Should Patients With Non-Muscle-Invasive Bladder Cancer Discontinue Fibrin Clot Inhibitors During BCG?

OBJECTIVE Previous reports attempting to evaluate the clinical efficacy of intravesical bacillus Calmette-Guerin (BCG) therapy in patients taking fibrin clot inhibitors (FCI) have yielded conflicting results and are primarily based on patient cohorts treated with only induction BCG. As a result, patients may receive conflicting instructions about whether or not to stop FCIs prior to BCG therapy. We aim to determine the impact of FCI use on oncological outcomes in a large contemporary cohort of patients with non-muscle-invasive bladder cancer (NMIBC) treated with adequate BCG. PATIENTS AND METHODS We performed an institutional review board-approved review of patients with NMIBC treated with adequate intravesical BCG, at our institution between 2000 and 2018. Fibrin clot inhibitor use at the time of BCG therapy was recorded for each patient. Patients were stratified according to use of FCI medication. Recurrence- and progression-free survival were analysed using Kaplan-Meier methods and Cox proportional hazard models. RESULTS Overall, 226 of 526 patients (43.0%) used a FCI: aspirin (n=205), clopidogrel (n=38), warfarin (n=18) and novel oral anticoagulant (NOAC; n=7). The use of FCIs did not adversely affect either recurrence- or progression-free survival (p=0.385 and p=0.131 respectively). These results did not change when the impact of aspirin, clopidogrel or warfarin/NOAC use on recurrence and progression was evaluated separately. On multivariate analysis, FCI use was neither associated with tumour recurrence nor progression. CONCLUSION The use of fibrin clot inhibitors was not associated with adverse oncological outcomes in a large contemporary cohort of patients receiving adequate intravesical BCG for non-muscle invasive bladder cancer. Based on these results, fibrin clot inhibitors may be safely continued during BCG immunotherapy.