Butterfly Glioblastoma: Genetic alterations and outcomes

Butterfly glioblastoma (bGBM) is an aggressive variant of glioblastoma(GBM) characterized by invasion of both hemispheres through the corpus callosum.The cause of its poor prognosis remains unclear, whether due to complex anatomy orintrinsic molecular traits. In this cohort, we aim to identify the genetic features of bGBMand factors associated with its prognosis.

We retrospectively identified GBM patients from our institutional database and groupedthem into non-butterfly glioblastoma (non-bGBM) and bGBM. Clinical features,genomic profiles, and survival outcomes were compared using statistical analysis.

We analyzed 324 GBM patients, including 36 with bGBM. Confusion was a commonpresenting symptom in bGBM (p = 0.005), and these tumors rarely invaded thetemporal lobes (p = 0.0004). bGBM was associated with higher mutation rates in CDK6 (13.64% vs. 3.11%, p = 0.04), PIK3R1 (22.73% vs. 7.64%, p = 0.03), and TSC2 (9.09% vs. 0.69%, p = 0.02); however, these results were not significant after adjustment for multiple comparisons. Median overall survival was significantly shorter in bGBM patients.(9 months) compared to non-bGBM (18 months, p = 0.001).

This study provides novel insights into the genetic blueprint of bGBM. Further research with larger cohorts is needed to validate these findings and better understand the molecular features of bGBM.