BACKGROUNDAngiogenesis is a well known prerequisite for tumor growth and metastasis. It is believed that angiogenin initiates cell migration and aids cell proliferation. Based on this, the authors hypothesized that individuals who had increased plasma levels of angiogenin were at an elevated risk for carcinoma of the urinary bladder.METHODSIn this ongoing case–control study, the authors used an enzyme‐linked immunosorbent assay to compare plasma levels of angiogenin in 209 patients with bladder carcinoma and in 208 healthy control participants who were matched according to age (± 5 years), gender, and ethnicity.RESULTSThe mean plasma angiogenin concentration was significantly higher in patients compared with controls (343.2 ng/mL vs. 308.0 ng/mL, respectively; P < 0.01). High plasma angiogenin levels were associated with a two‐fold increased risk for bladder carcinoma. Moreover, in patients who had superficial bladder carcinoma, plasma angiogenin levels were significantly higher among those who had recurrent disease than in those who were without recurrence (P < 0.01). Similarly, patients who had superficial bladder carcinoma with higher angiogenin levels had a shorter recurrence‐free survival than patients who had lower angiogenin levels (P < 0.01). Finally, elevated angiogenin levels were associated with an increased recurrence risk, with hazard ratio of 2.85.CONCLUSIONSThe results of this study demonstrated that the plasma levels of angiogenin were significantly higher in patients who had bladder carcinoma compared with healthy control participants and in patients with superficial bladder carcinoma who had recurrent disease compared with patients who were without recurrence. Therefore, an elevated plasma level of angiogenin may serve as a novel predictor for the risk of bladder carcinoma. Cancer 2005. © 2005 American Cancer Society.