|LETTER TO EDITOR
|Year : 2021 | Volume
| Issue : 3 | Page : 577-578
Recurrent glioblastoma and bevacizumab: Issues and prospects
Department of Radiotherapy, Mahavir Cancer Sansthan, Patna, Bihar, India
|Date of Submission||10-Aug-2021|
|Date of Decision||15-Aug-2021|
|Date of Acceptance||16-Aug-2021|
|Date of Web Publication||08-Oct-2021|
House No. N/35, Professor's Colony, Kankarbagh, Patna - 800 020, Bihar
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Chauhan R. Recurrent glioblastoma and bevacizumab: Issues and prospects. Cancer Res Stat Treat 2021;4:577-8
I read with great interest the article by D'souza et al. on the use of low-dose bevacizumab in patients with recurrent glioma. Regardless of receiving ideal multidisciplinary treatment, including maximal surgical resection, adjuvant radiation with concurrent temozolomide, followed by maintenance temozolomide, almost all patients with glioblastoma experience either progression or recurrence with a median survival of less than 15 months. Treatment options for such cases include surgery, re-irradiation, chemotherapy with concurrent irinotecan, lomustine, or temozolomide, monoclonal antibodies such as bevacizumab alone or in combination, tumor-treating fields, and best supportive care. Despite numerous clinical trials, no standard of care has been established for these patients.
As glioblastoma is a highly vascular tumor with an increased expression of vascular endothelial growth factor, the antiangiogenic drug bevacizumab has shown promising results in various doses and combinations. The efficacy, toxicities, and the cost factor of using bevacizumab in such patients have been well elaborated by Biswas in his accompanying editorial on bevacizumab in progressive or recurrent glioblastoma.
In a disease with dismal prognosis such as recurrent glioma, treatment should go beyond improving survival and should also aim at preserving the quality of life for both the patient and the caregivers by keeping the toxicities, including the financial toxicity as low as possible., In this context, I appreciate D'souza et al. for their study on the use of low-dose bevacizumab showing equivalent efficacy to the standard dose. I understand that, being a retrospective analysis, there are few limitations of the above study. The authors have not specified the criteria for defining recurrent gliomas, i.e., whether it was biopsy-proven or based on imaging and worsening of symptoms. Similarly, response evaluation has also not been well defined. Biopsy proof, though difficult and at times practically not possible, is important in trial settings as radiation-induced necrosis can mimic recurrence and it is difficult to differentiate between them on imaging.,, Further, low-dose bevacizumab is an effective treatment for radiation-induced necrosis as it prunes blood vessels, reduces vascular permeability in the necrotic brain tissue, and alleviates brain edema, thereby relieving the patient's symptoms. Hence, it might be a possibility that the patients responding to low-dose bevacizumab may actually have had radiation-induced necrosis. In addition, comparison of the standard-dose and low-dose bevacizumab arm to best supportive care would have showed the actual benefits of bevacizumab in cases of recurrent or progressive glioma.
To conclude, it can be said that although inhibition of angiogenesis for the treatment of cancer including recurrent glioma has successfully translated into few clinical benefits, the associated adverse events and high financial costs remain a challenge. Therefore, the identification and clinical application of cost-effective biomarkers, such as systemic hypertension and functional imaging that are able to identify patients who are more likely to benefit from the use of these molecules, is important. Future studies could stratify these patients on the basis of biomarkers of angiogenesis to receive either low-dose or standard-dose bevacizumab. Nonetheless, the study is an important one and will provide definite guidance while treating patients with recurrent or progressive glioblastoma, especially in resource-limited settings.
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Conflicts of interest
There are no conflicts of interest.
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