Relationship between molecular characteristics of glioblastoma multiforme and the subventricular zone.

OBJECTIVE

This study aims to assess the relationship between the molecular characteristics of glioblastoma multiforme (GBM) and the subventricular zone (SVZ).

MATERIAL AND METHODS

Eligible patients had their data anonymously collected from an institutional database, including age, sex, preoperative performance status, the extent of tumour resection, anatomical location, mutation and methylation status. An Institutional picture archiving and communications system was used for volumetric and morphometric analysis. All measurements were made on T1-weighted magnetic resonance images with gadolinium contrast enhancement. wild-type and mutant GBMs were stratified by methylation status. The relationship between tumour volume, distance from the tumour's enhancing edge and the tumour's geometric centre to the SVZ and their molecular characteristics were assessed.

RESULTS

Fifty wild-type GBMs were studied. Twenty-three were methylated, Twenty-seven were unmethylated. wild-type methylated GBMs were significantly associated with a tumour's enhancing boundary being contiguous to the SVZ ( < 0.001). Ninety percent of tumours contiguous to the SVZ were wild-type methylated ( = 18) and 10% were unmethylated ( = 2). Mean GBM geometric centre distance to SVZ was significantly less for methylated wild-type GBMs compared to unmethylated ( = 0.025) and median GBM distance from the tumour's edge of enhancement to the SVZ was significantly shorter in methylated tumours compared to unmethylated ( < 0.001). Mean and median distances to SVZ from the edge of enhancement was 3.8 millimetres (mm) and 0 mm, respectively, for wild-type methylated GBMs, while for unmethylated wild-types, 14.6 mm, and 12.5 mm. There was no anatomical localisation of wild-type GBMs by methylation status to a cerebral hemisphere or lobe.

CONCLUSION

wild-type GBMs contiguous to the SVZ are highly likely to be methylated. Replication by further studies is required to affirm our results and conclusion.