Clinical prognostic factors of adjuvant radiation therapy for low-grade gliomas: results of 10 years survival

Objective: Low-grade gliomas compose 5-20% of all glial tumors. The prognosis of the disease can be anticipated by specific clinical factors determined during diagnosis. For this purpose, our study investigated the clinical prognostic factors for low-grade gliomas. Methods: Patients diagnosed with histopathologically confirmed low-grade glioma, followed by Akdeniz University and Suleyman Demirel University School of Medicine, Department of Radiation Oncology between 1999 and 2013 were included in the study. The examination of survival by single variable analyses were performed by log rank test. For the multivariate analysis, independent factors for the prediction of survival by using possible factors determined by previous analyses were examined by using Cox regression analysis. Results: Fifty-five patients were included in the study. The mean follow-up period was determined as 60 +/- 57 ( 4.5-168.1) months. Five-year overall survival was determined as 69% and 10-year overall survival was determined as 40%. When the potential prognostic factors were studied in Cox regression model, pre-radiotherapy age below 40 and gross-total excision were determined as good prognostic factors. Conclusion: We demonstrated that the aggressive surgical resection provided a better survival advantage both in single variable analyses and multivariate analyses. Consequently, although the low number of patients was the most important limitation in our study, we consider that patient age and extent of resection are the most important clinical prognostic factors in low-grade gliomas.