Objectives: To evaluate the risk factors for disease progression in the frequent subgroup of Stage T1G2 (World Health Organization 1973) bladder tumors using an analysis of a large cohort of patients with Stage T1G2 disease.
Methods: A cohort of 616 patients with Stage T1G2 were treated with transurethral resection and random bladder biopsies. The mean follow-up was 4.2 years. Univariate and multivariate analyses were done using Cox regression analysis. The independent variables were multiplicity, association with carcinoma in situ (CIS), tumor size, tumor recurrence at 3 or 6 months, tumor grade, and association with CIS at first recurrence. The dependent variable was progression to muscle-invasive disease.
Results: Progression to muscle-invasive disease was identified in 28 of the 616 patients (4.5%). On multivariate analysis, when considering recurrence at 3 months, this factor was the principal prognostic factor, with a relative risk of 4.0 (95% confidence interval 1.2-13.3), followed by the presence of high-grade disease or CIS at first recurrence (relative risk 2.8, 95% confidence interval 1.3-5.8) and CIS associated with the primary tumor (relative risk 1.8, 95% confidence interval 1.1-2.9). When considering recurrence at 6 months, more prognostic factors were involved for progression, including as multiple tumors, CIS associated with the primary tumor, recurrence at 6 months, and the presence of high-grade disease or CIS at the first recurrence.
Conclusions: In primary urothelial T1G2 bladder cancer, recurrence at 3 months was the main prognostic factor related to progression. Additional factors were the association of CIS with the primary tumor and the presence of high-grade disease and/or CIS at first recurrence.