Real-world effectiveness and safety of radium-223 therapy in castration-resistant prostate cancer with bone metastases

The effectiveness and safety of radium-223 (Ra-223) in patients with metastatic castration-resistant prostate cancer (mCRPC) and bone metastasis in real-world clinical practice in China remain to be fully examined. This single-center, retrospective, real-world study included Chinese patients with mCRPC treated with Ra-223 between January 2021 and August 2023 in Fudan University Shanghai Cancer Center (Shanghai, China). This study examined the patient characteristics, overall survival (OS), 5-point Visual Analog Scale for pain and safety, as well as factors potentially influencing treatment effectiveness. Ninety-three patients were included. Among them, 25 (26.9%) patients were administered all six injections of Ra-223, and 41 (44.1%) patients received more than 3 injections. After a median follow-up of 19.8 months, median OS was 14.1 (95% confidence interval [CI]: 12.0-16.2) months. Multivariable analysis showed a total number of Ra-223 injections >3 was an independent protective factor of OS (hazard ratio [HR] = 0.443, 95% CI: 0.234-0.837; P = 0.012) after adjusting for age, combination therapy, and previous chemotherapy. For those administered all six injections of Ra-223, no patients had a pain score of 4 and only 4.2% of patients showed a pain score of 3. In total, 62.5% of patients had almost no pain (0 point). Median alkaline phosphatase showed a downward trend during the six-injection treatment period. The most common adverse event was anemia (30.1%), followed by thrombocytopenia (15.1%), nausea (9.7%), weakness (8.6%), and decreased white blood cells (7.5%). This real-world study strongly suggests that Ra-223 has good effectiveness and tolerability in Chinese patients with mCRPC and bone metastases.