Hypoxia-inducible factor 1α expression is a prognostic biomarker in patients with astrocytic tumors associated with necrosis on MR image.

Hypoxia-inducible factor (HIF)-1α and HIF-2α expression were investigated immunohistochemically as determinants of prognosis in 42 cases of astrocytic tumors associated with necrosis grade on magnetic resonance (MR) imaging. Expression of HIF-1α was determined immunohistologically. The degree of necrosis on MR images was divided into four grades. Kaplan-Meier analysis revealed a significant effect of necrosis grade on MR images on cumulative overall survival. Median survival times were 26, 14, and 13 months for patients with necrosis grades 1, 2, and 3, respectively (not defined for grade 0). Kaplan-Meier analysis revealed a significant effect of HIF-1α expression on cumulative overall survival. Median survival time of patients with HIF-1α expression was 17 months, whereas it was 80 months for patients without HIF-1α expression. However, overexpression of HIF-2α did not correlate with malignant features, for example angiogenesis or necrosis, and had no impact on overall survival of patients with glial tumors. In conclusion, HIF-1α, but not HIF-2α, is a useful prognostic factor in astrocytic tumor associated with necrosis on MR images.