Background
Limited data is available on the role, and extent of, postchemotherapy lymphadenectomy (PC-LND) in patients with clinical evidence of pelvic (cN1-3) or retroperitoneal (RP) lymph node spread from urothelial bladder carcinoma (UBC).
Objective
To compare the outcomes of operated versus non operated patients after first-line chemotherapy.
Design, Setting, Participants
Data from 34 centers was collected, totalling 522 patients, treated between 01/2000 and 06/2015. Criteria for patient selection were the following: bladder primary tumor, lymph node metastases (pelvic ± RP) only, 1st-line platinum-based chemotherapy given.
Intervention
LND (with cystectomy) versus observation after first-line chemotherapy for metastatic UBC.
Outcome measures and statistical analysis
Overall survival (OS) was the primary endpoint. Multiple propensity score (PS) techniques were adopted, including 1:1 PS matching and inverse probability of treatment weighting (IPTW). Additionally, the IPTW analysis was performed with the inclusion of the covariates, i.e. with “doubly robust” estimation (DREP).
Results and limitations
Overall, 242 (46.4%) patients received PC-LND and 280 (53.6%) observation after chemotherapy. There were 177 (33.9%) and 345 (66.1%) patients with either RP or pelvic LN only, respectively. DREP-adjusted comparison was not significant for improved OS for PC-LND (HR: 0.86, 95%CI: 0.56–1.31, p=0.479), confirmed by matched analysis (HR: 0.91, 95%CI: 0.60–1.36, p=0.628). This was also observed in the RP subgroup (HR: 1.12, 95%CI: 0.68–1.84). The retrospective nature of the data and the heterogeneous patient population were the major limitations.
Conclusions
Although there were substantial differences between the two groups, after accounting for major confounders we report a non-significant OS difference with PC-LND compared to observation only. These findings may be hypothesis-generating for future prospective trials.
Patient summary
We found no differences in survival by adding postchemotherapy lymphadenectomy in patients with pelvic or retroperitoneal lymph node metastatic bladder cancer. The indication to perform postchemotherapy lymphadenectomy in the most suitable patients requires additional studies.