Presentation Authors: Sahyun Pak*, Teak Jun Shin, Hwiwoo Kim, Donghyun Lee, Dalsan You, In Gab Jeong, Cheryn Song, Jae-Lyun Lee, Bumsik Hong, Jun Hyuk Hong, Choung-Soo Kim, Hanjong Ahn, Seoul, Korea, Republic of
Introduction: This study aimed to compare adjuvant chemotherapy (AC) versus observation after radical cystectomy in patients with pathologically node-positive bladder cancer (pN+). We also attempted to identify pN+ patients most likely to benefit from AC after RC.
Methods: Outcomes were reviewed in patients with pTanyN1-3M0 bladder cancer treated with RC between January 1995 and June 2017. Patients who underwent RC alone were assigned to the RC group and those who received AC were assigned to the AC group. Baseline characteristics between two groups were controlled with inverse probability of treatment weighting (IPTW)-adjusted analyses. Variables prognostic for survival were assessed by stratified time-varying covariate Cox model.
Results: Of 281 enrolled patients, 122 (43.4%) underwent RC alone and 159 (56.6%) received AC. The 3-year IPTW-adjusted rates of metastasis-free survival was similar between AC and RC groups (35.8% vs. 31.2%, p=0.471), whereas IPTW-adjusted overall survival rate was higher in the AC than RC group (46.4% vs. 33.7%, p=0.024). In the time-varying covariate Cox model, AC was an independent predictor of overall survival (HR=0.48; 95% CI, 0.34â€“0.67; P < 0.0001).When subdivided by tertiles of lymph node density (LND), the 3-year overall survival rates were similar between the AC and RC alone in patients with LND < 9% (58.7% vs. 51.7%, p=0.878), whereas 3-year overall survival rates of AC group were higher than RC group in patients with LND 9-25% (53.4% vs. 23.7%, p=0.003) and LND â‰¥25% (27.4% vs. 16.1%, p=0.032). The numbers needed to treat to prevent one death at 3 years were 3 and 9 in patients with LND 9-25% and â‰¥25%, respectively.
Conclusions: AC after RC was associated with improved overall survival in patients with node-positive bladder cancer. Patients with intermediate nodal burden may benefit most from AC, whereas the effect of AC was not apparent in low nodal burden disease. Randomized studies are needed to confirm the results of the present study.