Prognostic Effect of Immunohistochemical Scoring on Survival in Glioblastoma.

Objectives: We aimed to show whether the scoring system we developed using IDH, p53 and Ki-67 markers has a prognostic feature on survival in glioblastoma. Methods: Retrospective screening was conducted on 109 patients who were followed up in our clinic. IHC scoring was performed from pathology reports. Results: Fifty-five patients (50.5%) were IDH Wild, 44 (40.4%) of them were p53 mutant, and 51 (46.8%) of them were Ki-67 >30 status. Median PFS was 6.2 months (95% CI: 5.7-6.8 months), and median OS was 10.1 months (95% CI: 7.6-12.5 months). In multivariate analysis p53 status was independent prognostic factor for both PFS and OS [(HR: 2.03 (1.14-3.61), p=0.02) and (HR: 1.86 (1.03-3.36), p=0.04), respectively]. However, Ki-67 status was an independent prognostic factor for only OS [HR: 1.94 (1.02-3.69), p=0.04]. When the patients were examined by dividing them into four IHC score groups for the combined prognostic value of IDH, p53, and Ki-67 status; differences between group 0 and the others were statistically significant. Conclusion: This study demonstrated that p53 and Ki-67 are useful, independent prognostic markers for GBM patients. Furthermore, the combined use of these three IHC markers is a statistically significant indicator for PFS and OS. [ABSTRACT FROM AUTHOR]