Department of Therapeutic Radiology, Yale School of Medicine, New Haven, CT, USA.
Department of Urology, Yale School of Medicine, New Haven, CT, USA.
Prostate Cancer Prostatic Dis. 2021 Jun;24(2):414-422. doi: 10.1038/s41391-020-00291-3. Epub 2020 Sep 28.
Comparative effectiveness research (CER) using national registries influences cancer clinical trial design, treatment guidelines, and patient management. However, the extent to which treatment selection bias (TSB) affects overall survival (OS) in cancer CER remains poorly defined. We sought to quantify the TSB effect on OS in the setting of low-risk prostate cancer, where 10-year prostate cancer-specific survival (PCSS) approaches 100% regardless of treatment modality.
The Surveillance, Epidemiology, and End Results database was queried for patients with low-risk prostate cancer (cT1-T2a, PSA < 10, and Gleason 6) who received radical prostatectomy (RP), brachytherapy (BT), or external beam radiotherapy (EBRT) from 2005 to 2015. The TSB effect was defined as the unadjusted 10-year OS difference between modalities that was not due to differences in PCSS. Propensity score matching was used to estimate the TSB effect on OS due to measured confounders (variables present in the database and associated with OS) and unmeasured confounders.
A total of 50,804 patients were included (8845 RP; 18,252 BT; 23,707 EBRT) with a median follow-up of 7.4 years. The 10-year PCSS for the entire cohort was 99%. The 10-year OS was 92.9% for RP, 83.6% for BT, and 76.9% for EBRT (p < 0.001). OS differences persisted after propensity score matching of RP vs. EBRT (7.4%), RP vs. BT (4.6%), and BT vs. EBRT (3.7%) (all p < 0.001). The TSB effect on 10-year OS was estimated to be 15.0% for RP vs. EBRT (8.6% measured, 6.4% unmeasured), 8.5% for RP vs. BT (4.8% measured, 3.7% unmeasured), and 6.5% for BT vs. EBRT (3.1% measured, 3.4% unmeasured).
Patients with low-risk prostate cancer selected for RP exhibited large OS differences despite similar PCSS compared to radiotherapy, suggesting OS differences are almost entirely driven by TSB. The quantities of these effects are important to consider when interpreting prostate cancer CER using national registries.
利用国家注册中心进行的比较疗效研究（CER）影响癌症临床试验设计、治疗指南和患者管理。然而，治疗选择偏倚（TSB）对癌症 CER 中总生存率（OS）的影响程度仍未得到充分定义。我们旨在量化低危前列腺癌患者中 TSB 对 OS 的影响，因为无论治疗方式如何，这些患者 10 年前列腺癌特异性生存率（PCSS）均接近 100%。
使用 Surveillance, Epidemiology, and End Results 数据库，检索 2005 年至 2015 年间接受根治性前列腺切除术（RP）、近距离放射治疗（BT）或外束放射治疗（EBRT）的低危前列腺癌（cT1-T2a、PSA<10 和 Gleason 6）患者。TSB 效应被定义为模式之间未经 PCSS 差异调整的 10 年 OS 差异。使用倾向评分匹配来估计由于测量的混杂因素（数据库中存在并与 OS 相关的变量）和未测量的混杂因素导致的 TSB 对 OS 的影响。
共纳入 50804 例患者（RP 8845 例，BT 18252 例，EBRT 23707 例），中位随访时间为 7.4 年。整个队列的 10 年 PCSS 为 99%。RP、BT 和 EBRT 的 10 年 OS 分别为 92.9%、83.6%和 76.9%（p<0.001）。RP 与 EBRT（7.4%）、RP 与 BT（4.6%）和 BT 与 EBRT（3.7%）之间的 OS 差异在倾向评分匹配后仍然存在（均 p<0.001）。估计 RP 与 EBRT（8.6%测量，6.4%未测量）、RP 与 BT（4.8%测量，3.7%未测量）和 BT 与 EBRT（3.1%测量，3.4%未测量）之间的 10 年 OS TSB 效应分别为 15.0%、8.5%和 6.5%。
尽管与放疗相比，低危前列腺癌患者选择 RP 治疗后 OS 存在较大差异，但考虑到相似的 PCSS，这些差异几乎完全由 TSB 驱动。当使用国家登记处解释前列腺癌 CER 时，这些效应的数量非常重要。
