1) yielded promising results in several cancers. To understand the therapeutic potential in human gliomas, quantitative data describing the expression of PD‐1 are essential. Moreover, due the immune‐specialized region of the brain in which gliomas arise, differences between tumor‐infiltrating and circulating lymphocytes should be acknowledged. In this study we have used flow cytometry to quantify PD‐1 expression on tumor‐infiltrating T cells of 25 freshly resected glioma cell suspensions (10 newly and 5 relapsed glioblastoma, 10 lower grade gliomas) and simultaneously isolated circulating T cells. A strong upregulation of PD‐1 expression in the tumor microenvironment compared to the blood circulation was seen in all glioma patients. Additionally, circulating T cells were isolated from 15 age‐matched healthy volunteers, but no differences in PD‐1 expression were found compared to glioma patients. In the murine GL261 malignant glioma model, there was a similar upregulation of PD‐1 on brain‐infiltrating lymphocytes. Using a monoclonal PD‐1 blocking antibody, we found a marked prolonged survival with 55% of mice reaching long‐term survival. Analysis of brain‐infiltrating cells 21 days after GL261 tumor implantation showed a shift in infiltrating lymphocyte subgroups with increased CD8+ T cells and decreased regulatory T cells. Together, our results suggest an important role of PD‐1 in glioma‐induced immune escape, and provide translational evidence for the use of PD‐1 blocking antibodies in human malignant gliomas.     

New treatment strategies for malignant gliomas

Malignant gliomas are the most prevalent type of primary brain tumor in adults. Despite progress in brain tumor therapy, the prognosis of malignant glioma patients remains dismal. The median survival of patients with glioblastoma muhiforme, the most common grade of malignant glioma, is 10-12 months. Conventional therapy of surgery, radiation and chemotherapy is largely palliative. Essentially, tumor recurrence is inevitable. Salvage treatments upon recurrence are palliative at best and rarely provide significant survival benefit. Therapies targeting the underlying molecular pathogenesis of brain tumors are urgently required. Common genetic abnormalities in malignant glioma specimens are associated with aberrant activation or suppression of cellular signal transduction pathways and resistance to radiation and chemotherapy.     

Disparity in cancer care: a Canadian perspective

Canada is facing cancer crisis. Cancer has become the leading cause of death in Canada. Despite recent advances in cancer management and research, growing disparities in cancer care have been noticed, especially in socio-economically disadvantaged groups and under-served communities. With the rising incidence of cancer and the increasing numbers of minorities and of social disparities in general, and without appropriate interventions, cancer care disparities will become only more pronounced. This paper highlights the concepts and definitions of equity in health and health care and examines several health determinants that increase the risk of cancer. It also reviews cancer care inequity in the high-risk groups. A conceptual framework is proposed and recommendations are made for the eradication of disparities within the health care system and beyond.     

New treatment strategies for malignant gliomas

Malignant gliomas are the most prevalent type of primary brain tumor in adults. Despite progress in brain tumor therapy, the prognosis of malignant glioma patients remains dismal. The median survival of patients with glioblastoma multiforme, the most common grade of malignant glioma, is 10–12 months. Conventional therapy of surgery, radiation and chemotherapy is largely palliative. Essentially, tumor recurrence is inevitable. Salvage treatments upon recurrence are palliative at best and rarely provide significant survival benefit. Therapies targeting the underlying molecular pathogenesis of brain tumors are urgently required. Common genetic abnormalities in malignant glioma specimens are associated with aberrant activation or suppression of cellular signal transduction pathways and resistance to radiation and chemotherapy. Several low molecular weight signal transduction inhibitors have been examined in preclinical and clinical malignant glioma trials. The efficacy of these agents as monotherapies has been modest, at best; however, small subsets of patients who harbor specific genetic changes in their tumors may display favorable clinical responses to defined small molecule inhibitors. Multitargeted kinase inhibitors or combinations of agents targeting different mitogenic pathways may overcome the resistance of tumors to single-agent targeted therapies. Well designed studies of small molecule kinase inhibitors will include assessment of safety, drug delivery, target inhibition and correlative biomarkers to define mechanisms of response or resistance to these agents. Predictive biomarkers will enrich for patients most likely to respond in future clinical trials. Additional clinical studies will combine novel targeted therapies with radiation, chemotherapies and immunotherapies.     

New treatment strategies for malignant gliomas

Malignant gliomas are the most prevalent type of primary brain tumor in adults. Despite progress in brain tumor therapy, the prognosis of malignant glioma patients remains dismal. The median survival of patients with glioblastoma multiforme, the most common grade of malignant glioma, is 10-12 months. Conventional therapy of surgery, radiation and chemotherapy is largely palliative. Essentially, tumor recurrence is inevitable. Salvage treatments upon recurrence are palliative at best and rarely provide significant survival benefit. Therapies targeting the underlying molecular pathogenesis of brain tumors are urgently required. Common genetic abnormalities in malignant glioma specimens are associated with aberrant activation or suppression of cellular signal transduction pathways and resistance to radiation and chemotherapy. Several low molecular weight signal transduction inhibitors have been examined in preclinical and clinical malignant glioma trials. The efficacy of these agents as monotherapies has been modest, at best; however, small subsets of patients who harbor specific genetic changes in their tumors may display favorable clinical responses to defined small molecule inhibitors. Multitargeted kinase inhibitors or combinations of agents targeting different mitogenic pathways may overcome the resistance of tumors to single-agent targeted therapies. Well designed studies of small molecule kinase inhibitors will include assessment of safety, drug delivery, target inhibition and correlative biomarkers to define mechanisms of response or resistance to these agents. Predictive biomarkers will enrich for patients most likely to respond in future clinical trials. Additional clinical studies will combine novel targeted therapies with radiation, chemotherapies and immunotherapies.     

Clinical Trials with Retrovirus Mediated Gene Therapy – what Have we Learned?

Retrovirus (RV) has been one of the earliest recombinant vectors to be investigated in the context of cancer gene therapy. Experiments in cell culture and in animal brain tumor models have demonstrated the feasibility of RV mediated gene transduction and killing of glioma cells by toxicity generating transgenes. Phase I and II clinical studies in patients with recurrent malignant glioma have shown a favorable safety profile and some efficacy of RV mediated gene therapy. On the other hand, a prospective randomized phase III clinical study of RV gene therapy in primary malignant glioma failed to demonstrate significant extension of the progression-free or overall survival times in RV treated patients. The failure of this RV gene therapy study may be due to the low tumor cell transduction rate observed in vivo. The biological effects of the treatment may also heavily depend on the choice of transgene/prodrug system and on the vector delivery methods. Retrovirus clinical trials in malignant glioma have nevertheless produced a substantial amount of data and have contributed toward the identification of serious shortcomings of the non-replicating virus vector gene therapy strategy. Novel types of therapeutic virus vector systems are currently being designed and new clinical protocols are being created based on the lessons learned from the RV gene therapy trials in patients with malignant brain tumors.     

Utilization and Cost of Health Care Services Associated with Primary Malignant Brain Tumors in the United States

Objectives To evaluate the economic burden of primary malignant brain tumors in a commercially insured population in the United States, and to identify the primary drivers of health care resource use and cost. Patients and methods A retrospective cohort analysis was performed using a 1998–2000 database containing inpatient, outpatient, and pharmacy claims for employees, their dependents, and early retirees of over 50 large US employers with wide geographic distribution. Patients were followed from first brain tumor diagnosis until death, termination of health benefits coverage, or study end. Controls without any cancer diagnosis were matched at a 3:1 ratio by demographic characteristics and length of follow-up. Results Patients with malignant brain tumors (n = 653) had significantly greater health service utilization and costs for hospitalizations, emergency room visits, outpatient office visits, laboratory tests, radiology services, and pharmacy-dispensed drugs (all P < 0.05) than did controls (n = 1959). Regression-adjusted mean monthly costs were $6364 for brain tumor patients, compared with $277 for controls (P < 0.0001). The primary cost driver was inpatient care ($4502 per month). Total costs during the study period were $49,242 for those with brain tumors and $2790 for controls (P < 0.0001). Conclusion Patients with malignant brain tumors accrued health care costs that were 20 times greater than demographically matched control subjects without cancer. The costs for inpatient services were the primary drivers of total health resource use. Despite their low incidence, primary malignant brain tumors produce a substantial burden on the US health care system. There is a marked need for improved and new approaches to treatment to reduce the resource use and to offset health care costs associated with this disease. Financial support for this study was provided by Eli Lilly and Company.     

Disparities in Breast Cancer Treatment and Outcomes: Biological,Social, and Health System Determinants and Opportunities for Research

Racial disparities in breast cancer mortality have been widely documented for several decades and persist despite advances in receipt of mammography across racial groups. This persistence leads to questions about the roles of biological, social, and health system determinants of poor outcomes. Cancer outcomes are a function not only of innate biological factors but also of modifiable characteristics of individual behavior and decision making as well as characteristics of patient‐health system interaction and the health system itself. Attempts to explain persistent racial disparities have mostly been limited to discussion of differences in insurance coverage, socioeconomic status, tumor stage at diagnosis, comorbidity, and molecular subtype of the tumor. This article summarizes existing literature exploring reasons for racial disparities in breast cancer mortality, with an emphasis on treatment disparities and opportunities for future research. Because breast cancer care requires a high degree of multidisciplinary team collaboration, ensuring that guideline recommended treatment (such as endocrine therapy for hormone receptor positive patients) is received by all racial/ethnic groups is critical and requires coordination across multiple providers and health care settings. Recognition that variation in cancer care quality may be correlated with race (and socioeconomic and health system factors) may assist policy makers in identifying strategies to more equally distribute clinical expertise and health infrastructure across multiple user populations.     

Intraoperative radiotherapy for gliomas

Summary Intraoperative radiotherapy (IORT) was performed in 20 of 36 patients with glioma; 11 glioblastomas, 7 malignant astrocytomas, 2 benign astrocytomas. Twenty or 25 Gy of irradiation was delivered in a single fraction intraoperatively, followed by external beam irradiation. The electron beam energy was selected so that the 80% isodose line fell at 2 or 3 cm below the residual tumor surface. Median survival time of IORT group was 14 months and that of the control group was 10 months. Difference of survival curve was significant. There were 6 incidences of complication caused by IORT; 1 radionecrosis, 1 convulsion, 1 abscess, and 3 severe brain edemas. IORT is suited for the treatment of malignant gliomas.     

Treatment modalities for malignant gliomas with reference to their pathophysiology

The histological classification, pathophysiology, and treatment modalities of malignant gliomas (glioblastoma, malignant astrocytoma) were reviewed with reference to the WHO classification of primary brain tumors and the recent progress made in glioma biology. Patients with glioblastoma and malignant astrocytoma showed, respectively, 10.6% and 22.2 of the five-year survival rate according to the All Japan Brain Tumor Registry. In order to improve the prognosis of malignant glioma patients, many clinical trials have been conducted throughout the world. Malignant gliomas that grow in and invade the brain parenchyma cannot be cured by surgical resection. One should treat the residual tumor with irradiation, chemotherapy and immunotherapy. Radiation therapy alone and radiation therapy plus chemotherapy using nitrosoureas or procarbazine have been proved statistically to be more effective for malignant gliomas than supportive care and radiation therapy alone, respectively. Prospective clinical trials support the view that malignant gliomas should be treated vigorously using a multimodal approach that includes surgical resection, high-dose radiation therapy, and prolonged maintenance chemotherapy.     

树突状细胞和脑胶质瘤自体免疫治疗的实验和临床研究(英文)

目的对树突状细胞(DC)肿瘤疫苗进行实验和临床研究并探讨其应用前景。方法从脑胶质瘤患者外周血提取 DC 进行培养并对其进行形态学和免疫学鉴定。采用乳酸脱氢酶(LDH)释放法检测负载不同肿瘤抗原的 DC 诱导细咆毒性 T 细胞(CTL)体外杀伤活性。在实验研究的基础上拟定临床治疗方案:将56例脑胶质瘤术后患者分为3组,实验组19人接受冻融法制备的自体肿瘤抗原 DC 疫苗和卡介苗(BCG)治疗,阳性对照组17人接受全肿瘤组织匀浆和 BCG治疗,阴性对照组20人,术后仪接受放疗。结果采用粒细胞、巨噬细胞集落刺激因子(GM-CSF)及白细胞介素-4(IL-4)培养可获得高纯度的 DC。DC 在负载肿瘤抗原后诱导CTL 杀伤活性大大提高而 DC 与肿瘤细胞共培养对 CTL 杀伤活性无显著影响。临床治疗中实验组中位数生存时间大于38个月,阳性对照组为24个月,二者均高于阴性对照组(13个月)。生存分析示3组间的生存曲线分布差异有显著性意义。结论采用冻融法制备的自体脑胶质瘤抗原 DC 疫苗可抑制脑胶质瘤的复发和进展,从而有效地延长脑胶质瘤患者的生存时间,有良好的临床应用前景。     

树突状细胞和脑胶质瘤自体免疫治疗的实验和临床研究

目的 对树突状细胞(DC)肿瘤疫苗进行实验和临床研究并探讨其应用前景。方法 从脑胶质瘤患者外周血提取DC进行培养并对其进行形态学和免疫学鉴定。采用乳酸脱氢酶(LDH)释放法检测负载不同肿瘤抗原的DC诱导细胞毒性T细胞(CTL)体外杀伤活性。在实验研究的基础上拟定临床治疗方案:将56例脑胶质瘤术后患者分为3组,实验组19人接受冻融法制备的自体肿瘤抗原DC疫苗和卡介苗(BCG)治疗,阳性对照组17人接受全肿瘤组织匀浆和BCG治疗,阴性对照组20人,术后仅接受放疗。结果 采用粒细胞、巨噬细胞集落刺激因子(GM-CSF)及白细胞介素-4(IL-4)培养可获得高纯度的DC。DC在负载肿瘤抗原后诱导CTL杀伤活性大大提高而DC与肿瘤细胞共培养对CTL杀伤活性无显著影响。临床治疗中实验组中位数生存时间大于38个月,阳性对照组为24个月,二者均高于阴性对照组(13个月)。生存分析示3组间的生存曲线分布差异有显著性意义。结论 采用冻融法制备的自体脑胶质瘤抗原DC疫苗可抑制脑胶质瘤的复发和进展,从而有效地延长脑胶质瘤患者的生存时间,有良好的临床应用前景。     

恶性肿瘤化疗患者消化系统不良反应的饮食护理

目的探讨恶性肿瘤化疗患者消化系统不良反应的饮食护理方法及效果。方法选取120例恶性肿瘤化疗患者随机分为试验组和对照组,每组60例。对照组患者给予常规护理;试验组患者在常规护理的基础上实施化疗饮食护理,比较两组患者的护理效果。结果试验组患者的消化系统不良反应发生率低于对照组,差异有统计学意义(P<0.05);试验组患者的护理满意度为98.3%,对照组患者护理满意度为91.7%,两组比较差异有统计学意义(P<0.05)。结论恶性肿瘤化疗患者给予化疗饮食护理,不仅能够减轻化疗引起的消化系统不良反应,而且能够提高患者的生活质量,提高患者的护理满意度。     

The safety and efficacy of magnetic nano-iron hyperthermia therapy on rat brain glioma

Gliomas are a group of heterogeneous primary central nervous system tumors arising from glial cells. These tumors are associated with high morbidity and mortality. New opportunities for the development of effective therapies for malignant gliomas are urgently needed. Magnetic nano-particles can heat up tumor tissues and induce the killing of cancer cells. However, the in vivo action of magnetic nano-iron hyperthermia on brain gliomas has not been widely investigated. The safety, efficacy, and suitable dose of hyperthermia therapy remain unknown. We successfully established a rat model of brain glioma by injecting C6 glioma cells into the right caudate nuclei of rats. Fixed doses (2.5, 5, or 10 mg) of magnetic nano-iron were then injected into the tumors of tumor-bearing rats. The survival time of tumor-bearing rats was subsequently observed, and imaging studies were conducted on the brain tumors. Of the 80 rats that underwent C6 glioma cell implantation, 70 exhibited decreased mobility and appetite, and wasting. Establishment of this brain glioma model was confirmed to be successful by magnetic resonance imaging. After injection of different doses of magnetic nano-iron, the survival times of the different dose groups of tumor-bearing rats were not significantly different. However, the tumor size exhibited a significant decrease with magnetic nano-iron hyperthermia therapy. Injection of various doses of magnetic nano-iron was safe in tumor-bearing rats. The effective doses were 2.5 and 5 mg. Magnetic nano-iron hyperthermia significantly shrank the brain gliomas in tumor-bearing rats.     

A cystic meningioma misdiagnosed as malignant glioma by radiologic and intraoperative histological examinations

Cystic meningiomas are radiologically difficult to differentiate from malignant brain tumors, particularly when the tumors are intraparenchymally located. In such cases, a surgical strategy relies on intraoperative histological diagnosis. A 60-year-old man had a tumor with multiple cysts in the left parietal lobe that was diagnosed radiologically as malignant glioma. In operative findings, there was no dural attachment of the tumor, and the border between the tumor and normal brain tissue was unclear. Intraoperative histological examination supported the diagnosis of malignant glioma based on a high cellularity and an existence of a multinuclear giant cell in the tumor tissue. We finished the surgery with partial tumor resection; however, postoperative histological diagnosis of the tumor was a typical meningothelial meningioma showing characteristic whorl formations, and in conclusion, a definite diagnosis of the tumor was an intraparenchymal cystic meningioma. In further histological investigations, the tumor tissue around cysts exhibited significantly different features from meningothelial meningioma, demonstrating small lymphocytes and histiocytes with a large nucleus, which resembled intraoperative histological findings. We deliberated that the removal of the tumor tissue from the degenerated portion for intraoperative histological examination might lead to the misdiagnosis of malignant glioma. Operative strategy is strongly influenced by intraoperative histological diagnosis. Therefore, surgeons are obliged to facilitate more precise intraoperative histological examinations by obtaining sufficient tissue from different parts of the tumor.     

胶质瘤的免疫治疗

对于胶质瘤的常规治疗方法包括手术、放疗和化疗,但这些治疗方法仅使恶性胶质瘤的平均生存期达到1年左右。胶质瘤的这种不良预后与肿瘤细胞的侵袭性,以及这些非特异性疗法的毒副作用相关,因此需要开发新的有效的治疗方法以清除手术后残余浸润的肿瘤细胞,来提高恶性胶质瘤患者的生存率。建立有效的免疫疗法．激发人体自身的免疫系统,定位并杀伤恶性肿瘤细胞,也许可以提供一种有前途的治疗方案。随着对免疫系统了解的深入．研究者基于免疫系统的不同成分建立了多种胶质瘤免疫疗法。本文对胶质瘤免疫治疗的进展作一综述。     

Heme oxygenase-1 expression in human gliomas and its correlation with poor prognosis in patients with astrocytoma

In human glioma tumors, heme oxygenase-1 (HO-1) has been shown to be upregulated both when compared with normal brain tissues and also during oligodendroglioma progression. The cell types that express HO-1 have been shown to be mainly macrophages/microglia and T cells. However, many other reports also demonstrated that cell lines derived from glioma tumors and astrocytes express HO-1 after the occurrence of a wide variety of cell injuries and stressors. In addition, the significance of HO-1 upregulation in glioma had not, so far, been addressed. We therefore aimed at investigating the expression and significance of HO-1 in human glial tumors. For this purpose, we performed a wide screening of HO-1 expression in gliomas by using tissue microarrays containing astrocytomas, oligodendrogliomas, mixed tumors, and normal brain tissues. We subsequently correlated protein expression with patient clinicopathological data. We found differences in HO-1 positivity rates between non-malignant brain (22 %) and gliomas (54 %, p?=?0.01). HO-1 was expressed by tumor cells and showed cytoplasmic localization, although 19 % of tumor samples also depicted nuclear staining. Importantly, a significant decrease in the overall survival time of grade II and III astrocytoma patients with HO-1 expression was observed. This result was validated at the mRNA level in a cohort of 105 samples. However, no association of HO-1 nuclear localization with patient survival was detected. In vitro experiments aimed at investigating the role of HO-1 in glioma progression showed that HO-1 modulates glioma cell proliferation, but has no effects on cellular migration. In conclusion, our results corroborate the higher frequency of HO-1 protein expression in gliomas than in normal brain, demonstrate that HO-1 is expressed by glial malignant cells, and show an association of HO-1 expression with patients’ shorter survival time.     

Brain and other central nervous system tumor statistics, 2021

Brain and other central nervous system (CNS) tumors are among the most fatal cancers and account for substantial morbidity and mortality in the United States. Population-based data from the Central Brain Tumor Registry of the United States (a combined data set of the National Program of Cancer Registries [NPCR] and Surveillance, Epidemiology, and End Results [SEER] registries), NPCR, National Vital Statistics System and SEER program were analyzed to assess the contemporary burden of malignant and nonmalignant brain and other CNS tumors (hereafter brain) by histology, anatomic site, age, sex, and race/ethnicity. Malignant brain tumor incidence rates declined by 0.8% annually from 2008 to 2017 for all ages combined but increased 0.5% to 0.7% per year among children and adolescents. Malignant brain tumor incidence is highest in males and non-Hispanic White individuals, whereas the rates for nonmalignant tumors are highest in females and non-Hispanic Black individuals. Five-year relative survival for all malignant brain tumors combined increased between 1975 to 1977 and 2009 to 2015 from 23% to 36%, with larger gains among younger age groups. Less improvement among older age groups largely reflects a higher burden of glioblastoma, for which there have been few major advances in prevention, early detection, and treatment the past 4 decades. Specifically, 5-year glioblastoma survival only increased from 4% to 7% during the same time period. In addition, important survival disparities by race/ethnicity remain for childhood tumors, with the largest Black-White disparities for diffuse astrocytomas (75% vs 86% for patients diagnosed during 2009-2015) and embryonal tumors (59% vs 67%). Increased resources for the collection and reporting of timely consistent data are critical for advancing research to elucidate the causes of sex, age, and racial/ethnic differences in brain tumor occurrence, especially for rarer subtypes and among understudied populations.     

Prognostic significance of proteolytic enzymes in human brain tumors

Summary Proteases and their inhibitors have been shown to play roles in tumor invasion and metastasis in a number of experimental models. Recently, relative increases in the amounts of urokinase type plasminogen activator (uPA) and plasminogen activator inhibitor-1 (PAI-1) in tumor samples have been correlated with poorer pathological grade, shorter disease-free interval, and shorter survival. To date, all studies investigating the prognostic significance of proteases and their inhibitors have been limited to extracranial cancer. In this article, we review the literature and present our data on the prognostic significance of proteases in human brain tumors. High levels of uPA were seen in malignant glioma and metastatic tumors (n=82), whereas normal levels of uPA were found in low-grade gliomas. Analysis with magnetic resonance imaging (MRI) demonstrated a significant correlation between high levels of uPA and necrosis and edema (n=50; P < 0.05). Similarly, patients with high levels of uPA had shorter survival than did patients with low levels of uPA.Tissue-type plasminogen activator (tPA), which was virtually absent in glioblastoma multiforme (GBM), colon, lung, and breast metastasis, was found in normal quantities in anaplastic astrocytoma (AA), low-grade glioma (LGG), and meningioma. Melanoma had significantly more tPA activity than normal brain did. A reverse correlation was found between tPA and MRI findings of necrosis, enhancement, and edema. Similarly, patients with no detectable tPA activity had shorter survival than did patients with detectable tPA activity. We conclude that high levels of uPA and absent tPA activity correlate with histologically malignant brain tumors, aggressive characteristics, and shorter survival.     

Cognitive dysfunction following surgery for intracerebral glioma: influence of histopathology, lesion location, and treatment

Summary This study examined the relationship between cognitive function, tumor malignancy, adjunctive therapy, and lesion lateralization following surgery for intracerebral glioma. Neuropsychological test battery results showed no difference between patients with highly malignant gliomas and those with less malignant gliomas, but differences were found for tumor lateralization and type of therapy. Scores on a test of graphomotor speed were lowest for patients who had received radiation or a combination of radiation and chemotherapy, regardless of lesion location. Other test results did not differ according to type of prior treatment but were related instead to tumor lateralization. Left hemisphere lesions were associated with lower scores on verbal tests, while right hemisphere lesions were related to lower scores on a test of facial recognition.These findings suggest that neuropsychological tests may be useful for distinguishing between the diffuse side effects of brain tumor therapy and the focal effects of tumors and surgery on brain functions. In addition, it appears that any differences in cognitive function due to tumor malignancy are eliminated or reduced following surgical intervention.