Factors affecting survival in glioblastoma patients below and above 65 years of age: A retrospective observational study

Background: The purpose of this study is to identify the differences with respect to survival and prognostic factors in a comparison between radiotherapy-receiving glioblastoma (GBM) patients above and below 65 years of age. Methods: The results of 157 patients with GBM were analyzed retrospectively. Patients were divided into two groups as those below and above 65 years of age. A comparison was drawn with respect to each group's demographic characteristics, treatment methods, and findings. Results: Out of a total of 157 patients, 53 patients (33.8%) were above 65 years of age. Karnofsky performance status (KPS) was weaker among older patients (P = 0.002). On the other hand, with respect to radiotherapy dose, among older patient group, greater hypofractionation and whole-brain radiotherapy was applied (P = 0.003) compared with younger patients. The survival rates for 1, 2, and 5 years among patients aged <65 years were 63%, 30%, and 3%, respectively, and in patients aged >= 65 years were 43%, 13%, and 0%, respectively. In univariate analyses, a comparison between patients below and above 65 years of age revealed that values higher than 80 KPS (P = 0.002), applying total excision (P < 0.001), receiving concurrent chemotherapy (P = 0.004), receiving conventional radiotherapy (P < 0.001), and adjuvant chemotherapy (P < 0.001) were effective factors on overall survival rates. Conclusion: In the patient group above 65 years of age, the patient should be attentively selected before opting for a specific treatment, age alone should not be the sole determinant factor. Rather, by considering the KPS scores, potential aggressive treatment options should also be applied.