Ki-67 expression in astrocytomas
Objective: To apply immunohistochemical marker Ki-67 and to check it’s expression in various types of Astrocytomas according to their grades.
Methodology: The cross sectional study was conducted in Pathology department, Federal Government Services Hospital (Polyclinic), Islamabad from July to December 2015. All patients having diagnosis of astrocytomas grade II, III and IV on histopathology were included in the study. Microscopic examinations were carried out for accurate diagnosis and grading of astrocytomas. Immunohistochemical staining for Ki-67 was done and the percentage of cells with positive Ki-67 nuclear staining was determined. Quotients (positively stained tumor cells/totally counted tumor cells) were calculated as percentage and rounded to nearest integer.
Result: A total of 212 patients were included in the study. The mean age of the patients was 40.16 ± 12.763 years (Range 20 to 76 years). Majority of the patients (32%) were in age range of 30-40 years. In this study, 110 of 212 patients (51.9%) were males while 102 patients (48.1%) were females. Among the three types of Astrocytomas, Glioblastoma multiforme (WHO grade IV) was the most common variant. Overall Ki-67 staining was positive in 168 of 212 specimens (79.2%) and most commonly was in Glioblastoma multiforme WHO grade IV being 96.3%. Stratification of Ki-67 expression in tumors was also done according to age and gender of cases. P-value was found significant after stratification (P <0.05)
Conclusion: Ki-67 staining was positive in 79.2% cases of Astrocytomas and most commonly (96.3%) positivity was in Glioblastoma multiforme WHO grade IV. Increasing values of Ki-67 are associated with increasing grade of malignancy.