Diagnosis, evaluation and treatment of carcinoma in situ of the urinary bladder: the state of the art.

Urothelial carcinoma in situ (CIS) is regarded as a precursor of invasive bladder carcinoma. Although relatively uncommon as a primary entity, CIS is frequently seen in conjunction with other bladder tumors and represents a significant source of difficulty for surveillance of patients with known bladder cancer. CIS lesions are difficult to detect by cystoscopic examination or by currently available screening markers. Urothelial CIS is infrequently reported in the literature as a primary process; however, a wide variety of emerging methodologies are becoming available for screening and follow-up of bladder cancer. Most new methods demonstrate sensitivity and specificity similar to the current standard of urine cytology and cystoscopy. Detection of high-grade lesions such as CIS by these methods appears generally better than detection of low-grade lesions. Current molecular evidence suggests that a spectrum of genetic aberrations including p53 mutations are strongly associated with the potentially invasive CIS phenotype in contrast to low-grade papillary and hyperplastic lesions. These low-grade lesions frequently recur but infrequently become invasive. Patients with high-grade lesions including CIS and high-grade papillary tumors warrant aggressive treatment and life-long surveillance.