Immunohistochemical Expression of Ki-67, PCNA and CD34 in Astrocytomas: A Clinicopathological Study

To assess the immunohistochemical expression of Ki-67 and Proliferating Cell Nuclear Antigen (PCNA) as proliferative markers to study proliferative activity and CD34 as an endothelial cell marker in order to study vascular proliferation in astrocytomas in correlation with some clinicopathological parameters (age, gender, site of the tumor, and tumor grade).

A retrospective study wherein a total of 51 formalin-fixed paraffin-embedded brain astrocytoma excisional biopsies covering the period of June 2009 to February 2011 were retrieved from the archival materials of the Specialized Surgical Hospital in Medical City in Baghdad, Iraq. The histopathological diagnosis had been revised and all cases were stained by immunohistochemical technique with Ki-67, PCNA, and CD34 tumor markers. Values were considered statistically significant when p<0.05.

Fibrillary astrocytoma (WHO grade II) was found to be the most common type among astrocytic tumors with the peak age incidence of astrocytomas found in the second and fifth decades of life, and a slight male predominance had been identified. There was a significant correlation between the age of the patients and the grade of the tumor, Ki-67 and PCNA labeling indices, and microvessel density (MVD) detected by CD34 (p<0.05). There was a highly significant correlation between Ki-67 and PCNA labeling indices in astrocytomas (p<0.001).

A significant correlation was found between Ki-67, PCNA labeling indices, and MVD (microvessel density) detected by CD34, and between the clinicopathological variables of astrocytomas (age and grade of tumor). Hence, Ki-67 and PCNA, as markers for proliferation, and MVD as a marker of angiogenesis, could be used as ancillary methods in the differentiation of borderline grades of astrocytomas.