Immunohistochemical expression of p53 and p21 in gliomas: a clinicopathological study

Background and objective: To evaluate p53 and p21 proteins over expression in gliomas and their relation to some clinico-pathological parameters. Methods: From September 2009 to July 2010, a formalin fixed, paraffin embedded blocks of 60 gliomas cases were collected in addition to 44 astrocytomas, 5 oligodendrogliomas, 2 oligoastrocytomas, and 9 ependymomas. These cases were evaluated by immunohistochemistry using streptavidin-biotin method. Results: Overall, 53% of gliomas were positive for p53; these cases formed 66% of astrocytomas, 20% of oligodendrogliomas and 100% of oligoastrocytomas. In contrast to astrocytomas, all ependymoma cases were negative for p53 protein. There was a significant association of p53 expression with patient’s age and tumor site. On the other hand, p21 expression was positive in 25% of gliomas; they comprised 23% of astrocytomas, 40% of oligodendrogliomas, 50% of oligoastrocytomas and 22% of ependymomas. Both p53 and p21 expressions seemed to be raising from low to high grades astrocytoma but they did not reach level of significance. Conclusion: The results of the present study suggest that p53 overexpression is common in gliomas and p21 expression is less common. There was a trend of both marker expressions increasing with higher grades.