Faculty Bibliography

Bladder cancer is the fifth most prevalent cancer in the U.S., yet is understudied, and few laboratory models exist that reflect the biology of the human disease. Here, we describe a biobank of patient-derived organoid lines that recapitulates the histopathological and molecular diversity of human bladder cancer. Organoid lines can be established efficiently from patient biopsies acquired before and after disease recurrence and are interconvertible with orthotopic xenografts. Notably, organoid lines often retain parental tumor heterogeneity and exhibit a spectrum of genomic changes that are consistent with tumor evolution in culture. Analyses of drug response using bladder tumor organoids show partial correlations with mutational profiles, as well as changes associated with treatment resistance, and specific responses can be validated using xenografts in vivo. Our studies indicate that patient-derived bladder tumor organoids represent a faithful model system for studying tumor evolution and treatment response in the context of precision cancer medicine.

The intrinsic ability to exhibit self-organizing morphogenetic properties in ex vivo culture may represent a general property of tissue stem cells. Here we show that single luminal stem/progenitor cells can generate prostate organoids in a three-dimensional culture system in the absence of stroma. Organoids generated from CARNs (castration-resistant Nkx3.1-expressing cells) or normal prostate epithelia exhibit tissue architecture containing luminal and basal cells, undergo long-term expansion in culture and exhibit functional androgen receptor signalling. Lineage-tracing demonstrates that luminal cells are favoured for organoid formation and generate basal cells in culture. Furthermore, tumour organoids can initiate from CARNs after oncogenic transformation and from mouse models of prostate cancer, and can facilitate analyses of drug response. Finally, we provide evidence supporting the feasibility of organoid studies of human prostate tissue. Our studies underscore the progenitor properties of luminal cells, and identify in vitro approaches for studying prostate biology.

PURPOSE/OBJECTIVE:Response rates to current second line intravesical therapies for recurrent nonmuscle invasive bladder cancer range between 10% and 30%. Nanoparticle albumin bound (nab-)paclitaxel has increased solubility and lower toxicity compared to other taxanes. Results of the phase I intravesical trial of this compound demonstrated minimal toxicity during dose escalation. We now report the results of a phase II trial to assess efficacy. MATERIALS AND METHODS/METHODS:This study was an investigator initiated, single center, single arm, phase II trial investigating the use of nab-paclitaxel in patients with recurrent Tis, T1 and Ta urothelial carcinoma in whom at least 1 prior regimen of intravesical bacillus Calmette-Guérin failed. Patients received 500 mg/100 ml nab-paclitaxel administered in 6 weekly intravesical instillations. Efficacy was evaluated with cystoscopy, biopsy, cytology and imaging. If complete response was achieved, patients were treated with full dose monthly maintenance treatments for 6 months. RESULTS:A total of 28 patients were enrolled in the study. Of these patients 10 (35.7%) exhibited a complete response after initial treatment. At 1 year all of these responses remained durable after maintenance therapy. At a mean followup of 21 months (range 5 to 47) 19 of 28 (67.8%) patients retained their bladders without progression or distant metastases. A single patient had progression to muscle invasive disease at radical cystectomy. Treatment related adverse events were noted in 9 of 28 (32.1%) patients and were limited to grade 1 or 2. CONCLUSIONS:Intravesical nab-paclitaxel has minimal toxicity and a 35.7% response rate in patients with nonmuscle invasive bladder cancer and previous bacillus Calmette-Guérin failure. Complete response remained durable at 1 year followup in this heavily pretreated patient population.

Social media can benefit prostate cancer care through education and empowerment, but also have the potential for exposure to misinformation, leading to adverse health and/or economic impacts for patients and damaging the patient-physician relationship. Clinicians should promote digital health literacy and provide recommended sources of reliable online content for additional information.

OBJECTIVE:To evaluate urinalysis testing patterns within the Veterans Health Administration (VHA), estimate the proportion and likelihood of patients who completed a urinalysis to have microscopic hematuria (MH), and explore how urinalysis testing patterns may influence MH detection. METHODS:This was a retrospective cross-sectional study using VHA data. We identified adult patients without a known urologic cancer history who had at least 1 outpatient visit at any VHA site and at least 1 interpretable urinalysis performed in 2015. The factors associated with the number or urinalyses performed on each patient and associations with the presence of MH were investigated. RESULTS:Among 5,719,966 adults, 39% completed a urinalysis. Variation in the proportion of patients who completed urinalyses was highest by age, among patients with hypertension and diabetes, and by region. Of patients who underwent urinalysis and had no prior genitourinary cancer history, 54% did not have an interpretable urinalysis result. Among patients with at least one interpretable microscopic urinalysis, 37% had MH. This was more common among older patients, females, current smokers, and patients with more comorbidities. Variation in the likelihood of patients having MH remained after adjusting for multiple factors and when contextualized by urinalysis completion and interpretability patterns. CONCLUSION/CONCLUSIONS:The number of urinalyses performed in the VHA system is remarkably high. Detection of MH is influenced by the frequency of urinalysis testing and interpretability of results. The presence and detection of MH varies by factors which should be considered when adjudicating the need for further evaluation of MH.

Inaccurate information about prostate cancer is widespread on online social networks in English and Spanish and spans a variety of topics from prevention and screening to treatment and survivorship. Clinicians should raise awareness that social media can be a source of misinformation about prostate cancer, preemptively address prevalent myths, and actively participate in public dissemination of evidence-based information.

Mutagenic processes leave distinct signatures in cancer genomes. The mutational signatures attributed to APOBEC3 cytidine deaminases are pervasive in human cancers. However, data linking individual APOBEC3 proteins to cancer mutagenesis in vivo are limited. Here, we showed that transgenic expression of human APOBEC3G promotes mutagenesis, genomic instability, and kataegis, leading to shorter survival in a murine bladder cancer model. Acting as mutagenic fuel, APOBEC3G increased the clonal diversity of bladder cancer, driving divergent cancer evolution. Characterization of the single base substitution signature induced by APOBEC3G in vivo established the induction of a mutational signature distinct from those caused by APOBEC3A and APOBEC3B. Analysis of thousands of human cancers revealed the contribution of APOBEC3G to the mutational profiles of multiple cancer types, including bladder cancer. Overall, this study dissects the mutagenic impact of APOBEC3G on the bladder cancer genome, identifying it contributes to genomic instability, tumor mutational burden, copy-number loss events, and clonal diversity.

OBJECTIVE:To determine if there is an association between patient race and physician time spent with the patient during outpatient urology consultations. METHODS:We identified all adult urology new outpatient visits in the National Ambulatory Medical Care Survey dataset for 2012-2016. Patient race was dichotomized as White or non-White. Our primary outcome was time spent during the visit between the patient and urologist. Using population-level weighting, we compared differences in mean time spent during visits with White and non-White patients. Mixed-effects linear regression was used to adjust for confounding factors and to account for clustering among individual physicians. Secondary outcomes included number of services provided and if ancillary providers were seen. RESULTS:Over the 5 year period, 1668 raw visits met criteria and were used to estimate 21million new outpatient urology visits nationwide. 80% of all visits were with White patients. Mean physician time spent among visits with white patients was 23.9 minutes and 24.4 minutes for non-White patients. There was no difference in number of services provided but visits with non-white patients were less likely to include an ancillary provider. After adjustment, there was no significant difference in mean time spent with the urologist among visits with White and non-White patients (difference 0.9 minutes, 95% CI: -0.6-2.4). There were also no differences in adjusted mean time spent among return visits or new visits for hematuria, urologic cancers, or BPH. CONCLUSION/CONCLUSIONS:We found no statistically significant difference in time spent with a urologist during outpatient office consultations between White and non-White patients.