Recurrence patterns in bladder cancer patients with no residual disease (pT0N0) at radical cystectomy.

576 Background: Bladder cancer patients can achieve no residual disease status at the time of radical cystectomy (RC) following transurethral resection (TURBT) alone (pT0) or neoadjuvant chemotherapy (NAC) (ypT0). This population has favorable survival potential, yet limited data is available on their oncological outcomes. We examined the recurrence patterns in these patients and the implications for post-operative surveillance. Methods: A retrospective review of our IRB-approved bladder cancer database identified patients who underwent RC between 2000 - 2019 and were found to have no residual disease (pT0N0). The primary outcome was recurrence-free survival (RFS). Results: A total of 234 patients with a median age of 67 years were included. NAC was used in 89 (38%) patients and 145 (62%) cases were rendered pT0 following TURBT alone. After a median follow up of 44 months, 6/145 (4%) pT0 patients and 10/89 (11.2%) ypT0 cases developed a recurrence. None of the pT0 patients with previous history of clinical Ta/Tis disease had a recurrence after RC. The median time to recurrence was 9 months. All but one of the recurrences in the ypT0 group were within 2 years of cystectomy, while half of the recurrences in the pT0 group occurred after 2 years. Patients with ypT0 had worse 2- and 5-year RFS compared to the pT0 group (85% and 84% vs. 99% and 95%, respectively; p=0.003). Variant histology was noted in 49 (21%) patients and the recurrence rate was higher in this subgroup compared to those with pure urothelial carcinoma (12.2% vs. 5.4%, p = 0.02). Lung metastasis and involvement of distant organs, while rare, was noted at similar rates in both groups (Table). On univariate Cox regression analysis of RFS, clinical T stage > 3 (HR: 6.5, 95%CI: 2.4 – 17.3, p<0.001) and NAC (HR: 4.3, 95%CI: 1.5 – 12.5, p = 0.007) were associated with increased risk of recurrence. Conclusions: Most patients with pT0N0 pathology at the time of cystectomy are cured however metastasis can still develop up to 4 years after surgery. Patients achieving ypT0 after NAC exhibit worse prognosis and shorter times to recurrence, and closer follow-up may be considered.[Table: see text]