We investigate the immunoexpression of MIB-1 antigen on the outcome of the transitional carcinoma of the bladder. We revised 90 patients with a mean follow-up of 55 (2-231) months. Forty five (50%) tumors were grade I, 29 (32.2%), grade II and 16 (17.8%) grade III. The tumors were staged in pTa-1: 62 (68.9%) and pT2-4: 28 (31.1%). We considered positive the tumors with more than 10% imunostained cells. Sixty three patients (70%) expressed MIB-1, with significant difference (P <0,05) between invasive tumors (pT2-4) and non-invasive (pTA-1) and between pTA and pT1 tumors (P=0,01). There was also a significant association of MIB-1 immunostaining with tumor grade: G1 versus G2 (p < 0,001) and G1 versus G3 (p < 0,001). But such difference did not occur with G2 and G3 tumors ( p = 0,2). The relationship of MIB-1 expression with the size of the lesion was significant (p <0,02). The recurrence was not predicted by the MIB-1 labeling pattern (p=0,86), though, the MIB-1-positive patients had significant smaller metastasis free intervals (p = 0.04), and lower survival rates, both among superficial tumors (p=0.009) and in total sample (p = 0.0002).
