TY - JOUR AU - Parimi, Sunil AU - Tsang, Erica AU - Alexander, Abraham AU - McKenzie, Michael AU - Bachand, Francois AU - Sunderland, Katherine AU - Chi, Kim N. AU - Aparicio, Maria AU - Worsley, Daniel AU - Tyldesley, Scott PY - 2017/10/12 Y2 - 2024/03/28 TI - A population-based study of the use of radium 223 in metastatic castration-resistant prostate cancer: Factors associated with treatment completion JF - Canadian Urological Association Journal JA - CUAJ VL - 11 IS - 10 SE - Original Research DO - 10.5489/cuaj.4415 UR - https://cuaj.ca/index.php/journal/article/view/4415 SP - 350-5 AB - <p><strong>Introduction:</strong> Radium 223 (Ra223) given for six cycles has proven efficacy in clinical trials, but its population-level generalizability has not been well-described. The objectives of this study were to describe population-based Ra223 use in the abiraterone and enzalutamide era and identify factors associated with completion.</p><p><strong>Methods:</strong> All Ra223 patients at the British Columbia Cancer Agency between September 2013 and February 2016 were identified. Patients who completed &lt;5 vs. ≥5 cycles were compared on patient characteristics, lines of prior therapy, prostate-specific antigen (PSA) and alkaline phosphatase (ALP) decline &gt;30% from baseline (R30%), and survival, to identify factors associated with therapy completion.</p><p><strong>Results:</strong> Ninety-one patients were identified; 48 (52.7%) completed ≥5 cycles. Median overall survival (mOS) was 10.7 months, PSA and ALP R30% were 21% and 52%, respectively. Completion of &lt;5 cycles was associated with higher baseline ALP (p=0.05) and lower baseline hemoglobin (Hb) levels (p=0.03). Patients in the ≥5 cycles group had longer mOS than those in the &lt;5 cycles group (16.2 vs. 5.9 months; p&lt;0.0001), as well as higher PSA R30% (33.3% vs. 7.0%; p=0.002) and ALP R30% (66.7% vs. 34.9%; p=0.03). Patients with ALP ≥220 and Hb ≤118 had 3.85 times the odds of not completing ≥5 cycles vs. ALP &lt;220 and Hb &gt;118.</p><p><strong>Conclusions:</strong> Compared to clinical trials, patients in a populationbased setting had more lines of therapy and shorter survival. Lower ALP and higher hemoglobin were associated with completion of ≥5 cycles, longer mOS, and greater incidence of PSA and ALP response.</p> ER -