Supplementary Material for: Preoperative Thrombocytosis in Patients Undergoing Radical Cystectomy for Urothelial Cancer of the Bladder: An Independent Prognostic Parameter for an Impaired Oncological Outcome

Background: Preoperative thrombocytosis (PTC) is frequently observed in various solid malignancies and often associated with an unfavourable oncological outcome. Objectives: The aim of this study was to investigate the influence of PTC in patients undergoing radical cystectomy (RC) for urothelial carcinoma (UC) of the bladder on the oncological prognosis and additionally on perioperative blood transfusions (PBT). Method: A retrospective analysis of 866 patients undergoing RC in a tertiary care centre was performed. PTC was defined as a platelet count >400 G/L. A chi-square test and Mann-Whitney test were used to investigate the association of PTC with categorical clinicopathological variables. A logrank test and multivariable Cox regression analyses were used to assess the association of PTC with cancer-specific survival. Results: PTC was detected in 8% (n = 67) of the patients and was significantly associated with muscle invasion (p = 0.004), advanced tumour stages (p = 0.003) and nodal metastases (p < 0.001) and with a higher rate of PBT (p< 0.001). In the multivariate analysis, PTC was significantly related to poor oncological survival (hazard ratio 2.23, 95% CI 1.51–3.30, p < 0.001). Conclusion: PTC is significantly associated with an impaired oncological outcome in patients undergoing RC for UC. PTC therefore represents an independent and easy to determine prognostic parameter for patients’ oncological outcome. Intriguingly, PTC is significantly associated with an increased rate of PBT.