BJU Int. 2020 Aug 17. doi: 10.1111/bju.15209. Online ahead of print.
OBJECTIVES: To assess the change in rates of recurrence-free survival (RFS) and progression-free survival (PFS) based on duration of survival without recurrence or progression among patients with intermediate-risk (IR) non-muscle invasive bladder cancer (NMIBC), and to examine predictive factors of recurrence at different time points, we examined conditional RFS and PFS.
SUBJECTS/PATIENTS AND METHODS: A cohort of 602 patients treated with transurethral resection of bladder tumor (TURBT) and histopathologically diagnosed with IR NMIBC were included in this retrospective study.
RESULTS: The conditional RFS rate at 1, 2, 3, 4 and 5 years improved with increased duration of recurrence-free survival, however, the conditional PFS rate did not improve over time. Multivariable analyses showed that recurrent tumor, multiple tumors, tumor size (>3cm), immediate postoperative instillation of chemotherapy (IPIC), and administration of BCG were independent predictive factors for recurrence at baseline. The predictive ability of these factors disappeared with increasing recurrence-free survivorship. Sub-classification of these IR NMIBC patients into three groups using clinico-pathological factors (recurrent tumor, multiple tumors, tumor size) demonstrated that the high-IR group (2 factors) had significantly worse RFS than the intermediate (1 factor, p<0.001) and low-IR groups (0 factor, p=0.005) at baseline. This sub-classification stratified conditional risk of RFS also at 1, 3 and 5-year, which provides the basis for distinct surveillance protocols among patients with IR NMIBC.
CONCLUSION: Conditional survival analyses of patients with IR NMIBC demonstrate that RFS changes overtime, while PFS does not change. These data support distinct surveillance protocols based on the sub-classification of IR NMIBC.