NCIt definition : Stage 0is includes: Tis, N0, M0. Tis: For male penile urethra and female urethra:
Carcinoma in situ. For prostatic urethra: Carcinoma in situ involving the prostatic
urethra or periurethral or prostatic ducts without stromal invasion. N0: No regional
lymph node metastasis. M0: No distant metastasis. (AJCC 8th ed.);