Does Dialysis Type Matter? Re-Evaluating Prognosis in UTUC Patients Following Surgery

Background: Patients with end-stage renal disease (ESRD) undergoing radical nephroureterectomy (RNU) for upper tract urothelial carcinoma (UTUC) represent a uniquely high-risk population. While prior studies have demonstrated worse postoperative outcomes among dialysis-dependent patients, no study has systematically compared oncological outcomes between peritoneal dialysis (PD) and hemodialysis (HD) modalities following RNU. This multicenter study evaluates whether dialysis modality (peritoneal dialysis versus hemodialysis) acts as an independent prognostic factor following radical nephroureterectomy. Methods: Using the Taiwan UTUC Collaboration Group Registry—a multicenter, nationwide database comprising 21 tertiary and regional medical centers —we identified 350 ESRD patients who underwent RNU for UTUC between September 1988 and December 2023. Patients were categorized by dialysis modality at the time of surgery: 310 on HD and 40 on PD. Propensity score overlap weighting was applied to account for baseline differences. Multivariate Cox proportional hazards and Fine-Gray competing risk regression models were utilized to evaluate overall survival (OS), cancer-specific survival (CSS), progression-free survival (PFS), and non-UTUC mortality. Results: After overlap weighting, PD was independently associated with significantly worse OS (HR = 2.34, 95% CI 1.29–4.25, p = 0.005) and PFS (HR = 2.06, 95% CI 1.16–3.66, p = 0.013) compared to HD and exhibited a trend toward worse CSS in univariate analysis (log-rank p = 0.094). Survival curve divergence between PD and HD was most pronounced from 12 to 24 months post-surgery onward. Notably, this survival disadvantage persisted despite PD patients being significantly younger (mean age 58.8 vs. 65.1 years) and receiving adjuvant chemotherapy more frequently (20.0% vs. 6.5%). PD was also independently associated with higher non-UTUC mortality on multivariate competing risk analysis (sHR = 2.17, 95% CI 1.22–3.88, p = 0.009). Conclusions: In this first multicenter systematic comparison of PD versus HD patients undergoing RNU for UTUC, PD modality was independently associated with worse OS and PFS and exhibited a trend toward worse CSS in univariate analysis, compared to HD. This survival disadvantage persists despite favorable baseline characteristics and higher rates of adjuvant chemotherapy. We hypothesize these outcomes may be driven by a dual vulnerability: impaired systemic tumor control and elevated non-cancer mortality following surgical disruption of the peritoneal environment. To mitigate these risks, prioritizing minimally invasive or retroperitoneal surgical approaches to preserve peritoneal integrity, combined with modality-specific multidisciplinary surveillance, is recommended.