Clinicopathological study on upper urinary tract tumors and associated bladder tumors

We reviewed 82 patients with 83 upper urinary tract tumors and investigated those who had associated bladder tumors. Of these patients, 7 (9%) had previous bladder tumors, 14 (17%) had concurrent bladder tumors, and 18 (22%) subsequently developed bladder tumors. As 1 patient subsequently developed a bladder and a upper urinary tract tumor at different times, 38 patients (46%) had associated bladder tumors. The time interval between the occurrence of a previous bladder tumor and the subsequent upper urinary tract tumor was 11 to 144 months (mean: 41 months), while that between an upper urinary tract tumor and the subsequent bladder tumor was 3-31 months (mean: 12 months). Most of the previous bladder tumors were papillary, multiple, and noninvasive (pT1 or less). Multiple upper urinary tract tumors were associated with a high incidence of concurrent bladder tumors, while high-grade (G2, G3) or invasive (pT2 or more) upper urinary tract tumors were associated with a high incidence of concurrent and subsequent bladder tumors. Patients with concurrent bladder tumors had a worse prognosis than those with previous or subsequent bladder tumors due to the increased incidence of high-stage tumors at either the upper tract or bladder site. Our findings suggest that tumor cell implantation is a possible mechanism for the recurrence of bladder tumors and upper urinary tract tumors.