Upper urinary tract tumors after primary superficial bladder tumors: Prognostic factors and risk groups

Purpose: We evaluated the prognostic factors of primary superficial bladder cancer that may predict a metachronous upper urinary tract tumor. We also determined whether the incidence of upper urinary tract disease varies acco rding to risk group based on primary superficial bladder tumor classificati on. Materials and Methods: We studied disease evolution in a cohort of 1,529 pa tients with a primary superficial bladder tumor. To determine the prognosti c factors of upper urinary tract cancer we performed multivariate analysis using Cox regression. Independent variables were grade, T stage, multiplici ty, tumor size, carcinoma in situ association, previous or synchronous uppe r urinary tract tumor and intravesical instillation. We also performed the chi-square test and Kaplan-Meier survival analysis to assess the variable i ncidence of upper urinary tract tumors according to primary superficial bla dder tumor risk group classification. Results: The incidence of upper urinary tract cancer was 2.6%. The only fac tor prognostic for an upper urinary tract tumor was multiplicity (relative risk 2.7, 95% confidence interval [CI] 1.06 to 6.84). All patients with an upper urinary tract tumor had a previously recurrent primary superficial bl adder tumor. In the low, intermediate and high risk groups the incidence of upper urinary tract cancer was 0.6% (relative risk 1), 1.8% (relative risk 3.1, 95% CI 0.4 to 23.9) and 4.1% (relative risk 8.3, 95% CI 1.1 to 61.6), respectively (chi-square and log rank tests p = 0.007 and p <0.05, respect ively). Conclusions: A higher risk of upper urinary tract cancer must be expected i n cases of multiple primary superficial bladder tumors. This finding suppor ts the multicentricity theory of transitional cell carcinoma. Primary super ficial bladder tumor classification by risk group is also useful for predic ting the various risks of metachronous upper urinary tract cancer.