Can the burden of follow-up in low-grade noninvasive bladder cancer be reduced by photodynamic diagnosis, perioperative instillations, imaging, and urine markers?

Improved Non-Invasive Diagnosis of Bladder Cancer with an Electronic Nose: A Large Pilot Study

BACKGROUND

Bladder cancer (BCa) emits specific volatile organic compounds (VOCs) in the urine headspace that can be detected by an electronic nose. The diagnostic performance of an electronic nose in detecting BCa was investigated in a pilot study.

METHODS

A prospective, single-center, controlled, non-randomized, phase 2 study was carried out on 198 consecutive subjects (102 with proven BCa, 96 controls). Urine samples were evaluated with an electronic nose provided with 32 volatile gas analyzer sensors. The tests were repeated at least two times per sample. Accuracy, sensitivity, specificity, and variability were evaluated using mainly the non-parametric combination method, permutation tests, and discriminant analysis classification.

RESULTS

Statistically significant differences between BCa patients and controls were reported by 28 (87.5%) of the 32 sensors. The overall discriminatory power, sensitivity, and specificity were 78.8%, 74.1%, and 76%, respectively; 13/96 (13.5%) controls and 29/102 (28.4%) BCa patients were misclassified as false positive and false negative, respectively. Where the most efficient sensors were selected, the sensitivity and specificity increased up to 91.1% (72.5-100) and 89.1% (81-95.8), respectively. None of the tumor characteristics represented independent predictors of device responsiveness.

CONCLUSIONS

The electronic nose might represent a potentially reliable, quick, accurate, and cost-effective tool for non-invasive BCa diagnosis.

[Prophylaxis of recurrence in low-to-intermediate risk non-muscle invasive bladder cancer (NMIBC)]

BACKGROUND

Low- and intermediate-risk non-muscle invasive bladder cancer (NMIBC) is characterized by a relatively high risk of recurrence and adjuvant instillation therapy is considered standard of treatment for the majority of patients.

OBJECTIVES

To provide a current and in-depth review on the role of adjuvant therapy in low-to-intermediate risk NMIBC.

METHODS

A PubMed-based search focusing on specific keywords (BCG, EORTC, early instillation, intermediate-risk, low-risk, mitomycin, NMIBC, recurrence) was conducted to identify studies published between 2000 and 2021. The corresponding publications were assessed based on their clinical relevance to the question at hand and their pro/retrospective approach.

RESULTS

The EORTC risk tables are most frequently used to determine the risk of recurrence. In low-risk NMIBC, transurethral bladder tumor resection (TURBT) followed by early instillation is considered standard of treatment. In intermediate-risk NMIBC, TUR-BT is followed by adjuvant instillations with either chemoinstillation or BCG.

CONCLUSIONS

Consequent use of adjuvant instillation therapy is necessary to reduce the risk of recurrence. New agents and modes of drug delivery (i.e. chemoablation) on the horizon have the potential to further improve outcomes.

Ability of a urine gene expression classifier to reduce the number of follow-up cystoscopies in bladder cancer patients

This study aimed to improve our previous urine gene expression classifiers focusing on the detection of non-high-risk non-muscle-invasive bladder cancer (NMIBC), and develop a new classifier able to decrease the frequency of cystoscopies during bladder cancer (BC) patients' surveillance. A total of 597 urines from BC patients, controls and patients in follow-up for BC (PFBC) were included. The study has 3 phases. In the urinary biomarker discovery phase, 84 urines from BC and control patients were retrospectively included and analyzed by Ribonucleic Acid (RNA) sequencing. In the classifier development phase, a total of 132 selected genes from previous phase were evaluated by nCounter in 214 prospectively collected urines from PFBC (98 with tumor). A diagnostic classifier was generated by logistic regression. Finally, in the classifier validation phase, a multicentric and international cohort of 248 urines (134 BC and 114 nonrecurrent PFBC) was used to validate classifier performance. A total of 521 genes were found differentially expressed between non-high-risk NMIBC samples and all other groups (P < 0.05). An 8-gene diagnostic classifier with an area under curve (AUC) of 0.893 was developed. Validation of this classifier in a cohort of PFBC achieved an overall sensitivity (SN) and a negative predictive value (NPV) of 96% and 97%, respectively (AUC = 0.823). Notably, this accuracy was maintained in non-high-risk NMIBC group (SN = 94%; NPV = 98%). In conclusion, this 8-gene expression classifier has high SN and NPV in a real clinical scenario. The use of this classifier can reduce the number of follow-up cystoscopies in PFBC, although assessing its final place in clinical setting is necessary.

Gene expression test for the non-invasive diagnosis of bladder cancer: A prospective, blinded, international and multicenter validation study

OBJECTIVE

This study aimed to validate, in a prospective, blinded, international and multicenter cohort, our previously reported four non-invasive tests for bladder cancer (BC) diagnosis based on the gene expression patterns of urine.

METHODS

Consecutive voided urine samples from BC patients and controls were prospectively collected in five European centres (n=789). Finally, 525 samples were successfully analysed. Gene expression values were quantified using TaqMan Arrays and previously reported diagnostic algorithms were applied to gene expression data. Results from the most accurate gene signature for BC diagnosis were associated with clinical parameters using analysis of variance test.

RESULTS

High diagnostic accuracy for the four gene signatures was found in the independent validation set (area under curve [AUC]=0.903-0.918), with the signature composed of two genes (GS_D2) having the best performance (sensitivity: 81.48%; specificity: 91.26%; AUC: 0.918). The diagnostic accuracy of GS_D2 was not affected by the number of tumours (p=0.58) but was statistically associated with tumour size (p=0.008). Also, GS_D2 diagnostic accuracy increases with increasing BC tumour risk. We found no differences in the performance of the GS_D2 test among the populations and centres in detecting tumours (p=0.7) and controls (p=0.2).

CONCLUSIONS

Our GS_D2 test is non-invasive, non-observer dependent and non-labour-intensive, and has demonstrated diagnostic accuracy in an independent, international and multicenter study, equal or superior to the current gold standard (cystoscopy combined with cytology). Additionally, it has higher sensitivity than cytology while maintaining its specificity. Consequently, it meets the requirements for consideration as a molecular test applicable to clinical practice in the management of BC.

[Non-muscle-invasive high-grade bladder cancer]

BACKGROUND

Non-muscle-invasive bladder cancer with a low-grade differentiation represents a special challenge.

METHOD

Although urine cytology is still the most reliable and effective urine-based marker and there are no substantial novel aspects in this field, photodynamic diagnostics have the most important value in transurethral resection of the bladder (TURB) of high-grade T1 tumors and new techniques, such as hybrid knife TURB are coming up. The histopathological assessment of T1 tumors can be supplemented by a description of the exact penetration depth, so-called substaging and the invasion pattern.

RESULTS

Intravesicle therapy with Bacillus Calmette-Guèrin (BCG) represents the gold standard and a pillar of bladder-preserving therapy and should be planned as maintenance therapy for at least 1 year. With the right risk constellation cystectomy is a safe and proven concept for high-grade bladder cancer, even without proof of muscle invasion.

The role of inflammation in bladder cancer

The aim of this book chapter is to present the latest basic research developments on the role of inflammation in bladder cancer and provide insights into their future clinical significance in preventing bladder carcinogenesis and progression. Bladder cancer is a highly immunogenic malignancy. Urothelial cancer cells aim to manipulate the immune system by inhibiting its cytotoxic function while stimulating the secretion of growth promoting factors. Cytokine-induced imbalances in the distribution and differentiation of tumor-infiltrating cytotoxic cells can boost bladder cancer cell proliferation. Tumor-induced release of excessive amount of cytokines causes an "inflammatory storm" which drives metastasis formation via degradation of extracellular matrix proteins. Tumor-related selective cyclooxygenase-2 (COX-2) upregulation suppresses the cell-mediated immune response via aberrant prostaglandin metabolism resulting in failure of differentiation of myeloid cell progenitors into mature antigen-presenting cells. T cells are capable of increasing the oxidative stress on bladder cancer cells via induction of COX-2 and STEAP expression. Some evidence also suggests that COX-2 activation may be also involved in inflammation-mediated cancer stem cell proliferation. Antibodies against the VEGF-co-receptor neuropilin decrease the angiogenetic potential of bladder cancer cells. Inflammation-based predictive bladder cancer models have demonstrated to accurately predict response to treatment both in the curative and palliative setting. While randomized trials do not support a clinical benefit for the use of anti-inflammatory drugs (i.e., celecoxib, atorvastatin) in preventing recurrence of low-grade bladder cancer, further investigations are warranted in the setting of high-grade tumors since the immune response to cancer stimuli is most probably more pronounced in advanced stages.

Protocadherin 17 promoter methylation in tumour tissue from patients with bladder transitional cell carcinoma

OBJECTIVE

To investigate the clinical significance of protocadherin 17 (PCDH17) promoter methylation in bladder cancer.

METHODS

Methylation-specific polymerase chain reaction was used to examine the promoter methylation status of PCDH17 in tumour tissue specimens obtained from patients with bladder cancer, and in normal bladder epithelial tissue specimens obtained from age- and sex-matched controls. The correlations between methylation status and demographic and clinicopathological parameters, and disease outcome, were assessed.

RESULTS

Methylation of the PCDH17 promoter was detected in 77/115 (67.0%) patients with bladder cancer and 0/43 (0%) of the controls. Methylation was significantly associated with high cancer grade (G3), advanced cancer stage (T2-T4), large tumour diameter (> 3 cm) and tumour recurrence. Methylation was also associated with significantly shorter survival time compared with unmethylated PCDH17 in patients with bladder cancer, and was an independent predictor of overall survival.

CONCLUSIONS

PCDH17 promoter methylation is closely associated with bladder cancer malignancy and may be used as an independent predictor of clinical outcomes in patients with bladder cancer.

A pilot study combining a GC-sensor device with a statistical model for the identification of bladder cancer from urine headspace

There is a need to reduce the number of cystoscopies on patients with haematuria. Presently there are no reliable biomarkers to screen for bladder cancer. In this paper, we evaluate a new simple in–house fabricated, GC-sensor device in the diagnosis of bladder cancer based on volatiles. Sensor outputs from 98 urine samples were used to build and test diagnostic models. Samples were taken from 24 patients with transitional (urothelial) cell carcinoma (age 27-91 years, median 71 years) and 74 controls presenting with urological symptoms, but without a urological malignancy (age 29-86 years, median 64 years); results were analysed using two statistical approaches to assess the robustness of the methodology. A two-group linear discriminant analysis method using a total of 9 time points (which equates to 9 biomarkers) correctly assigned 24/24 (100%) of cancer cases and 70/74 (94.6%) controls. Under leave-one-out cross-validation 23/24 (95.8%) of cancer cases were correctly predicted with 69/74 (93.2%) of controls. For partial least squares discriminant analysis, the correct leave-one-out cross-validation prediction values were 95.8% (cancer cases) and 94.6% (controls). These data are an improvement on those reported by other groups studying headspace gases and also superior to current clinical techniques. This new device shows potential for the diagnosis of bladder cancer, but the data must be reproduced in a larger study.

Bladder cancer diagnosis and identification of clinically significant disease by combined urinary detection of Mcm5 and nuclear matrix protein 22

Background

Urinary biomarkers for bladder cancer detection are constrained by inadequate sensitivity or specificity. Here we evaluate the diagnostic accuracy of Mcm5, a novel cell cycle biomarker of aberrant growth, alone and in combination with NMP22.

Methods

1677 consecutive patients under investigation for urinary tract malignancy were recruited to a prospective blinded observational study. All patients underwent ultrasound, intravenous urography, cystoscopy, urine culture and cytologic analysis. An immunofluorometric assay was used to measure Mcm5 levels in urine cell sediments. NMP22 urinary levels were determined with the FDA-approved NMP22® Test Kit.

Results

Genito-urinary tract cancers were identified in 210/1564 (13%) patients with an Mcm5 result and in 195/1396 (14%) patients with an NMP22 result. At the assay cut-point where sensitivity and specificity were equal, the Mcm5 test detected primary and recurrent bladder cancers with 69% sensitivity (95% confidence interval = 62–75%) and 93% negative predictive value (95% CI = 92–95%). The area under the receiver operating characteristic curve for Mcm5 was 0.75 (95% CI = 0.71–0.79) and 0.72 (95% CI = 0.67–0.77) for NMP22. Importantly, Mcm5 combined with NMP22 identified 95% (79/83; 95% CI = 88–99%) of potentially life threatening diagnoses (i.e. grade 3 or carcinoma in situ or stage ≥pT1) with high specificity (72%, 95% CI = 69–74%).

Conclusions

The Mcm5 immunoassay is a non-invasive test for identifying patients with urothelial cancers with similar accuracy to the FDA-approved NMP22 ELISA Test Kit. The combination of Mcm5 plus NMP22 improves the detection of UCC and identifies 95% of clinically significant disease. Trials of a commercially developed Mcm5 assay suitable for an end-user laboratory alongside NMP22 are required to assess their potential clinical utility in improving diagnostic and surveillance care pathways.