Martin Lisa J, Alibhai Shabbir M H, Komisarenko Maria, Timilshina Narhari, Finelli Antonio
Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada.
Toronto General Research Institute, University Health Network, Toronto, ON, Canada.
Can Urol Assoc J. 2019 Jun;13(6):192-200. doi: 10.5489/cuaj.5586.
Radiographic imaging is used to monitor disease progression for men with metastatic castrate-resistant prostate cancer (mCRPC). The optimal frequency of imaging, a costly and limited resource, is not known. Our objective was to identify predictors of radiographic progression to inform the frequency of imaging for men with mCRPC.
We accessed data for men with chemotherapy-naive mCRPC in the abiraterone acetate plus prednisone (AA-P) group of a randomized trial (COU-AA-302) (n=546). We used Cox proportional hazards modelling to identify predictors of time to progression. We divided patients into groups based on the most important predictors and estimated the probability of radiographic progression-free survival (RPFS) at six and 12 months.
Baseline disease and change in prostate-specific antigen (PSA) at eight weeks were the strongest determinants of RPFS. The probability of RPFS for men with bone-only disease and a ≥50% fall in PSA was 93% (95% confidence interval [CI] 87-96) at six months and 80% (95% CI 72-86) at 12 months. In contrast, the probability of RPFS for men with bone and soft tissue metastasis and <50% fall in PSA was 55% (95% CI 41-67) at six months and 34% (95% CI 22-47) at 12 months. These findings should be externally validated.
Patients with chemotherapy-naive mCRPC treated with first-line AA-P can be divided into groups with significantly different risks of radiographic progression based on a few clinically available variables, suggesting that imaging schedules could be individualized.
放射成像用于监测转移性去势抵抗性前列腺癌（mCRPC）男性患者的疾病进展情况。然而，对于这种成本高昂且资源有限的成像检查，最佳频率尚不清楚。我们的目标是确定影像学进展的预测因素，以便为mCRPC男性患者的成像检查频率提供依据。
我们获取了一项随机试验（COU-AA-302）中醋酸阿比特龙加泼尼松（AA-P）组初治mCRPC男性患者的数据（n = 546）。我们使用Cox比例风险模型来确定疾病进展时间的预测因素。我们根据最重要的预测因素将患者分组，并估计6个月和12个月时无影像学进展生存期（RPFS）的概率。
基线疾病情况和8周时前列腺特异性抗原（PSA）的变化是RPFS的最强决定因素。仅骨转移且PSA下降≥50%的男性患者，6个月时RPFS的概率为93%（95%置信区间[CI] 87 - 96），12个月时为80%（95% CI 72 - 86）。相比之下，有骨和软组织转移且PSA下降<50%的男性患者，6个月时RPFS的概率为55%（95% CI 41 - 67），12个月时为34%（95% CI 22 - 47）。这些发现应进行外部验证。
基于一些临床可用变量，一线AA-P治疗的初治mCRPC患者可分为影像学进展风险显著不同的组，这表明成像检查计划可以个体化。
