Comparison of clinical features and prognosis of oligodendroglioma versus astrocytoma

  Background  Glioma is the most common primary central system tumor in human. Among them, WHO grade 2 adult-type diffuse gliomas include oligodendroglioma and astrocytoma. The two types of tumors have different origins. Although surgery, radiotherapy and adjuvant temozolomide chemotherapy are currently used, there are differences in biological behavior, molecular pathology, sensitivity to radiotherapy and chemotherapy, and prognosis of the two groups.

  Objective  To explore the clinical features, molecular pathology results, prognosis, and adverse effects of temozolomide treatment of oligodendroglioma and astrocytoma, so as to provide a theoretical reference for optimizing the long-term temozolomide regimen for patients with low-grade glioma.

  Methods  Clinical data about 60 patients with low-grade (WHO class Ⅱ) glioma who underwent neurosurgical treatment and regular radiotherapy and chemotherapy (temozolomide for at least 3 cycles) in the First Medical Center of Chinese PLA General Hospital from January 2016 to June 2021 were retrospectively analyzed. Among them, 37 cases were simple oligodendroglioma and 23 cases were astrocytoma. The tumor invasion site, molecular pathological results, incidence of temozolomide adverse reactions, progression-free survival (PFS) and overall survival (OS) were compared between the two groups.

  Results  Compared with astrocytoma, oligodendroglioma had a higher frequency of MGMT promoter methylation (81.08% vs 56.52%, P=0.04), and longer PFS (P=0.034) and OS (P=0.028). However, oligodendroglioma and astrocytoma had no statistical difference in tumor invasion sites and incidence of TMZ side effects.

  Conclusion  Oligodendroglioma has better biological characteristics than astrocytoma. Patients with oligodendroglioma have longer progression-free survival and overall survival after the same total resection of tumor and postoperative radiotherapy and chemotherapy, but there is no difference in incidence of TMZ side effects.