D. Schrijvers MD, PhD, A. Baitar , T. Debacker MD, F. van Acker MD
Radium-223 is one of the treatment options for patients with metastatic castration-resistant prostate cancer (mCRPC), based on the ALSYMPCA trail, a large randomised study.
In this retrospective study, the experience with radium-223 in patients with mCRPC, treated in a single centre, is reported in relation to the number of cycles of radium-223 given; reason of discontinuing radium-223 treatment, overall survival according to radium-223 treatments received; next treatment and interval to next treatment after discontinuing radium-223.
The Kaplan-Meier method was used to describe overall survival, and the log-rank was used to compare different groups.
Thirty-eight patients were analysed. A total of 26 patients (68.4%) completed all six cycles of radium-223, while twelve patients (31.6%) stopped treatment earlier. The reasons for discontinuing treatment early were progressive disease during treatment with radium-223 (four patients); myelotoxicity (one patient, who was previously treated for a small cell carcinoma of the ureter with six cycles of carboplatinum); intercurrent death due to non-prostate cancer-related diseases (four patients); patient refusal (one patient); complication due to co-morbid condition (one patient). And, one patient who stopped treatment after five cycles was lost to follow up.
Patients who completed all six cycles had a median survival time of 27.4 months (95% CI: 16.4-non applicable [NA; because the upper confidence limit never reaches the 50% survival]); and patients who completed one to four cycles 9.0 months (95% CI: 4.6-NA, log rank test: p<0.001).
Of the 26 patients who completed all six cycles, sixteen patients started another line of treatment for mCRPC after a median time of 30.0 weeks (95% CI: 18.1-NA) after the last injection of radium-223.
Radium-223 is an appropriate treatment for patients with mCRPC with a median overall survival of 27.4 months and a drug-free interval of 30 weeks after six cycles of radium-223.