East meets West for the treatment of glioma: A discussion of real-world cases

Abstract

Background and Aim: The standard of care for patients with gliomas should follow established guidelines. In real-world management, however, the management sometimes deviates from these guidelines. We organized a discussion of real-world clinical cases and summarized different considerations from Chinese and European specialists.Case Presentation: A multidisciplinary team comprising experts from Europe and China discussed two patients with glioma treated at Sun Yat-sen University Cancer Center and Liaoning Cancer Hospital and Institute, China. Patient 1 was a 43-year-old man with a recurrent oligodendroglioma in the left frontal lobe diagnosed based on histology alone. He had undergone a biopsy and was diagnosed with an oligodendroglioma 3 years previously. He underwent chemoradiotherapy followed by 12 cycles of chemotherapy with temozolomide (TMZ), and complete remission was achieved. However, the tumor recurred within a short period of time and was resected by a second surgery. The pathologic diagnosis of the recurrent tumor was a glioblastoma because 1p/19q was intact when detected by sequencing. Pathologic consultation from another hospital still considered an anaplastic oligodendroglioma based on the positive result of 1p19q loss of heterozygosity (LOH) determined by fluorescence in situ hybridization. Patient 2 was a 50-year-old man with a left temporal glioblastoma. He underwent tumor resection but no radiotherapy. After seven cycles of TMZ (5/28-day regimen), his symptoms deteriorated, and his treatment was changed to a TMZ dose-dense regimen (7 days on/7 days off) and bevacizumab (7.5 mg/kg every 2 weeks), plus tumor-treating field therapy. Consultation Results: The pathological diagnosis based on biopsy for Patient 1 was an oligodendroglioma (World Health Organization Grade II), whereas the result of the second surgical sample was glioblastoma or anaplastic oligodendroglioma (questionable). Although the accuracy of fluorescence in situ hybridization for the detection of 1p/19q LOH requires improvement, 1p/19q LOH is typically not reconstituted in oligodendroglioma. More likely, it was due to sampling; a positive observation field may be missed with consequent negative results, and both oligodendroglioma (with 1p/19q co-deletion and isocitrate dehydrogenase mutation) and astrocytoma (without 1p/19q co-deletion) may exist. With respect to further treatment for cases such as Patient 1, both Chinese and European experts agree that procarbazine + lomustine chemotherapy is appropriate, while re-irradiation is suggested only if the tumor recurs outside the original radiotherapy field or within the radiotherapy field in the future. Considering the medical history, the rapid tumor regrowth without postoperative radiotherapy in Patient 2 was not surprising. After application of a rescue treatment regimen, the general condition of the patient improved, which may have resulted from the bevacizumab. A consensus was reached between the Chinese and European experts regarding subsequent treatment of Patient 2. Continuation of TMZ and bevacizumab was suggested until further deterioration. Whether tumor-treating field therapy should play a role in this patient could not be evaluated. However, some other molecular targeted agents (e.g. vascular endothelial growth factor receptor tyrosine kinase inhibitors such as regorafenib or apatinib) after bevacizumab failure, the effectiveness of these drugs remains unclear. Conclusion: In clinical practice, although we should follow established guidelines, the final treatment regimen requires informed consent from the patient. Thus, some real-world cases may deviate from the established guidelines. When patients reach end-stage disease with a marked decrease in their performance status and no standard treatment options, active antitumor treatment might be more likely to be attempted in China, while symptomatic treatment is more frequently performed in Europe. Although treatment philosophies for patients with glioma are slightly different between Eastern and Western medical experts, any treatment strategies should satisfy these patients.