Nitrosourea-based chemotherapy for low grade gliomas failing initial treatment with temozolomide

Intranasal Administration of Catechol-Based Pt(IV) Coordination Polymer Nanoparticles for Glioblastoma Therapy

Cisplatin has been described as a potent anticancer agent for decades. However, in the case of glioblastomas, it is only considered a rescue treatment applied after the failure of second-line treatments. Herein, based on the versatility offered by coordination chemistry, we engineered nanoparticles by reaction of a platinum (IV) prodrug and iron metal ions showing in vitro dual pH- and redox-sensitivity, controlled release and comparable cytotoxicity to cisplatin against HeLa and GL261 cells. In vivo intranasal administration in orthotopic preclinical GL261 glioblastoma tumor-bearing mice demonstrated increased accumulation of platinum in tumors, leading in some cases to complete cure and prolonged survival of the tested cohort. This was corroborated by a magnetic resonance imaging follow-up, thus opening new opportunities for intranasal glioblastoma therapies while minimizing side effects. The findings derived from this research showed the potentiality of this approach as a novel therapy for glioblastoma treatment.

FM19G11 inhibits O6 -methylguanine DNA-methyltransferase expression under both hypoxic and normoxic conditions

FM19G11 is a small molecular agent that inhibits hypoxia-inducible factor-1-alpha (HIF-1α) and other signaling pathways. In this study, we characterized the modulating effects of FM19G11 on O⁶ -methylguanine DNA-methyltransferase (MGMT), the main regulator of temozolomide (TMZ) resistance in glioblastomas. This study included 2 MGMT-positive cell lines (GBM-XD and T98G). MGMT promoter methylation status, mRNA abundance, and protein levels were determined before and after FM19G11 treatment, and the roles of various signaling pathways were characterized. Under hypoxic conditions, MGMT mRNA and protein levels were significantly downregulated by FM19G11 via the HIF-1α pathway in both GBM-XD and T98G cells. In normoxic culture, T98G cells were strongly positive for MGMT, and MGMT expression was substantially downregulated by FM19G11 via the NF-κB pathway. In addition, TMZ resistance was reversed by treatment with FM19G11. Meanwhile, FM19G11 has no cytotoxicity at its effective dose. FM19G11 could potentially be used to counteract TMZ resistance in MGMT-positive glioblastomas.

Management of patients with recurrence of diffuse low grade glioma: A systematic review and evidence-based clinical practice guideline

TARGET POPULATION

These recommendations apply to adult patients with recurrent low-grade glioma (LGG) with initial pathologic diagnosis of a WHO grade II infiltrative glioma (oligodendroglioma, astrocytoma, or oligo-astrocytoma).

PATHOLOGY AT RECURRENCE

QUESTION

Do pathologic and molecular characteristics predict outcome/malignant transformation at recurrence?

RECOMMENDATIONS

IDH STATUS AND RECURRENCE: (Level III) IDH mutation status should be determined as LGGs with IDH mutations have a shortened time to recurrence. It is unclear whether knowledge of IDH mutation status provides benefit in predicting time to progression or overall survival. TP53 STATUS AND RECURRENCE: (Level III) TP53 mutations occur early in LGG pathogenesis, remain stable, and are not recommended as a marker of predisposition to malignant transformation at recurrence or other measures of prognosis. MGMT STATUS AND RECURRENCE: (Level III) Assessment of MGMT status is recommended as an adjunct to assessing prognosis as LGGs with MGMT promoter methylation are associated with shorter PFS (in the absence of TMZ) and longer post-recurrence survival (in the presence of TMZ), ultimately producing similar overall survival to LGGs without MGMT methylation. The available retrospective reports are conflicting and comparisons between reports are limited CDK2NA STATUS AND RECURRENCE: (Level III) Assessment of CDK2NA status is recommended when possible as the loss of expression of the CDK2NA via either methylation or loss of chromosome 9p is associated with malignant progression of LGGs. PROLIFERATIVE INDEX AND RECURRENCE: (Level III) It is recommended that proliferative indices (MIB-1 or BUdR) be measured in LGGs as higher proliferation indices are associated with increased likelihood of recurrence and shorter progression free and overall survival. 1P/19Q STATUS AND RECURRENCE: There is insufficient evidence to make any recommendations.

CHEMOTHERAPY AT RECURRENCE

QUESTION

What role does chemotherapy have in LGG recurrence?

RECOMMENDATIONS

TEMOZOLOMIDE AND RECURRENCE: (Level III) Temozolomide is recommended in the therapy of recurrent LGG as it may improve clinical symptoms. Oligodendrogliomas and tumors with 1p/19q co-deletion may derive the most benefit. PCV AND RECURRENCE: (Level III) PCV is recommended in the therapy of LGG at recurrence as it may improve clinical symptoms with the strongest evidence being for oligodendrogliomas. CARBOPLATIN AND RECURRENCE : (Level III) Carboplatin is not recommended as there is no significant benefit from carboplatin as single agent therapy for recurrent LGGs. OTHER TREATMENTS (NITROSUREAS, HYDROXYUREA/IMANITIB, IRINOTECAN, PACLITAXEL) AND RECURRENCE: There is insufficient evidence to make any recommendations. It is recommended that individuals with recurrent LGGs be enrolled in a properly designed clinical trial to assess these chemotherapeutic agents.

RADIATION AT RECURRENCE

QUESTION

What role does radiation have in LGG recurrence?

RECOMMENDATIONS

RADIATION AT RECURRENCE WITH NO PREVIOUS IRRADIATION: (Level III) Radiation is recommended at recurrence if there was no previous radiation treatment. RE-IRRADIATION AT RECURRENCE: (Level III) It is recommended that re-irradiation be considered in the setting of LGG recurrence as it may provide benefit in disease control.

SURGERY AT RECURRENCE

There is insufficient evidence to make any specific recommendations. It is recommended that individuals with recurrent LGGs be enrolled in a properly designed clinical trial to assess the role of surgery at recurrence.

Recent Technical Advances and Indications for Radiation Therapy in Low-Grade Glioma

The use of radiotherapy in low-grade glioma has been a topic of controversy over the past 2 decades. Although earlier studies showed no overall survival benefit and no dose response, recent studies demonstrate a possible synergism between radiotherapy and chemotherapy. However, many questions remained unanswered regarding the proper management including the potential roles of biological imaging in treatment planning, the role of reirradiation after recurrence, the role of intensity-modulated radiation therapy and proton beam radiotherapy, and the proper choice of chemotherapy agents. Further clinical trials are necessary to help integrate these new therapies and technologies into clinical practice.

Chemotherapy in low-grade gliomas

PURPOSE OF REVIEW

This review summarizes the recent studies in adults' diffuse low-grade gliomas (LGGs) chemotherapy, including response assessment and potential predictive biomarkers of chemosensitivity.

RECENT FINDINGS

Recent studies have confirmed that chemotherapy is an interesting treatment option in LGGs. About 25-50% of LGGs achieve radiological responses with temozolomide or a procarbazine-CCNU-vincristine (PCV) regimen. Clinical and quality-of-life improvements are commonly observed with more than half of the patients with epilepsy, demonstrating a significant reduction of seizure frequency. Dynamic volumetric studies have provided a better description of LGGs evolution after chemotherapy. They have shown that an ongoing volume decrease can be observed many months after chemotherapy discontinuation, particularly after PCV, raising the question of how and for how long should LGGs be treated. New response criteria have been defined by the Response Assessment in Neuro-Oncology group. In addition to 1p/19q codeletion and MGMT promoter methylation, IDH1 mutation might also be a potential predictive biomarker of chemosensitivity.

SUMMARY

It has now been widely accepted that chemotherapy is an interesting treatment option in LGGs. However, several questions remain unanswered regarding its optimal use. Ongoing phase III studies will allow a better delineation of the role of chemotherapy in LGGs and will also help to better determine the potential predictive value of a 1p/19q codeletion, a MGMT promoter methylation and an IDH1 mutation.