Birlik B et al. (2006) Tumour vascularity is of prognostic significance in adult, but not paediatric astrocytomas. Neuropathol Appl Neurobiol [doi: 10.1111/j.1365-2990.2006.00763.x]

Astrocytomas are the most common form of brain tumor in both adults and children, and are associated with a poor prognosis. A Turkish group has investigated whether tumor vascularity can predict prognosis in adults and children with this tumor type.

Birlik and colleagues enrolled 45 adults (aged 19–82 years) and 25 children (aged 1–16 years) with astrocytomas. They determined the vascularity of the tumors according to microvessel density, vascular grading and Chalkley counting. During a median follow-up of 12–24 months, 22 adults and 4 children died from disease progression. In univariate analysis, all three tumor vascularity parameters were significantly associated with postoperative survival in adults (P ≤0.005 for all). Higher-grade tumor histology in adults and older age in the overall group also correlated with reduced survival. In multivariate analysis, microvessel density was a significant independent prognostic indicator (P = 0.001); adults with microvessel density ≥70 per 200× field had significantly shorter survival than those with lower microvessel densities (P <0.001). By contrast, tumor histology and vascular parameters were not significantly associated with survival in children. The authors suggest that the observed differences between adults and children probably arise from biological variation in patients of different ages, relating to the ability of different tumors to induce angiogenesis.

The authors conclude that quantification of tumor vascularity may be useful in planning and monitoring antiangiogenic therapies for adult astrocytomas, but might not be of benefit in pediatric astrocytomas. This hypothesis needs confirming in further studies with longer follow-up in pediatric patients with high-grade astrocytomas.