Sano Takeshi, Ohe Chisato, Nakamoto Takahiro, Yoshida Takashi, Taniguchi Hisanori, Yanishi Masaaki, Kinoshita Hidefumi
Department of Urology and Andrology, Kansai Medical University, Osaka, Japan.
Department of Pathology, Graduate School of Medicine, Osaka Metropolitan University, Osaka, Japan.
Int J Urol. 2025 Jun;32(6):729-736. doi: 10.1111/iju.70045. Epub 2025 Mar 26.
To demonstrate the diagnostic performance of photodynamic diagnosis (PDD) for bladder cancer using oral 5-aminolaevulinic acid in patients with or without a history of intravesical Bacillus Calmette-Guérin (BCG) therapy, and to investigate the potential causes of false-positive results.
This retrospective study included 110 patients with suspected non-muscle-invasive bladder cancer who underwent PDD. Among them, 80 patients had no history of BCG therapy (BCG-naïve group) and 30 had received BCG therapy (BCG group). Pathological examination of false-positive and true-negative PDD samples was performed.
In the BCG-naïve group, 215 samples were PDD-positive, of which 53 (24.7%) showed no malignancy. In the BCG group, 94 samples were PDD-positive, of which 51 (54.3%) showed no malignancy. The sensitivity, specificity, positive predictive value, and negative predictive value of PDD in the BCG-naïve versus BCG group were 70.1 versus 76.8, 82.6 versus 56.0, 75.3 versus 45.7, and 78.5 versus 83.3, respectively. Only six of 100 samples (6%) with false-positive PDD results showed precancerous findings. Irrespective of whether patients had received intravesical BCG therapy, > 90% of the samples with false positivity in PDD showed reactive changes, whereas 22 of 95 samples (23.2%) with true negativity in PDD showed reactive changes (p < 0.0001).
Both the specificity and positive predictive value of PDD were lower in the BCG group than in the BCG-naïve group. In most false-positive PDD samples, reactive changes, rather than precancerous findings, were observed-even in the BCG-naïve group.
