Abstract and Introduction
Purpose of review: The standard diagnosis of carcinoma in situ (CIS) of the bladder, based on white light cystoscopy and urine cytology, is limited because CIS can vary from normal-appearing mucosa to a lesion indistinguishable from an inflammatory process. Intravesical instillation of Bacillus Calmette–Guerin (BCG) remains first-line therapy; however, a significant proportion of cases persist or recur after BCG treatment. This review summarizes recent improvements in the detection and treatment of CIS.
Recent findings: The new optical technologies improve CIS detection, with a potential positive impact on oncological outcomes. The usefulness of MRI-photodynamic diagnosis fusion transurethral resection in CIS detection is unclear and further studies are needed. BCG instillation remains the first-line therapy in CIS patients and seems to improve recurrence and progression rates, especially with the use of maintenance. Intravesical device-assisted therapies could be effective in both BCG-naïve and BCG-unresponsive CIS patients, but further studies are ongoing to clarify their clinical benefit. A phase II clinical trial with pembrolizumab has shown the potential effectiveness of immune checkpoint inhibitors in BCG-unresponsive CIS patients and further trials are ongoing.
Summary: New optical techniques increase the CIS detection rate. BCG instillation remains the first-line treatment. Immune checkpoint inhibitors could be a future alternative in BCG-naïve and BCG-unresponsive CIS patients.
Carcinoma in situ (CIS) of the bladder is a high-grade flat lesion limited to the urothelial layer. A recent meta-analysis in patients with nonmuscle-invasive bladder cancer (NMIBC) who underwent random biopsies showed a pooled incidence of CIS of 17.35%.
Histopathological and molecular analyses confirm that CIS presents morphometric features similar to muscle invasive bladder cancer (MIBC). Without treatment, more than 50% of patients progress to MIBC at 5 years of follow-up.
According to European Association of Urology (EAU) guidelines, CIS may be classified as: primary; CIS without a previous history of bladder cancer; concurrent; CIS in the presence of an exophytic tumor; or secondary; CIS detected during follow-up of a previous tumor that was not CIS. However, the prognostic impact of this classification remains controversial.[6,7]
The diagnosis of CIS can be difficult since it can vary from normal-appearing mucosa to a lesion indistinguishable from an inflammatory process; therefore, a pathological report is required for the diagnosis. However, the introduction of new optical technologies has been shown to improve detection.
The first-line treatment of bladder CIS is Bacillus Calmette–Guerin (BCG) instillation, which has been shown to decrease recurrence and progression, especially with the use of maintenance. Clinical trials are ongoing to investigate the potential benefit of other agents such as immune checkpoint inhibitors.
Curr Opin Urol. 2020;30(3):392-399. © 2020 Wolters Kluwer Health, Inc.