Clinical value of minimum apparent diffusion coefficient for prediction of clinically significant prostate cancer in the transition zone.

BACKGROUND: This study investigated the association between apparent diffusion coefficients in Prostate Imaging Reporting and Data System 4/5 lesions and clinically significant prostate cancer in the transition zone. METHODS: We included 102 patients who underwent transperineal cognitive fusion targeted biopsy for Prostate Imaging Reporting and Data System 4/5 lesions in the transition zone between 2016 and 2020. The association between apparent diffusion coefficients and prostate cancers in the transition zone was analyzed. RESULTS: The detection rate of prostate cancer was 49% (50/102), including clinically significant prostate cancer in 37.3% (38/102) of patients. The minimum apparent diffusion coefficients in patients with clinically significant prostate cancer were 494.5 ± 133.6 µm2/s, which was significantly lower than 653.8 ± 172.5 µm2/s in patients with benign histology or clinically insignificant prostate cancer. Age, prostate volume, transition zone volume, and mean and minimum apparent diffusion coefficients were associated with clinically significant prostate cancer. Multivariate analysis demonstrated that only the minimum apparent diffusion coefficient value (odds ratio: 0.994; p < 0.001) was an independent predictor of clinically significant prostate cancer. When the cutoff value of the minimum apparent diffusion coefficient was less than 595 µm2/s, indicating the presence of prostate cancer in the transition zone, the detection rate increased to 59.2% (29/49) in this cohort. CONCLUSION: The minimum apparent diffusion coefficient provided additional value to indicate the presence of clinically significant prostate cancer in the transition zone. It may help consider the need for subsequent biopsies in patients with Prostate Imaging Reporting and Data System 4/5 lesions and an initial negative targeted biopsy.

A Case of Primary Small-Cell Carcinoma of the Bladder.

Primary small-cell carcinoma arising from the bladder (SmCCB) is uncommon. It differs from urothelial carcinoma (UC), the most common type of bladder cancer, with respect to its cell of origin, biology, and prognosis. Biologically, prostatic SmCCB is much more aggressive than UC, and the prognosis for cases with distant metastasis is especially poor. We report here a case of primary SmCCB (cT3bN1M0) treated with radical cystectomy.