ObjectiveTo conduct a population‐based study examining cancer‐specific mortality (CSM) and other‐cause mortality (OCM) differences in patients with radiation‐induced secondary bladder cancer (RT‐BCa) vs those with primary bladder cancer (pBCa) undergoing radical cystectomy (RC).MethodsWithin the Surveillance, Epidemiology, and End Results database (2004–2020), we identified patients with T2–4N0–3M0 bladder cancer treated with RC, who had previously been treated with external beam radiation therapy (EBRT) or brachytherapy for prostate cancer, as well as patients with T2–4N0–3M0 pBCa treated with RC. Cumulative incidence plots and multivariable competing risks regression (CRR) models were used to assess CSM after additional adjustment for OCM. The same methodology was then repeated based on organ‐confined (OC: T2N0M0) and non‐organ‐confined (NOC: T3–4 and/or N1–3) disease.ResultsOf 9957 RC patients, RT‐BCa was identified in 347 (3%) compared with 9610 (97%) who had pBCa. In multivariable CRR models, no CSM differences were recorded in the overall comparison (P = 0.8), nor in sub‐groups based on OC and NOC disease (P = 0.8 and 0.7, respectively). Conversely, multivariable CRR models identified RT‐BCa as an independent predictor of 1.3‐fold higher OCM in the overall cohort and of 1.5‐fold higher OCM in those with NOC disease. In a sensitivity analysis of patients with NOC disease, EBRT was associated with higher OCM rates (hazard ratio 1.5). By contrast, OCM rates were not different in those with OC disease (P = 0.8).ConclusionOur study showed that RC for RT‐BCa was associated with similar CSM rates as RC for pBCa, regardless of disease stage. However, patients who had undergone EBRT exhibited significantly higher OCM in the NOC sub‐group.

中文翻译：

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前列腺癌放疗后根治性膀胱切除术膀胱癌患者的死亡率


目的进行一项基于人群的研究，检查放射诱导的继发性膀胱癌 （RT-BCa） 患者与接受根治性膀胱切除术 （RC） 的原发性膀胱癌 （pBCa） 患者的癌症特异性死亡率 （CSM） 和其他原因死亡率 （OCM） 差异。方法在监测、流行病学和最终结果数据库 （2004-2020） 中，我们确定了接受 RC 治疗的 T2-4N0-3M0 膀胱癌患者，这些患者之前接受过前列腺癌外照射放射治疗 （EBRT） 或近距离放射治疗，以及接受 RC 治疗的 T2-4N0-3M0 pBCa 患者。在对 OCM 进行额外调整后，使用累积发生率图和多变量竞争风险回归 （CRR） 模型评估 CSM。然后根据器官限制 （OC： T2N0M0） 和非器官限制 （NOC： T3-4 和/或 N1-3） 疾病重复相同的方法。结果在 9957 例 RC 患者中，347 例 （3%） 检测到 RT-BCa，而 pBCa 患者有 9610 例 （97%）。在多变量 CRR 模型中，总体比较中未记录 CSM 差异 （P = 0.8），基于 OC 和 NOC 疾病的亚组中也未记录 CSM 差异 （P = 0.8 和 0.7）。相反，多变量 CRR 模型确定 RT-BCa 是整个队列中 OCM 高 1.3 倍和 NOC 疾病患者 OCM 高 1.5 倍的独立预测因子。在对 NOC 疾病患者的敏感性分析中，EBRT 与较高的 OCM 率相关 （风险比 1.5）。相比之下，OC 疾病患者的 OCM 率没有差异 （P = 0.8）。结论我们的研究表明，无论疾病分期如何，RT-BCa 的 RC 与 pBCa 的 RC 的 CSM 发生率相似。然而，接受 EBRT 的患者在 NOC 亚组中表现出显着更高的 OCM。