Incidence and management of prostatic urethra recurrence in a cohort of 21 patients who received BCG induction for non-muscle invasive bladder cancer.

PURPOSE: To describe the incidence and management of patients who develop a prostatic urethral (PU) urothelial carcinoma recurrence after Bacillus Calmette-Guerin (BCG) induction for non-muscle invasive bladder cancer (NMIBC). MATERIALS AND METHODS: We performed a retrospective cohort study of all patients who received BCG induction at our institution from 1996 to 2021 (N = 642) for NMIBC. All patients with pathologically confirmed PU involvement following BCG induction with no known PU involvement pre-BCG were included. We describe the presentation, management, and outcomes for PU recurrence. RESULTS: Among the 642 patients, 21 (3.3%) patients had a PU recurrence after BCG induction. 8 (38%) patients received >2 cycles of BCG induction prior to the recurrence. Median time from induction to PU recurrence was 21 months and 12 (57.1%) patients had concurrent bladder recurrence. At the time of their PU recurrence, 14/21 (67%) of patients were deemed BCG Unresponsive. Nearly all (18/21) were high grade, and 10 were stage Tis, 7 Ta, and 3 T1, and 1 T2. 19/21 (90%) patients received bladder sparing treatment: 6 with TURBT and BCG, 6 with TURBT and intravesical chemotherapy, 5 with TURBT only, and 2 did not receive immediate treatment of their PU recurrence due to advanced stage of disease. 2/21 (9.5%) received a radical cystectomy for initial treatment of the post-BCG PU recurrence, of which all were >pT2. Median follow-up time from BCG induction to the patient's last visit was 64.5 months. Following treatment of PU recurrence, 15/18 patients had another recurrence at a median of 5 months: about 47% of recurrences were bladder only and 14% recurred only in the PU as well. About 1 patient received a RC after the second recurrence and was pT2. CONCLUSION: Patients with PU recurrences following intravesical BCG have a high-risk disease phenotype with a significant risk of recurrence. Conservative management may be appropriate for well-selected patients who do not desire a cystoprostatectomy.

Meta-analyses of mouse and human prostate single-cell transcriptomes reveal widespread epithelial plasticity in tissue regression, regeneration, and cancer.

Recent advances in single-cell RNA-sequencing (scRNA-seq) technology have facilitated studies of cell states and plasticity in tissue maintenance and cancer, including in the prostate. Here we present meta-analyses of multiple new and published scRNA-seq datasets to establish reference cell type classifications for the normal mouse and human prostate. Our analyses demonstrate transcriptomic similarities between epithelial cell states in the normal prostate, in the regressed prostate after androgen-deprivation, and in primary prostate tumors. During regression in the mouse prostate, all epithelial cells shift their expression profiles towards a proximal periurethral (PrU) state, demonstrating an androgen-dependent plasticity that is restored to normal during androgen restoration and regeneration. In the human prostate, we find progressive rewiring of transcriptional programs across epithelial cell types in benign prostate hyperplasia and treatment-naïve prostate cancer. Notably, we detect copy number variants predominantly within Luminal Acinar cells in prostate tumors, suggesting a bias in their cell type of origin, as well as a larger field of transcriptomic alterations in non-tumor cells. Finally, we observe that Luminal Acinar tumor cells in treatment-naïve prostate cancer display heterogeneous androgen receptor (AR) signaling activity, including a split between high-AR and low-AR profiles with similarity to PrU-like states. Taken together, our analyses of cellular heterogeneity and plasticity provide important translational insights into the origin and treatment response of prostate cancer.