Cell kinetic analysis in recurrent neuro-epithelial tumours.

The biological behaviour of brain tumours is variable. In the majority of cases, recurrence of the tumour is the decisive factor determining the prognosis and individual survival of patients suffering from a neuro-epithelial neoplasm. The time course of recurrences varies significantly according to differences in tumour cell proliferation. In this study, predictive factors concerning the expected prognosis following the resection of neuro-epithelial tumours were investigated with the aim of improving the histological diagnosis. A retrospective analysis of 22 recurrent neuro-epithelial tumours (recurrent tumour group) and 12 neuro-epithelial tumours with a minimum survival rate of 5 years following radical excision (cured tumour group) was performed by means of flow cytometry and immunohistochemistry using the MIB 1 antibody. Histological samples of the subgroups of the recurrent tumour group, i. e., the primary tumours and their recurrences were compared with each other, and the subgroups were compared with the cured tumour group. A multivariate analysis of the data was performed with the BMPD Hotteling T square test. A statistically significant difference was found between the recurrent tumour group (primary tumours + recurrences) and the cured group from every investigated aspect. On the other hand, no difference could be found between the sub-groups primary tumours and their recurrences. All tumours in the recurrent group had an accelerated, active cell cycle, which was expressed in a high proliferation activity. The following conclusion was drawn: an increased risk of recurrence is to be expected in neuro-epithelial tumours characterized by: an S-phase fraction higher than 6-9%, an MIB 1-labelled cell number higher than 2-3/high-power fields, and a number of mitoses higher than 1/10 high-power fields.