Risk Scoring System for Ra-223 Discontinuation and Its Effect on Prognosis: A Retrospective Study

Cancer Diagn Progn. 2021 Jul 3;1(4):323-330. doi: 10.21873/cdp.10043. eCollection 2021 Sep-Oct.

Abstract

Background/aim: Radium-223 therapy prolongs overall survival in castration-resistant prostate cancer (CRPC) patients with bone metastasis. Patients who are unable to complete six courses of radium-223 therapy reportedly have a poor prognosis. This study aimed to develop a risk score using the discontinuation factors of the above therapy modality.

Patients and methods: Seventy patients who received radium-223 therapy for metastatic CRPC at two Japanese Institutions were evaluated. Univariate and multivariate analyses were performed to identify the discontinuation factors and determine the risk scores.

Results: The median survival time was 24.3 and 9.5 months in patients who did and did not complete the therapy, respectively. Multivariate analysis revealed haemoglobin and prostate-specific antigen as key factors. A risk score was developed using these factors, and patients were stratified into three groups. The discontinuation rate and survival after radium-223 therapy were significantly different.

Conclusion: Our risk score may help evaluate the suitability of radium-223 in CRPC patients.

Keywords: Bone metastasis; Radium-223; metastatic castration-resistant prostate cancer; risk factors; survival.