Oncological impact of perioperative blood transfusion in bladder cancer patients undergoing radical cystectomy: Do we need to consider storage time of blood units, donor age, or gender matching?

Background The oncological impact of perioperative blood transfusions (PBTs) of patients undergoing radical cystectomy (RC) because of bladder cancer (BCa) has been a controversial topic discussed in recent years. The main cause for the contradictory findings of existing studies might be the missing consideration of the storage time of red blood cell units (BUs), donor age, and gender matching. Study Design and Methods We retrospectively analyzed BCa patients who underwent RC in our department between 2004 and 2021. We excluded patients receiving BUs before RC, >10 BUs, or RC in a palliative setting. We assessed the effect of blood donor characteristics and storage time on overall survival (OS) and cancer‐specific survival (CSS) through univariate and multivariable Cox regression analysis. We also performed a propensity score matching with patients who received BUs and patients who did not on a 1:1 ratio. Results We screened 1692 patients and included 676 patients for the propensity score matching. In the multivariable analysis, PBT was independently associated with worse OS and CSS (p