Brazilian profile of Radium-223 in metastatic prostate cancer: a multicentric, retrospective study.

Background: Radium-223 (²²³Ra) therapy has been available since 2013 for metastatic castrate-resistant prostate cancer (mCRPC). However, only in 2017 ²²³Ra was approved by the National Health Surveillance Agency in Brazil. We aimed to perform a multicenter analysis of mCRPC patients treated with ²²³Ra in referral centers in Brazil and describe their clinical outcomes. For this reason, we retrospectively analyzed mCRPC patients who underwent ²²³Ra treatment. Clinical and laboratory data were evaluated.

Results: 308 patients submitted to 1402 ²²³Ra cycles from 9 centers were studied. Previous treatments prior to ²²³Ra were chemotherapy (59.1%), radiation therapy (54.8%) and hormone therapy (92.2%). ²²³Ra was used as the fifth or more line of treatment in 58.4% of the patients. The mean number of ²²³Ra cycles was 4.6; 51% of patients completed all 6 cycles and 52.9% progressed during ²²³Ra. Concomitant treatment with ²²³Ra occurred in 69.4% of patients. The median overall survival (OS) for all patients was 13.7 months. The OS was higher for patients completing 6 cycles compared to < 6 cycles (22.6 vs 6.4 months, respectively). When stratified according to Brazilian regions, the median OS for the southeast region was higher (range: 14.5-30.2 months) than the other regions.

Conclusions: The OS of ²²³Ra for patients completing 6 cycles was very high. However, there were major discrepancies when stratified according to different regions in the nation. The data is an important demonstration of the country's educational referral discrepancies related to proper patient management for ²²³Ra therapy, which has a major impact on maximum OS benefit.