Prediction of Bone Metastasis in Prostate Cancer Using Blood Glucose-6-Phosphate Dehydrogenase Activity: A Retrospective Medical Record Review

<b>Background</b>: Globally, the incidence of prostate cancer is estimated to increase by approximately 80% by 2040 compared to 2018. Bone is the most common metastatic site in prostate cancer and accurate prediction of bone metastasis in prostate cancer is crucial for deciding treatment decisions. The aim of this study is to evaluate the potential of G6PD activity level as a biomarker for predicting bone metastasis in patients with prostate cancer. <b>Methods</b>: A total of 56 patients participated in this study and participants included in the study were prostate cancer patients aged 19 years or older who visited YCH Hospital. We compared G6PD activity levels according to presence of bone metastasis. Also, ROC analysis was conducted to evaluate the predictive performance of G6PD activity level for bone metastasis. Optimal cutoff value of G6PD activity level was determined using Youden's index and corresponding sensitivity and specificity were calculated. <b>Results</b>: The median G6PD activity was significantly higher in the group with bone metastasis than in the group without bone metastasis. According to ROC curve analysis, the area under the curve (AUC) was 0.78 (95% CI, 0.66-0.90). The optimal cutoff value of G6PD activity level for predicting bone metastasis was determined to be 11.5 U/g Hb. At this cutoff value, sensitivity and specificity were 0.81 and 0.73, respectively. <b>Conclusions</b>: G6PD activity is a complementary non-invasive biomarker for predicting bone metastasis in patients with prostate cancer.