Efficacy of cystectomy in single-site oligometastatic bladder cancer: a Surveillance, Epidemiology, and End Results (SEER) study of 1,381 patients.

Abstract

Background: The treatment paradigm of metastatic bladder cancer has remained largely unchanged for decades and the prognosis is extremely poor. This study aimed to evaluate the role of cystectomy in patients with single-site oligometastatic bladder cancer.

Methods: Patients with single-site distant metastasis at the time of bladder cancer diagnosis from 2010-2017 were identified from Surveillance, Epidemiology, and End Results (SEER) database. Cohorts were defined by target organ [bone, brain, lung, liver, distant lymph nodes (DLNs)] and then stratified by local treatment received [no surgery, transurethral resection of bladder tumor (TURBT) and cystectomy]. Patients not receiving chemotherapy were excluded. Two-year cancer specific survival (CSS) was assessed using Kaplan-Meier (K-M) analysis and multivariable Cox proportional hazards analysis, adjusting for demographic, clinical and pathologic factors.

Results: A total of 1,381 patients met study criteria. K-M analysis indicated that cystectomy was associated with improved survival when compared to no surgery in patients with bone and DLNs metastasis. In multivariable analysis, patients with bone [hazard ratio (HR) =0.58; P=0.03] or DLNs (HR =0.51; P=0.005) metastasis who underwent cystectomy had a significant survival advantage over those receiving systemic therapy only. And patients with liver (HR =0.40; P=0.07) and lung (HR =0.84; P=0.58) who underwent cystectomy failed to exhibit superior survival than those receiving chemotherapy only. Patients with brain metastasis were omitted in subgroup analysis due to the limit of small sample size (n=20). In addition, the advent of immune checkpoint inhibitors improved the survival of patients, with HR of 0.78, indicating the reduction of death risk by 22%.

Conclusions: Cystectomy in the setting of multimodality protocols may prolong survival in bladder cancer patients with single-site metastasis of the bone and DLNs. It should be considered in a multidisciplinary setting.