Landmarks in non-muscle-invasive bladder cancer

In Situ Constructed Nano-Drug Depots through Intracellular Hydrolytic Condensation for Chemotherapy of Bladder Cancer

Intravesical administration of first-line drugs has shown failure in the treatment of bladder cancer owing to the poor tumor retention time of chemotherapeutics. Herein, we report an intracellular hydrolytic condensation (IHC) system to construct long-term retentive nano-drug depots in situ, wherein sustained drug release results in highly efficient suppression of bladder cancer. Briefly, the designed doxorubicin (Dox)-silane conjugates self-assemble into silane-based prodrug nanoparticles, which condense into silicon particle-based nano-drug depots inside tumor cells. Significantly, we demonstrate that the IHC system possesses highly potent antitumor efficacy, which leads to the regression and eradication of large established tumors and simultaneously extends the overall survival of air pouch bladder cancer mice compared with that of mice treated with Dox. The concept of intracellular hydrolytic condensation can be extended via conjugating other chemotherapeutic drugs, which may facilitate rational design of novel nanomedicines for augmentation of chemotherapy.

Explainable artificial intelligence (XAI): closing the gap between image analysis and navigation in complex invasive diagnostic procedures

Literature review

Cystoscopy is the gold standard for initial macroscopic assessments of the human urinary bladder to rule out (or diagnose) bladder cancer (BCa). Despite having guidelines, cystoscopic findings are diverse and often challenging to classify. The extent of the false negatives and false positives in cystoscopic diagnosis is currently unknown. We suspect that there is a certain degree of under-diagnosis (like the failure to detect malignant tumours) and over-diagnosis (e.g. sending the patient for unnecessary transurethral resection of bladder tumors with anesthesia) that put the patient at risk.

Conclusions

XAI robot-assisted cystoscopes would help to overcome the risks/flaws of conventional cystoscopy. Cystoscopy is considered a less life-threatening starting point for automation than open surgical procedures. Semi-autonomous cystoscopy requires standards and cystoscopy is a good procedure to establish a model that can then be exported/copied to other procedures of endoscopy and surgery. Standards also define the automation levels—an issue for medical product law. These cystoscopy skills do not give full autonomy to the machine, and represent a surgical parallel to ‘Autonomous Driving’ (where a standard requires a human supervisor to remain in the ‘vehicle’). Here in robotic cystoscopy, a human supervisor remains bedside in the ‘operating room’ as a ‘human‐in‐the‐loop’ in order to safeguard patients. The urologists will be able to delegate personal- and time-consuming cystoscopy to a specialised nurse. The result of automated diagnostic cystoscopy is a short video (with pre-processed photos from the video), which are then reviewed by the urologists at a more convenient time.

Contrast-Enhanced Ultrasound in the Bladder: Critical Features to Differentiate Occupied Lesions

Objective

To study the clinical diagnostic value of contrast-enhanced ultrasound (CEUS) in bladder occupied lesions.

Methods

38 cases of conventional-ultrasound-found bladder occupied lesions did color Doppler flow imaging (CDFI) and CEUS checks. By comparing the difference between two types of blood flow imaging technologies in displaying the flow of bladder occupied lesions and observing the perfusion modes of contrast agents to enter lesions, the perfusion characteristics of CEUS were analyzed. Finally, they were contrasted with the surgical pathology results.

Results

Of all the 38 cases, there were 51 bladder occupied lesions, including 43 bladder malignant tumors, 2 bladder inverted papillomas, and 6 glandular cystitis lesions. The blood flow display rate of bladder occupied lesions was 100% using CEUS. Apparently, it was higher than that of CDFI (62.7%), and the result of these showed a statistically significant difference (P < 0.05). Using CEUS, 46 malignant lesions and 5 glandular cystitis lesions were indicated, and the diagnostic accuracy rate was 86.3%.

Conclusion

CEUS can improve the blood flow display rate of bladder occupied lesions, and it can also observe the real-time blood flow of these lesions. It can help judge their nature and has a higher clinical value in differentiating the benign from the malignant.

Integrative Transcriptome Profiling Reveals SKA3 as a Novel Prognostic Marker in Non-Muscle Invasive Bladder Cancer

Approximately 80% of all new bladder cancer patients are diagnosed with non-muscle invasive bladder cancer (NMIBC). However, approximately 15% of them progress to muscle-invasive bladder cancer (MIBC), for which prognosis is poor. The current study aimed to improve diagnostic accuracy associated with clinical outcomes in NMIBC patients. Nevertheless, it has been challenging to identify molecular biomarkers that accurately predict MIBC progression because this disease is complex and heterogeneous. Through integrative transcriptome profiling, we showed that high SKA3 expression is associated with poor clinical outcomes and MIBC progression. We performed RNA sequencing on human tumor tissues to identify candidate biomarkers in NMIBC. We then selected genes with prognostic significance by analyzing public datasets from multiple cohorts of bladder cancer patients. We found that SKA3 was associated with NMIBC pathophysiology and poor survival. We analyzed public single-cell RNA-sequencing (scRNA-seq) data for bladder cancer to dissect transcriptional tumor heterogeneity. SKA3 was expressed in an epithelial cell subpopulation expressing genes regulating the cell cycle. Knockdown experiments confirmed that SKA3 promotes bladder cancer cell proliferation by accelerating G2/M transition. Hence, SKA3 is a new prognostic marker for predicting NMIBC progression. Its inhibition could form part of a novel treatment lowering the probability of bladder cancer progression.

Association of Dietary Carrot Intake With Bladder Cancer Risk in a Prospective Cohort of 99,650 Individuals With 12.5 Years of Follow-Up

Previous studies have provided limited evidence for the effect of carrot intake on bladder cancer incidence. This study aimed to evaluate the association between carrot consumption and bladder cancer risk in the Prostate, Lung, Colorectal, and Ovarian Cancer (PLCO) Screening cohort. PLCO enrolled 154,897 participants between November 1993 and July 2001 from 10 clinical screening centers throughout the United States. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox regression model adjusting for confounders. A meta-analysis was also performed based on all available prospective studies with DerSimonian and Laird random-effects model to calculate summary relative risk (RR) and 95% CI. After a median of 12.5 years of follow-up, 762 incident bladder cancer cases occurred. We found no statistically significant association between dietary carrot intake and bladder cancer risk. The multivariate-adjusted HR of bladder cancer for participants in the highest category of total carrot intake compared with those in the lowest category was 0.96 (95% CI: 0.76–1.22; P for trend = 0.436). Corresponding adjusted HR was 0.98 (95% CI 0.90–1.06) per 1 SD increment of carrot intake. A meta-analysis based on two previous cohort studies and our study also found no significant association between carrot intake and bladder cancer risk (Summary HR 1.02, 95% CI 0.95–1.10) without obvious heterogeneity between studies (P = 0.859, I² = 0.0%). In summary, analysis of the PLCO cohort did not provide evidence that dietary consumption of carrot was associated with the risk of bladder cancer.

The impact of the social construct of race on outcomes among bacille Calmette-Guérin-treated patients with high-risk non-muscle-invasive bladder cancer in an equal-access setting

BACKGROUND

The objective of this study was to describe bladder cancer outcomes as a function of race among patients with high-risk non-muscle-invasive bladder cancer (NMIBC) in an equal-access setting.

METHODS

A total of 412 patients with high-risk NMIBC who received bacille Calmette-Guérin (BCG) from January 1, 2010, to December 31, 2015, were assessed. The authors used the Kaplan-Meier method to estimate event-free survival and Cox regression to determine the association between race and recurrence, progression, disease-specific, and overall survival outcomes.

RESULTS

A total of 372 patients who had complete data were included in the analysis; 48 (13%) and 324 (87%) were Black and White, respectively. There was no difference in age, sex, smoking status, or Charlson Comorbidity Index by race. White patients had a higher socioeconomic status with a greater percentage of patients living above the poverty level in comparison with Black patients (median, 85% vs 77%; P < .001). A total of 360 patients (97%) received adequate induction BCG, and 145 patients (39%) received adequate maintenance BCG therapy. There was no significant difference in rates of adequate induction or maintenance BCG therapy according to race. There was no significant difference in recurrence (hazard ratio [HR], 1.53; 95% confidence interval [CI], 0.64-3.63), progression (HR, 0.77; 95% CI, 0.33-1.82), bladder cancer-specific survival (HR, 1.01; 95% CI, 0.30-3.46), or overall survival (HR, 0.97; 95% CI, 0.56-1.66) according to Black race versus White race.

CONCLUSIONS

In this small study from an equal-access setting, there was no difference in the receipt of BCG or any differences in bladder cancer outcomes according to race.

Dominant role of CDKN2B/p15INK4B of 9p21.3 tumor suppressor hub in inhibition of cell-cycle and glycolysis

Human chromosome 9p21.3 is susceptible to inactivation in cell immortalization and diseases, such as cancer, coronary artery disease and type-2 diabetes. Although this locus encodes three cyclin-dependent kinase (CDK) inhibitors (p15^INK4B, p14^ARF and p16^INK4A), our understanding of their functions and modes of action is limited to the latter two. Here, we show that in vitro p15^INK4B is markedly stronger than p16^INK4A in inhibiting pRb1 phosphorylation, E2F activity and cell-cycle progression. In mice, urothelial cells expressing oncogenic HRas and lacking p15^INK4B, but not those expressing HRas and lacking p16^INK4A, develop early-onset bladder tumors. The potency of CDKN2B/p15^INK4B in tumor suppression relies on its strong binding via key N-terminal residues to and inhibition of CDK4/CDK6. p15^INK4B also binds and inhibits enolase-1, a glycolytic enzyme upregulated in most cancer types. Our results highlight the dual inhibition of p15^INK4B on cell proliferation, and unveil mechanisms whereby p15^INK4B aberrations may underpin cancer and non-cancer conditions.

The human chromosome locus 9p21.3 is a tumour suppressor hub which encodes three CDK inhibitors, p15INK4B, p14ARF and p16INK4A. Here, the authors show that p15INK4B inhibits the cell cycle and glycolysis in a murine model of HRas + ‐mediated urothelial carcinoma and has a more relevant role as a tumour suppressor than its neighbouring p16INK4A.

The Clinical Application and Potential Roles of Circulating Tumor Cells in Bladder Cancer and Prostate Cancer

Circulating tumor cells (CTCs) are considered to be promising biomarkers in malignant diseases. Recently, molecular profiles of CTCs in prostate cancer (PCa) and the role of CTCs in neoadjuvant chemotherapy and transurethral resections of bladder cancer (BCa) are intensely studied. However, localized PCa and nonmuscle-invasive BCa are less investigated and discussed. Moreover, the benefit and feasibility of clinical applications of CTCs should be critically questioned and reevaluated. This review focuses mainly on clinical issues and lesser on methodologies, and summarizes the quintessence of available works dealing with clinical applications of CTCs in PCa and BCa management.

Dietary glycemic index, glycemic load and risk of bladder cancer: a prospective study

PURPOSE

Previous studies have provided limited evidence for an adverse effect of high glycemic index (GI) and glycemic load (GL) on bladder cancer risk. This study aimed to examine the association between GI, GL and bladder cancer risk in the Prostate, Lung, Colorectal, and Ovarian Cancer (PLCO) Screening Trial.

METHODS

GI and GL scores were computed among 101,721 participants in the PLCO study. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox regression model adjusting for confounders.

RESULTS

After a median of 12.5 years of follow-up, 776 incident bladder cancer cases occurred. There was no significant association between bladder cancer risk and GI (HR_Q5vsQ1 = 1.18, 95% CI 0.94-1.48, p for trend = 0.177) or GL (HR_Q5vsQ1 = 0.92, 95% CI 0.65-1.30, p for trend = 0.826). The associations did not differ by continuous analyses. Spline regression plots revealed a lower risk of bladder cancer with higher GI or GL, but the difference was not statistically significant. There was no statistical evidence for nonlinearity (P for nonlinearity > 0.05).

CONCLUSION

In summary, analysis of the PLCO cohort did not provide evidence that higher GI or GL diets were associated with greater bladder cancer risk.

A Renal-Clearable Macromolecular Reporter for Near-Infrared Fluorescence Imaging of Bladder Cancer

Bladder cancer (BC) is a prevalent disease with high morbidity and mortality; however, in vivo optical imaging of BC remains challenging because of the lack of cancer-specific optical agents with high renal clearance. Herein, a macromolecular reporter (CyP1) was synthesized for real-time near-infrared fluorescence (NIRF) imaging and urinalysis of BC in living mice. Because of the high renal clearance (ca. 94 % of the injection dosage at 24 h post-injection) and its cancer biomarker (APN=aminopeptidase N) specificity, CyP1 can be efficiently transported to the bladder and specially turn on its NIRF signal to report the detection of BC in living mice. Moreover, CyP1 can be used for optical urinalysis, permitting the ex vivo tracking of tumor progression for therapeutic evaluation and easy translation of CyP2 as an in vitro diagnostic assay. This study not only provides new opportunities for non-invasive diagnosis of BC, but also reveals useful guidelines for the development of molecular reporters for the detection of bladder diseases.

Circular RNA expression is abundant and correlated to aggressiveness in early-stage bladder cancer

The functions and biomarker potential of circular RNAs (circRNAs) in various cancer types are a rising field of study, as emerging evidence relates circRNAs to tumorigenesis. Here, we profiled the expression of circRNAs in 457 tumors from patients with non-muscle-invasive bladder cancer (NMIBC). We show that a set of highly expressed circRNAs have conserved core splice sites, are associated with Alu repeats, and enriched with Synonymous Constraint Elements as well as microRNA target sites. We identified 113 abundant circRNAs that are differentially expressed between high and low-risk tumor subtypes. Analysis of progression-free survival revealed 13 circRNAs, among them circHIPK3 and circCDYL, where expression correlated with progression independently of the linear transcript and the host gene. In summary, our results demonstrate that abundant circRNAs possess multiple biological features, distinguishing them from low-expressed circRNAs and non-circularized exons, and suggest that circRNAs might serve as a new class of prognostic biomarkers in NMIBC.

Expression levels of non-coding “circular” RNA molecules could be used as a prognostic biomarker for patients with early-stage bladder cancer. A team led by Trine Line Hauge Okholm and Jakob Skou Pedersen from Aarhus University Hospital, Denmark, profiled the expression of these loop-forming, potentially gene-regulating RNAs in biopsied tumor samples from 457 patients with bladder cancer that had not invaded nearby muscle tissue. They identified a suite of 113 circular RNAs that were abundant and differentially expressed between patients with different molecular subtypes of bladder cancer. The researchers also found a smaller set of 13 circular RNAs for which expression levels correlated with disease progression. These non-coding RNA molecules, by indicating likely patient outcomes, could potentially serve as future diagnostic aids to inform treatment strategies and decisions.

Comprehensive immune transcriptomic analysis in bladder cancer reveals subtype specific immune gene expression patterns of prognostic relevance

Recent efforts on genome wide profiling of muscle invasive bladder cancer (MIBC) have led to its classification into distinct genomic and transcriptomic molecular subtypes that exhibit variability in prognosis. Evolving evidence from recent immunotherapy trials has demonstrated the significance of pre-existing tumour immune profiles that could guide treatment decisions. To identify immune gene expression patterns associated with the molecular subtypes, we performed a comprehensive in silico immune transcriptomic profiling, utilizing transcriptomic data from 347 MIBC cases from The Cancer Genome Atlas (TCGA). To investigate subtype-associated immune gene expression patterns, we assembled 924 immune response genes and specifically those involved in T-cell cytotoxicity and the Type I/II interferon pathways. A set of 157 ranked genes was able to distinguish the four subtypes in an unsupervised analysis in an original training cohort (n=122) and an expanded, validation cohort (n=225). The most common overrepresented pathways distinguishing the four molecular subtypes, included JAK/STAT signaling, Toll-like receptor signaling, interleukin signaling, and T-cell activation. Some of the most enriched biological processes were responses to IFN-γ, antigen processing and presentation, cytokine mediated signaling, hemopoeisis, cell proliferation and cellular defense response in the TCGA cluster IV. Our novel findings provide further insights into the association between genomic subtypes and immune activation in MIBC and may open novel opportunities for their exploitation towards precise treatment with immunotherapy.

Proceedings of the 3rd Annual Albert Institute for Bladder Cancer Research Symposium

The Third Annual Albert Institute Bladder Symposium was held on September 8–10th, 2016, in Denver Colorado. Participants discussed several critical topics in the field of bladder cancer: 1) Best practices for tissue analysis and use to optimize correlative studies, 2) Modeling bladder cancer to facilitate understanding and innovation, 3) Targeted therapies for bladder cancer, 4) Tumor phylogeny in bladder cancer, 5) New Innovations in bladder cancer diagnostics. Our understanding of and approach to treating urothelial carcinoma is undergoing rapid advancement. Preclinical models of bladder cancer have been leveraged to increase our basic and mechanistic understanding of the disease. With the approval of immune checkpoint inhibitors for the treatment of advanced urothelial carcinoma, the treatment approach for these patients has quickly changed. In this light, molecularly-defined subtypes of bladder cancer and appropriate pre-clinical models are now essential to the further advancement and appropriate application of these therapeutic improvements. The optimal collection and processing of clinical urothelial carcinoma tissues samples will also be critical in the development of predictive biomarkers for therapeutic selection. Technological advances in other areas including optimal imaging technologies and micro/nanotechnologies are being applied to bladder cancer, especially in the localized setting, and hold the potential for translational impact in the treatment of bladder cancer patients. Taken together, advances in several basic science and clinical areas are now converging in bladder cancer. These developments hold the promise of shaping and improving the clinical care of those with the disease.

Downregulation of DOCK1 sensitizes bladder cancer cells to cisplatin through preventing epithelial-mesenchymal transition

During the past several decades, resistance to single or multiple anticancer agents has posed a great challenge in cancer therapy. Dedicator of cytokinesis 1 (DOCK1), the first identified member in DOCK family, plays diverse roles in cellular processes, including tumorigenesis. In this study, we explored the biological role of DOCK1 in the chemotherapeutic resistance in bladder cancer and its underlying mechanism. Our results showed that the bladder cancer cell lines UM-UC-3 and J82 with higher DOCK1 are more resistant to cisplatin, whereas B87 cells with the lowest expression of DOCK1 exhibited the highest sensitivity to cisplatin. Down-regulation of DOCK1 with small interfering RNA (siRNA) increased the cisplatin sensitivity in bladder cancer cells. Moreover, treatment with cisplatin induced epithelial–mesenchymal transition (EMT), while transfection with Twist siRNA restored the chemosensitivity to cisplatin. In addition, we found that downregulation of DOCK1 reversed EMT program in bladder cancer cells. However, cotransfection with DOCK1 siRNA could not further enhance the cisplatin sensitivity and cellular phenotypic changes in tumor cells. Taken together, these results demonstrate that downregulation of DOCK1 could increase the chemosensitivity in bladder cancer cells via preventing cisplatin-induced EMT, suggesting that DOCK1 may serve as a potential therapeutic target in bladder cancer.

Incidental computed tomographic bladder wall abnormalities: harbinger or herring?

OBJECTIVE

To evaluate the outcomes of incidental radiographically identified bladder wall abnormalities in the absence of other urologic indications for evaluation.

METHODS

All screening cystoscopy evaluations performed at our center over 4 years were identified using surgical logs. We identified patients for whom cystoscopy was performed for a radiographic bladder wall abnormality, defined as diffuse bladder wall thickening, focal bladder wall thickening, or intraluminal bladder mass. Patients with other indications for cystoscopy such as previous bladder cancer, pelvic radiation, or hematuria were excluded. The outcomes including any relevant biopsy or malignant diagnosis were recorded.

RESULTS

A total of 2483 cystoscopies were performed in 1418 unique patients, with 34 (2%) performed for radiographic bladder wall abnormalities in the absence of other indications for cystoscopy. Eleven of 34 patients (32.4%) were evaluated for diffuse bladder wall thickening, of which 2 had high-grade carcinoma. Fifteen patients (44.1%) had focal bladder wall thickening, all negative at cystoscopy. Four of the 8 patients (23.5%) evaluated for bladder mass had disease (1 high grade, 3 low grade).

CONCLUSION

Although generally nonspecific for malignancy, incidental radiographic finding of bladder wall abnormality led to diagnosis of urothelial carcinoma in >15% of our patients including 3 worrisome tumors. This finding argues for routine cystoscopy in patients with radiographic bladder wall abnormality even in the absence of hematuria.