Proliferating cell nuclear antigen immunostaining and survival in cerebral astrocytoma

In order to test the prognostic value of a proliferation index in cerebral astrocytoma, proliferating cell nuclear antigen immunostaining was performed on formalin-fixed and paraffin-embedded biopsies of 42 astrocytomas (21 serial stereotactic and 21 open surgical biopsies). Tumours were categorized as having a low (< 50%) or high (> 50%) labelling index. Tumour grading was also carried out. Several clinico-therapeutic factors were recorded. At least 40 months follow-up was available on all surviving patients. Survival estimated by the Kaplan and Meier method was significantly longer in tumours with a low proliferation index than in those with a high one (mean 20.4 months v. 10 months). According to Cox multiple regression analysis, the age of the patient and grading were significantly related to survival, whereas the proliferation index lost its significance.