The correlation between osteopontin level and radiation response of malignant gliomas at Cipto Mangunkusumo Hospital

Osteopontin is an endogenous molecular marker for tumor hypoxia, and hypoxia is one of the factors that determine the aggressiveness of the disease. The purpose of this study is to determine the correlation between osteopontin levels and radiation response in malignant glioma. A retrospective cohort study was conducted on 15 malignant glioma patients who underwent radiation therapy from July 2004 to May 2015 at the RSUPN Dr. Cipto Mangunkusumo Hospital. Osteopontin levels were measured from paraffin-embedded tissue using a commercial ELISA kit. Tumor volume was calculated using computed tomography (CT) scan and magnetic resonance imaging (MRI) images, based on three-dimensional volume measurements. Tumor response was evaluated by comparing pre- and post-radiation tumor volumes using CT scan and MRI images. The mean osteopontin level was 0.49 ± 0.45 ng/mL and the mean percentage change in tumor volume was 8.59 ± 54.22%, with a 60% enlargement in tumor volume. A progressive disease was found in 26.7% of patients. There was a weak but insignificant negative correlation (r = 0.39, p = 0.146) between the level of osteopontin and radiation response. In contrast, there was a strong but insignificant positive correlation (r = +0.68, p = 0.219) between the level of osteopontin and radiation response in the patient group that used the chemosensitizer temozolamide.