Histopathological investigation of the 1p/19q-codeleted gliomas resected following alkylating agent chemotherapy

Tokunori Kanazawa, Kentaro Ohara, Yohei Kitamura, Masato Nakaya, Kazunari Yoshida, Hikaru Sasaki

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)


Purpose: Lower grade gliomas with 1p/19q codeletion are often responsive to chemotherapy, and several of these have been treated using upfront chemotherapy and subsequent resection following tumor volume decrease. This study aimed to elucidate the histological changes and the mechanism of recurrence after alkylating agent chemotherapy in 1p/19-codeleted gliomas. Methods: Fourteen 1p/19q-codeleted gliomas resected following tumor volume decrease after alkylating agent chemotherapy were included and compared with their pre-chemotherapy specimens. Histological changes were investigated using hematoxylin–eosin staining, and changes in proliferative activity, status of glioma stem cells (GSCs), and tumor-infiltrating macrophages were assessed using immunohistochemistry for Ki-67/MIB-1, CD68 as a pan-macrophage/monocyte marker, CD163 as a presumed marker of M2 polarity, and nestin and CD133 as markers of GSCs. Results: The most frequent histological findings following chemotherapy included a sparse glial background and abundant foamy cell infiltration. The Ki-67/MIB-1 index decreased and the number of CD68 + cells increased after chemotherapy. The increasing rate of CD68 + cells in the post-/pre-chemotherapy specimens was inversely correlated with patient prognosis but not tumor response. The number of CD163 + cells, M2/M1 + M2 ratio, and the ratio of GSCs to total tumor cells increased after chemotherapy, and those in the post-chemotherapy specimens were negatively correlated with patient prognosis. There was a correlation between the M2/M1 + M2 ratio and the ratio of GSCs in both pre- and post-chemotherapy specimens. Conclusion: GSCs in conjunction with M2 macrophages constitute the mechanism of resistance to and recurrence after alkylating agent chemotherapy in 1p/19q-codeleted gliomas.

Original languageEnglish
Pages (from-to)235-246
Number of pages12
JournalJournal of Neuro-Oncology
Issue number3
Publication statusPublished - 2021 Dec


  • 1p/19q codeletion
  • Glioma stem cell
  • M2 macrophage
  • Neoadjuvant chemotherapy
  • PAV chemotherapy

ASJC Scopus subject areas

  • Oncology
  • Neurology
  • Clinical Neurology
  • Cancer Research


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