Ki‐67 immunolabelling index is a prognostic indicator in childhood posterior fossa ependymomas

Abstract

Conventional histological evaluation and subclassification of childhood ependymomas poorly predict their biological behaviour. The Ki‐67 labelling index (Ki‐67 LI), a measure of growth fraction, correlates with the biological behaviour of several neoplasms, and this retrospective study tested the hypothesis that Ki‐67 LI is a prognostic indicator in childhood posterior fossa ependymomas. Immunocytochemistry using an antibody to Ki‐67 was undertaken on 5 μm sections of formalin‐fixed, paraffin‐embedded tissue from 74 cases of childhood (age PPP<0.01). Age, sex, and the presence of necrosis or microvascular proliferation did not correlate with survival. In our defined population of patients with ependymomas, Ki‐67 LI is a strong prognostic indicator. We recommend that Ki‐67 LI is used in the histological evaluation of childhood posterior fossa ependymomas during trials of novel adjunctive therapies.