Superficial bladder cancer: part 1. Update on etiology, classification and natural history

Environmental and occupational exposures and prognosis in patients with non-muscle-invasive bladder cancer in the Be-Well Study

Bladder cancer is primarily diagnosed as non-muscle-invasive bladder cancer (NMIBC), with high recurrence and progression rates. Environmental and occupational exposures to carcinogens are well-known risk factors for developing bladder cancer, yet their effects on prognosis remain unknown. In the Be-Well Study, a population-based prospective cohort study of 1472 Kaiser Permanente patients newly diagnosed with NMIBC in California from 2015 to 2019, we examined history of environmental and occupational exposures in relation to tumor stage and grade at initial diagnosis by multivariable logistic regression, and subsequent recurrence and progression by Cox proportional hazards regression. Exposure to environmental and occupational carcinogens was significantly associated with increased risk of progression (hazard ratio (HR) = 1.79; 95% CI, 1.04-3.09), specifically with increased progression to muscle-invasive disease (HR = 2.28; 95% CI, 1.16-4.50). Exposures to asbestos and arsenic were associated with increased odds of advanced stage at diagnosis (asbestos: odds ratio (OR) = 1.43 [95% CI, 1.11-1.84]; arsenic: OR = 1.27 [95% CI, 1.01-1.63]), and formaldehyde exposure was associated with increased risk of recurrence (HR = 1.38; 95% CI, 1.12-1.69). Our findings suggest that considering a patient's history of these exposures may benefit current risk stratification systems in better tailoring clinical care and improving prognosis among patients with NMIBC.

Assessing the Causal Relationship between Waterpipe Smoking and Bladder Cancer

Rates of waterpipe use increase with very little data reporting any potential health consequences. The current study, a large case-control study, of 4,194 patients from Iran denotes an elevated risk of bladder cancer in exclusive waterpipe smokers compared with non-users. Additional studies are needed to further understand the risk waterpipe smoking has on bladder cancer. See related article by Hadji et al., p. 509.

Associations of dietary isothiocyanate exposure from cruciferous vegetable consumption with recurrence and progression of non-muscle-invasive bladder cancer: findings from the Be-Well Study

BACKGROUND

High recurrence and progression rates are major clinical challenges for non-muscle-invasive bladder cancer (NMIBC). Dietary isothiocyanates (ITCs), phytochemicals primarily from cruciferous vegetables (CV), show strong anticancer activities in preclinical BC models, yet their effect on NMIBC prognosis remains unknown.

OBJECTIVES

This study aimed to investigate the associations of dietary ITC exposure at diagnosis with NMIBC recurrence and progression.

METHODS

The study analyzed 1143 participants from the Be-Well study, a prospective cohort of newly diagnosed NMIBC cases in 2015-2019 with no prior history of BC. Dietary ITC exposure was indicated by self-reported CV intake, estimated ITC intake, urinary metabolites, and plasma ITC-albumin adducts. Cox proportional hazards regression models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for recurrence and progression, and unconditional logistic regression models were used to calculate odds ratios (ORs) and 95% CIs for delayed and multiple recurrence.

RESULTS

Over a mean follow-up of 25 mo, 347 (30%) developed recurrence and 77 (6.7%) had disease progression. Despite no significant associations with the overall risk of recurrence, urinary ITC metabolites (OR: 1.96; 95% CI: 1.01, 4.43) and dietary ITC intake (OR: 2.13; 95% CI: 1.03, 4.50) were associated with late recurrence after 12-mo postdiagnosis compared with before 12-mo postdiagnosis. Raw CV intake was associated with reduced odds of having ≥2 recurrences compared with having one (OR: 0.34; 95% CI: 0.16, 0.68). Higher plasma concentrations of ITC-albumin adducts were associated with a reduced risk of progression, including progression to muscle-invasive disease (for benzyl ITC, HR: 0.40; 95% CI: 0.17, 0.93; for phenethyl ITC, HR: 0.40; 95% CI: 0.19, 0.86).

CONCLUSIONS

Our findings indicate the possible beneficial role of dietary ITCs in NMIBC prognosis. Given the compelling preclinical evidence, increasing dietary ITC exposure with CV intake could be a promising strategy to attenuate recurrence and progression risks in patients with NMIBC.

Smoking Behaviors and Prognosis in Patients With Non-Muscle-Invasive Bladder Cancer in the Be-Well Study

Importance

Tobacco smoking is an established risk factor associated with bladder cancer, yet its impact on bladder cancer prognosis is unclear.

Objective

To examine associations of use of tobacco (cigarettes, pipes, and cigars), e-cigarettes, and marijuana with risk of recurrence and progression of non-muscle-invasive bladder cancer (NMIBC) and to explore use of smoking cessation interventions.

Design, Setting, and Participants

The Be-Well Study is a prospective cohort study of patients with NMIBC diagnosed from 2015 to 2019 and followed-up for 26.4 months in the Kaiser Permanente Northern and Southern California integrated health care system. Eligibility criteria were age at least 21 years, first NMIBC diagnosis (stages Ta, Tis, or T1), alive, and not in hospice care. Exclusion criteria were previous diagnosis of bladder cancer or other cancer diagnoses within 1 year prior to or concurrent with NMIBC diagnosis. Data were analyzed from April 1 to October 4, 2022.

Exposures

Use of cigarettes, pipes, cigars, e-cigarettes, and marijuana was reported in the baseline interview. Use of smoking cessation interventions (counseling and medications) was derived from electronic health records.

Main Outcomes and Measures

Hazard ratios (HRs) and 95% CIs of recurrence and progression of bladder cancer were estimated by multivariable Cox proportional hazards regression.

Results

A total of 1472 patients (mean [SD] age at diagnosis, 70.2 [10.8%] years; 1129 [76.7%] male patients) with NMIBC were enrolled at a mean (SD) of 2.3 (1.3) months after diagnosis, including 874 patients (59.4%) who were former smokers and 111 patients (7.5%) who were current cigarette smokers; 67 patients (13.7%) smoked pipes and/or cigars only, 65 patients (4.4%) used e-cigarettes, 363 patients (24.7%) used marijuana. Longer cigarette smoking duration and more pack-years were associated with higher risk of recurrence in a dose-dependent manner, with the highest risks for patients who had smoked for 40 or more years (HR, 2.36; 95% CI, 1.43-3.91) or 40 or more pack-years (HR, 1.97; 95% CI, 1.32-2.95). There was no association of having ever smoked, being a former or current cigarette smoker, and years since quit smoking with recurrence risk. No associations with pipes, cigars, e-cigarettes, or marijuana were found. Of 102 patients offered a smoking cessation intervention, 57 (53.8%) received an interventions after diagnosis, with female patients more likely than male patients to engage in such interventions (23 of 30 female patients [76.7%] vs 34 of 76 male patients [44.7%]; P = .003).

Conclusions and Relevance

These findings suggest that longer duration and more pack-years of cigarette smoking were associated with higher risk of NMIBC recurrence. Cigarette smoking remains a critical exposure before and after diagnosis in survivors of NMIBC.

Post-Bacille Calmette–Guerin surveillance for non-muscle invasive bladder cancer: do random biopsies offer an advantage?

Background

The optimal surveillance method for recurrence of non-muscle invasive bladder cancer (NMIBC) after intravesical BCG treatment is unknown. The aim of this study is to assess the difference between two surveillance methods: cystoscopy with bladder biopsies and office-based flexible cystoscopy in detecting NMIBC recurrence and time to recurrence.

Methods

Charts of patients who underwent transurethral resection of bladder tumor with subsequent intravesical Bacillus Calmette–Guerin (BCG) treatment were reviewed between January 2015 and December 2018. Baseline demographics and oncological parameters were compared between the two methods of surveillance. Then, the role of the surveillance method for NMIBC recurrence and time to recurrence were evaluated in backward logistic regression and hazard ratios estimated in Cox regression models, respectively.

Results

Fifty-one patients (50.5%) underwent office-based flexible cystoscopy and 50 patients (49.5%) had bladder biopsies. The patients undergoing either surveillance methods were comparable for baseline demographic and oncological parameter. The predictors of recurrence and earlier BCG relapse were increased body mass index, the presence of multifocal tumors, the presence of concurrent carcinoma in situ, and tumor size at presentation. Bladder cancer recurrence was mostly affected by multifocality of the disease [OR 3.61 95%CI (1.17–11.15)] and the presence of concomitant carcinoma in situ [4.35 (1.29–14.68)]. Yet, the surveillance method neither predicted a higher recurrence yield nor earlier diagnosis.

Conclusion

In our cohort, there is neither difference in recurrence yield nor earlier diagnosis of recurrence between office-based flexible cystoscopy and bladder biopsies. Larger prospective studies are needed to assess the generalizability of these findings.

The Green Anti-Cancer Weapon. The Role of Natural Compounds in Bladder Cancer Treatment

Bladder cancer (BC) is the second most common genitourinary cancer. In 2018, 550,000 people in the world were diagnosed with BC, and the number of new cases continues to rise. BC is also characterized by high recurrence risk, despite therapies. Although in the last few years, the range of BC therapy has considerably widened, it is associated with severe side effects and the development of drug resistance, which is hampering treatment success. Thus, patients are increasingly choosing products of natural origin as an alternative or complementary therapeutic options. Therefore, in this article, we aim to elucidate, using the available literature, the role of natural substances such as curcumin, sulforaphane, resveratrol, quercetin, 6-gingerol, delphinidin, epigallocatechin-3-gallate and gossypol in the BC treatment. Numerous clinical and preclinical studies point to their role in the modulation of the signaling pathways, such as cell proliferation, cell survival, apoptosis and cell death.

VI-RADS score and tumor contact length in MRI: A potential method for the detection of muscle invasion in bladder cancer

BACKGROUND

Vesical Imaging Reporting and Data System (VI-RADS) is a useful tool for evaluating muscle layer invasion of bladder cancer (BCa) on magnetic resonance imaging (MRI).

PURPOSE

To evaluate the diagnostic performance of bladder MRI to detect the muscle layer invasion of BCa using VI-RADS score and quantitative MRI parameters.

METHODS

Preoperative bladder MRI was performed in 73 BCa patients. Two observers independently evaluated the MR blinded to histopathological data and classified the tumors according to VI-RADS criteria. Moreover, the quantitative parameters (maximum tumor diameter; Dmax, tumor contact length; TCL, and tumor apparent diffusion coefficient; ADC values) were independently measured by observers. The diagnostic performance of the VI-RADS score and quantitative values were evaluated by using receiver operating characteristic (ROC) analysis. Interobserver agreement was evaluated using the weighted-kappa coefficient (κ).

RESULTS

For the VI-RADS score, the AUC (area under the curve) was 0.968 and accuracy was 90.4% for Observer 1, and AUC was 0.953, accuracy was 89% for Observer 2. The AUC of TCL, TCL/DMax, and ADC values was 0.918, 0.675, and 0.832. In patients with a VI-RADS score ≥ 3, when a threshold value of TCL > 19.5 mm is used as complementary to the VI-RADS score, the accuracy of MRI for Observer-1 increases 100% and 97.26% for Observer-2. There was a good-excellent agreement between the observers in assessing the VI-RADS scores and quantitative parameters.

CONCLUSION

Evaluation of bladder MRI using both VI-RADS criteria and TCL is successful and highly reproducible for detecting muscle layer invasion in patients with BCa.

Bladder cancer mortality after a diagnosis of nonmuscle-invasive bladder carcinoma

Aim: To assess mortality from bladder cancer following a diagnosis of nonmuscle-invasive bladder cancer. Materials & methods: This is a SEER registry-based study. The risk of death from bladder cancer was compared with that of the general population. Cox proportional model was performed to calculate the hazard ratio (HR) for death according to baseline characteristics. Results: The bladder cancer-specific mortality at 20 years was 11%; and it was higher for black patients compared with white patients (adjusted HR: 1.711 [95% CI: 1.564-1.872]; p  <  0.0001); additionally, it was higher for patients older than 70 years old compared with younger patients (adjusted HR: 2.005 [95% CI: 1.916-2.099]; p  < 0 .0001). The risk of bladder cancer mortality increased after diagnosis of a recurrent bladder cancer (both nonmuscle-invasive and muscle-invasive; adjusted HR: 6.97 [95% CI: 6.56-7.40]; p  < 0 .0001). Conclusion: Important predictors for death from bladder cancer following a diagnosis of nonmuscle-invasive bladder cancer include older age at diagnosis and black race.

The Be-Well Study: a prospective cohort study of lifestyle and genetic factors to reduce the risk of recurrence and progression of non-muscle-invasive bladder cancer

PURPOSE

Bladder cancer is one of the top five cancers diagnosed in the U.S. with a high recurrence rate, and also one of the most expensive cancers to treat over the life-course. However, there are few observational, prospective studies of bladder cancer survivors.

METHODS

The Bladder Cancer Epidemiology, Wellness, and Lifestyle Study (Be-Well Study) is a National Cancer Institute-funded, multi-center prospective cohort study of non-muscle-invasive bladder cancer (NMIBC) patients (Stage Ta, T1, Tis) enrolled from the Kaiser Permanente Northern California (KPNC) and Southern California (KPSC) health care systems, with genotyping and biomarker assays performed at Roswell Park Comprehensive Cancer Center. The goal is to investigate diet and lifestyle factors in recurrence and progression of NMIBC, with genetic profiles considered, and to build a resource for future NMIBC studies.

RESULTS

Recruitment began in February 2015. As of 30 June 2018, 1,281 patients completed the baseline interview (774 KPNC, 511 KPSC) with a recruitment rate of 54%, of whom 77% were male and 23% female, and 80% White, 6% Black, 8% Hispanic, 5% Asian, and 2% other race/ethnicity. Most patients were diagnosed with Ta (69%) or T1 (27%) tumors. Urine and blood specimens were collected from 67% and 73% of consented patients at baseline, respectively. To date, 599 and 261 patients have completed the 12- and 24-month follow-up questionnaires, respectively, with additional urine and saliva collection.

CONCLUSIONS

The Be-Well Study will be able to answer novel questions related to diet, other lifestyle, and genetic factors and their relationship to recurrence and progression among early-stage bladder cancer patients.

Certain BCG-reactive responses are associated with bladder cancer prognosis

A subset of bladder patients does not respond to BCG treatment effectively and the underlying reason behind this observation is currently unclear. CD4+ T cells are composed of various subsets that each expresses a distinctive set of cytokines and can potently shift the immune response toward various directions. In this study, we examined the CD4+ T-cell cytokine response in bladder cancer patients toward BCG stimulation. We found that bladder cancer patients presented a variety of responses toward BCG, with no uniform characteristics. Those patients with high IFN-γ and IL-21 expression in CD4+ T cells presented significantly better prognosis than patients with low cytokine secretion in CD4+ T cells. Tumor-infiltrating CD4+ T cells were significantly less potent in expressing IFN-γ, IL-4, and IL-17, and more potent in expressing IL-10 than circulating CD4+ T cells. In addition, we found no difference in CD80, CD86, or MHC II expression by macrophages from patients with different IFN-γ and IL-21 levels. However, the secretion of IL-12, a Th1-skewing cytokine, was released at significantly higher level by macrophages from patients with high IFN-γ or high IL-21 secretion. We also identified that modulating monocytes/macrophages by GM-CSF-mediated polarization resulted in significantly elevated expression of IFN-γ and IL-21 from CD4+ T cells. Overall, these results suggested that the specific types of responses mounted by CD4+ T cells were critical to the final outcome of bladder cancer patients and can be influenced by monocyte/macrophage polarization.

Lifestyle and nutritional modifiable factors in the prevention and treatment of bladder cancer

Bladder cancer is one of the top 5 most common cancers diagnosed in the U.S. It is also one of the most expensive cancers to treat through the life course given its high rate of recurrence. While cigarette smoking and occupational exposures have been firmly established as risk factors, it is less certain whether modifiable lifestyle factors such as diet and physical activity play roles in bladder cancer etiology and prognosis. This literature review based on a PubMed search summarizes the research to date on key dietary factors, types of physical activity, and smoking in relation to bladder cancer incidence, and discusses the potential public health implications for formalized smoking cessation programs among recently diagnosed patients. Overall, population-based research in bladder cancer is growing, and will be a key platform to inform patients diagnosed and living with bladder cancer, as well as their treating clinicians, how lifestyle changes can lead to the best outcomes possible.

Can CT Virtual Cystoscopy Replace Conventional Cystoscopy in Early Detection of Bladder Cancer?

Aim. To correlate findings of conventional cystoscopy with CT virtual cystoscopy (CTVC) in detecting bladder tumors and to evaluate accuracy of virtual cystoscopy in early detection of bladder cancer. Material and Method. From June 2013 to June 2014, 50 patients (46 males, four females) with history and investigations suggestive of urothelial cancer, with mean age 62.76 ± 10.45 years, underwent CTVC by a radiologist as per protocol and subsequently underwent conventional cystoscopy (CPE) the same day or the next day. One urologist and one radiologist, blinded to the findings of conventional cystoscopy, independently interpreted the images, and any discrepant readings were resolved with consensus. Result. CTVC detected 23 out of 25 patients with bladder tumor(s) correctly. Two patients were falsely detected as negative while two were falsely labeled as positive in CTVC. Virtual and conventional cystoscopy were comparable in detection of tumor growth in urinary bladder. The sensitivity, specificity, positive predictive value, and negative predictive value of virtual cystoscopy were 92% each. Conclusion. CTVC correlates closely with the findings of conventional cystoscopy. Bladder should be adequately distended and devoid of urine at the time of procedure. However, more studies are required to define the role of virtual cystoscopy in routine clinical practice.

Virtual cystoscopy: the evaluation of bladder lesions with computed tomographic virtual cystoscopy

PURPOSE

Our objective was to assess the accuracy of computed tomographic virtual cystoscopy (CTVC) in the detection of urinary bladder lesions.

METHODS

Twenty-five patients were examined using CTVC. Bladder scanned using multislice CT at a slice thickness of 1 mm. The data were transferred to a workstation for interactive navigation using surface rendering. Findings obtained from CTVC were compared with results from conventional cystoscopy and with pathological findings.

RESULTS

Thirty-eight lesions were identified. The smallest was 0.2 × 0.3 cm; the largest was 7 × 4.5 cm. Both CTVC and conventional cystoscopy were used. Conventional cystoscopy detected the same number of lesions that were detected by CTVC. On morphological examination, 26 of the lesions were polypoid, 7 were sessile and 5 were bladder wall-thickening. While one of the polypoid lesions was reported as an inverted papilloma, 2 of the 5 lesions that were identified as wall-thickening were malignant and 3 were benign. The sensitivity of using CTVC to identify neoplasias was 100%; the accuracy was 89%.

CONCLUSION

Although the definitive diagnosis of some suspected urinary bladder tumours is only possible with conventional cystoscopy and biopsy, CTVC is a minimally invasive technique which provides beneficial information about urinary bladder lesions.

Intake of cruciferous vegetables modifies bladder cancer survival

BACKGROUND

Intake of cruciferous vegetables, a rich source of dietary isothiocyanates, has been inversely associated with risk of bladder cancer. Due to the potent antiproliferative effects of dietary isothiocyanates on bladder cancer in in vitro and in vivo models, cruciferous vegetable intake may also play a role in survival among patients with bladder cancer.

METHODS

Using information obtained from the Roswell Park Cancer Institute Tumor Registry, patient medical records, and routinely collected questionnaire data, we examined potential associations between intake of cruciferous vegetables and survival among bladder cancer patients. As cooking can substantially reduce or destroy isothiocyanates, consumption of raw versus cooked cruciferous vegetables was examined separately. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated using Cox proportional hazard models.

RESULTS

A total of 239 bladder cancer patients were included in the study. After an average of 8 years of follow-up, 179 deaths occurred, with 101 deaths attributable to bladder cancer. After adjustment for other prognostic factors, a strong and significant inverse association was observed between bladder cancer mortality and broccoli intake, in particular raw broccoli intake (> or =1 versus <1 serving per month; HR for overall death, 0.57; 95% CI, 0.39-0.83; HR for disease-specific death, 0.43; 95% CI, 0.25-0.74). There were no significant associations for total vegetables, total fruits, or other individual cruciferous vegetables.

CONCLUSIONS

Considering the strong preclinical evidence, intake of broccoli may improve bladder cancer survival.

IMPACT

Further prospective investigation is warranted to confirm the potential role of cruciferous vegetables in bladder cancer prognosis.

Office-based transurethral resection of multiple bladder tumors using blue dye-mixed local anesthesia: a descriptive cohort study

OBJECTIVE

Hospitalization and general anesthesia to perform transurethral resection of bladder tumors (BTs) may not be necessary for small recurrent BTs. We developed a new outpatient procedure.

PATIENTS AND METHODS

Patients with recurrent small tumors who had previously undergone transurethral resection of BTs for low-grade, noninvasive BTs were eligible for this new procedure. Between July 2005 and 2007, 21 surgeries were performed on 11 patients. The patients' mean age was 65.6 years. The bladder was dilated with CO(2) using a 15.5F flexible cystoscope. Blue dye-mixed local anesthetic (2% xylocaine:indigo carmine 8:2) was injected into the tumor base. The tumor was resected using electric current via a hot cup. Patients went home without an indwelling catheter if there was no hematuria in the first urination after the procedure.

RESULTS

Fifteen surgeries revealed one tumor, two had two tumors, two had three tumors, and two had six tumors. No complications requiring hospitalization occurred. Each resected specimen included a submucosal layer that allowed differentiation between pTa and pT1. No thermal degeneration was apparent in the resected stumps on pathological examination. Sixteen cases were urothelial carcinoma, and five cases were benign. Fifteen of the malignancies were noninvasive/low-grade tumors, but one case was microinvasive/high grade (G3pT1). During follow-up (mean, 8.8 months) recurrence in the bladder was found in 47%, but there was no orthotopic recurrence in the tumor-resected region.

CONCLUSION

Our method allows safe resection of multiple recurrent BTs on an outpatient basis. This approach is a promising method for pathological diagnosis and favorable local control.

Promoter hypermethylation in tumour suppressor genes and response to interleukin-2 treatment in bladder cancer: a pilot study

PURPOSE

Non-muscle invasive bladder cancer (BC) is a highly recurrent disease, with the first recurrences arising shortly after transurethral resection of the bladder (TURB). Topical administration of interleukin-2 (IL-2) has been shown as an effective adjuvant therapy for BC; however, predictive biomarkers that may identify suitable subgroups of patients are lacking. In this pilot study we sought to determine the prognostic value of epigenetic and genetic inactivation of tumour suppressor genes (TSGs) among BC patients treated with IL-2.

METHODS

After complete TURB, patients with multifocal superficial BC were treated with five daily intravesical instillations of IL-2. Promoter hypermethylation in six TSGs and the TP53 gene mutations were prospectively assessed by methylation-specific PCR and automated capillary single-strand conformation polymorphism in 21 primary bladder cancer specimens and ten bladder wall biopsies collected during follow-up.

RESULTS

After IL-2 treatment, 9 out of 21 (43%) patients did not develop recurrent tumour within the 1 year of follow-up period. The mean duration of recurrence-free survival in the rest of the study group was 112 days. In the current pilot study, BC with p16 gene hypermethylation had a lower risk of recurrence after treatment with IL-2, as compared to IL-2 treated BC without p16 hypermethylation (p = 0.02). Significant associations were observed between tumour grade and the mean methylation index (p = 0.003), as well as the hypermethylation of the RARbeta gene (p = 0.048).

CONCLUSION

Our preliminary data suggest that DNA methylation biomarkers may assist in selection of BC patients for efficient IL-2 therapy.

A novel approach to using matrix metalloproteinases for bladder cancer

PURPOSE

Given the steadily growing cancer survivor population, increasing pressure has been placed on more effective clinical approaches and biomarker assays to manage care. For bladder cancer despite the high probability of recurrence the number of patients with recurrent disease is significantly lower than the number that remains cancer free at any monitoring interval. We developed a noninvasive urine assay using a novel approach to identify patients without recurrent cancer with extremely high confidence.

MATERIALS AND METHODS

Previous studies show that matrix metalloproteinases are increased in the urine of patients with cancer compared to that in disease-free individuals. To determine the clinical usefulness of these markers as monitors for bladder cancer recurrence we measured and compared metalloproteinase-2, metalloproteinase-9 and metalloproteinase-9/neutrophil gelatinase-associated lipocalin by enzyme-linked immunosorbent assay and zymography in a set of 530 samples, including 84 samples from patients with bladder cancer.

RESULTS

Initial studies using urine metalloproteinase to discriminate disease-free patients from those with bladder cancer resulted in 80% sensitivity (67 of 84) and 71% specificity (318 of 446) for metalloproteinase-9. By applying our novel Clinical Intervention Determining Diagnostic() clinical approach to metalloproteinase-9 we correctly identified 42% of cases that were cystoscopy negative with 98% negative predictive value.

CONCLUSIONS

A noninvasive urine diagnostic assay that uses metalloproteinases with the Clinical Intervention Determining Diagnostic could lead to more efficient treatment in bladder cancer survivors by decreasing the number of negative cystoscopies (42%), allowing physicians to more selectively monitor those at high risk.

Oral silibinin inhibits in vivo human bladder tumor xenograft growth involving down-regulation of survivin

PURPOSE

Chemoprevention is an upcoming approach to control bladder cancer, which is one of the commonly diagnosed malignancies showing recurrence rate of 70% or even higher. Recently, we observed the in vitro efficacy of silibinin, a flavanolignan, in human bladder transitional cell papilloma RT4 cells. Here, we investigated the antitumor efficacy and associated mechanisms of silibinin in RT4 tumor xenograft.

EXPERIMENTAL DESIGN

RT4 tumor xenograft was implanted s.c. in athymic nude mice, and then animals were oral gavaged with silibinin at 100 and 200 mg/kg doses, 5 days/week for 12 weeks. Tumor growth, body weight, and diet consumption were recorded, and tumors were analyzed for proliferation, apoptosis, and angiogenesis biomarkers and molecular alterations by immunohistochemistry, immunoblot analysis, and ELISA. p53 small interfering RNA was used in cell culture to examine the role of p53 in survivin expression.

RESULTS

Silibinin feeding inhibited tumor xenograft growth without any gross signs of toxicity. Silibinin decreased tumor volume by 51% to 58% (P <or= 0.01) and tumor weight by 44% to 49% (P < 0.05). Silibinin moderately (P < 0.001) decreased cell proliferation and microvessel density and strongly (P < 0.001) increased apoptosis in tumors. Silibinin robustly decreased survivin protein expression and its nuclear localization, as well as tumor-secreted level in mouse plasma, but increased p53 and cleaved caspase-3 levels in tumors. Silibinin-caused decrease in survivin was independent of p53.

CONCLUSION

These findings identified in vivo antitumor efficacy of silibinin against human bladder tumor cells involving down-regulation of survivin and an increase in p53 expression together with enhanced apoptosis.