CARCINOMA IN-SITU OF THE URINARY-BLADDER - CLUES TO HOST INVOLVEMENT IN HUMAN CARCINOGENESIS

Background. Carcinoma in situ (CIS) of the urinary bladder is a neopla sm of uncertain biologic behavior. It rarely occurs as the primary dis ease and exists most often in association with high grade, invasive tu mors. The unfavorable prognosis ascribed to CIS may not be due to tumo r-related factors but to low host resistance or to host-tumor relation ships established for previous or coincident invasive cancers. The sca nt available evidence indicates that a large proportion of patients wi th primary CIS have a low frequency of muscle invasion and death from disease. Methods. Of 2000 patients with bladder neoplasms in our patho logy files and tumor registry, 102 had CIS confirmed on histologic rev iew. There were 29 cases of primary CIS and 73 cases of secondary CIS. These cases were compared, with an emphasis on patient outcome. Resul ts. The data indicate that primary and secondary CIS are histologicall y identical lesions whose effect on patients is related mainly to the presence of multifocal disease, often associated with previous or coin cident invasive cancers. Progression or death from disease is unusual among patients presenting with primary CIS but common among individual s with CIS associated with other bladder cancers. Conclusion. The auth ors suggest that the appearance of urothelial CIS identifies patients with at least localized resistance to the development of invasive blad der cancer. The degree of patient resistance to carcinogenic events le ading to bladder carcinoma is manifested by the type, grade, and stage of their initial neoplasms.