Anatomical distribution and prognostic heterogeneity in glioma: unique clinical features of occipital glioblastoma.

Background: Adult-type diffuse gliomas, particularly IDH-wildtype glioblastoma, exhibit significant differences in incidence across brain regions, with the occipital lobe being the rarest location. However, whether occipital glioblastoma differs from tumour in other regions in terms of prognosis and biological characteristics remains poorly understood.

Methods: This study included a total of 7,583 adult-type diffuse glioma patients from the SEER database, two public glioma datasets (UCSF-PDGM and UPENN-GBM), and a private dataset (Beijing Tiantan Hospital). For imaging data, Tumour location was classified using the USCLobes atlas, and white matter Tract Density Index (TDI) was computed to assess structural infiltration. Survival analyses employed Cox models and propensity score matching (PSM), adjusting for age, resection extent, and other confounders.

Results: The occipital lobe was the least common location for adult-type diffuse glioma (p < 0.001). Multivariable analysis adjusting for extent of resection and other confounders demonstrated that occipital tumours retained a significant survival advantage (adjusted HR = 0.82, 95% CI: 0.69-0.97, p = 0.019), corroborated in PSM cohorts (median OS 14 vs. 13 months, p = 0.012) and validated across independent datasets (HR = 0.73, 95% CI: 0.55-0.97, p = 0.027). Occipital glioblastoma exhibited lower TDI (p < 0.001).

Conclusion: Occipital glioblastoma represents a distinct clinical entity associated with improved survival outcomes. This survival advantage may be attributed to reduced white matter tract infiltration. Future research should focus on the differences in biological characteristics and treatment strategies of gliomas at different locations.