pT1 bladder tumors invade the lamina propria and are more aggressive biologically than superficial pTa or in situ carcinomas (Tis). Among patients with pT1 tumors treated by transurethral resection (TUR), 30% develop a muscle-invasive neoplasm within 3-5 years, but intravesical chemotherapy or BCG reduce progression rates to 20 and 14%, respectively. Tumor variables favoring progression include multiple, recurrent pT1 tumors, high grade (G3), solid configuration and associated Tis. Many pT1 tumors can be managed conservatively, but patients failing an adequate trial (3-6 months) of TUR and intravesical therapy are best treated by cystectomy.
