[Regional variation in usage of TTF (Optune)]

The standard treatment of glioblastoma, an aggressive brain tumour, includes radiotherapy combined with temozolomide. Based on a randomised trial, showing five months increased survival, TTF has been introduced in the management of patients with good performance status. Data from the Swedish national quality registry for CNS tumours have been analysed for TTF usage. The results demonstrate that 65 percent of the patients accepted treatment with TTF. More than half of the treated patients interrupted treatment due to low compliance or their own wish. Median treatment time was 164 days, with a range from 0 to 774 days. There was a large variation between different regions in how many patients were offered TTF treatment. A non-significant trend to better survival was seen for the group of TTF-treated patients compared to individually matched controls. In summary, TTF is a new treatment for glioblastoma, with potential to prolong survival also in real world patients. Today, the treatment is not offered equally to all patients, despite national guidelines.

The sex-dependent role of the androgen receptor in glioblastoma: results of molecular analyses

We sought to analyse the androgen receptor (AR) in glioblastoma (GBM) due to the location of the AR gene on chromosome X, often reported with shorter survival and higher prevalence of GBM among males. Copy number (CN) and mRNA expression of AR were tested with droplet digital PCR in 91 fresh‐frozen GBM samples and 170 formalin‐fixed, paraffin‐embedded samples collected at Linköping University Hospital. The fresh‐frozen cohort was also subjected to pyrosequencing methylation analysis of 17 CpG sites in the AR promoter. Additionally, the gene expression of AR was analysed in the fresh‐frozen cohort and The Cancer Genome Atlas (TCGA) cohort of isocitrate dehydrogenase wild‐type primary GBM (135 females and 219 males). The association of AR expression and overall survival (OS) was tested with Kaplan–Meier log rank analysis after dichotomisation by maximally selected rank statistics. We found that AR CN alterations were more common in female GBM. AR gene expression correlated with methylation levels of different CpG sites in males and females but there was no difference in expression between sexes. Survival analysis of TCGA cohort revealed the opposite effect of AR overexpression on OS of males and females, with high AR expression correlating with shorter OS in females and longer OS in males. Additional gene set enrichment analysis showed that AR expression correlated with DNA repair response, especially in the male group. In summary, we found that high AR gene expression in GBM exhibits sex‐dependent effects on patient survival, which, for males, is linked to DNA repair response.

A randomized phase II trial of efficacy and safety of the immunotherapy ALECSAT as an adjunct to radiotherapy and temozolomide for newly diagnosed glioblastoma

Background

There is an urgent need for effective treatments against glioblastoma (GBM). In this trial, we investigated the efficacy and safety of an adoptive cell-based immunotherapy.

Methods

Patients with newly diagnosed GBM were recruited at 4 study sites in Sweden. The patients were randomized 1:2 to receive either radiotherapy (RT), 60 Gy/30 fractions, with concomitant and adjuvant temozolomide (TMZ) only, or RT and TMZ with the addition of Autologous Lymphoid Effector Cells Specific Against Tumor (ALECSAT) in an open-label phase II trial. The primary endpoint was investigator-assessed progression-free survival (PFS). The secondary endpoints were survival and safety of ALECSAT.

Results

Sixty-two patients were randomized to either standard of care (SOC) with RT and TMZ alone (n = 22) or SOC with ALECSAT (n = 40). Median age was 57 years (range 38–69), 95% of the patients were in good performance status (WHO 0–1). There was no significant difference between the study arms (SOC vs ALECSAT + SOC) in PFS (7.9 vs 7.8 months; hazard ratio [HR] 1.28; 95% confidence interval [CI] 0.70–2.36; P = .42) or in median overall survival (OS) (18.3 vs 19.2 months; HR 1.16, 95% CI 0.58–2.31; P = .67). The treatment groups were balanced in terms of serious adverse events (52.4% vs 52.5%), but adverse events ≥grade 3 were more common in the experimental arm (81.0% vs 92.5%).

Conclusion

Addition of ALECSAT immunotherapy to standard treatment with radiochemotherapy was well tolerated but did not improve PFS or OS for patients with newly diagnosed GBM.

P13.03 Sex-specific influence of androgen receptor gene expression on survival of glioblastoma patients

BACKGROUND

The mRNA and protein expression of androgen receptor (AR) are upregulated in glioblastoma (GBM) and studies show that use of AR antagonists leads to apoptosis of GBM cells in vitro and reduction of tumor volume in a mouse model. With increased prevalence of GBM among males, the role and genetic alterations of AR are worth investigating, especially taking into account the location of AR on chromosome X and possible sex differences associated with it.

MATERIAL AND METHODS

Copy number (CN) and mRNA expression of AR were tested with droplet digital PCR in 106 fresh frozen GBM samples (34 females and 72 males) collected at Linköping University Hospital. This cohort was also subjected to AR promoter methylation analysis, where 17 CpG sites were the target of pyrosequencing. Methylation levels were then correlated with mRNA gene expression, independently for each sex, using Pearson correlation coefficient. Gene expression of AR was also analyzed in The Cancer Genome Atlas cohort of primary IDH wild type GBM (135 females and 219 males) and association of AR expression and overall survival (OS) was tested with Kaplan-Meier log rank analysis after dichotomization by maximally selected rank statistics.

RESULTS

DNA amplifications, as well as deletions of the AR were detected, with a higher frequency of alterations found in females (26.4% vs. 8.3%). AR gene expression correlated with methylation levels of two CpG sites in females (chrX:67543271, chrX:67543762) and three different CpG sites in males (chrX:67543889, chrX:67543895, chrX:67543899). There was no difference in the AR expression between males and females in neither of the cohorts, but significantly higher AR expression was found in the classical subtype of GBM in TCGA. Survival analysis of the TCGA cohort revealed the opposite effect of AR expression on OS of males and females, with high AR expression correlating with shorter OS in females (13.6 vs.15.7 months, p=0.035) and longer OS in males (16.6 vs. 12.2 months, p=0.04). Additional gene set enrichment analysis of these samples showed that high AR expression was strongly correlated with DNA repair but only in the male group.

CONCLUSION

Our results show that high AR mRNA expression in GBM exhibits different effects on patients’ survival depending on their sex, despite common occurrence of high AR expression and CN changes in males and females. The reasons for potential protective influence of AR in males remain unclear and require further investigations.

Deletions on Chromosome Y and Downregulation of the SRY Gene in Tumor Tissue Are Associated with Worse Survival of Glioblastoma Patients

BACKGROUND

Biological causes of sex disparity seen in the prevalence of cancer, including glioblastoma (GBM), remain poorly understood. One of the considered aspects is the involvement of the sex chromosomes, especially loss of chromosome Y (LOY).

METHODS

Tumors from 105 isocitrate dehydrogenase (IDH) wild type male GBM patients were tested with droplet digital PCR for copy number changes of ten genes on chromosome Y. Decreased gene expression, a proxy of gene loss, was then analyzed in 225 IDH wild type GBM derived from TCGA and overall survival in both cohorts was tested with Kaplan-Meier log-rank analysis and maximally selected rank statistics for cut-off determination.

RESULTS

LOY was associated with significantly shorter overall survival (7 vs. 14.6 months, p = 0.0016), and among investigated individual genes survival correlated most prominently with loss of the sex-determining region Y gene (SRY) (10.8 vs. 14.8 months, p = 0.0031). Gene set enrichment analysis revealed that epidermal growth factor receptor, platelet-derived growth factor receptor, and MYC proto-oncogene signaling pathways are associated with low SRY expression.

CONCLUSION

Our data show that deletions and reduced gene expression of chromosome Y genes, especially SRY, are associated with reduced survival of male GBM patients and connected to major susceptibility pathways of gliomagenesis.

Assessment of genetic and non-genetic risk factors for venous thromboembolism in glioblastoma - The predictive significance of B blood group

INTRODUCTION

Venous thromboembolism (VTE) is a common problem among patients with glioblastoma multiforme (GBM) and with some other cancers. Here, we evaluated genetic and non-genetic potential risk factors for VTE among GBM patients.

MATERIALS AND METHODS

A cohort of 139 patients treated with concomitant radiotherapy and temozolomide were included in the study. Next generation sequencing and genotyping approaches were applied to assess genetic risk factors in the haemostatic system. Clinical data including surgery, reoperation as well as blood group and patient information such as age and gender were available from patient records. Logistic regression analysis was performed to asses VTE risk.

RESULTS

In the study 47 patients (34%) were diagnosed for VTE during the course of their disease. When genetic and non-genetic potential risk factors were evaluated, only B blood group was found to be significantly associated with VTE incidence (odds ratio [OR] = 6.91; confidence interval [CI] = 2.19-24.14; P = 0.001). In contrast, A and O blood groups did not correlate with VTE risk. Frontal lobe tumor location also seemed to slightly increase VTE risk compared to other brain sites (OR = 3.14; CI = 1.1-10.7) although the significance level was at borderline (P = 0.05). Current study identified B blood group as the component in non-O blood groups that is responsible for increased VTE risk.

CONCLUSION

In conclusion, these results suggest for the first time that B blood group is predictive for VTE incidence among patients with glioblastoma, information that may be potentially valuable when selecting GBM patients who are at risk for VTE for anticoagulant prophylaxis.

ABCB1 single-nucleotide variants and survival in patients with glioblastoma treated with radiotherapy concomitant with temozolomide

Standard treatment for glioblastoma (GBM) patients is surgery and radiochemotherapy (RCT) with temozolomide (TMZ). TMZ is a substrate for ABCB1, a transmembrane drug transporter. It has been suggested that survival for GBM patients receiving TMZ is influenced by different single-nucleotide variants (SNV) of ABCB1. We therefore examined SNV:s of ABCB1, namely 1199G>A, 1236C>T, 2677G>T/A, and 3435C>T and correlated to survival for GBM patients receiving RCT. In a pilot cohort (97 patients) a significant correlation to survival was found for SNV 1199G>A, with median OS for variant G/G patients being 18.2 months versus 11.5 months for A/G (p = 0.012). We found no correlation to survival for the other SNV:s. We then expanded the cohort to 179 patients (expanded cohort) and also included a confirmatory cohort (49 patients) focusing on SNV 1199G>A. Median OS for G/G versus A/G plus A/A was 15.7 and 11.5 months, respectively (p = 0.085) for the expanded cohort and 13.8 versus 16.8 months (p = 0.19) for the confirmatory. In conclusion, in patients with GBM receiving RCT with TMZ, no correlation with survival was found for the SNV:s 1236C>T, 2677G>T/A, and 3435C>T of ABCB1. Although the SNV 1199G>A might have some impact, a clinically significant role could not be confirmed.

The Influence of Single Nucleotide Polymorphisms and Adjuvant Radiotherapy on Systemic Inflammatory Proteins, Chemokines and Cytokines of Patients With Breast Cancer

Independently of tumour and treatment modulation, the host immune response status plays an important role in the clinical outcome of patients with cancer. The influence of single nucleotide polymorphisms (SNPs) and adjuvant radiotherapy (RT) on the systemic immune response status of patients with breast cancer was investigated.

MATERIALS AND METHODS

Eighty-six female patients recovering from breast cancer surgery were investigated. As a control cohort, 82 healthy female blood donors were used. Blood-based SNPs, plasma C-reactive protein (CRP), cytokines and chemokines were analyzed for this purpose.

RESULTS

Independently of tumour stage and hormone receptor status, dysregulation of plasma CRP, chemokine (C-C motif) ligand 4 (CCL4) and interleukin 2 (IL2), but not CCL5, CCL2, platelet-derived growth factor, IL6, IL10, IL12, interferon-gamma or tumour necrosis factor alpha were detected in the patients when compared to controls. The extent of alteration in plasma levels of CRP and IL2 patients was significantly associated with SNPs in CRP rs1800947 and IL2 rs6822844, respectively. These SNPs had no influence on the levels of corresponding plasma biomarkers in the healthy controls. Adjuvant RT reduced plasma CRP and CCL5 levels in patients with regards to CRP rs1800947CC, CCL5 rs2107538GG and CCL5 rs2280789AA sequences.

CONCLUSION

Dysregulation of immune responses, as indicated by plasma levels of CRP, CCL4 and IL2 were found in patients with breast cancer despite the removal of the tumour mass. The benefit of adjuvant RT, as indicated by reduced plasma amounts of inflammatory protein CRP and chemokine CCL5 were based on the SNPs of the patients. Analyses of blood-based SNPs, plasma CRP, IL2 and CCL5 are low cost, rapid and can be carried out using general laboratory facilities while requiring only a peripheral blood sample. The possibility of using these blood-based biomarkers as an indicator of patient immune status for selection of individual patient treatment warrants further investigation.