Intravesical Instillation Chemotherapy Research Articles

High and selective cytotoxicity of ex vivo expanded allogeneic human natural killer cells from peripheral blood against bladder cancer: implications for natural killer cell instillation after transurethral resection of bladder tumor

BackgroundNon-muscle-invasive bladder cancer (NMIBC) is treated with transurethral resection of bladder tumor (TURBT) followed by intravesical instillation of chemotherapy or Bacillus Calmette–Guérin therapy. However, these treatments have a high recurrence rate and side effects, emphasizing the need for alternative instillations. Previously, we revealed that expanded allogeneic human natural killer (NK) cells from peripheral blood are a promising cellular therapy for prostate cancer. However, whether NK cells exhibit a similar killing effect in bladder cancer (BCa) remains unknown.MethodsExpansion, activation, and cryopreservation of allogeneic human NK cells obtained from peripheral blood were performed as we previously described. In vitro cytotoxicity was evaluated using the cell counting kit-8. The levels of perforin, granzyme B, interferon-γ, tumor necrosis factor-α, and chemokines (C-C-motif ligand [CCL]1, CCL2, CCL20, CCL3L1, and CCL4; C-X-C-motif ligand [CXCL]1, CXCL16, CXCL2, CXCL3, and CXCL8; and X-motif ligand 1 and 2) were determined using enzyme-linked immunosorbent assay. The expression of CD107a, major histocompatibility complex class I (MHC-I), MHC-I polypeptide-related sequences A and B (MICA/B), cytomegalovirus UL16-binding protein-2/5/6 (ULBP-2/5/6), B7-H6, CD56, CD69, CD25, killer cell Ig-like receptors (KIR)2DL1, KIRD3DL1, NKG2D, NKp30, NKp46, and CD16 of NK cells or BCa and normal urothelial cells were detected using flow cytometry. Cytotoxicity was evaluated using lactate dehydrogenase assay in patient-derived organoid models. BCa growth was monitored in vivo using calipers in male NOD-scid IL2rg−/− mice subcutaneously injected with 5637 and NK cells. Differential gene expressions were investigated using RNA sequence analysis. The chemotaxis of T cells was evaluated using transwell migration assays.ResultsWe revealed that the NK cells possess higher cytotoxicity against BCa lines with more production of cytokines than normal urothelial cells counterparts in vitro, demonstrated by upregulation of degranulation marker CD107a and increased interferon-γ secretion, by MICA/B/NKG2D and B7H6/NKp30-mediated activation. Furthermore, NK cells demonstrated antitumor effects against BCa in patient-derived organoids and BCa xenograft mouse models. NK cells secreted chemokines, including CCL1/2/20, to induce T-cell chemotaxis when encountering BCa cells.ConclusionsThe expanded NK cells exhibit potent cytotoxicity against BCa cells, with few toxic side effects on normal urothelial cells. In addition, NK cells recruit T cells by secreting a panel of chemokines, which supports the translational application of NK cell intravesical instillation after TURBT from bench to bedside for NMIBC treatment.

Hydrogel: a new material for intravesical drug delivery after bladder cancer surgery.

The standard treatment for non-muscle invasive bladder cancer (NMIBC) is transurethral resection of bladder tumor (TURBT). However, this procedure may miss small lesions or incompletely remove them, resulting in cancer recurrence or progression. As a result, intravesical instillation of chemotherapy or immunotherapy drugs is often used as an adjunctive treatment after TURBT to prevent cancer recurrence. In the traditional method, drugs are instilled into the patient's bladder through a urinary catheter under sterile conditions. However, this treatment exposes the bladder mucosa to the drug directly, leading to potential side effects like chemical cystitis. Furthermore, this treatment has several limitations, including a short drug retention period, susceptibility to urine dilution, low drug permeability, lack of targeted effect, and limited long-term clinical efficacy. Hydrogel, a polymer material with a high-water content, possesses solid elasticity and liquid fluidity, making it compatible with tissues and environmentally friendly. It exhibits great potential in various applications. One emerging use of hydrogels is in intravesical instillation. By employing hydrogels, drug dilution is minimized, and drug absorption, retention, and persistence in the bladder are enhanced due to the mucus-adhesive and flotation properties of hydrogel materials. Furthermore, hydrogels can improve drug permeability and offer targeting capabilities. This article critically examines the current applications and future prospects of hydrogels in the treatment of bladder cancer.

The optimal intravesical maintenance chemotherapy scheme for the intermediate-risk group non-muscle-invasive bladder cancer

ObjectiveAlthough the current European Association of Urology(EAU) guideline recommends that patients with intermediate-risk non-muscle-invasive bladder cancer (NMIBC) should accept intravesical chemotherapy or Calmette-Guerin (BCG) for no more than one year after transurethral resection of bladder tumor(TURBT), there is no consensus on the optimal duration of chemotherapy. Hence, we explored the optimal duration of maintenance intravesical chemotherapy in patients with intermediate-risk NMIBC.Subjects and MethodsThis was a real-world single-center retrospective cohort study. In total 158 patients with pathologically confirmed intermediate-risk NMIBC were included, who were divided into 4 subgroups based on the number of instillations given. We used Cox regression analysis and survival analysis chart to explore the 3-yr recurrence outcomes of tumor.The optimal duration was determined by receive operating characteristic curve (ROC).ResultsThe median follow-up was 5.2 years. Compared with instillation for 1–2 months, the Hazard Ratios(HR) values of instillation for less than 1 month, maintenance instillation for 3–6 months and > 6 months were 3.57、1.57 and 0.22(95% CI 1.27–12.41;0.26–9.28;0.07–0.80, P = 0.03;0.62;0.02, respectively). We found a significant improvement in 3-yr relapse-free survival in intermediate-risk NMIBC patients who maintained intravesical instillation chemotherapy for longer than 6 months, and the best benefit was achieved with 10.5 months of maintenance chemotherapy by ROC.ConclusionsIn our scheme, the optimal duration of intravesical instillation with pirrubicin is 10.5 months. This new understanding provides valuable experience for the precise medical treatment model of intermediate-risk NMIBC.

Tumour factors and the variation in non-muscle invasive bladder cancer recurrence after transurethral resection surgery between sites: Results from the RESECT study.

4510 Background: To determine if there is significant variation in early recurrence after transurethral resection (TURBT) surgery between sites taking part in the RESECT study (NCT05154084) after accounting for tumour characteristics. Methods: An international, multi-centre, observational study. A mixed effects logistic regression model with tumour size, tumour number, tumour grade, tumour stage as fixed effects and site as a random effect was fitted. Cases with first, presumed non-muscle invasive bladder cancer (NMIBC) undergoing TURBT were included. Cases were excluded if first check follow up had not been completed. Sites were excluded if they did not have at least 10 cases with first check follow up. Local and/or national approvals or ethical exemptions were obtained prior to commencing the study at participating sites. Results: After exclusions, 186 sites (UK: 80; Europe: 59; North America: 18; Asia: 17; Africa 7; South America: 3; Oceania: 2), contributing a total 4597 cases (average 25 cases) were included. Median recurrence rate per site was 12% (IQR 0-22) for low grade tumours and 27% (IQR 13-42) for high grade tumours. After controlling for tumour size, number, stage and grade (all significantly and independently associated with early recurrence) there was significant residual variation attributable to site (p<0.0001, intra-class correlation, 0.1). Adjustment for sites improved the regression model from an area under the receiver operating characteristic curve of 0.66 to 0.74. Initial analysis of surgical and peri-operative practice showed wide variation, mean 75% (IQR 66-92) cases per site had detrusor muscle resection and 42% (IQR 17-58) had use of single instillation of intravesical chemotherapy. Other differences in operative and perioperative practice were identified through surveys. Conclusions: There is significant variation in the early recurrence rate of NMIBC after TURBT surgery between sites that could not be explained by currently understood tumour features. We have identified differences in surgical technique and perioperative practice that may impact this and further investigation is warranted to understand how these factors impact recurrence rates. Clinical trial information: NCT05154084 . [Table: see text]

Should continuous bladder irrigation be recommended when single instillation of intravesical chemotherapy cannot be used after transurethral resection in low-risk non-muscle invasive bladder cancer?

Reducing the recurrence rate in patients with low-risk non-muscle invasive bladder cancer patients is a critical concern in the urologic community. The gold standard treatment is single instillation (SI) of intravesical chemotherapy after transurethral resection of bladder tumor (TURBT), but unfortunately, it is underused. Continuous bladder irrigation (CBI) after TURBT is an alternative strategy to SI for the prevention of bladder tumor implantation and recurrence. The aim of this review was to present the evidence that supports CBI after TURBT when SI is not possible.

Risk-Based Assessment Of the Impact Of Intravesical Therapy on Recurrence-Free Survival Rate Following Resection of Suspected Low-grade, Non-muscle-invasive Bladder Cancer (NMIBC): A Southwest Oncology Groups (SWOG) S0337 Posthoc Analysis.

Nonmuscle invasive bladder cancer (NMIBC) has an elevated risk of recurrence, and immediate postresection intravesical instillation of chemotherapy (IVC) significantly reduces the risk of recurrence. Questions remain about which subpopulation may maximally benefit from IVC. Our aim was to develop risk groups based on recurrence risk in NMIBC, and then evaluate the impact of a single, postoperative instillation of IVC on the subsequent risk of recurrence for each risk group. Using the SWOG S0337 trial cohort, we performed a posthoc analysis of 345 patients who were diagnosed with suspected low-grade NMIBC, underwent transurethral resection of the bladder tumor (TURBT), and received post-operative IVC (gemcitabine vs. saline). Using regression tree analysis, the regression tree stratified patients based on their risk of recurrence into low-risk - single tumor and aged < 57 years, intermediate-risk - single tumor and aged ≥ 57 years, and high-risk - multiple tumors. We used Cox proportional hazard models to test the impact of recurrence-free rate, and after adjustment to available covariates. Median age of the cohort was 66.5 (IQR: 59.7-75.8 years) with 85% of patients being males. Median overall follow-up time was 3.07 years (IQR: 0.75-4.01 years). When testing the impact of treatment in each risk group separately, we found that patients in the intermediate-risk treated with gemcitabine had a 24-month recurrence free rate of 77% (95% CI: 68%-86%) vs. 59% (95% CI: 49%-70%) in the saline group. This survival difference was confirmed on multivariable analysis (hazard ratio: 0.39, 95% CI: 23%-66%, P < 0.001). This group represented 53% of our cohort. Conversely, we did not observe a significant difference in recurrence-free survival among patients in the low- (P = 0.7) and high-risk (P = 0.4) groups. Our findings indicate that older patients with a single tumor of suspected low-grade NMIBC at TURBT maximally benefit from immediate postresection IVC (gemcitabine).

Efficient Delivery of P3H4 siRNA and Chlorin e6 by cRGDfK-Installed Polyarginine Nanoparticles for Tumor-Targeting Therapy of Bladder Cancer.

Purpose: Prolyl 3-hydroxylase family member 4 (P3H4) is a potent prognostic oncogene in bladder cancer (BC), and the inhibition of P3H4 suppresses BC tumor growth. This study aimed to evaluate the efficiency of P3H4 inhibition for BC tumor therapy via tumor-targeting nanoparticles. Methods and results: A linear polyarginine peptide (R9) was synthesized, azide-modified, and then assembled with cyclic pentapeptide cRGDfK. Chlorin e6 (ce6)-conjugated CH3-R9-RGD nanoparticles were prepared for the delivery of siP3H4 into T24 cells in vitro and BC tumors in vivo. Dynamic light scattering analysis identified that the optimum CH3-R9-RGD@siP3H4 molar ratio was 30/1. CH3-R9-RGD@ce6/siP3H4 nanocomposites decreased P3H4 expression and cell proliferation and promoted reactive oxygen species production, apoptosis, and calreticulin exposure in T24 cells in vitro. In vivo experiments showed that CH3-R9-RGD@ce6/siP3H4 nanocomposites caused pathological changes, suppressed BC tumor growth, promoted caspase 3 expression, and enhanced calreticulin exposure in tumor cells. Conclusions: The tumor-targeting CH3-R9-RGD nanocomposites encapsulating siP3H4 and ce6 might be an alternative therapeutic strategy or intravesical instillation chemotherapy for BC.

Immediate post-operative intravesical instillation of a single dose chemotherapy is not superior to continuous saline irrigation

Introduction and objectivesTo evaluate whether there is any difference between immediate postoperative instillation of intravesical chemotherapy (IPOIC) and continuous saline bladder irrigation (CSBI) in terms of bladder cancer (BC) recurrence in patients with primary low- or intermediate-risk non-muscle-invasive BC (NMIBC). Materials and methodsMedical records of 1482 patients who underwent transurethral resection of bladder tumor between March 1994 and August 2020 were reviewed retrospectively. Patients were divided into two groups according to IPOIC and/or CSBI administration status [Group-1 = CSBI alone; Group-2 = CSBI following IPOIC]. Low- and intermediate-risk NMIBC patients were also divided into subgroups according to IPOIC and/or CSBI administration status. ResultsA total of 594 patients with primary NMIBC were included. Of the patients, 86 (14.5%) were female and 508 (85.5%) were male with a median age of 69 (60–78) years. The frequency of patients in Group-1 and Group-2 were 361 (60.8%) and 233 (39.2%), respectively. Recurrent disease was observed in 213 (35.9%) patients. There was no difference between the groups when they were compared for recurrent disease frequency, median time to first recurrence and frequency of recurrence within first 12 months (P = .064, P = .671, and P = .145, respectively). Disease recurrence rates in low-risk NMIBC patients was lower when they were treated with “CSBI following IPOIC” when compared to “CSBI alone” (P = .042). However, no difference was observed in low-risk NMIBC subgroups when they were compared for pathological features of recurrent tumors such as number, size, grade, stage, and presence of carcinoma in situ (P > .05, for each). Conclusions“CSBI following IPOIC” combination was not superior to “CSBI alone” for preventing adverse pathological outcomes in recurrent low- and intermediate-risk NMIBC.

Improvement of the bladder perfusion curative effect through tight junction protein degradation induced by magnetic temperature-sensitive hydrogels.

Postoperative intravesical instillation of chemotherapy is a routine procedure for non-muscular invasive bladder cancer (NMIBC). However, traditional bladder perfusion methods have insufficient exposure time, resulting in unsatisfactory therapeutic effects. In the present study, a chitosan (CS)-based in situ forming depot (ISFD) delivery system, including Fe3O4 magnetic nanoparticles (Fe3O4-MNP), CS, and β-glycerophosphate (GP) as main components, was synthesized. Pirarubicin (THP), as a chemotherapeutic drug, was loaded into the new system. Results showed that our carrier system (Fe3O4-THP-CS/GP) was converted into gel and attached to the bladder wall, possessing loose network structures with magnetic targeting and sustained release properties. Moreover, its retention time in bladder was more than 72 h accompanied by a suitable expansion rate and good degradation characteristics. The antitumor activities of Fe3O4-THP-CS/GP were more effective both in vitro and in vivo than the free THP solution. In the study of its mechanism, results showed that Fe3O4-THP-CS/GP suppressed the expression of occludin (OCLN) and affected tight junctions (TJ) between urothelial cells to promote THP absorption.

Bladder cancer selective chemotherapy with potent NQO1 substrate co-loaded prodrug nanoparticles

Currently, clinical intravesical instillation chemotherapy has been greatly compromised by the toxicological and physiological factors. New formulations that can specifically and efficiently kill bladder cancer cells are in urgent need to overcome the low residence efficiency and dose limiting toxicity of current ones. The combination of mucoadhesive nanocarriers and cancer cell selective prodrugs can to great extent address these limitations. However, the insignificant endogenous stimulus difference between cancer cells and normal cells in most cases and the high local drug concentration make it essential to develop new drugs with broader selectivity-window. Herein, based on the statistically different NQO1 expression between cancerous and normal bladder tissues, the reactive oxygen species (ROS) activatable epirubicin prodrug and highly potent NQO1 substrate, KP372-1, was co-delivered using a GSH-responsive mucoadhesive nanocarrier. After endocytosis, epirubicin could be promptly activated by the NQO1-dependent ROS production caused by KP372-1, thus specifically inhibiting the proliferation of bladder cancer cells. Since KP372-1 is much more potent than some commonly used NQO1 substrates, for example, β-lapachone, the cascade drug activation could occur under much lower drug concentration, thus greatly lowering the toxicity in normal cells and broadening the selectivity-window during intravesical bladder cancer chemotherapy.

La dosis única de instilación intravesical postoperatoria inmediata de quimioterapia no es superior al lavado continuo con suero

Introduction and objectivesTo evaluate whether there is any difference between immediate postoperative instillation of intravesical chemotherapy (IPOIC) and continuous saline bladder irrigation(CSBI) in terms of bladder cancer(BC) recurrence in patients with primary low- or intermediate-risk non-muscle-invasive BC (NMIBC). Materials and methodsMedical records of 1482 patients who underwent transurethral resection of bladder tumor between March 1994 and August 2020 were reviewed retrospectively. Patients were divided into two groups according to IPOIC and/or CSBI administration status (Group 1: CSBI alone; Group 2: CSBI following IPOIC). Low- and intermediate-risk NMIBC patients were also divided into subgroups according to IPOIC and/or CSBI administration status. ResultsA total of 594 patients with primary NMIBC were included. Of the patients, 86 (14.5%) were female and 508 (85.5%) were male with a median age of 69 (60-78) years. The frequency of patients in group 1 and group 2 were 361 (60.8%) and 233 (39.2%), respectively. Recurrent disease was observed in 213 (35.9%) patients. There was no difference between the groups when they were compared for recurrent disease frequency, median time to first recurrence and frequency of recurrence within first 12 months (P=.064, P=.671, and P=.145, respectively). Disease recurrence rates in low-risk NMIBC patients was lower when they were treated with “CSBI following IPOIC” when compared to “CSBI alone” (P=.042). However, no difference was observed in low-risk NMIBC subgroups when they were compared for pathological features of recurrent tumors such as number, size, grade, stage, and presence of carcinoma in situ (P>.05, for each). Conclusions“CSBI following IPOIC” combination was not superior to “CSBI alone” for preventing adverse pathological outcomes in recurrent low- and intermediate-risk NMIBC.

Robotic nephroureterectomy in the management of upper tract urothelial cancer: inching toward standard of care?

Upper-tract urothelial carcinoma is a relatively rare malignancy. Current guidelines strongly recommend radical nephroureterectomy with bladder cuff excision and template-based lymph node dissection for all high-risk upper-tract urothelial carcinomas. Although the open approach is still considered the standard of care, evolution of minimally invasive approaches especially the robotic-assisted approach, has been found to be oncologically equivalent. Since its initial description in 2006, the surgical technique as well as the robotic surgical system has gone through a major evolution. With well-established advantages of the minimally invasive approach, robotic radical nephroureterectomy also has the ability to address both upper and lower urinary tract simultaneously without the need of patient repositioning, standardized single docking technique, ease of performing crucial steps like excision of ureterovesical junction and bladder cuff with watertight cystotomy closure, allowing perioperative instillation of intra-vesical chemotherapy. Robot-assisted radical nephro-ureterectomy and template-based lymph node dissection is gradually emerging as the current standard of care to achieve the best possible oncologic and functional outcomes. In this review article we are focusing on the evolution of this approach in the management of upper-tract urothelial carcinoma along with a review of oncologic outcomes.

Single immediate instillation of chemotherapy is associated with decreased recurrence and progression in patients with high-risk non-muscle-invasive bladder cancer who receive adjuvant induction bacillus Calmette-Guérin therapy.

To investigate whether a single intravesical instillation of chemotherapy is associated with improved oncological outcomes in patients with high-risk non-muscle-invasive bladder cancer who receive adjuvant induction bacillus Calmette-Guérin therapy. This multi-institutional retrospective study included 205 patients with high-risk non-muscle-invasive bladder cancer who received adjuvant induction bacillus Calmette-Guérin therapy. Patients were divided into two groups: those who received the combined therapy of a single instillation of chemotherapy plus subsequent adjuvant induction bacillus Calmette-Guérin therapy (combined therapy group), and those who received adjuvant induction bacillus Calmette-Guérin therapy alone (bacillus Calmette-Guérin monotherapy group). Multivariable analyses using the inverse probability of treatment weighting method and Fine-Gray competing risk regression models were performed to evaluate the impact of a single instillation of chemotherapy on intravesical recurrence-free survival and muscle-invasive bladder cancer-free survival. Among the 205 patients, 130 (63%) and 75 (37%) were classified as the combined therapy and bacillus Calmette-Guérin monotherapy groups, respectively. Multivariable analyses using the inverse probability of treatment weighting method showed that a single instillation of chemotherapy was significantly associated with longer intravesical recurrence-free survival (hazard ratio 0.279; P < 0.001) and muscle-invasive bladder cancer-free survival (hazard ratio 0.078; P < 0.001). Fine-Gray competing risk regression model revealed that a single instillation of chemotherapy was associated with a significantly lower probability of intravesical recurrence and muscle-invasive bladder cancer progression, with an adjusted subdistribution hazard ratio of 0.477 (P = 0.008) and 0.261 (P = 0.043), respectively. A single intravesical instillation of chemotherapy may be a potential treatment option in patients with high-risk non-muscle-invasive bladder cancer who receive adjuvant induction bacillus Calmette-Guérin therapy.

Current practices of urologists regarding intravesical therapy use for non-muscle-invasive bladder cancer patients.

Background: Leading urology guidelines recommend intravesical chemotherapy and immunotherapy for non-muscle invasive bladder cancer (NMIBC) to reduce the risk of recurrence and progression. This study aims to evaluate the self-reported practices regarding intravesical therapy use for patients with non-muscle-invasive bladder cancer among urologists in Karachi. Methodology: In this cross-sectional study, a proforma-based survey was conducted between January and March 2018, in which printed questionnaires regarding adjuvant treatment options for NMIBC were administered and collected by primary investigators among urologists in leading institutions of Karachi. Results: Overall, 80% of respondents reported routine administration of single instillation of intravesical chemotherapy (SICA) after transurethral resection of bladder tumor (TURBT), and almost one-third of them (37.3%) give SICA within 6 hours inward. A quarter of respondents practice induction therapy routinely in low-risk BC using Mitomycin, whereas 76.5% in high-risk cases use Bacillus Calmette Geurin (BCG) as immunotherapy. Regarding the time duration of intravesical therapy installation, most of the urologists reported for 45 mins (49%) followed by 30 mins (29.4%), 2 hrs (17.6%), and 3 hrs (3.9%). Only 39% reported routinely using maintenance therapy with BCG for high-risk BC. As for BCG failure, 76.5% of participants reported radical cystectomy. Conclusion: Our survey results provide evidence of variation in practices among urologists and poor guideline adherence with the risk of under-treatment of patients with NMIBC. This requires joint efforts of all those involved in the treatment of non-muscle invasive bladder cancer to improve the quality of care.

Functional Nanomedicines for Targeted Therapy of Bladder Cancer.

Bladder cancer is one of most common malignant urinary tract tumor types with high incidence worldwide. In general, transurethral resection of non-muscle-invasive bladder cancer followed by intravesical instillation of chemotherapy is the standard treatment approach to minimize recurrence and delay progression of bladder cancer. However, conventional intravesical chemotherapy lacks selectivity for tumor tissues and the concentration of drug is reduced with the excretion of urine, leading to frequent administration and heavy local irritation symptoms. While nanomedicines can overcome all the above shortcomings and adhere to the surface of bladder tumors for a long time, and continuously and efficiently release drugs to bladder cancers. The rapid advances in targeted therapy have led to significant improvements in drug efficacy and precision of targeted drug delivery to eradicate tumor cells, with reduced side-effects. This review summarizes the different available nano-systems of targeted drug delivery to bladder cancer tissues. The challenges and prospects of targeted therapy for bladder cancer are additionally discussed.

Intravesical Instillation of Azacitidine Suppresses Tumor Formation through TNF-R1 and TRAIL-R2 Signaling in Genotoxic Carcinogen-Induced Bladder Cancer.

Simple SummaryApproximately 70% of all bladder cancer is diagnosed as non-muscle invasive bladder cancer and can be treated by transurethral resection of the bladder tumor, followed by intravesical instillation chemotherapy. Bacille Calmette-Guérin (BCG) is the first-line agent for intravesical instillation, but its accessibility has been limited for years due to a BCG shortage. Here, our aim was to evaluate the therapeutic role of intravesical instillation of azacitidine, a DNA methyltransferase inhibitor, in bladder cancer. Cell model experiments showed that azacitidine inhibited TNFR1 downstream pathways to downregulate HIF-1α, claspin, and survivin. Concomitant upregulation of the TRAIL R2 pathway by azacitidine ultimately drove the tumor cells to apoptosis. Rats with genotoxic carcinogen-induced bladder cancer showed a significantly reduced in vivo tumor burden after intravesical instillation of azacitidine. These findings might support further clinical trials of azacitidine in bladder cancer.Azacitidine, an inhibitor of DNA methylation, shows therapeutic effects against several malignancies by inducing apoptosis and inhibiting tumor cell proliferation. However, the anti-tumor effects of azacitidine on urinary bladder urothelial carcinoma (UBUC), especially following intravesical instillation (IVI), are not established. Here, UBUC cell lines were used to analyze the in vitro therapeutic effects of azacitidine. Potential signaling pathways were investigated by antibody arrays and Western blotting. The N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN)-induced rat UBUC model was used for in vivo quantitative analysis of tumor burden. Azacitidine significantly inhibited DNMT expression in UBUC cell lines and reduced cell viability and clonogenic activity, as determined by MTT and colony formation assays, while also inducing significant cytotoxic effects in the form of increased sub-G1 and Annexin V-PI populations (all p < 0.05). Antibody arrays confirmed the in vitro suppression of TNF-R1 and the induction of TRAIL-R2 and their downstream signaling molecules. TNF-R1 suppression reduced claspin and survivin expression, while TRAIL-R2 activation induced cytochrome C and caspase 3 expression. Rats with BBN-induced bladder cancer had a significantly reduced tumor burden and Ki67 index following IVI of azacitidine (p < 0.01). Our study provides evidence for a reduction in BBN-induced bladder cancer by IVI of azacitidine through alterations in the TRAIL-R2 and TNF-R1 signaling pathways. These findings might provide new insights for further clinical trials.

P0736 - Very low risk of severe complications after a single, post-operative instillation of intravesical chemotherapy in patients with low- or intermediate risk urothelial carcinoma of the bladder

P0736 - Very low risk of severe complications after a single, post-operative instillation of intravesical chemotherapy in patients with low- or intermediate risk urothelial carcinoma of the bladder

Low Risk of Severe Complications After a Single, Post-Operative Instillation of Intravesical Chemotherapy in Patients with TaG1G2 Urothelial Bladder Carcinoma

BACKGROUND: EAU guidelines recommend a single instillation (SI) of intravesical chemotherapy (e.g. Mitomycin C) within 24 hours after transurethral resection of a bladder tumour (TURBT) in patients with low- to intermediate risk non-muscle invasive bladder cancer without (suspected) bladder perforation or bleeding requiring bladder irrigation. However, remarkable variation exists in the use of SI. The risk of severe complications is likely to contribute to this variation, but evidence is limited. OBJECTIVE: To investigate the absolute severe complication and mortality risk after SI in low- and intermediate risk bladder cancer. METHODS: In this observational, historic cohort study, data on 25,567 patients diagnosed with TaG1G2 urothelial bladder carcinoma (UBC) between 2009 and 2018 who underwent TURBT were collected from the Netherlands Cancer Registry. Data were supplemented with information on cause of death and severe complications after cancer treatment by re-examining the electronic health records and the 14-day complication risk and the 30-day mortality risk were evaluated. RESULTS: On average, 55% of patients had a SI after TURBT, varying from 0–&gt;80% between hospitals. The 30-day mortality risk was 0.02% and the 14-day risk of severe complications was 1.6%. CONCLUSIONS: As the absolute risk of mortality and severe complications is very low, SI after TURBT can be considered a safe treatment in patients with low- to intermediate UBC without contraindications for SI. These results imply that a part of eligible patients is denied effective treatment.

Continuous bladder irrigation after transurethral resection of non-muscle invasive bladder cancer for prevention of tumour recurrence: a systematic review.

Non-muscle invasive bladder cancer (NMIBC) can recur despite transurethral resection of bladder tumour (TURBT) that clears macroscopic disease, partly from re-implantation of exfoliated cells. Immediate instillation of intravesical chemotherapy (IC) can reduce recurrence, is guideline-recommended but is under-utilized. Continuous bladder irrigation (CBI) immediately post-TURBT is postulated to prevent re-implantation, and may provide a simple, cheap and practical alternative. We undertook a systematic review to assess the effect of CBI on NMIBC recurrence. Following PRISMA guidelines, relevant publications were identified by online search of databases, including Ovid Medline and EMBASE (1980-2019). All published prospective randomized controlled trials comparing CBI post-TURBT to a control group were included. The primary end-point was recurrence. Our search yielded 514 studies, of which six met inclusion criteria. Two studies (935 participants), albeit without peer-reviewed publication, comparing CBI to no CBI both showed a reduction in recurrence at 2 years. Four publications from three trials (331 participants) compared CBI to IC, showing similar recurrence rates at 1year (odds ratio 1.29, 95% confidence interval 0.78-2.13) but a lower risk of adverse events (6-34% versus 27-48%). CBI post-TURBT appears to yield 1-year recurrence rates of NMIBC comparable to immediate IC. However, existing studies are small and of heterogenous design, precluding definitive conclusions. Further trials are required to determine if CBI can be implemented routinely to reduce NMIBC recurrence, as well as the optimal irrigant, volume and duration.

What influences adherence to guidance for postoperative instillation of intravesical chemotherapy to patients with bladder cancer?

To understand the barriers and facilitators to single instillation of intravesical chemotherapy (SI-IVC) use after resection of non-muscle-invasive bladder cancer (NMIBC) in Scotland and England using a behavioural theory-informed approach. In a cross-sectional descriptive study of practices at seven hospitals, we investigated care pathways, policies, and interviewed 30 urology staff responsible for SI-IVC. We used the Theoretical Domains Framework (TDF) to organise our investigation and conducted deductive thematic analyses, while inductively coding emergent beliefs. Barriers to SI-IVC were present at different organisational levels and professional roles. In four hospitals, there was a policy to not instil SI-IVC in theatre. Six hospitals' staff reported delays in mitomycin C (MMC) ordering and/or local storage. Lack of training, skills and perceived workload affected motivation. Facilitators included access to modern instilling devices (four hospitals) and incorporating reminders in operation proforma (four hospitals). Performance targets (with audit and feedback) within a national governance framework were present in Scotland but not England. Differences in coordinated leadership, sharing best practices, and disliking being perceived as underperforming, were evident in Scotland. High-certainty evidence shows that SI-IVC, such as MMC, after NMIBC resection reduces recurrences. This evidence underpins international guidance. The number of eligible patients receiving SI-IVC is variable indicating suboptimal practice. Improving SI-IVC adherence requires modifications to theatre instilling policies, delivery and storage of MMC, staff training, and documentation. Centralising care, with bladder cancer expert leadership and best practices sharing with performance targets, likely led to improvements in Scotland. National quality improvement, incorporating audit and feedback, with additional implementation strategies targeted to professional role could improve adherence and patient outcomes elsewhere. This process should be controlled to clarify implementation intervention effectiveness.