Role of delayed salvage bevacizumab at symptomatic progression of chemorefractory glioblastoma

Hypofractionated re-irradiation with bevacizumab for relapsed chemorefractory glioblastoma after prior high dose radiotherapy: a feasible option for patients with large-volume relapse

PURPOSE

There remains no standard of care for patients with recurrent and chemorefractory glioblastoma. Re-irradiation (reRT) provides an additional management option. However, published series predominantly focus on small reRT volumes utilizing stereotactic hypofractionated regimens. Concerns regarding toxicity have limited utilisation of reRT for larger recurrences, however this may be mitigated with use of bevacizumab (BEV).

METHODS AND MATERIALS

A prospective database of patients managed with the EORTC-NCIC (Stupp) protocol 60 Gy chemoradiotherapy protocol for glioblastoma between 2007 and 2021 was reviewed for those patients receiving reRT for chemorefractory relapse. Serial MRI and PET were used to establish true progression and exclude patients with pseudoprogression or radionecrosis from reRT. The primary endpoint was overall survival (OS) from date of reRT. Prognostic factors were also assessed.

RESULTS

447 patients managed for glioblastoma under the Stupp protocol were identified, of which 372 had relapsed and were thus eligible for reRT. 71 patients underwent reRT. Median relapse-free survival from diagnosis for the reRT and overall cohorts were similar at 11.6 months (95%CI:9.4-14.2) and 11.8 months (95%CI:9.4-14.2) respectively. 60/71 (85%) reRT patients had received BEV prior to reRT and continued concurrent BEV during reRT. Of the 11 patients not managed with BEV during reRT, 10 required subsequent salvage BEV. ReRT patients were younger (median 53 vs. 59 years, p < 0.001), had better performance status (86% vs. 69% ECOG 0-1, p = 0.002) and more commonly had MGMT promoter-methylated tumours (54% vs. 40%, p = 0.083) compared to non-reRT patients. Median reRT PTV volume was 135cm3 (IQR: 69-207cm3). Median OS from reRT to death was 7.1 months (95%CI:6.3-7.9). Patients aged < 50, 50-70 and > 70 years had post-reRT median OS of 7.7, 6.4 and 6.0 months respectively (p = 0.021). Median post-reRT survival was longer for patients with ECOG performance status 0-1 compared to 2-3 (8.1 vs. 6.3 months, p = 0.039). PTV volume, site of relapse, MGMT promoter-methylation status and extent of initial surgical resection were not associated with post-reRT survival. ReRT was well-tolerated. Out of the 6 patients (8%) admitted to hospital after reRT, only one was for reRT toxicity. This was a CTCAE grade 3 radiation necrosis event in a patient managed without prior BEV.

CONCLUSION

Patients with recurrent glioblastoma who have been previously treated with 60 Gy radiotherapy have a meaningful survival benefit from large volume re-irradiation which is well tolerated. ReRT should not be ignored as a salvage treatment option in patients with chemorefractory progressive disease.

Proteomic analysis predicts anti-angiogenic resistance in recurred glioblastoma

BACKGROUND

Recurrence is common in glioblastoma multiforme (GBM) because of the infiltrative, residual cells in the tumor margin. Standard therapy for GBM consists of surgical resection followed by chemotherapy and radiotherapy, but the median survival of GBM patients remains poor (~ 1.5 years). For recurrent GBM, anti-angiogenic treatment is one of the common treatment approaches. However, current anti-angiogenic treatment modalities are not satisfactory because of the resistance to anti-angiogenic agents in some patients. Therefore, we sought to identify novel prognostic biomarkers that can predict the therapeutic response to anti-angiogenic agents in patients with recurrent glioblastoma.

METHODS

We selected patients with recurrent GBM who were treated with anti-angiogenic agents and classified them into responders and non-responders to anti-angiogenic therapy. Then, we performed proteomic analysis using liquid-chromatography mass spectrometry (LC-MS) with formalin-fixed paraffin-embedded (FFPE) tissues obtained from surgical specimens. We conducted a gene-ontology (GO) analysis based on protein abundance in the responder and non-responder groups. Based on the LC-MS and GO analysis results, we identified potential predictive biomarkers for anti-angiogenic therapy and validated them in recurrent glioblastoma patients.

RESULTS

In the mass spectrometry-based approach, 4957 unique proteins were quantified with high confidence across clinical parameters. Unsupervised clustering analysis highlighted distinct proteomic patterns (n = 269 proteins) between responders and non-responders. The GO term enrichment analysis revealed a cluster of genes related to immune cell-related pathways (e.g., TMEM173, FADD, CD99) in the responder group, whereas the non-responder group had a high expression of genes related to nuclear replisome (POLD) and damaged DNA binding (ERCC2). Immunohistochemistry of these biomarkers showed that the expression levels of TMEM173 and FADD were significantly associated with the overall survival and progression-free survival of patients with recurrent GBM.

CONCLUSIONS

The candidate biomarkers identified in our protein analysis may be useful for predicting the clinical response to anti-angiogenic agents in patients with recurred GBM.

Treatment options for progression or recurrence of glioblastoma: a network meta-analysis

BACKGROUND

Glioblastoma (GBM) is a highly malignant brain tumour that almost inevitably progresses or recurs after first line standard of care. There is no consensus regarding the best treatment/s to offer people upon disease progression or recurrence. For the purposes of this review, progression and recurrence are considered as one entity.

OBJECTIVES

To evaluate the effectiveness of further treatment/s for first and subsequent progression or recurrence of glioblastoma (GBM) among people who have received the standard of care (Stupp protocol) for primary treatment of the disease; and to prepare a brief economic commentary on the available evidence.

SEARCH METHODS

We searched MEDLINE and Embase electronic databases from 2005 to December 2019 and the Cochrane Central Register of Controlled Trials (CENTRAL, in the Cochrane Library; Issue 12, 2019). Economic searches included the National Health Service Economic Evaluation Database (NHS EED) up to 2015 (database closure) and MEDLINE and Embase from 2015 to December 2019.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and comparative non-randomised studies (NRSs) evaluating effectiveness of treatments for progressive/recurrent GBM. Eligible studies included people with progressive or recurrent GBM who had received first line radiotherapy with concomitant and adjuvant temozolomide (TMZ).

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies and extracted data to a pre-designed data extraction form. We conducted network meta-analyses (NMA) and ranked treatments according to effectiveness for each outcome using the random-effects model and Stata software (version 15). We rated the certainty of evidence using the GRADE approach.

MAIN RESULTS

We included 42 studies: these comprised 34 randomised controlled trials (RCTs) and 8 non-randomised studies (NRSs) involving 5236 participants. We judged most RCTs to be at a low risk of bias and NRSs at high risk of bias. Interventions included chemotherapy, re-operation, re-irradiation and novel therapies either used alone or in combination. For first recurrence, we included 11 interventions in the network meta-analysis (NMA) for overall survival (OS), and eight in the NMA for progression-free survival (PFS). Lomustine (LOM; also known as CCNU) was the most common comparator and was used as the reference treatment. No studies in the NMA evaluated surgery, re-irradiation, PCV (procarbazine, lomustine, vincristine), TMZ re-challenge or best supportive care. We could not perform NMA for second or later recurrence due to insufficient data. Quality-of-life data were sparse. First recurrence (NMA findings) Median OS across included studies in the NMA ranged from 5.5 to 12.6 months and median progression-free survival (PFS) ranged from 1.5 months to 4.2 months. We found no high-certainty evidence that any treatments tested were better than lomustine. These treatments included the following. Bevacizumab plus lomustine: Evidence suggested probably little or no difference in OS between bevacizumab (BEV) combined with lomustine (LOM) and LOM monotherapy (hazard ratio (HR) 0.91, 0.75 to 1.10; moderate-certainty evidence), although BEV + LOM may improve PFS (HR 0.57, 95% confidence interval (CI) 0.44 to 0.74; low-certainty evidence). Bevacizumab monotherapy: Low-certainty evidence suggested there may be little or no difference in OS (HR 1.22, 95% CI 0.84 to 1.76) and PFS (HR 0.90, 95% CI 0.58 to 1.38; low-certainty evidence) between BEV and LOM monotherapies; more evidence on BEV is needed. Regorafenib (REG): REG may improve OS compared with LOM (HR 0.50, 95% CI 0.33 to 0.76; low-certainty evidence). Evidence on PFS was very low certainty and more evidence on REG is needed. Temozolomide (TMZ) plus Depatux-M (ABT414): For OS, low-certainty evidence suggested that TMZ plus ABT414 may be more effective than LOM (HR 0.66, 95% CI 0.47 to 0.92) and may be more effective than BEV (HR 0.54, 95% CI 0.33 to 0.89; low-certainty evidence). This may be due to the TMZ component only and more evidence is needed. Fotemustine (FOM): FOM and LOM may have similar effects on OS (HR 0.89, 95% CI 0.51 to 1.57, low-certainty evidence). Bevacizumab and irinotecan (IRI): Evidence on BEV + irinotecan (IRI) versus LOM for both OS and PFS is very uncertain and there is probably little or no difference between BEV + IRI versus BEV monotherapy (OS: HR 0.95, 95% CI 0.70 to 1.30; moderate-certainty evidence). When treatments were ranked for OS, FOM ranked first, BEV + LOM second, LOM third, BEV + IRI fourth, and BEV fifth. Ranking does not take into account the certainty of the evidence, which also suggests there may be little or no difference between FOM and LOM. Other treatments Three studies evaluated re-operation versus no re-operation, with or without re-irradiation and chemotherapy, and these suggested possible survival advantages with re-operation within the context of being able to select suitable candidates for re-operation. A cannabinoid treatment in the early stages of evaluation, in combination with TMZ, merits further evaluation. Second or later recurrence Limited evidence from three heterogeneous studies suggested that radiotherapy with or without BEV may have a beneficial effect on survival but more evidence is needed. Evidence was insufficient to draw conclusions about the best radiotherapy dosage. Other evidence suggested that there may be little difference in survival with tumour-treating fields compared with physician's best choice of treatment. We found no reliable evidence on best supportive care. Severe adverse events (SAEs) The BEV+LOM combination was associated with significantly greater risk of SAEs than LOM monotherapy (RR 2.51, 95% CI 1.72 to 3.66, high-certainty evidence), and ranked joint worst with cediranib + LOM (RR 2.51, 95% CI 1.29 to 4.90; high-certainty evidence). LOM ranked best and REG ranked second best. Adding novel treatments to BEV was generally associated with a higher risk of severe adverse events compared with BEV alone.

AUTHORS' CONCLUSIONS

For treatment of first recurrence of GBM, among people previously treated with surgery and standard chemoradiotherapy, the combination treatments evaluated did not improve overall survival compared with LOM monotherapy and were often associated with a higher risk of severe adverse events. Limited evidence suggested that re-operation with or without re-irradiation and chemotherapy may be suitable for selected candidates. Evidence on second recurrence is sparse. Re-irradiation with or without bevacizumab may be of value in selected individuals, but more evidence is needed.

Characterization of serial hyperpolarized 13C metabolic imaging in patients with glioma

•

Serial HP ¹³C MRI was evaluated for data consistency and abnormal metabolism.

•

Metabolism of [1-¹³C]pyruvate to lactate and bicarbonate was kinetically modeled.

•

Conversion rates within NAWM were consistent in healthy volunteer and patient scans

•

Progressed tumor lesions showed higher relative conversion rates to [1-¹³C]lactate.

•

Globally elevated rate constants were observed with anti-angiogenic treatment.

Background

Hyperpolarized carbon-13 (HP-¹³C) MRI is a non-invasive imaging technique for probing brain metabolism, which may improve clinical cancer surveillance. This work aimed to characterize the consistency of serial HP-¹³C imaging in patients undergoing treatment for brain tumors and determine whether there is evidence of aberrant metabolism in the tumor lesion compared to normal-appearing tissue.

Methods

Serial dynamic HP [1-¹³C]pyruvate MRI was performed on 3 healthy volunteers (6 total examinations) and 5 patients (21 total examinations) with diffuse infiltrating glioma during their course of treatment, using a frequency-selective echo-planar imaging (EPI) sequence. HP-¹³C imaging at routine clinical timepoints overlapped treatment, including radiotherapy (RT), temozolomide (TMZ) chemotherapy, and anti-angiogenic/investigational agents. Apparent rate constants for [1-¹³C]pyruvate conversion to [1-¹³C]lactate (k_PL) and [¹³C]bicarbonate (k_PB) were simultaneously quantified based on an inputless kinetic model within normal-appearing white matter (NAWM) and anatomic lesions defined from ¹H MRI. The inter/intra-subject consistency of k_PL-NAWM and k_PB-NAWM was measured in terms of the coefficient of variation (CV).

Results

When excluding scans following anti-angiogenic therapy, patient values of k_PL-NAWM and k_PB-NAWM were 0.020 s⁻¹ ± 23.8% and 0.0058 s⁻¹ ± 27.7% (mean ± CV) across 17 HP-¹³C MRIs, with intra-patient serial k_PL-NAWM/k_PB-NAWM CVs ranging 6.8–16.6%/10.6–40.7%. In 4/5 patients, these values (0.018 s⁻¹ ± 13.4% and 0.0058 s⁻¹ ± 24.4%; n = 13) were more similar to those from healthy volunteers (0.018 s⁻¹ ± 5.0% and 0.0043 s⁻¹ ± 12.6%; n = 6) (mean ± CV). The anti-angiogenic agent bevacizumab was associated with global elevations in apparent rate constants, with maximum k_PL-NAWM in 2 patients reaching 0.047 ± 0.001 and 0.047 ± 0.003 s⁻¹ (±model error). In 3 patients with progressive disease, anatomic lesions showed elevated k_PL relative to k_PL-NAWM of 0.024 ± 0.001 s⁻¹ (±model error) in the absence of gadolinium enhancement, and 0.032 ± 0.008, 0.040 ± 0.003 and 0.041 ± 0.009 s⁻¹ with gadolinium enhancement. The lesion k_PB in patients was reduced to unquantifiable values compared to k_PB-NAWM.

Conclusion

Serial measures of HP [1-¹³C]pyruvate metabolism displayed consistency in the NAWM of healthy volunteers and patients. Both k_PL and k_PB were globally elevated following bevacizumab treatment, while progressive disease demonstrated elevated k_PL in gadolinium-enhancing and non-enhancing lesions. Larger prospective studies with homogeneous patient populations are planned to evaluate metabolic changes following treatment.

Epithelioid glioblastoma presenting as multicentric glioma: A case report and review of the literature

Background:

Epithelioid glioblastoma is a rare aggressive variant of glioblastoma multiforme (GBM), which was formally recognized by the World Health Organization classification of the central nervous system in 2016. Clinically, epithelioid GBMs are characterized by aggressive features, such as metastases and cerebrospinal fluid dissemination, and an extremely poor prognosis. A rare case of epithelioid GBM that was discovered as a multicentric glioma with different histopathology is reported.

Case Description:

A 78-year-old man was admitted to our hospital with mild motor weakness of the right leg. Neuroimaging showed small masses in the left frontal and parietal lobes on magnetic resonance imaging. The abnormal lesion had been increasing rapidly for 3 weeks, and a new lesion appeared in the frontal lobe. 11C-methionine positron emission tomography (PET) showed abnormal uptake corresponding to the lesion. To reach a definitive diagnosis, surgical excision of the right frontal mass lesion was performed. Histological findings showed diffuse astrocytoma. Only radiotherapy was planned, but the left frontal and parietal tumors progressed further within a short period. Therefore, it was thought that these tumors were GBM, and a biopsy of the left parietal tumor was performed. The histological diagnosis was epithelioid GBM. Immunohistochemistry showed that most tumor cells were negatively stained for p53 and isocitrate dehydrogenase 1. BRAF V600E mutations were not identified, but TERT promoter mutations were identified. Immediately after surgery, the patient was given chemotherapy using temozolomide, extended local radiotherapy and then bevacizumab. After 6 months, he showed no signs of recurrence.

Conclusion:

Epithelioid GBM is one of the rarest morphologic subtypes of GBM and has a strongly infiltrative and aggressive nature. Therefore, careful identification of preoperative imaging studies and detailed evaluation of genetic studies are necessary to select the appropriate treatment for epithelioid GBM.