Photodynamic diagnosis (5-aminolevulinic acid) of transitional cell carcinoma after bacillus Calmette-Guérin immunotherapy and mitomycin C intravesical therapy

BACKGROUND: Photodynamic diagnosis (PDD) is a technique that enhances the detection of occult bladder tumors during cystoscopy using a fluorescent dye.

OBJECTIVE: To study the differential effects of bacillus Calmette-Guérin (BCG) and mitomycin C (MMC) intravesical therapy on the false-positive rate of PDD of bladder cancer.

DESIGN, SETTING, AND PARTICIPANTS: This study included 552 procedures and 1874 biopsies.

INTERVENTION: Tumors were resected and biopsies were taken from suspicious areas, under guidance of white-light endoscopy and 5-ALA (5-aminolevulinic acid)-induced fluorescence cystoscopy.

MEASUREMENTS: The influence of intravesical BCG immunotherapy and intravesical MMC chemotherapy on pyuria, inflammation, and PDD specificity was examined in univariate analyses.

RESULTS AND LIMITATIONS: BCG significantly results in inflammation (odds ratio [OR]: 1.53, p=0.002), leukocyturia (OR: 1.84, p=0.034), and false positives in PDD (OR: 1.49, p=0.001). However, a single BCG instillation within 3 mo before PDD is most likely not associated with increased false-positive rates (OR: 0.35, p=0.26). Leukocyturia normalizes within 6 wk after the last BCG instillation, but PDD specificity is reduced up to 3 mo.

CONCLUSIONS: BCG is an important predictor for false positives in PDD (5-ALA). More than one BCG instillation within 3 mo before fluorescence cystoscopy decreases the specificity of PDD.