Study type: Diagnosis (exploratory cohort).
Level of evidence: 2b.
Objective: To clarify the relationship between estimated blood loss (EBL) and biochemical recurrence, assessed by prostate-specific antigen (PSA) level, as blood loss is a long-standing concern associated with radical prostatectomy (RP), and no studies to date have examined the association between blood loss and cancer control.
Patients and methods: In all, 1077 patients were identified in the Shared Equal-Access Regional Cancer Hospital database who underwent retropubic RP (between 1998 and 2008) and had EBL and follow-up data available. We examined the relationship between EBL and recurrence using multivariate Cox regression analyses.
Results: Increased EBL was correlated with PSA recurrence in a multivariate-adjusted model (P = 0.01). When analysed by 500-mL EBL categories, those with an EBL of <1500 mL had a similar risk of recurrence. However, the risk of PSA recurrence tended to increase for an EBL of 1500-3499 mL, before decreasing again for patients with an EBL of > or =3500 mL. Men with an EBL of 2500-3499 mL had more than twice the risk of recurrence than men with an EBL of <1500 mL (P = 0.02). EBL was not associated with adverse tumour stage, grade or margin status.
Conclusions: There was a significant correlation between EBL at the time of RP and biochemical recurrence. We hypothesized that this association might be due to transfusion-related immunosuppression, excessive blood obscuring the operative field, EBL being a marker of aggressive disease, or EBL being a marker of poor surgical technique. However, our data did not completely fit any one of these hypotheses, and thus the ultimate cause for the increased risk of recurrence remains unclear and requires further study.