Tumor Location and Survival Outcomes in Adult Patients with Supratentorial Glioblastoma by Levels of Toll-Like Receptor 9 Expression

Abstract

Toll-like receptor 9 (TLR9) is a key immunotherapy target for glioblastoma (GBM). This study explored the correlation of TLR9 expression with tumor location and survival outcomes in patients with supratentorial GBM. We retrospectively identified 46 patients with supratentorial GBMs and divided them into those with high TLR9 (TRL9High) and low TLR9 (TRL9Low) levels. The 2 groups were compared by patients' ages, sex, preoperative Karnofsky Performance Scale (KPS) score, resection extent, tumor location, progression-free survival (PFS), and overall survival (OS). The TLR9 expression percentages for the GBM specimens were TRL9High: 72% (33/46) and TRL9Low: 28% (13/46). The 2 groups showed no differences in patient age (P= 0.147) and sex (χ2= 0.002, P= 0.966), preoperative KPS score (χ2= 0.033, P= 0.855), or resection extent (χ2= 2.405, P= 0.121). Location differed significantly, with 85% (11/13) of TRL9Low tumors in the left hemisphere and 45% (15/33) of TRL9High tumors on the same side (χ2= 5.82, P= 0.016). The TRL9Low group had a median PFS of 612 days (range, 77-926 days), significantly longer than the TRL9High group (355 days; range, 105-861 days; P= 0.042). Median OS of the TRL9Low group (733 days; range, 163-969 days) was also significantly longer than in the TRL9High group (396 days; range, 135-1024 days; P= 0.020). Patients with TRL9Low supratentorial GBM tend to have longer survival than those with higher TLR9 expression. Such tumors show a location preference for the left hemisphere.