Gemistocytes in astrocytomas: are they a significant prognostic factor?

Our aim was to retrospectively evaluate the influence of gemistocytic astrocytes, cellular proliferation indices, immunoexpression of proteins p53 and bcl-2 in the clinical outcome of 39 patients with WHO grade II and III astrocytomas with the presence of gemistocytes. The mean proportion of gemistocytes was 18.7% and the mean proliferative index was 3.3%. Immunoexpression of p53 was detected in 29 cases (74.4%) and all cases (100%) were positive for bcl-2. The median overall survival was 97.2 months and the progression-free survival was 43.1 months. Estimated 1-, 5- and 10-year overall survival rates were 94.3%, 69.5% and 46.4%; 1-, 5- and 10-year progression-free survival rates were 91.1%, 26.1% and 13.1%. Out of 24 who presented clinical and neuroimaging worsening, characterized as tumor progression or recurrence, 16 had histological confirmation and were also analyzed. We could not detect significant differences when comparing all the indices between WHO grade II and III and also between the first and second biopsies. We also could not detect significant differences in progression-free and overall survival when analyzing the gemistocyte index and the immunohistochemical labeling indices p53, bcl-2 and MIB-1, as well as patientsa9 age (median value, up to 34 vs. over 34 years) and histological grade (II or III). Our finding confirms recent reports that question the role of gemistocytes as a prognostic factor in diffuse astrocytomas. The significance and role of gemistocytes in astrocytomas has yet to be defined and warrants further study.