Benefits of adjuvant chemotherapy in high-grade gliomas

Association of area deprivation index (ADI) with demographics and postoperative outcomes in pediatric brain tumor patients

PURPOSE

Although social determinants of health (SDOH) have been associated with adverse surgical outcomes, cumulative effects of multiple SDOH have never been studied. The area deprivation index (ADI) assesses cumulative impact of SDOH factors on outcomes. We analyzed the relationship between ADI percentile and postoperative outcomes in pediatric patients diagnosed with brain tumors.

METHODS

A retrospective, observational study was conducted on our consecutive series of pediatric brain tumor patients presenting between January 1, 1999, and May 31, 2022. Demographics and outcomes were collected, identifying SDOH factors influencing outcomes found in the literature. ADI percentiles were identified based on patient addresses, and patients were stratified into more (ADI 0-72%) and less (ADI 73-100%) disadvantaged cohorts. Univariate and multivariate logistic regression analyses were completed for demographics and outcomes.

RESULTS

A total of 272 patients were included. Demographics occurring frequently in the more disadvantaged group were Black race (13.1% vs. 2.8%; P = .003), public insurance (51.5% vs. 27.5%; P < .001), lower median household income ($64,689 ± $19,254 vs. $46,976 ± $13,751; P < .001), and higher WHO grade lesions (15[11.5%] grade III and 8[6.2%] grade IV vs. 8[5.6%] grade III and 5[3.5%] grade IV; P = .11). The more disadvantaged group required adjunctive chemotherapy (25.4% vs. 12.05%; P = .007) or radiation therapy (23.9% vs. 12.7%; P = .03) more frequently and had significantly greater odds of needing adjunctive chemotherapy (odds ratio [OR], 1.11; confidence interval [CI], 1.01-1.22; P = .03) in a multivariate model, which also identified higher WHO tumor grades at presentation (OR, 1.20; CI, 1.14-1.27; P < .001).

CONCLUSION

These findings are promising for use of ADI to represent potential SDOH disadvantages that pediatric patients may face throughout treatment. Future studies should pursue large multicenter collaborations to validate these findings.

Plasmid pORF-hTRAIL targeting to glioma using transferrin-modified polyamidoamine dendrimer

A gene drug delivery system for glioma therapy based on transferrin (Tf)-modified polyamidoamine dendrimer (PAMAM) was prepared. Gene drug, tumor necrosis factor-related apoptosis-inducing ligand (hTRAIL)-encoding plasmid open reading frame (pORF-hTRAIL, Trail), was condensed by Tf-modified PAMAM to form nanoparticles (NPs). PAMAM-PEG-Tf/DNA NPs showed higher cellular uptake, in vitro gene expression, and cytotoxicity than PAMAM-PEG/DNA NPs in C6 cells. The in vivo targeting efficacy of NPs was visualized by ex vivo fluorescence imaging. Tf-modified NPs showed obvious glioma-targeting trend. Plasmid encoding green fluorescence protein (GFP) was also condensed by modified or unmodified PAMAM to evaluate the in vivo gene expression level. The PAMAM-PEG-Tf/plasmid encoding enhanced green fluorescence protein (pEGFP) NPs exhibited higher GFP expression level than PAMAM-PEG/pEGFP NPs. TUNEL assay revealed that Tf-modified NPs could induce much more tumor apoptosis. The median survival time of PAMAM-PEG-Tf/Trail-treated rats (28.5 days) was longer than that of rats treated with PAMAM-PEG/Trail (25.5 days), temozolomide (24.5 days), PAMAM-PEG-Tf/pEGFP (19 days), or saline (17 days). The therapeutic effect was further confirmed by magnetic resonance imaging. This study demonstrated that targeting gene delivery system had potential application for the treatment of glioma.

NMR as evaluation strategy for cellular uptake of nanoparticles

Advanced nanostructured materials, such as gold nanoparticles, magnetic nanoparticles, and multifunctional materials, are nowadays used in many state-of-the-art biomedical application. However, although the engineering in this field is very advanced, there remain some fundamental problems involving the interaction mechanisms between nanostructures and cells or tissues. Here we show the potential of (1)H NMR in the investigation of the uptake of two different kinds of nanostructures, that is, maghemite and gold nanoparticles, and of a chemotherapy drug (Temozolomide) in glioblastoma tumor cells. The proposed experimental protocol provides a new way to investigate the general problem of cellular uptake for a variety of biocompatible nanostructures and drugs.

Peri-tumoral leakage during intra-tumoral convection-enhanced delivery has implications for efficacy of peri-tumoral infusion before removal of tumor

In cases of malignant brain tumors, infiltrating tumor cells that exist at the tumor-surrounding brain tissue always escape from cytoreductive surgery and, protected by blood-brain barrier (BBB), survive the adjuvant chemoradiotherapy, eventually leading to tumor recurrence. Local interstitial delivery of chemotherapeutic agents is a promising strategy to target these cells. During our effort to develop effective drug delivery methods by intra-tumoral infusion of chemotherapeutic agents, we found consistent pattern of leakage from the tumor. Here we describe our findings and propose promising strategy to cover the brain tissue surrounding the tumor with therapeutic agents by means of convection-enhanced delivery. First, the intracranial tumor isograft model was used to define patterns of leakage from tumor mass after intra-tumoral infusion of the chemotherapeutic agents. Liposomal doxorubicin, although first distributed inside the tumor, distributed diffusely into the surrounding normal brain once the leakage happen. Trypan blue dye was used to evaluate the distribution pattern of peri-tumoral infusions. When infused intra- or peri-tumorally, infusates distributed robustly into the tumor border. Subsequently, volume of distributions with different infusion scheduling; including intra-tumoral infusion, peri-tumoral infusion after tumor resection, peri-tumoral infusion without tumor removal with or without systemic infusion of steroids, were compared with Evans-blue dye. Peri-tumoral infusion without tumor removal resulted in maximum volume of distribution. Prior use of steroids further increased the volume of distribution. Local interstitial drug delivery targeting tumor surrounding brain tissue before tumor removal should be more effective when targeting the invading cells.

Novel treatment strategies for malignant gliomas using neural stem cells

Recent studies in stem cell biology have refined our understanding of the origin and progression of cancer. Identification and characterization of endogenous neural stem cells (NSCs), especially those in the adult human brain, have inspired new ideas for selectively targeting and destroying malignant gliomas. Gliomas consist of a heterogeneous population of cells, and some of these cells have characteristics of cancer stem cells. These brain tumor stem cells (BTSCs) share certain characteristics with normal NSCs. It is still unclear, however, whether malignant gliomas in human patients originate from these aberrant BTSCs. Nonetheless, the cellular and molecular similarities between BTSCs and normal NSCs suggest a common research landscape underlying both normal and cancer stem cell biology, wherein findings of one field are relevant to the other. Furthermore, the natural tropism of NSCs to gliomas has generated the idea that modified NSCs can deliver modified genes to selectively destroy malignant brain tumor cells, and even BTSCs, while leaving healthy surrounding neurons intact. These studies and others on the basic biology of both BTSCs and NSCs will be crucial to expanding our treatment strategies for malignant gliomas.

Experience with irinotecan for the treatment of malignant glioma

Malignant glioma is the most commonly occurring primary malignant brain tumor. It is difficult to treat and is usually associated with an inexorable, rapidly fatal clinical course. Chemotherapy, radiotherapy, and surgical excision are core components in the management of malignant glioma. However, chemotherapy, even with the most active regimens currently available, achieves only modest improvement in overall survival. Novel agents and new approaches to therapy are required to improve clinical outcomes. Irinotecan, a first-line treatment for metastatic colorectal cancer and an agent with high activity against solid tumors of the gastrointestinal tract, is an inhibitor of topoisomerase I, a critical enzyme needed for DNA transcription. Irinotecan crosses the blood-brain barrier and, in preclinical investigations, has demonstrated cytotoxic activity against central nervous system tumor xenografts. Its antitumor activity has also been demonstrated against glioblastoma cells with multidrug resistance. Studies in adult and pediatric patients with recurrent, intractable malignant glioma have evaluated irinotecan as monotherapy and in combination with other agents, including temozolomide, carmustine, thalidomide, and bevacizumab. Studies of irinotecan in combination with other medications, particularly temozolomide and bevacizumab, have yielded promising results. Irinotecan monotherapy has demonstrated efficacy; however, its efficacy appears to be enhanced when used in combination with other chemotherapeutic agents. When administered concurrently with enzyme-inducing antiepileptic drugs, the dosage must be increased to compensate for enhanced cytochrome CY3A4/5 enzyme activity. Toxicities associated with irinotecan have been manageable; the most important dose-limiting toxicities are neutropenia and diarrhea. Irinotecan-based chemotherapy of malignant glioma merits further study.

Clinical impact of adjuvant chemotherapy in glioblastoma multiforme : a meta-analysis

BACKGROUND

A meta-analysis of chemotherapy for glioblastoma multiforme (GBM) was performed. We sought to update prior analyses by focusing exclusively on GBM, including new trials of novel treatments, assessing effectiveness of individual treatment categories and presenting data in a clinically useful format.

METHODS

A search of MEDLINE and EMBASE was conducted for randomised controlled trials of chemotherapy in GBM.

RESULTS

Relative risks (RRs) for survival in 16 trials comparing chemotherapy with no chemotherapy were 1.18 (95% CI 1.08, 1.30) at 6 months, 1.53 (95% CI 1.26, 1.86) at 12 months and 2.12 (95% CI 1.60, 2.80) at 24 months. Nitrosourea compounds, local therapy (e.g. carmustine [1,3-bis [2-chloroethyl]-1-nitrosourea] wafers) and temozolomide were all more effective than no chemotherapy. Absolute increases in survival at 6, 12 and 24 months were 11%, 8% and 1%, respectively, for nitrosourea compounds; 8%, 24% and 5%, respectively, for local therapy; and 4%, 15% and 17%, respectively, for temozolomide. Efficacy of local therapy and temozolomide peaked at 12 and 18 months, respectively. After 2 years, nitrosourea compounds no longer provided clinically relevant benefit (number needed-to-treat [NNT] = 100; effect size [ES] = 0.17 SD), local therapy had diminishing returns (NNT = 20) that remained clinically relevant (ES = 0.71 SD) and temozolomide continued to show good efficacy (NNT = 5.9; ES = 0.74 SD). Survival was not significantly improved with multi-agent versus single-agent nitrosourea-based therapy in five trials: 6-month RR 0.91 (95% CI 0.71, 1.16); 24-month RR 1.33 (95% CI 0.72, 2.46).

CONCLUSION

Although nitrosourea compounds, local therapy and temozolomide are all effective in the treatment of GBM, local therapy and temozolomide may be associated with greater response, with clinically significant benefits extending to 24 months. The timing of peak benefits of local and temozolomide therapy suggests this combination may be more effective than single-agent chemotherapy and warrants further study.

[What type of adjuvant chemotherapy should be proposed for the initial treatment of glioblastoma?]

Carmustine wafers (Gliadel) and temozolomide (Temodal) were recently approved for initial management of glioblastoma. Gliadel) is a polymer wafer containing carmustine. These wafers are designed to be placed in the surgical cavity after glioblastoma resection to deliver local chemotherapy. This treatment is intended for tumors for which gross total resection is possible. Temozolomide is administered concomitantly with radiotherapy for six weeks followed by six cycles of adjuvant temozolomide (EORTC 26981, also known as "Stupp's protocol"). Temozolomide administered according to this protocol produced a median survival benefit of 2 months in glioblastomas, and carmustine a similar benefit in high-grade gliomas. The two-year survival rate was 26.5% with radiotherapy plus temozolomide compared with 10.4% with radiotherapy alone. In patients with complete resection, two-year survival reached 38%. These two new treatments are essentially intended for patients younger than 70 years and with a Karnofsky index>70. Ongoing studies are evaluating the possible value of combining these two treatments.

Dynamics of chemosensitivity and chromosomal instability in recurrent glioblastoma

Glioblastoma multiforme is characterised by invasive growth and frequent recurrence. Here, we have analysed chromosomal changes in comparison to tumour cell aggressiveness and chemosensitivity of three cell lines established from a primary tumour and consecutive recurrences (BTL1 to BTL3) of a long-term surviving glioblastoma patient together with paraffin-embedded materials of five further cases with recurrent disease. Following surgery, the BTL patient progressed under irradiation/ lomustine but responded to temozolomide after re-operation to temozolomide. The primary tumour -derived BTL1 cells showed chromosomal imbalances typical of highly aggressive glioblastomas. Interestingly, BTL2 cells established from the first recurrence developed under therapy showed signs of enhanced chromosomal instability. In contrast, BTL3 cells from the second recurrence resembled a less aggressive subclone of the primary tumour. Although BTL2 cells exhibited a highly aggressive phenotype, BTL3 cells were characterised by reduced proliferative and migratory potential. Despite persistent methylation of the O6-methylguanine-DNA methyltransferase promoter, BTL3 cells exhibited the highest temozolomide sensitivity. A comparable situation was found in two out of five glioblastoma patients, both characterised by enhanced survival time, who also relapsed after surgery/chemotherapy with less aggressive recurrences. Taken together, our data suggest that pretreated glioblastoma patients may relapse with highly chemosensitive tumours confirming the feasibility of temozolomide treatment even in case of repeated recurrence.

Apoptosis induced by chemotherapeutic agents involves c-Jun N-terminal kinase activation in sarcoma cell lines

Molecular mechanisms underlying chemotherapeutic agent-induced apoptosis in sarcoma cells are not well known. Induction of apoptosis is regulated by several components including mitogen-activated protein kinases (MAPKs) comprising ERK, p38MAPKs, and c-Jun N-terminal kinase (JNK). In the present study, we examined whether activation of JNK is induced by the chemotherapeutic agents cis-diaminedichloroplatinum (cisplatin, CDDP) or doxorubicin (DXR), and whether the ectopic expression of constitutively active (MKK7-JNK1) or dominant-negative form of JNK (dnJNK) influenced apoptosis in response to the CDDP or DXR in sarcoma cell lines MG-63 and SaOS-2. The CDDP or DXR induced JNK activation in the both cell lines, as assessed by Western blotting using phosphospecific antibodies. A transient expression of the activated form of JNK sensitized the MG-63 and SaOS-2 cells to the drug-induced apoptosis, while dnJNK1 reduced the proportion of apoptotic cell death. Apoptosis was determined by flow cytometry using annexin-V Cy5. Collectively, our results indicate that JNK activation is involved in apoptotic cell death in sarcoma cell lines following stimulation with CDDP or DXR.

Photodynamic therapy of high grade glioma - long term survival

Haemetaporphyrin derivative (HpD) mediated photodynamic therapy (PDT) has been investigated as an adjuvant treatment for cerebral glioma. This study records the survival of patients at the Royal Melbourne Hospital with residences in the State of Victoria, utilizing the Victorian Cancer Registry database for patients treated with adjuvant PDT following surgical resection of the tumour. For primary (newly diagnosed) tumours, median survival from initial diagnosis was 76.5 months for anaplastic astrocytoma (AA) and 14.3 months for glioblastoma multiforme (GBM). Seventy-three percent of patients with AA and 25% with GBM survived longer than 36 months. For recurrent tumour, median survival from the time of surgery was 66.6 months for AA and 13.5 months for GBM. Fifty-seven percent of patients with recurrent AA and 41% of patients with recurrent GBM survived longer than 36 months. Older age at the time of diagnosis was associated with poorer prognosis. Laser light doses above the sample median of 230 J/cm2 were associated with better prognosis in the 136 patients studied (primary tumour patients - (HR=0.50[0.27,0.95],p=0.033); recurrent tumour patients (HR=0.75[0.42,1.31],p=0.312). There was no mortality directly associated with the therapy, three patients had increased cerebral oedema thought to be related to photodynamic therapy that was controlled with conventional therapies.

Epidermal growth factor receptor inhibition for the treatment of glioblastoma multiforme and other malignant brain tumours

Gliomas are the most common primary central nervous system tumours and about 55% are glioblastoma multiforme (GBM). Between 40% and 50% of GBM have dysregulated epidermal growth factor receptor (HER1/EGFR), and almost half of these co-express the mutant receptor subtype EGFRvIII, which may contribute to the aggressive and refractory course of GBM. Limited therapeutic options exist for GBM, and recurrence is common. Standard therapy is surgical resection, where possible, and radiotherapy. Adjuvant chemotherapy provides a modest survival benefit. New therapies are essential, and HER1/EGFR-targeted agents may provide a viable strategy. The HER1/EGFR tyrosine kinase inhibitors erlotinib and gefitinib are in advanced clinical development for glioma, and a number of trials are in progress, or have recently been completed. Preliminary results with gefitinib show no objective responses, but do provide evidence of disease control. In contrast, preliminary data with erlotinib appear more encouraging. Erlotinib inhibits wild-type HER1/EGFR and EGFRvIII, which may underlie its promising clinical activity. Other HER1/EGFR-targeted agents are also being investigated for glioma, including monoclonal antibodies, radio-immuno conjugates, ligand-toxin conjugates, antisense oligonucleotides and ribozymes. Further studies will define their clinical potential and hopefully provide new, effective treatments for GBM and other malignant brain tumours.

Use of 11C-methionine PET to monitor the effects of temozolomide chemotherapy in malignant gliomas

PURPOSE

The purpose of this study was to monitor the metabolic effects of temozolomide (TMZ) chemotherapy in malignant gliomas by means of repeated positron emission tomography (PET) with [(11)C]methionine (MET).

METHODS

Fifteen patients with histologically proven malignant glioma were treated by TMZ chemotherapy. MET-PET studies were performed before and after the third cycle of TMZ chemotherapy in all patients, and in 12 patients also after the sixth cycle. Gadolinium-enhanced MRI studies were performed in 12 patients before the first and after the sixth cycle. Clinical status was assessed by the modified Rankin scale. Long-term outcome was assessed by calculating the time to progression (TTP) in months.

RESULTS

Decline in MET uptake during therapy corresponded to a stable clinical status. The median TTP was significantly longer in patients with decline in MET uptake than in those with increasing MET uptake (23 vs 3.5 months; p=0.01, log rank test). There was no significant correlation between change in MET uptake and change in contrast enhancement during treatment for all patients.

CONCLUSION

The present data demonstrate that clinical stability, which is often achieved under TMZ chemotherapy of malignant glioma, corresponds to a decline in or stability of tumour amino acid metabolism. Tumour responses can already be demonstrated with MET-PET after three cycles of chemotherapy, and absence of progression at that time indicates a high probability of further stability during the next three cycles. A reduction in MET uptake during TMZ treatment predicts a favourable clinical outcome. Molecular imaging of amino acid uptake by MET-PET offers a new method of measurement of the biological activity of recurrent glioma.

HER1/EGFR tyrosine kinase inhibitors for the treatment of glioblastoma multiforme

Glioblastoma multiforme (GBM) is a highly malignant brain tumor with limited therapeutic options, a high recurrence rate and mortality. Standard therapy is maximal surgical resection and radiotherapy (RT). Recent data suggest combining temozolomide with RT is better than RT alone. Adjuvant chemotherapy has a modest impact on survival. For relapsed patients there is no standard therapy, but options include chemotherapeutic agents or new agents in development. One approach to improve outcome is using targeted agents that interfere with cell-surface receptors or intracellular signaling pathways. Between 40% and 50% of GBM tumors show HER1/EGFR dysregulation, and almost half co-express the constitutively active mutant receptor subtype EGFRvIII, which may contribute to the aggressive and refractory course of GBM. Numerous studies show a relationship between aberrant HER1/EGFR biology and tumorigenicity in GBM cells. Two available HER1/EGFR tyrosine kinase inhibitors (TKIs) are gefitinib (Iressa) and erlotinib (Tarceva); both show antitumor and radiosensitization effects in vitro and in animal models of GBM. Clinical trials in patients with GBM and other gliomas are ongoing. Preliminary and published results from trials of gefitinib in recurrent GBM show no increased time to progression or overall survival (OS) compared with historical controls. Studies with erlotinib show greater antitumor activity in patients with GBM than with gefitinib, although the impact of both agents on OS remains unclear. GBM treatment with HER1/EGFR TKIs alone or combined with other targeted therapies and conventional modalities deserve further investigation and refinement, as does our understanding of their mechanisms of action and the role of genetics.

Combined cimetidine and temozolomide, compared with temozolomide alone: significant increases in survival in nude mice bearing U373 human glioblastoma multiforme orthotopic xenografts

OBJECT

Malignant gliomas consist of both heterogeneous proliferating and migrating cell subpopulations, with migrating glioma cells exhibiting less sensitivity to antiproliferative or proapoptotic drugs than proliferative cells. Therefore, the authors combined cimetidine, an antiinflammatory agent already proven to act against migrating epithelial cancer cells, with temozolomide to determine whether the combination induces antitumor activities in experimental orthotopic human gliomas compared with the effects of temozolomide alone.

METHODS

Cimetidine added to temozolomide compared with temozolomide alone induced survival benefits in nude mice with U373 human glioblastoma multiforme (GBM) cells orthotopically xenografted in the brain. Computer-assisted phase-contrast microscopy analyses of 9L rat and U373 human GBM cells showed that cimetidine significantly decreased the migration levels of these tumor cells in vitro at concentrations at which tumor growth levels were not modified (as revealed on monotetrazolium colorimetric assay). Computer-assisted microscope analyses of neoglycoconjugate-based glycohistochemical staining profiles of 9L gliosarcomas grown in vivo revealed that cimetidine significantly decreased expression levels of endogenous receptors for fucose and, to a lesser extent, for N-acetyl-lactosamine moieties. Endogenous receptors of this specificity are known to play important roles in adhesion and migration processes of brain tumor cells.

CONCLUSIONS

Cimetidine, acting as an antiadhesive and therefore an antimigratory agent for glioma cells, could be added in complement to the cytotoxic temozolomide compound to combat both migrating and proliferating cells in GBM.