The ROC curve analysis showed that the area under the curve (AUC) of BLCA-4, BTA, NMP22, CEA, body mass index, smoking, family history of bladder cancer, occupational exposure to aromatic amine chemicals, number of tumours, and bladder instillation of chemotherapeutic agents were 0.804, 0.807, 0.705, 0.780, 0.680, 0.636, 0.531, 0.578, 0.731 and 0.553 in the recurrence group, respectively (Fig. 4). This evidence concerns the gene CEACAM5 and urinary bladder carcinoma.