Irradiation of Cancer Stem Cell Niches Improves Glioblastoma Patient Survival

Researchers at the University of California, Department of Radiation Oncology, have conducted a study on the irradiation of potential cancer stem cell niches in the adult brain, which may improve progression-free survival of patients with malignant glioma. The study, published in Bmc Cancer, found that higher radiation doses to the subventricular zone (SVZ) and subgranular layer (SGL) improved patient survival by eradicating cancer stem cells. This suggests that targeting these niches with radiotherapy could yield significant benefits over treating the primary tumor mass alone.

Key Takeaways:

• The study involved 55 adult patients with Grade 3 or Grade 4 glial cancer treated with radiotherapy at UCLA between February 2003 and May 2009.
• Patients who received a bilateral SVZ dose greater than the median dose (43 Gy) had a significant improvement in progression-free survival compared to those who received less than the median dose (15.0 vs 7.2 months PFS, p=0.028).
• A mean dose of 43 Gy to the bilateral SVZ yielded a hazard ratio of 0.73 (p=0.019), suggesting that damage caused by smaller fractions of radiation may be less efficiently detected by DNA repair mechanisms in CSCs.
• The study's findings support the hypothesis that targeted radiotherapy of the stem cell niches in the adult brain could improve patient survival.
• The researchers propose that damage caused by smaller fractions of radiation may be less efficiently detected by DNA repair mechanisms in CSCs, leading to improved patient outcomes.

Statistics:

• 55 adult patients with Grade 3 or Grade 4 glial cancer were included in the study.
• Patients received radiotherapy at UCLA between February 2003 and May 2009.
• The median dose of SVZ radiation associated with improved progression-free survival was 43 Gy (15.0 months vs 7.2 months, p=0.028).
• A mean dose of 43 Gy to the bilateral SVZ yielded a hazard ratio of 0.73 (p=0.019).
• The study's findings suggest that higher radiation doses to the SVZ and SGL may improve patient survival by eradicating CSCs.

Sources:

• Evers, P. et al. "Irradiation of the potential cancer stem cell niches in the adult brain improves progression-free survival of patients with malignant glioma." Bmc Cancer, 2010;10():384.
• University of California, Department of Radiation Oncology
• Biomedical Central Ltd., Middlesex House, 34-42 Cleveland St., London W1T 4LB, England (publisher contact information for Bmc Cancer)