Objective To analyze the clinicopathological characteristics and prognosis of oligodendroglioma with IDH mutation and 1p/19q codeletion.

Methods We collected the data of 54 oligodendroglioma patients with IDH mutation and 1p/19q codeletion.The patients'clinicopathological data, including age, histological grade, and tumor site, were analyzed for the effects on progression-free and overall survival.

Results Among the 54 patients, 46 cases were with tumor sites in one lobe, and eight cases involved tumor sites in more than two lobes.A total of 12 and 42 cases had WHO grades 2 and 3 oligodendroglioma, respectively.Detection by fluorescence in situ hybridization showed 1p/19q co-deletion in all cases.Immunohistochemical tests revealed diffuse and strong positive results for Olig2.All glial fibrillary acidic proteins were positive.p53 was strongly positive in six cases.ATRX was expressed in all 48 cases.Ki-67 proliferation index ranged from 5% to 60%.Sanger sequencing showed that all 54 cases had IDH gene mutations (40 cases were IDH1 mutations, and 14 were IDH2 mutations), and 33 cases had telomerase reverse transcriptase promoter mutations.Relapse and metastasis occurred in 16 patients during treatment.Univariate analysis indicated that the postoperative recurrence and metastasis interval of more than two years can prolong the progression-free and overall survival of patients.All 54 patients had a mean progression-free survival of 33.5 months and the mean overall survival of 40.7 months.

Conclusion For oligodendroglioma with IDH mutation and 1p/19q codeletion, precision chemoradiotherapy after surgery can reduce the risk of progression, and the postoperative recurrence and metastasis interval is associated with the prognosis.