Pain predicts overall survival in men with metastatic castration-resistant prostate cancer treated with radium-223

Background: Radium-223 dichloride is an alpha emitter approved for metastatic castration-resistant prostate cancer (mCRPC). Unfortunately, little data are available on the prognostic factors during radium-223-based therapy. Patients and methods: Patients with histologically confirmed progressive CRPC with two or more bone metastases and symptomatic disease were eligible. Previous therapy with a novel hormonal therapy was allowed. The patients received six intravenous injections of radium-223 every 4 weeks. A visual analog scale (VAS) was adopted to evaluate patients' basal pain. Results: A total of 25 patients were evaluated. Of these, 6 (24%) reported VAS <4. After a median follow-up of 8 months, all patients died with a median overall survival of 8.3 months (95% CI: 5.2-11.8 months), 12.6 months in the patients with VAS <4 vs 6.6 months in the patients with VAS ≥4 (P=0.03). Conclusion: The present study suggests that VAS could be prognostic of the survival of mCRPC treated with radium-223 irrespective of the limitations of a small number of patients and the retrospective nature of the data.