INI1 immunohistochemical expression in glioblastoma: correlation with MGMT gene promoter methylation status and patient survival

Summary Aims INI1 expression and its correlation with MGMT gene promoter methylation status and follow-up was investigated in 77 surgically removed glioblastomas then treated with radiotherapy (RT) or RT plus temozolomide (RT+TMZ). Methods INI1 was determined by immunohistochemistry and MGMT by methylation-specific PCR. Results INI1 was expressed in 83.1% of cases. The median overall survival (OS) was 13.6 months in INI1 positive tumours and 7.2 months in INI1 negative tumours; 31.3% of patients with INI1 positive tumours were alive compared with 15.4% of patients with INI1 negative tumours. MGMT methylation was detected in 31.2% of cases. OS was significantly different between patients with methylated tumours and unmethylated tumours (p 0.04), and between patients with RT+TMZ and RT alone (p Conclusions Loss of INI1 immunohistochemical expression in glioblastoma may be indicating an underlying molecular aberration accounting for the more aggressive clinical behaviour.