H3K27M and promoter mutations are poor prognostic factors in surgical cases of adult thalamic high-grade glioma.

BACKGROUND

Thalamic high-grade gliomas (HGGs) are rare tumors with a dismal prognosis. H3K27M and telomerase reverse transcriptase promoter () mutations reportedly contribute to poor prognoses in HGG cases. We investigated the outcomes of surgically treated adult thalamic HGGs to evaluate the prognostic significance of H3K27M and mutations.

METHODS

We retrospectively analyzed 25 adult patients with thalamic HGG who underwent maximum surgical resection from January 1997 to March 2020. The histological and molecular characteristics, progression-free survival (PFS), and overall survival (OS) of the patients were compared. For molecular characteristics, target sequencing was used to determine the , , and mutations.

RESULTS

H3K27M mutations were detected in 12/25 (48.0%) patients. mutations were not detected in H3K27M-mutant gliomas but were detected in 8/13 (61.5%) of H3 wild-type gliomas. Although it was not significant, H3K27M-mutant gliomas tended to have a shorter PFS (6.7 vs 13.1 months; = .2928) and OS (22.8 vs 24.4 months; = .2875) than H3 wild-type gliomas. Moreover, the prognosis of -mutant gliomas was as poor as that of H3K27M-mutant gliomas. Contrary, 5 gliomas harboring both H3 and wild-type showed a better median PFS (59.2 vs 6.4 months; = .0456) and OS (71.8 vs 24.4 months; = .1168) than those harboring H3K27M or mutations.

CONCLUSIONS

-mutant gliomas included in the H3 wild-type glioma group limited patient survival as they exhibited an aggressive course similar to H3K27M-mutant gliomas. Comprehensive molecular work-up for the H3 wild-type cases may further confirm this finding.