The value of bladder mapping and prostatic urethra biopsies for detection of carcinoma in situ (CIS)

Abstract

What ' s known on the subject? and What does the study add?It is well known that CIS is a major risk factor for muscle-invasive bladder cancer and that this entity can be diffi cult to diagnose. Taking cold-cup mapping biopsies from different areas of the bladder (BMAP) is commonly used in patients at risk of harbouring CIS. The diagnostic accuracy of this approach has not been assessed until now.By using the CIS found in the cystoprostatectomy specimen as an indicator of the true occurrence of CIS and comparing that with the fi ndings of BMAP, it is clear that the sensitivity of BMAP to detect CIS when present is low and that negative fi ndings should be considered unreliable. OBJECTIVES• To assess the value of bladder mapping and prostatic urethra biopsies for detection of urothelial carcinoma in situ (CIS).• CIS of the urinary bladder is a fl at high-grade lesion of the mucosa associated with a signifi cant risk of progression to muscle-invasive disease. CIS is diffi cult to identify on cystoscopy, and defi nite diagnosis requires histopathology. Traditionally, if CIS is suspected, multiple cold-cup biopsies are taken from the bladder mucosa, and resection biopsies are obtained from the prostatic urethra in males. This approach is often called bladder mapping (BMAP). The accuracy of BMAP as a diagnostic tool is not known. PATIENTS AND METHODS• Male patients with bladder cancer scheduled for cystectomy underwent cold-cup bladder biopsies (sidewalls, posterior wall, dome, trigone), and resection biopsies were taken from the prostatic urethra.• After cystectomy, the surgical specimen was investigated in a standardised manner and subsequently compared with the BMAP biopsies for the presence of CIS. RESULTS• The histopathology reports of 162 patients were analysed. CIS was detected in 46% of the cystoprostatectomy specimens, and multiple ( ≥ 2) CIS lesions were found in 30%.• BMAP (cold-cup bladder biopsies + resection biopsies from the prostatic urethra) provided sensitivity of 51% for any CIS, and 55% for multiple CIS lesions. The cold-cup biopsies for CIS in the bladder mucosa showed sensitivity and specifi city of 46% and 89%, respectively. CONCLUSION• Traditional cold-cup biopsies are unreliable for detecting CIS in bladder mucosa and negative fi ndings must be interpreted with caution. KEYWORDSbladder cancer , carcinoma in situ (CIS) , bladder mapping , biopsies , prostatic urethra Study Type -Diagnostic (case series) Level of Evidence 4

Guideline of guidelines: non‐muscle‐invasive bladder cancer

“…Some urothelial carcinomas, in particular CIS, may not be visible cystoscopically and may only be detected by random or ‘mapping’ biopsies . Given the low yield in all‐comers, no organization advocates random bladder biopsy routinely.…”

The sensitivity of fluorescent‐light cystoscopy for the detection of carcinoma in situ (CIS) of the bladder: a meta‐analysis with comments on gold standard

“…Happily though, a recent study by Gudjónsson et al . [3] that examined the diagnostic performance of five‐biopsy bladder mapping did use cystectomy specimens as gold standard.…”

“…A recent bladder mapping study of 308 patients by Gudjónsson et al . [3] based on five biopsies from unremarkable bladder mucosa indicates a sensitivity of 46% using cystectomy specimens as gold standard. A recent population‐based study of 538 patients with bladder cancer by Thorstenson et al .…”

Outcome in patients with exclusive carcinoma in situ (CIS) after radical cystectomy

“…Recently, Gudjónsson et al. assessed the value of bladder mapping and prostatic urethra biopsies for the detection of CIS and reported sensitivity rates of only 51%, highlighting the importance of interpreting negative findings with caution. Importantly, early diagnosis of recurrent urethral low‐stage cancer allows endourethral BCG perfusion, which can be successful in >80% of patients, potentially avoiding the need for urethrectomy and consequent sacrifice of the bladder substitute .…”

“…Patients with carcinoma in situ (CIS) of the urinary bladder are at risk of progression to invasive disease and death if left untreated . Attempts to control CIS with transurethral bladder resection (TURB) alone are unsuccessful in most cases, and therefore not considered an ideal therapeutic option.…”