The Cytidine Deaminase APOBEC3G Contributes to Cancer Mutagenesis and Clonal Evolution in Bladder Cancer.

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 that it contributes to genomic instability, tumor mutational burden, copy-number loss events, and clonal diversity. SIGNIFICANCE: APOBEC3G plays a role in cancer mutagenesis and clonal heterogeneity, which can potentially inform future therapeutic efforts that restrict tumor evolution. See related commentary by Caswell and Swanton, p. 487.

A National Assessment of the Association Between Patient Race and Physician Visit Time During New Outpatient Urology Consultations.

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: We found no statistically significant difference in time spent with a urologist during outpatient office consultations between White and non-White patients.

Racial and ethnic representation in primary research contributing to pelvic organ prolapse treatment guidelines.

INTRODUCTION AND HYPOTHESIS: To evaluate whether the studies contributing to the national treatment guidelines on pelvic organ prolapse adequately represent the racial and/or ethnic makeup of the American population. METHODS: This analysis examines the racial and ethnic makeup of all primary study cohorts contributing to the American College of Obstetricians and Gynecologists/American Urogynecologic Society Practice Bulletin No. 214 on pelvic organ prolapse. References were excluded if they lacked a primary patient population or were from outside the US. Mean proportional representation of racial/ethnic groups was compared to the 2018 United States Census data on race/ethnicity. The representation quotient was also calculated to evaluate for relative representation of each group. Descriptive statistics were used. RESULTS: Of the 110 references, 53 primary studies were included in the final analysis with 30 studies reporting on race/ethnicity. On average, 82% (SD = 15%) of study populations were White, while Blacks, Hispanics, and Asians represented 67% (SD = 7%), 4% (SD = 8%), and < 1% (SD = 1%), respectively, differing significantly from the 2018 US Census (p < 0.01.) The representation quotients for White women was 1.36, demonstrating a 36% overrepresentation, while Black, Hispanic, and Asian women were underrepresented among studies of all evidence levels, with representative quotients of 0.50, 0.23, and 0.09, respectively. CONCLUSIONS: Our study demonstrates a significant underrepresentation of non-White populations in primary cohorts of studies contributing to the ACOG/AUGS Practice Bulletin No. 214 on POP. This analysis reinforces that more efforts are required to include and report on racial and ethnically diverse cohorts to better serve all patients.

Tumor Evolution and Drug Response in Patient-Derived Organoid Models of Bladder Cancer.

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 Role of Gut Microbiome in the Pathogenesis of Prostate Cancer: A Prospective, Pilot Study.

OBJECTIVE: To elucidate potential biomarkers or mechanistic principles involved with the gut microbiota and its impact on prostate cancer pathogenesis. MATERIALS AND METHODS: We performed a prospective case-control pilot study evaluating the gut microbiome of 20 men with either benign prostatic conditions (n = 8) or intermediate or high risk clinically localized prostate cancer (Gleason ≥4 + 3 cN0M0) (n = 12) undergoing care at tertiary referral center from September 1, 2015 to March 1, 2016. Key exclusion criteria included recent antibiotic use, significant gastrointestinal disorders, hormonal or systemic therapy for prostate cancer. Computational genomics analysis was performed on collected stool samples using MetaPhlAn2 and HUMAnN2 platforms. Linear discriminant analysis effect size method was used to support high-dimensional class comparisons to find biologically relevant features. Kruskal-Wallis sum-rank test was used to detect features with significant differential abundance with respect to class, with biological consistency investigated using a set of pairwise tests among subclasses using the Wilcoxon rank-sum test, both to an α ≤0.05. RESULTS: Higher relative abundance of Bacteriodes massiliensis was seen in prostate cancer cases compared to controls. Faecalibacterium prausnitzii and Eubacterium rectalie had higher relative abundance among controls. Biologically significant differences were also found in relative gene, pathway, and enzyme abundance. CONCLUSION: Biologically significant differences exist in the gut microbial composition of men with prostate cancer compared to benign controls. These differences may play a role in the pathobiology of prostate cancer, and warrant further exploration.

The Timing of Radical Cystectomy for bacillus Calmette-Guérin Failure: Comparison of Outcomes and Risk Factors for Prognosis.

PURPOSE: We compared the pathological and survival outcomes of patients who underwent radical cystectomy soon after bacillus Calmette-Guérin failure with those of patients who received additional salvage intravesical chemotherapy before cystectomy for nonmuscle invasive bladder cancer. We also identified predictors of prognosis in the entire cohort. MATERIALS AND METHODS: We retrospectively analyzed the records of 117 patients who underwent radical cystectomy for recurrent nonmuscle invasive bladder cancer at our institution from 1990 to 2012. The cohort was divided into group 1 of 61 patients treated only with bacillus Calmette-Guérin with or without interferon-α and group 2 of 56 who received at least 1 additional salvage intravesical chemotherapy after bacillus Calmette-Guérin. RESULTS: Final pathology and survival outcomes did not differ significantly between the groups. Five-year overall and cancer specific survival was similar in groups 1 and 2 at 80% and 85%, respectively, at approximately equivalent followups. Median bladder retention was 1.7 years longer in group 2 (p <0.001). On multivariate Cox regression analysis delayed cystectomy in group 2 did not convey a significant hazard for all cause mortality after cystectomy (HR 1.08, p = 0.808). Only up-staging to cT1 (HR 1.88, p = 0.045), lymph node invasion (HR 2.58, p = 0.023) and prostatic urethra involvement (HR 1.95, p = 0.029) achieved significance. CONCLUSIONS: With appropriate selection for salvage intravesical chemotherapy patients who elect bladder sparing treatment instead of earlier radical cystectomy after bacillus Calmette-Guérin fails do not sacrifice positive pathological or oncologic outcomes while retaining bladder function for a significantly longer duration.

The Correlation of Media Ranking's "Best" Hospitals and Surgical Outcomes Following Radical Cystectomy for Urothelial Cancer.

OBJECTIVE: To evaluate whether there is a correlation between publicized health ranking systems and surgical outcomes after radical cystectomy (RC) in New York State (NYS). MATERIALS AND METHODS: Using the Statewide Planning and Research Cooperative System, data were collected in an aggregated fashion per hospital for the 20 hospitals with the highest RC volume in NYS from 2009 to 2012. Hospital characteristics were obtained from the publicly available sources such as the Centers for Medicare and Medicaid Services. Publicized ranking systems evaluated included the US News & World Health Report for Urology ranking (USHR), Healthgrades (HG) score, and Consumer Reports (CR) safety ranking. Outcomes measured included mortality, readmissions, and causes of readmissions. RESULTS: CR safety scores were inversely associated with overall death at 90 days after surgery (R = -0.527, P = .030), number of readmissions (R = -0.608, P = .030), and readmissions because of surgical complications (R = -0.523, P = .031) on a Pearson correlation test. On Kendall rank tau test, USHR and HG were not associated with any outcome of interest, although the scores correlated with increasing RC volume. CONCLUSION: In our analysis of 20 hospitals with the highest RC volume in NYS, USHR and HG scores were not strongly associated with any clinical outcome after RC. CR performed well in comparison with USHR and HG. Nevertheless, better metrics are needed to compare hospitals and to incorporate curative rates for morbid surgeries.

Single luminal epithelial progenitors can generate prostate organoids in culture.

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.

Phase II trial of intravesical nanoparticle albumin bound paclitaxel for the treatment of nonmuscle invasive urothelial carcinoma of the bladder after bacillus Calmette-Guérin treatment failure.

PURPOSE: 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: 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.

Experience with newer intravesical chemotherapy for high-risk non-muscle-invasive bladder cancer.

The definitive treatment for patients with high-risk non-muscle-invasive bladder cancer (NMIBC) who fail to respond to intravesical bacillus Calmette-Guérin (BCG) is cystectomy. However, many patients who experience recurrence after BCG are either poor operative candidates or refuse surgery due to the long-term impact on their quality of life. In the last decade, there has been an increased interest in alternative intravesical therapies, and several novel chemotherapeutics have emerged as promising agents for high-risk NMIBC patients unable or unwilling to undergo cystectomy. Additionally, extended treatment regimens with combined induction and maintenance therapy have been investigated, and may increase the durability of response to these new agents, as has been shown for conventional intravesical therapy.

Long-term survival outcomes with intravesical docetaxel for recurrent nonmuscle invasive bladder cancer after previous bacillus Calmette-Guérin therapy.

PURPOSE: Docetaxel is a safe agent for intravesical therapy. Adding monthly maintenance treatments can extend response durability. We report our cumulative experience with intravesical docetaxel in a larger cohort with extended followup. MATERIALS AND METHODS: A total of 54 patients received salvage intravesical docetaxel for bacillus Calmette-Guérin refractory nonmuscle invasive bladder cancer between 2003 and 2012, including 18 treated during the original phase I trial. All patients received 6 weekly instillations of intravesical docetaxel. After the phase I trial, those with a complete response to induction treatment were offered single dose monthly maintenance treatments for a total of up to 12 months of docetaxel therapy. Recurrence was defined as positive biopsy or urine cytology. Recurrence-free, disease specific and overall survival was determined by Kaplan-Meier analysis. RESULTS: Median followup was 39.1 months. Of the 54 patients 32 (59%) had a complete initial response after induction therapy, including 18 who received additional monthly maintenance treatments. Median time to recurrence in initial responders treated with vs without docetaxel maintenance was 39.3 vs 19.0 months. One and 3-year recurrence-free survival rates for the entire cohort were 40% and 25%, respectively. Of the 54 patients 17 (24%) underwent radical cystectomy at a median of 24 months of followup. Five-year disease specific and overall survival rates were 85% and 71%, respectively. CONCLUSIONS: Intravesical docetaxel appears to be a promising agent with significant efficacy and durability for bacillus Calmette-Guérin refractory nonmuscle invasive bladder cancer. Adding maintenance treatments may increase the duration of recurrence-free survival.

Tumour diameter and decreased preoperative estimated glomerular filtration rate are independently correlated in patients with renal cell carcinoma.

OBJECTIVE: To examine the relationship between tumour diameter and estimated GFR (eGFR) in patients with renal cell carcinoma (RCC). PATIENTS AND METHODS: In total, 1009 patients undergoing partial or radical nephrectomy for unilateral RCC were identified in the Columbia Urologic Database. eGFR was calculated using the modification of diet in renal disease equation using demographic data and preoperative serum creatinine values. Data on patient demographics, tumour characteristics, and comorbidities were analyzed using univariate and multivariate regression analysis. RESULTS: Mean (sd, range) tumour diameter was 5.29 (3.8, 0.3-29) cm. Mean (sd, range) eGFR was 75 (23.4, 3-173) mL/min per 1.73 m(2) . In multivariate regression analysis, tumour diameter independently predicted decreased preoperative eGFR (coefficient, -0.513; P= 0.008) when controlling for hypertension and race. Consistent with this, decreased preoperative eGFR independently predicted increased tumour diameter (coefficient, -0.013; P= 0.007) when controlling for race, histology and smoking status. CONCLUSION: Tumour diameter and decreased preoperative eGFR are independently correlated in patients with RCC.

A comparison of the outcomes of neoadjuvant and adjuvant chemotherapy for clinical T2-T4aN0-N2M0 bladder cancer.

BACKGROUND: Despite evidence supporting perioperative chemotherapy, few randomized studies compare neoadjuvant and adjuvant chemotherapy for bladder cancer. Consequently, the standard of care regarding the timing of chemotherapy for locally advanced bladder cancer remains controversial. We compared patient outcomes following neoadjuvant or adjuvant systemic chemotherapy for cT2-T4aN0-N2M0 bladder cancer. METHODS: In a retrospective review of a single institutional database from 1988 through 2009, we identified patients receiving neoadjuvant or adjuvant multiagent platinum-based systemic chemotherapy for locally advanced bladder cancer. Survival analysis was performed comparing disease-specific survival (DSS) and overall survival (OS). RESULTS: A total of 146 patients received systemic perioperative chemotherapy (73 neoadjuvant, 73 adjuvant). Of these, 84% (122/146) received cisplatin-based chemotherapy compared with carboplatin-based chemotherapy (24/146, 16.4%). Most patients receiving cisplatin-based chemotherapy were treated with methotrexate/vinblastine/adriamycin/cisplatin (79/122, 64.8%), whereas the remaining patients received gemcitabine/cisplatin (GC) (43/122, 35.2%). In multivariable analysis, there was no significant difference in DSS (P = .46) or OS (P = .76) between neoadjuvant or adjuvant chemotherapy groups. There was statistically significant improvement in DSS when patients received neoadjuvant GC rather than adjuvant GC (P = .049, hazard ratio, 10.6; 95% confidence interval, 1.01-112.2). CONCLUSION: In this study, there was no statistically significant difference in OS and DSS between patients receiving neoadjuvant versus adjuvant systemic platinum-based chemotherapy for locally advanced bladder cancer. In addition, there was no significant difference between neoadjuvant and adjuvant cisplatin- or carboplatin-based chemotherapy. Chemotherapy sequence relative to surgery appeared less important than whether or not a patient actually received perioperative chemotherapy.

A phase I trial of intravesical nanoparticle albumin-bound paclitaxel in the treatment of bacillus Calmette-Guérin refractory nonmuscle invasive bladder cancer.

PURPOSE: Up to 50% of patients treated with intravesical agents for high grade nonmuscle invasive bladder cancer will have disease recurrence. Response rates to current second line intravesical therapies are low and for these high risk patients novel agents are necessary. Our previously completed phase I trial showed docetaxel was a safe agent for intravesical use. Nanoparticle albumin-bound paclitaxel (Abraxane®, ABI-007) has been shown to have increased solubility and lower toxicity compared to docetaxel in systemic therapy. Thus, we assessed the dose limiting toxicity and maximum deliverable dose of intravesical nanoparticle albumin-bound paclitaxel. MATERIALS AND METHODS: Inclusion criteria for this institutional review board approved phase I trial were recurrent high grade Ta, T1 and Tis transitional cell carcinoma of the bladder for which at least 1 prior standard intravesical regimen failed. Six weekly instillations of nanoparticle albumin-bound paclitaxel were administered with a modified Fibonacci dose escalation model used until the maximum deliverable dose was achieved. The primary end point was dose limiting toxicity and the secondary end point was response rate. RESULTS: A total of 18 patients were enrolled in the study. One patient demonstrated measurable systemic absorption after 1 infusion. Grade 1 local toxicities were experienced by 10 (56%) patients with dysuria being the most common, and no grade 2, 3 or 4 drug related local toxicities were encountered. Of the 18 patients 5 (28%) had no evidence of disease at posttreatment evaluation. CONCLUSIONS: Intravesical nanoparticle albumin-bound paclitaxel exhibited minimal toxicity and systemic absorption in the first human intravesical phase I trial to our knowledge. A larger phase II study has begun to formally evaluate the activity of this regimen.

Serum tumor markers in the evaluation of male germ cell tumors.

Serum tumor markers play a critical role in the diagnosis, staging, risk stratification, and surveillance of patients with testicular germ cell tumors (GCTs). Production of the oncofetal substances α fetoprotein and human chorionic gonadotropin can aid the diagnosis of testicular GCTs, and specific patterns of marker elevation can be used to determine the type of tumor, particularly as it pertains to nonseminoma. These markers, in addition to lactate dehydrogenase, have been incorporated in the standard TNM staging system for testicular tumors; the S stage category corresponds to serum elevation of these proteins. Furthermore, the degree of serum tumor marker elevation has been incorporated into standardized patient risk groupings, which are used to guide therapeutic management. The rate of tumor marker decay after radical orchiectomy is an important index to monitor, as a slow decline might be indicative of metastatic disease and should prompt a thorough systemic survey. The rate of tumor marker decline is already being utilized in the setting of metastatic GCTs to determine response to chemotherapy, and has been used in some scenarios to individualize the type of chemotherapy patients received. Compared to any other solid organ malignancy, the role of serum tumor markers in GCT is unprecedented; these markers are instrumental in the diagnosis and management of testicular GCT.

Single institutional experience with nephron-sparing surgery for pathologic stage T3bNxM0 renal cell carcinoma confined to the renal vein.

OBJECTIVE: To assess our institution's experience with the management of pathologic stage T3bNxM0 renal cell carcinoma with tumor thrombus confined to the renal vein treated with nephron-sparing surgery (NSS). METHODS: Of the 492 patients who have undergone NSS at Columbia University from 1998 to 2009, 8 patients were found to have stage T3bNxM0 renal cell carcinoma (RCC) on final pathology. Records were reviewed for indication for NSS, imaging studies, perioperative management, surgical details, pathology, and both functional and disease-specific outcomes. Postoperative renal function was estimated by most recent glomerular filtration rate using Modification of Diet in Renal Disease formula. Recurrence of RCC was monitored using serial axial imaging. RESULTS: The 8 patients were presumed to be clinical stage T1aN0M0 RCC before surgery; however, tumor thrombus was identified in the renal vein intraoperatively and on final pathology in 4, and 4 cases, respectively, corresponding to stage T3bNxM0 RCC by current American Joint Committee on Cancer-Tumor-Necrosis-Metastasis 2002 criteria. After a median follow-up of 19.8 months, the patients experienced a mean decrease in estimated glomerular filtration rate of 27.1%. One patient developed new-onset renal failure, defined as an estimated glomerular filtration rate below 30 mL/min/1.73 m(2). Clean surgical margins were obtained in 7 patients. Carcinoma was identified at the parenchymal margin in 1 patient. No patients have evidence of recurrence of RCC by serial axial imaging. CONCLUSIONS: NSS does not seem to have had a negative impact on a small series of patients with pathologic stage T3bNxM0 RCC limited to the renal vein and may be a feasible option when the clinical situation indicates a need for preservation of renal function.