In the Jewett-Strong-Marshall staging system, Stage 0 means the tumor is very superficial and does not even invade the lamina propria. It has not spread to lymph nodes and there are no metastases.
Tumors can be either a papillary exophytic mass (Ta or like a bunch of grapes on a thin stalk) or a flat Tis (Tumor in situ).
There is some controversy about the designation of Grade 1 (very well differentiated) Ta lesions, since the malignant potential for spreading into lymph nodes or metastasizing is almost non-existent. Many urologists believe Ta Grade 1 tumors should be designated as non-cancerous benign papillomas, in contrast to Grades 2 and 3 Ta masses that are true cancers having the potential to invade their stalk and travel down into the lamina propria and then into muscle. People who develop one papilloma have about a 30 percent chance of developing another, while those with two or more have a 70 percent chance. Flat Tis lesions are considered aggressive.
Standard Treatment Surgery is the first treatment of choice and is generally curative. There is almost no requirement for a total cystectomy for benign papillomas. In selected cases, however, a segmental or partial cystectomy may be appropriate.