Long-term Recurrence Rates of Low-risk Non-muscle-invasive Bladder Cancer-How Long Is Cystoscopic Surveillance Necessary?

Abstract

Background: While low-risk non-muscle-invasive bladder cancer (LR-NMIBC) has a low propensity to progress, the risk of recurrence remains high (50% within 4 yr). Guidelines recommend cystoscopic surveillance after resection, but the necessary duration of follow-up is debated.

Objective: To determine the risk of recurrence beyond 5 yr after diagnosis in patients with LR-NMIBC, and to identify risk factors of recurrence.

Design, setting, and participants: In this multicenter retrospective observational study, patients who received their first transurethral bladder tumor resection before 2016 for LR-NMIBC were included. Low risk was defined as a primary, solitary, low grade, Ta bladder tumor measuring <3 cm.

Outcome measurements and statistical analysis: The primary endpoint was determination of the recurrence rates at 1, 2, and 5 yr. The secondary endpoints included overall recurrence-free survival (RFS) and high-risk RFS. A univariate analysis and multivariable logistic regression were performed to assess the risk factors for recurrence over the study period.

Results and limitations: The median age of the 577 patients was 70.9 yr, and 126 (21.8%) patients were female. The median follow-up was 69.6 (interquartile range: 58.4) mo, and recurrence was observed in 236 (40.9%) patients. The 1-, 2-, and 5-yr RFS rates were 81.6% (95% confidence interval 78.4-84.9), 72.4% (68.7-76.3), and 59.2% (55-63.8), respectively. Recurrence after 5 yr was observed in 13.1% (28/213). High-risk recurrence, defined as the first recurrence of a high-grade and/or ≥T1 tumor, occurred in 6.2% (36/579) overall and 2.8% (6/213) after 5 yr. The lack of a single postoperative dose of chemotherapy and tumor size >2 cm were prognostic factors of recurrence.

Conclusions: The risk of recurrence in patients with LR-NMIBC decreases progressively after the 1st year and remains low beyond 5 yr. Discontinuation of endoscopic surveillance after 5 yr in patients with LR-NMIBC can be discussed. Treatment with postoperative chemotherapy and tumor size <2 cm may be relevant variables to identify patients who will benefit from cystoscopic follow-up as short as 12 mo.

Patient summary: In this study, we observed that 13% of patients who did not have a recurrence during the first 5 yr following the diagnosis of low-risk non-muscle-invasive bladder cancer will recur after this time point. Discontinuation of cystoscopic surveillance can be discussed after 5 yr in these patients.

Keywords: Cystoscopy; Long-term follow-up; Low grade; Urinary bladder neoplasm.