Temozolomide: The evidence for its therapeutic efficacy in malignant astrocytomas

Metformin with Temozolomide for Newly Diagnosed Glioblastoma: Results of Phase I Study and a Brief Review of Relevant Studies

Glioblastoma (GBM) inevitably recurs due to a resistance to current standard therapy. We showed that the antidiabetic drug metformin (MF) can induce the differentiation of stem-like glioma-initiating cells and suppress tumor formation through AMPK-FOXO3 activation. In this study, we design a phase I/II study to examine the clinical effect of MF. We aim to determine a recommended phase II MF dose with maintenance temozolomide (TMZ) in patients with newly diagnosed GBM who completed standard concomitant radiotherapy and TMZ. MF dose-escalation was planned using a 3 + 3 design. Dose-limiting toxicities (DLTs) were assessed during the first six weeks after MF initiation. Three patients were treated with 1500 mg/day MF and four patients were treated with 2250 mg/day MF between February 2021 and January 2022. No DLTs were observed. The most common adverse effects were appetite loss, nausea, and diarrhea, all of which were manageable. Two patients experienced tumor progression at 6.0 and 6.1 months, and one died 12.2 months after initial surgery. The other five patients remained stable at the last follow-up session. The MF dose of up to 2250 mg/day combined with maintenance TMZ appeared to be well tolerated, and we proceeded to a phase II study with 2250 mg/day MF.

Tumor Microenvironment in Glioma Invasion

A major malignant trait of gliomas is their remarkable infiltration capacity. When glioma develops, the tumor cells have already reached the distant part. Therefore, complete removal of the glioma is impossible. Recently, research on the involvement of the tumor microenvironment in glioma invasion has advanced. Local hypoxia triggers cell migration as an environmental factor. The transcription factor hypoxia-inducible factor (HIF) -1α, produced in tumor cells under hypoxia, promotes the transcription of various invasion related molecules. The extracellular matrix surrounding tumors is degraded by proteases secreted by tumor cells and simultaneously replaced by an extracellular matrix that promotes infiltration. Astrocytes and microglia become tumor-associated astrocytes and glioma-associated macrophages/microglia, respectively, in relation to tumor cells. These cells also promote glioma invasion. Interactions between glioma cells actively promote infiltration of each other. Surgery, chemotherapy, and radiation therapy transform the microenvironment, allowing glioma cells to invade. These findings indicate that the tumor microenvironment may be a target for glioma invasion. On the other hand, because the living body actively promotes tumor infiltration in response to the tumor, it is necessary to reconsider whether the invasion itself is friend or foe to the brain.

Ageritin-The Ribotoxin-like Protein from Poplar Mushroom (Cyclocybe aegerita) Sensitizes Primary Glioblastoma Cells to Conventional Temozolomide Chemotherapy

Here, we propose Ageritin, the prototype of the ribotoxin-like protein family, as an adjuvant treatment to control the growth of NULU and ZAR, two primary human glioblastoma cell lines, which exhibit a pharmacoresistance phenotype. Ageritin is able to inhibit NULU and ZAR growth with an IC50 of 0.53 ± 0.29 µM and 0.42 ± 0.49 µM, respectively. In this study, Ageritin treatment highlighted a macroscopic genotoxic response through the formation of micronuclei, which represents the morphological manifestation of genomic chaos induced by this toxin. DNA damage was not associated with either the deregulation of DNA repair enzymes (i.e., ATM and DNA-PK), as demonstrated by quantitative PCR, or reactive oxygen species. Indeed, the pretreatment of the most responsive cell line ZAR with the ROS scavenger N-acetylcysteine (NAC) did not follow the reverse cytotoxic effect of Ageritin, suggesting that this protein is not involved in cellular oxidative stress. Vice versa, Ageritin pretreatment strongly enhanced the sensitivity to temozolomide (TMZ) and inhibited MGMT protein expression, restoring the sensitivity to temozolomide. Overall, Ageritin could be considered as a possible innovative glioblastoma treatment, directly damaging DNA and downregulating the MGMT DNA repair protein. Finally, we verified the proteolysis susceptibility of Ageritin using an in vitro digestion system, and considered the future perspective use of this toxin as a bioconjugate in biomedicine.

Efficacy and safety of bevacizumab combined with temozolomide in the treatment of recurrent malignant gliomas and its influence on serum tumor markers

OBJECTIVE

To determine the efficacy and safety of bevacizumab (Bz) combined with temozolomide (TMZ) in the treatment of recurrent malignant gliomas and its influence on serum tumor markers (STMs).

METHODS

The clinical data of 73 patients with recurrent malignant gliomas admitted to the First People's Hospital of Shuangliu District from April 2016 to June 2018 were analyzed retrospectively. Patients were divided into two groups according to different therapies: the control group (n=33) treated with TMZ, and the research group (n=40) treated with Bz combined with TMZ (Bz+TMZ). The overall response rate (ORR), disease control rate (DCR) and incidence of adverse reactions (ARs) were observed after 4 courses of treatment. The levels of STMs were detected. Additionally, the Karnofsky Performance Scale (KPS) score and quality of life (QoL) before and after treatment were compared between the two groups. The 1-year and 2-year survival rates as well as median survival time (MST) were also compared after 2-year follow-up. Treatment satisfaction was recorded and compared.

RESULTS

After treatment, the research group exhibited better ORR and DCR than the control group; The incidence of ARs differed insignificantly between the two arms; The serum levels of Vascular endothelial growth factor (VEGF), epidermal growth factor (EGF) and transforming growth factor β (TGF-β) in the research group were statistically lower than those in the control group; The KPS score and QoL score increased significantly in both arms, and were higher in the research group compared with the control group; the research group was also superior to the control group in treatment satisfaction. The research group showed higher 1-year and 2-year survival rates than the control group.

CONCLUSIONS

BZ+TMZ is effective in treating recurrent malignant gliomas, which can improve the QoL and survival of patients.

Cytotoxicity Effect of Quinoin, Type 1 Ribosome-Inactivating Protein from Quinoa Seeds, on Glioblastoma Cells

Ribosome-inactivating proteins (RIPs) are found in several edible plants and are well characterized. Many studies highlight their use in cancer therapy, alone or as immunoconjugates, linked to monoclonal antibodies directed against target cancer cells. In this context, we investigate the cytotoxicity of quinoin, a novel type 1 RIP from quinoa seeds, on human continuous and primary glioblastoma cell lines. The cytotoxic effect of quinoin was assayed on human continuous glioblastoma U87Mg cells. Moreover, considering that common conventional glioblastoma multiforme (GBM) cell lines are genetically different from the tumors from which they derive, the cytotoxicity of quinoin was subsequently tested towards primary cells NULU and ZAR (two cell lines established from patients’ gliomas), also in combination with the chemotherapeutic agent temozolomide (TMZ), currently used in glioblastoma treatment. The present study demonstrated that quinoin (2.5 and 5.0 nM) strongly reduced glioblastoma cells’ growth. The mechanisms responsible for the inhibitory action of quinoin are different in the tested primary cell lines, reproducing the heterogeneous response of glioblastoma cells. Interestingly, primary cells treated with quinoin in combination with TMZ were more sensitive to the treatment. Overall, our data highlight that quinoin could represent a novel tool for glioblastoma therapy and a possible adjuvant for the treatment of the disease in combination with TMZ, alone or as possible immunoconjugates/nanoconstructs.

Exosomal connexin 43 regulates the resistance of glioma cells to temozolomide

Glioblastoma is the most common and aggressive brain tumor and it is characterized by a high mortality rate. Temozolomide (TMZ) is an effective chemotherapy drug for glioblastoma, but the resistance to TMZ has come to represent a major clinical problem, and its underlying mechanism has yet to be elucidated. In the present study, the role of exosomal connexin 43 (Cx43) in the resistance of glioma cells to TMZ and cell migration was investigated. First, higher expression levels of Cx43 were detected in TMZ‑resistant U251 (U251r) cells compared with those in TMZ‑sensitive (U251s) cells. Exosomes from U251s or U251r cells (sExo and rExo, respectively) were isolated. It was found that the expression of Cx43 in rExo was notably higher compared with that in sExo, whereas treatment with rExo increased the expression of Cx43 in U251s cells. Additionally, exosomes stained with dioctadecyloxacarbocyanine (Dio) were used to visualized exosome uptake by glioma cells. It was observed that the uptake of Dio‑stained rExo in U251s cells was more prominent compared with that of Dio‑stained sExo, while ^37,43Gap27, a gap junction mimetic peptide directed against Cx43, alleviated the rExo uptake by cells. Moreover, rExo increased the IC₅₀ of U251s to TMZ, colony formation and Bcl‑2 expression, but decreased Bax and cleaved caspase‑3 expression in U251s cells. ^37,43Gap27 efficiently inhibited these effects of rExo on U251s cells. Finally, the results of the wound healing and Transwell assays revealed that rExo significantly enhanced the migration of U251s cells, whereas ^37,43Gap27 significantly attenuated rExo‑induced cell migration. Taken together, these results indicate the crucial role of exosomal Cx43 in chemotherapy resistance and migration of glioma cells, and suggest that Cx43 may hold promise as a therapeutic target for glioblastoma in the future.

Challenges and Perspectives of Standard Therapy and Drug Development in High-Grade Gliomas

Despite their low incidence rate globally, high-grade gliomas (HGG) remain a fatal primary brain tumor. The recommended therapy often is incapable of resecting the tumor entirely and exclusively targeting the tumor leads to tumor recurrence and dismal prognosis. Additionally, many HGG patients are not well suited for standard therapy and instead, subjected to a palliative approach. HGG tumors are highly infiltrative and the complex tumor microenvironment as well as high tumor heterogeneity often poses the main challenges towards the standard treatment. Therefore, a one-fit-approach may not be suitable for HGG management. Thus, a multimodal approach of standard therapy with immunotherapy, nanomedicine, repurposing of older drugs, use of phytochemicals, and precision medicine may be more advantageous than a single treatment model. This multimodal approach considers the environmental and genetic factors which could affect the patient's response to therapy, thus improving their outcome. This review discusses the current views and advances in potential HGG therapeutic approaches and, aims to bridge the existing knowledge gap that will assist in overcoming challenges in HGG.

Comparison of the Effect of Native 1,4-Naphthoquinones Plumbagin, Menadione, and Lawsone on Viability, Redox Status, and Mitochondrial Functions of C6 Glioblastoma Cells

Background: 1,4-naphthoquinones, especially juglone, are known for their anticancer activity. However, plumbagin, lawsone, and menadione have been less investigated for these properties. Therefore, we aimed to determine the effects of plumbagin, lawsone, and menadione on C6 glioblastoma cell viability, ROS production, and mitochondrial function. Methods: Cell viability was assessed spectrophotometrically using metabolic activity method, and by fluorescent Hoechst/propidium iodide nuclear staining. ROS generation was measured fluorometrically using DCFH-DA. Oxygen uptake rates were recorded by the high-resolution respirometer Oxygraph-2k. Results: Plumbagin and menadione displayed highly cytotoxic activity on C6 cells (IC₅₀ is 7.7 ± 0.28 μM and 9.6 ± 0.75 μM, respectively) and caused cell death by necrosis. Additionally, they increased the amount of intracellular ROS in a concentration-dependent manner. Moreover, even at very small concentrations (1–3 µM), these compounds significantly uncoupled mitochondrial oxidation from phosphorylation impairing energy production in cells. Lawsone had significantly lower viability decreasing and mitochondria-uncoupling effect, and exerted strong antioxidant activity. Conclusions: Plumbagin and menadione exhibit strong prooxidant, mitochondrial oxidative phosphorylation uncoupling and cytotoxic activity. In contrast, lawsone demonstrates a moderate effect on C6 cell viability and mitochondrial functions, and possesses strong antioxidant properties.

Minerval (2-hydroxyoleic acid) causes cancer cell selective toxicity by uncoupling oxidative phosphorylation and compromising bioenergetic compensation capacity

This work tests bioenergetic and cell-biological implications of the synthetic fatty acid Minerval (2-hydroxyoleic acid), previously demonstrated to act by activation of sphingomyelin synthase in the plasma membrane (PM) and lowering of phosphatidylethanolamine (PE) and phosphatidylcholine (PC) and their carcinogenic signaling. We show here that Minerval also acts, selectively in cancer cell lines, as an ATP depleting uncoupler of mitochondrial oxidative phosphorylation (OxPhos). As a function of its exposure time, Minerval compromised the capacity of glioblastoma U87-MG cells to compensate for aberrant respiration by up-modulation of glycolysis. This effect was not exposure time-dependent in the lung carcinoma A549 cell line, which was more sensitive to Minerval. Compared with OxPhos inhibitors FCCP (uncoupler), rotenone (electron transfer inhibitor), and oligomycin (F1F0-ATPase inhibitor), Minerval action was similar only to that of FCCP. This similarity was manifested by mitochondrial membrane potential (MMP) depolarization, facilitation of oxygen consumption rate (OCR), restriction of mitochondrial and cellular reactive oxygen species (ROS) generation and mitochondrial fragmentation. Additionally, compared with other OxPhos inhibitors, Minerval uniquely induced ER stress in cancer cell lines. These new modes of action for Minerval, capitalizing on the high fatty acid requirements of cancer cells, can potentially enhance its cancer-selective toxicity and improve its therapeutic capacity.

In Vitro Radiosensitizing Effects of Temozolomide on U87MG Cell Lines of Human Glioblastoma Multiforme

BACKGROUND

Glioma is the most common primary brain tumor with poor prognosis. Temozolomide (TMZ) has been used with irradiation (IR) to treat gliomas. The aim of the present study was to evaluate the cytotoxic and radiosensitizing effect of TMZ when combined with high-dose and high-dose rate of gamma irradiation in vitro.

METHODS

Two 'U87MG' cell lines and skin fibroblast were cultured and assigned to five groups for 24, 48, and 72 hours. The groups were namely, TMZ group (2000 μM/L), IR group (5 Gy), TMZ plus IR group, control group, and control solvent group. MTT assay was applied to evaluate cell viability. Data were analyzed with SPSS 21.0 software using one-way ANOVA and Kruskal-Wallis test. P<0.05 were considered statistically significant.

RESULTS

The slope of growth curve U87MG cells in semi-logarithmic scale was equal to 27.36±0.89 hours. The viability of cells was determined for different TMZ and IR treatment groups. In terms of cell viability, there were no significant differences between the control and control solvent groups (P=0.35) and between treated group by IR (5 Gy) alone and TMZ (2000 µM/ml) alone (P=0.15). Data obtained for the cell viability of combined TMZ plus IR in both cell lines compared to TMZ or IR treated group alone showed a significant difference (P=0.002).

CONCLUSION

The evaluation of cells viability showed that TMZ in combination with IR on glioma cells led to a significant radiosensitivity compared to IR alone.

Effect of siRNA-Livin on drug resistance to chemotherapy in glioma U251 cells and CD133+ stem cells

The aim of the present study was to observe the effect of siRNA-Livin on the expression of multidrug resistance-associated protein (MRP) genes in a U251 cell line and U251 stem cells. CD133⁺ cancer stem cells were identified and isolated from the U251 glioblastoma cells, and morphological observations were used to detect the cell survival conditions. In addition, quantitative polymerase chain reaction was used to detect the mRNA expression levels of Livin, MRP1 and MRP3. Following transfection with the lentivirus containing the siRNA-Livin, the expression of Livin was significantly inhibited in the U251 cells and stem cells (P<0.01). Following temozolomide intervention, the proliferation of the U251 cells and U251 stem cells was restrained, with a lot of cell debris present and the structure of the cell spheres destroyed. The inhibitory effect was more significant following transfection with siRNA-Livin. Prior to siRNA-Livin transfection, the expression of MRP1 presented an increasing trend in the U251 cells and U251 stem cells with increasing drug concentrations and intervention times (P<0.05). Following siRNA-Livin transfection, the expression of MRP1 decreased in the U251 cells and U251 stem cells under the same drug concentration and intervention time (P<0.05), while the expression of MRP3 increased in the U251 stem cells under the same intervention concentration and time (P<0.05). Therefore, siRNA-Livin was shown to decrease the expression of MRP1 in U251 cells and U251 stem cells, increase the expression of MRP3 in U251 stem cells and decrease the proliferation of U251 cells and U251 stem cells. Thus, Livin may be associated with the high expression of MRP1, and siRNA-Livin may be used to lower the expression of MRP1 in order to reduce the drug resistance to chemotherapy in cases of glioblastoma.

Effects of temozolomide (TMZ) on the expression and interaction of heat shock proteins (HSPs) and DNA repair proteins in human malignant glioma cells

We previously reported the association of HSPA1A and HSPB1 with high-grade astrocytomas, suggesting that these proteins might be involved in disease outcome and response to treatment. With the aim to better understand the resistance/susceptibility processes associated to temozolomide (TMZ) treatment, the current study was performed in three human malignant glioma cell lines by focusing on several levels: (a) apoptotic index and senescence, (b) DNA damage, and (c) interaction of HSPB1 with players of the DNA damage response. Three human glioma cell lines, Gli36, U87, and DBTRG, were treated with TMZ evaluating cell viability and survival, apoptosis, senescence, and comets (comet assay). The expression of HSPA (HSPA1A and HSPA8), HSPB1, O6-methylguanine-DNA methyltransferase (MGMT), MLH1, and MSH2 was determined by immunocytochemistry, immunofluorescence, and Western blot. Immunoprecipitation was used to analyze protein interaction. The cell lines exhibited differences in viability, apoptosis, and senescence after TMZ administration. We then focused on Gli36 cells (relatively unstudied) which showed very low recovery capacity following TMZ treatment, and this was related to high DNA damage levels; however, the cells maintained their viability. In these cells, MGMT, MSH2, HSPA, and HSPB1 levels increased significantly after TMZ administration. In addition, MSH2 and HSPB1 proteins appeared co-localized by confocal microscopy. This co-localization increased after TMZ treatment, and in immunoprecipitation analysis, MSH2 and HSPB1 appeared interacting. In contrast, HSPB1 did not interact with MGMT. We show in glioma cells the biological effects of TMZ and how this drug affects the expression levels of heat shock proteins (HSPs), MGMT, MSH2, and MLH1. In Gli36 cells, the results suggest that interactions between HSPB1 and MSH2, including co-nuclear localization, may be important in determining cell sensitivity to TMZ.

Tumor treating field therapy in combination with bevacizumab for the treatment of recurrent glioblastoma

A novel device that employs TTF therapy has recently been developed and is currently in use for the treatment of recurrent glioblastoma (rGBM). It was FDA approved in April 2011 for the treatment of patients 22 years or older with rGBM. The device delivers alternating electric fields and is programmed to ensure maximal tumor cell kill¹.

Glioblastoma is the most common type of glioma and has an estimated incidence of approximately 10,000 new cases per year in the United States alone². This tumor is particularly resistant to treatment and is uniformly fatal especially in the recurrent setting^3-5. Prior to the approval of the TTF System, the only FDA approved treatment for rGBM was bevacizumab⁶. Bevacizumab is a humanized monoclonal antibody targeted against the vascular endothelial growth factor (VEGF) protein that drives tumor angiogenesis⁷. By blocking the VEGF pathway, bevacizumab can result in a significant radiographic response (pseudoresponse), improve progression free survival and reduce corticosteroid requirements in rGBM patients^8,9. Bevacizumab however failed to prolong overall survival in a recent phase III trial²⁶. A pivotal phase III trial (EF-11) demonstrated comparable overall survival between physicians’ choice chemotherapy and TTF Therapy but better quality of life were observed in the TTF arm¹⁰.

There is currently an unmet need to develop novel approaches designed to prolong overall survival and/or improve quality of life in this unfortunate patient population. One appealing approach would be to combine the two currently approved treatment modalities namely bevacizumab and TTF Therapy. These two treatments are currently approved as monotherapy^11,12, but their combination has never been evaluated in a clinical trial. We have developed an approach for combining those two treatment modalities and treated 2 rGBM patients. Here we describe a detailed methodology outlining this novel treatment protocol and present representative data from one of the treated patients.

Temozolomide during and after Radiotherapy for Newly Diagnosed Glioblastomas : A Prospective Multicenter Study of Korean Patients

OBJECTIVE

This study was performed to determine the safety and outcome of concurrent chemoradiotherapy (CCRT) and adjuvant chemotherapy with temozolomide for Korean patients with a newly diagnosed glioblastoma.

METHODS

Patients were recruited from four institutions between 2004 and 2007. The patients received fractionated focal irradiation in daily fractions of 2 Gy given 5 days per week for 6 weeks and daily temozolomide, followed by 6 cycles of adjuvant temozolomide. The primary endpoint was overall survival (OS) and the secondary endpoints were progression-free survival (PFS), response, and safety.

RESULTS

A total of 103 patients were enrolled in this study. Ninety-six patients (93%) completed the CCRT and 54 patients (52%) received 6 cycles of adjuvant temozolomide. The response rate was 73% (53/73) and the tumor control rate was 92% (67/73). Of the 96 patients who completed the CCRT, the median OS was 18.0 months and the 1- and 2-year OS rates were 74 and 38%, respectively. The median PFS was 10.0 months and the 1- and 2-year PFS rates were 33 and 16%, respectively. The only significant prognostic factor of survival was the extent of surgical resection (p<0.05). CCRT resulted in grade 3 or 4 hematologic toxic effects in 8% of patients. No opportunistic infections were noted.

CONCLUSION

This study is the first prospective multi-institutional report of CCRT and adjuvant chemotherapy with temozolomide for patients with a newly diagnosed glioblastoma in Korea. The current protocol may prolong the survival of Korean patients with a glioblastoma and may be tolerable in terms of toxicity.

2-Hydroxyoleate, a nontoxic membrane binding anticancer drug, induces glioma cell differentiation and autophagy

Despite recent advances in the development of new cancer therapies, the treatment options for glioma remain limited, and the survival rate of patients has changed little over the past three decades. Here, we show that 2-hydroxyoleic acid (2OHOA) induces differentiation and autophagy of human glioma cells. Compared to the current reference drug for this condition, temozolomide (TMZ), 2OHOA combated glioma more efficiently and, unlike TMZ, tumor relapse was not observed following 2OHOA treatment. The novel mechanism of action of 2OHOA is associated with important changes in membrane-lipid composition, primarily a recovery of sphingomyelin (SM) levels, which is markedly low in glioma cells before treatment. Parallel to membrane-lipid regulation, treatment with 2OHOA induced a dramatic translocation of Ras from the membrane to the cytoplasm, which inhibited the MAP kinase pathway, reduced activity of the PI3K/Akt pathway, and downregulated Cyclin D-CDK4/6 proteins followed by hypophosphorylation of the retinoblastoma protein (RB). These regulatory effects were associated with induction of glioma cell differentiation into mature glial cells followed by autophagic cell death. Given its high efficacy, low toxicity, ease of oral administration, and good distribution to the brain, 2OHOA constitutes a new and potentially valuable therapeutic tool for glioma patients.

Radiotherapy and temozolomide in anaplastic astrocytoma: a retrospective multicenter study by the Central Nervous System Study Group of AIRO (Italian Association of Radiation Oncology)

Although the evidence for the benefit of adding temozolomide (TMZ) to radiotherapy (RT) is limited to glioblastoma patients, there is currently a trend toward treating anaplastic astrocytomas (AAs) with combined RT + TMZ. The aim of the present study was to describe the patterns of care of patients affected by AA and, particularly, to compare the outcome of patients treated exclusively with RT with those treated with RT + TMZ. Data of 295 newly diagnosed AAs treated with postoperative RT ± TMZ in the period from 2002 to 2007 were reviewed. More than 75% of patients underwent a surgical removal. All the patients had postoperative RT; 86.1% of them were treated with 3D-conformal RT (3D-CRT). Sixty-seven percent of the entire group received postoperative chemotherapy with TMZ (n = 198). One-hundred sixty-six patients received both concomitant and sequential TMZ. Prescription of postoperative TMZ increased in the most recent period (2005-2007). One- and 4-year survival rates were 70.2% and 28.6%, respectively. No statistically significant improvement in survival was observed with the addition of TMZ to RT (P = .59). Multivariate analysis showed the statistical significance of age, presence of seizures, Recursive Partitioning Analysis classes I-III, extent of surgical removal, and 3D-CRT. Changes in the care of AA over the past years are documented. Currently there is not evidence to justify the addition of TMZ to postoperative RT for patients with newly diagnosed AA outside a clinical trial. Results of prospective and randomized trials are needed.

Long survival of primary diffuse leptomeningeal gliomatosis following radiotherapy and temozolomide: case report and literature review

Objective

Primary diffuse leptomeningeal gliomatosis (PDLG) is a rare neoplasm with a short survival time of a few months. there is currently no standardized therapeutic approach for PDLG.

Materials and methods

We report on a 53-year-old male patient who presented with epileptic seizures, gait disturbance, paraparesis and sensory deficits in the dermatomes T8-10.

Results

Magnetic resonance imaging (MRI) revealing numerous spinal and cranial gadolinium-enhancing nodules in the meninges and histopathology led us to diagnose primary diffuse leptomeningeal gliomatosis with WHO grade III astrocytic cells. Consecutively, the patient underwent craniospinal radiotherapy (30 Gy) and 11 sequential cycles of temozolomide. This regimen led to partial tumor regression. Thirteen months later, spinal MRI revealed tumor progression. Second-line chemotherapy with 5 cycles of irinotecan and bevacizumab did not prevent further clinical deterioration. The patient died twenty-two months after diagnosis, being the longest survival time described thus far with respect to PDLG consisting of astrocytic tumor cells.

Conclusions

Radiochemotherapy including temozolomide, as established standard therapy for brain malignant astrocytomas, might be valid as a basic therapeutic strategy for this PDLG subtype.