Natural history of early bladder cancer.

Non-invasive transitional cell carcinoma (TCC) occurs as two distinct growth patterns, papillary and non-papillary (flat), which display significant differences in biologic potential. Papillary carcinoma usually presents as a low-grade lesion which frequently recurs multiple times prior to invasion; conversely, non-papillary (flat) carcinoma in situ is usually high-grade at presentation (carcinoma in situ) and frequently associated with invasion. These lesions may occur together, although papillary cancer is more easily visualized cystoscopically due to its exophytic growth; flat carcinoma in situ is often cystoscopically invisible. This report reviews existing data concerning the prognostic value of pathologic grading and staging of non-invasive and early invasive TCC. Emphasis is placed on those studies reporting surgical treatment rather than other forms of treatment.