A Comparison of the Progression and Recurrence Risk Index in Non-Muscle-Invasive Bladder Tumors Detected by Narrow-Band Imaging Versus White Light Cystoscopy, Based on the EORTC Scoring System

Diagnostic and therapeutic effects of fluorescence cystoscopy and narrow-band imaging in bladder cancer: a systematic review and network meta-analysis

BACKGROUND

This review aims to compare the efficacies of fluorescence cystoscopy, narrow-band imaging (NBI), and white light cystoscopy in the treatment and diagnosis of bladder cancer.

METHODS

The authors searched PubMed, EMbase, Web of Science, and the Cochrane Library from January 1990 to April 2022. A total of 26 randomized controlled studies and 22 prospective single-arm studies were selected. Most patients had nonmuscle-invasive bladder cancer. The study protocol has been registered at PROSPERO.

RESULTS

In the pairwise meta-analysis, 5-aminolevulinic acid (5-ALA) reduced the short-term and long-term recurrence rates of bladder cancer compared with white light cystoscopy (WLC); however, no statistical difference was observed in intermediate-term recurrence rates (RR=0.79, 95% CI: 0.57-1.09). Hexaminolevulinic acid and NBI reduced short-term, intermediate-term, and long-term recurrence rates. The sensitivity of 5-ALA, hexaminolevulinic acid, NBI, and WLC for bladder cancer were 0.89 (95% CI: 0.81-0.94), 0.96 (95% CI: 0.92-0.98), 0.96 (95% CI: 0.92-0.98), and 0.75 (95% CI: 0.70-0.79), respectively; however, only NBI had the same specificity as WLC (0.74 vs. 0.74). Compared with WLC, 5-ALA improved the detection rate of carcinoma in situ and Ta stage bladder cancer but had no advantage in T1 stage tumors (OR=2.39, 95% CI:0.79-7.19). Hexaminolevulinic acid and NBI improved the detection rates of all nonmuscular-invasive bladder cancers. In the network meta-analysis, there was no significant difference in either recurrence or detection rates between 5-ALA, hexaminolevulinic acid, and NBI.

CONCLUSION

Fluorescence cystoscopy and NBI are advantageous for treating and diagnosing patients with nonmuscle-invasive bladder cancer.

Role of Macroscopic Image Enhancement in Diagnosis of Non-Muscle-Invasive Bladder Cancer: An Analytical Review

Early diagnosis of non-muscle-invasive bladder cancer (NMIBC) is of paramount importance to prevent morbidity and mortality due to bladder cancer. Although white light imaging (WLI) cystoscopy has long been considered the gold standard in the diagnosis of bladder cancer, it can miss lesions in a substantial percentage of patients and is very likely to miss carcinoma in situ and dysplasia. Tumor margin detection by WLI can be inaccurate. Moreover, WLI could, sometimes, be inadequate in distinguishing inflammation and malignancy. To improve the diagnostic efficacy of cystoscopy, various optical image enhancement modalities have been studied. These image enhancement modalities have been classified as macroscopic, microscopic, or molecular. Photodynamic diagnosis (PDD), narrow band imaging (NBI), and Storz image 1 S enhancement (formerly known as SPIES) are macroscopic image enhancement modalities. A relevant search was performed for literature describing macroscopic image enhancement modalities like PDD, NBI, and image 1 S enhancement. The advantages, limitations, and usefulness of each of these in the diagnosis of bladder cancer were studied. Photodynamic diagnosis requires intravesical instillation of a photosensitizing agent and a special blue light cystoscope system. PDD has been shown to be more sensitive than WLI in the detection of bladder cancer. It is superior to WLI in the detection of flat lesions. Bladder tumor resection (TURBT) by PDD results in more complete resection and reduced recurrence rates. PDD-guided TURBT may have some role in reducing the risk of progression. Narrow band imaging provides increased contrast between normal and abnormal tissues based on neovascularization, thereby augmenting WLI. NBI requires a special light source. There is no need for intravesical contrast instillation. NBI is superior to WLI in the detection of bladder cancer. The addition of NBI to WLI improves the detection of flat lesions like carcinoma in situ. NBI is not useful in predicting invasive tumors or grades of tumors. NBI-directed TURBT reduces recurrence rates and recurrence free survival. But its efficacy in retarding progression is unproven. Image 1 S-enhancement utilizes software-based image enhancement modes without the need for a special light source or intravesical contrast instillation. This system provides high-quality images and identifies additional abnormal-looking areas. Another advantage of this system is simultaneous side-by-side visualization of WLI and enhanced image, providing WLI images as the control for comparison. As with PDD, S-enhancement produces a lower rate of a missed bladder cancer diagnosis. The system significantly improves the diagnosis of NMIBC. The sensitivity and negative predictive value of image 1 S enhancement increase with the increase in cancer grade. A negative test by S-enhancement effectively rules out NMIBC. All the image enhancement modalities have proven their utility in improving detection and short-term cancer control. But none of these modalities have proven their utility in delaying progression, or in long-term cancer control. Cancer progression and long-term control are governed by the biological nature of cancer cells. Early detection by optical enhancement may not be of utility in this regard. Well-designed studies are needed to establish the efficacy of these modalities in the evaluation of patients with bladder cancer. The last word, in this regard, is yet to be written.

Enhanced Visualization Methods for First Transurethral Resection of Bladder Tumour in Suspected Non-muscle-invasive Bladder Cancer: A Health Technology Assessment

BACKGROUND

Bladder cancer begins in the innermost lining of the bladder wall and, on histological examination, is classified as one of two types: non-muscle-invasive bladder cancer (NMIBC) or muscle-invasive bladder cancer. Transurethral resection of bladder tumour (TURBT) is the standard treatment for people with NMIBC, but the high rate of cancer recurrence after first TURBT is a challenge that physicians and patients face. Tumours seen during follow-up may have been missed or incompletely resected during first TURBT. TURBT is conventionally performed using white light to see the tumours. However, small papillary or flat tumours may be missed with the use of white light alone. With the emergence of new technologies to improve visualization during TURBT, better diagnostic and patient outcomes may be expected. We conducted a health technology assessment of two enhanced visualization methods, both as an adjunct to white light to guide first TURBT for people with suspected NMIBC-hexaminolevulinate hydrochloride (HAL), a solution that is instilled into the bladder to make tumours fluoresce under blue-violet light, and narrow band imaging (NBI), a technology that filters light into wavelengths that can be absorbed by hemoglobin in the tumours, making them appear darker. Our assessment included an evaluation of effectiveness, safety, cost-effectiveness, and the budget impact of publicly funding these new technologies to improve patient outcomes following first TURBT. The use of NBI in diagnostic cystoscopy was out of scope for this health technology assessment.

METHODS

We performed a systematic literature search of the clinical evidence from inception to April 15, 2020. We searched for randomized controlled trials (RCTs) that compared the outcomes of first TURBT with the use of HAL or NBI, both as an adjunct to white light, with the outcomes of first TURBT using white light alone, or studies that made such comparison between HAL and NBI. We conducted pairwise meta-analyses using a fixed effects model where head-to-head comparisons were available. In the absence of any published RCT for comparison between HAL and NBI, we indirectly compared the two technologies through indirect treatment comparison (ITC) analysis. We assessed the risk of bias of each included study using the Cochrane risk-of-bias tool. We assessed the quality of the body of evidence according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group criteria. We performed a systematic economic literature search and conducted a cost-utility analysis with a 15-year time horizon from a public payer perspective. We also analyzed the budget impact of publicly funding HAL and NBI as an adjunct to white light in people undergoing their first TURBT for suspected non-muscle-invasive bladder cancer in Ontario.

RESULTS

In the clinical evidence review, we identified 8 RCTs that used HAL or NBI as an adjunct to white light during first TURBT. Pairwise meta-analysis of HAL studies showed that HAL-guided TURBT as an adjunct to white light significantly reduces recurrence rate at 12 months compared with TURBT using white light alone (risk ratio 0.70, 95% confidence interval [CI] 0.51-0.95) (GRADE: Moderate). Five-year recurrence-free survival was significantly higher when HAL was used as an adjunct to white light than when white light was used alone (GRADE: Moderate). There was little to no difference in the tumour progression rate (GRADE: Moderate).Meta-analysis of NBI studies did not show a significant difference between NBI-guided TURBT as an adjunct to white light and TURBT using white light alone in reducing the rate of recurrence at 12 months (risk ratio 0.94, 95% CI 0.75-1.19) (GRADE: Moderate). No evidence on the effect on recurrence-free survival or tumour progression rate was identified for NBI-guided TURBT. The indirect estimate from the network analysis showed a trend toward a lower rate of recurrence after HAL-guided TURBT than after NBI-guided TURBT but the difference was not statistically significant (risk ratio 0.76, 95% CI 0.51-1.11) (GRADE: Low). Studies showed that use of HAL or NBI during TURBT was generally safe.The incremental cost-effectiveness ratio of HAL-guided TURBT compared with NBI-guided TURBT, both as an adjunct to white light, is $12,618 per quality-adjusted life-year (QALY) gained. Compared with TURBT using white light alone and using adjunct NBI, the probability of HAL-guided TURBT being cost-effective is 69.1% at a willingness-to-pay value of $50,000 per QALY gained and 74.6% at a willingness-to-pay of $100,000 per QALY gained. The annual budget impact of publicly funding HAL-guided TURBT in Ontario over the next 5 years ranges from an additional $0.6 million in year 1 to $2.5 million in year 5.

CONCLUSIONS

First TURBT guided by HAL as an adjunct to white light likely reduces the rate of recurrence at 12 months and increases 5-year recurrence-free survival when compared with first TURBT using white light alone. There is likely little to no difference in the tumour progression rate. First TURBT guided by NBI as an adjunct to white light likely results in little to no difference in the rate of recurrence at 12 months when compared with first TURBT using white light alone. Based on an indirect comparison, there may be little to no difference in cancer recurrence rate between HAL-guided and NBI-guided first TURBT. Use of HAL or NBI during first TURBT is generally safe. For people undergoing their first TURBT for suspected non-muscle-invasive bladder cancer, using HAL as an adjunct to white light is likely to be cost-effective compared with using white light alone or with using NBI as an adjunct to white light. We estimate that publicly funding HAL as an adjunct to white light to guide first TURBT for people in Ontario with suspected NMIBC would result in additional costs of between $0.6 million and $2.5 million per year over the next 5 years.

Comparison of Re-TUR Results in Primary Patients with Non-muscle-Invasive Bladder Cancer (NMIBC) of Low, Intermediate, and High-risk for Recurrence Based on the EORTC Scoring System

Background: Bladder cancer is the second most common urologic malignancy. Transurethral resection (TUR) is the standard initial treatment for non-muscle-invasive bladder cancer (NMIBC). The high prevalence of residual tumor in some patients has necessitated repeat TUR (re-TUR). Previous studies have shown the quality of primary resection to impact re-TUR outcomes, but the role of tumor biology remains unclear. Objectives: This study aimed to evaluate the impact of tumor biology on re-TUR results in primary (non-recurrent) patients with superficial bladder tumors. Methods: We studied a cohort of consecutive primary patients with superficial bladder cancer undergoing resection and routine re-TUR between March 2018 and February 2019 at our unit. Patients with TaG1 or T2 on primary pathologic report, deliberately incomplete initial resection, or absence of detrusor muscle on the initial specimen were excluded from the study. Re-TUR was performed in the sixth week. All procedures were performed by the same surgeon. The patients were divided into three groups according to the European Organization for Research and Treatment of Cancer (EORTC) risk scoring system and compared for recurrence of NMIBC. Results: Of 58 primary patients, 16 were classified as low-risk, 32 as intermediate-risk, and 10 as high-risk. The mean age of subjects was 62.1 years. Residual tumor was detected on re-TUR in 19 (32.7%) cases. Also, 3 (5.2%) cases entailed stage progression to pT2, all of whom belonged to the high-risk group. Residual tumor rate was 0%, 40.6%, and 60% in the low-, intermediate-, and high-risk groups, respectively. In addition, 13 patients had macroscopic residual. Conclusions: Despite the modest study size, our results suggest that tumor biology might have an impact on residual tumor characteristics, and the EORTC scoring system may help to predict the risk of progression and residual tumor rate on re-TUR.

[Analysis of self-control trial results of narrow band imaging and white light in transurethral resection of bladder tumor]

OBJECTIVE

To investigate the effect of NBI assisted white light transurethral resection of bladder tumor (TURBT) in the treatment of bladder urothelial carcinoma and to summarize the experience of narrow band imaging (NBI) operation.

METHODS

Patients with bladder urothelial carcinoma were selected, and TURBT was performed after anesthesia. First of all, the bladder tumor was found and resected under white light. Then we replaced with NBI, looked for suspicious lesions and resected them, The specimens excised under white light and NBI were collected separately. The number, location and pathological results of the lesions under white light were recorded, and the residual lesions under NBI were also recorded. To evaluate the effect of NBI, the ratio of residual bladder tumor was calculated. The cases were divided into three groups according to the time sequence. The clinical data of each group were collected and the learning curve of TURBT under NBI assisted white light was observed.

RESULTS

A prospective study of 45 patients with bladder tumor from April 2018 to January 2020, including 32 males and 13 females, aged from 23 to 89 years, with an average age of 65.2 years. All the operations were successfully completed, without obvious complications after operation. Nine cases were single and 36 cases were multiple. The maximum diameter of the tumors was 0.5 to 4.0 cm, with an average of 2.2 cm. The histopathology of the resected tissue under white light was urothelial carcinoma, and 19 cases (42.2%) were pathologically positive by NBI resection. The 45 cases were divided into three groups according to the time sequence, 15 cases in each group. The true positive rate of NBI was 33.3%, 46.7% and 46.7%, respectively, and the false positive rate was 60.0%, 46.7% and 26.7%, respectively in the three groups.

CONCLUSION

TURBT is an effective way to treat bladder urothelial cancer, NBI is an effective supplement of white light, which can increase the detection rate of bladder cancer and reduce post-operative recurrence. The NBI light source has a certain learning curve. With the increase of cases, the false-positive rate of NBI is gradually reduced. After the NBI operator has rich experience, the recognition degree of flat tumor is gradually improved under white light, and the residual rate of NBI is reduced after the removal under white light.

Risk stratification for bladder cancer: Biomarkers of inflammation and immune activation

OBJECTIVE

Recent development is reviewed in biomarkers of inflammation and immune activation in risk stratification of bladder cancer (BC).

METHODS

PubMed, Wiley Online Library, and Science Direct databases were reviewed in November 2019 for relevant studies limited to those published in English from 2008 to 2019. Articles were included if they contained references to BC, urological cancers, inflammation, immune activation, disease risk, disease progression, genomics, proteomics, and biomarkers.

RESULTS

Inflammatory biomarkers show promise in prognostication in BC, including neutrophil-to-lymphocyte ratio, C-reactive protein, selected cytokines and stress proteins. Most of the current evidence, however, stems from retrospective studies. None of these biomarkers are sufficient by themselves to be used for prognostication. Using a panel of different biomarkers, alongside clinical and pathological data, seems to improve risk stratification. More robust data is necessary, however, before these biomarkers will be suitable for use in routine practice.

CONCLUSION

Biomarkers of inflammation and immune system activation can assist in risk stratification of BC. Currently most of these biomarkers lack robust external validity. In the future these biomarkers likely will have an important role in augmenting the conventional clinical and pathological predictors of outcomes in BC.

Involvement of haptoglobin phenotypes and genotypes in non-muscle invasive bladder cancer: A possible prognostic marker for risk stratification

The association of haptoglobin (Hp) with various cancers has been reported and also it has been documented that the Hp phenotypes/genotypes have different functional ability. So, we examined phenotypes/genotypes of Hp in newly diagnosed, untreated non-muscle invasive bladder cancer (NMIBC) patients and investigated its prognostic value for risk stratification of the cancer. In eighty NMIBC patients and 80 healthy individuals the Hp genotypes and phenotypes were analyzed using polymerase chain reaction (PCR) and two-dimensional gel electrophoresis (2D-GE), respectively. Besides, the presence of the Hpα1, α2, and β chains in the sera was confirmed by Mass Spectrometry (MS). The frequencies of the 1-1 and 2-2 genotypes/phenotypes were respectively higher and lower in healthy subjects compared to the patients. Our results revealed that the 2-2 genotype/phenotype could increase the risk of NMIBC. There was a positive association between the 2-2 genotype/phenotype with the T category/grade of cancer (p<0.05). The present study implied a strong association between the Hp phenotypes and genotypes with NMIBC. It was found that the 2-2 genotype and phenotype could be a risk factor for NMIBC incidence, as well as, progression. This study introduced Hp genotyping as a possible cost-effective and precise method for prognosis of individuals at the risk of NMIBC.

Diagnostic accuracy of photodynamic diagnosis with 5-aminolevulinic acid, hexaminolevulinate and narrow band imaging for non-muscle invasive bladder cancer

Objective: To assess the diagnostic test accuracy (DTA) of photodynamic diagnosis with 5-aminolaevulinic acid (5-ALA), hexylaminolevulinate (HAL) and narrow band imaging (NBI) for non-muscle-invasive bladder cancer (NMIBC), with white light-guided cystoscopy (WLC) as reference standard. Materials and Methods: A systematic review and narrative synthesis was performed in accordance with PRISMA. Major electronic databases were searched until 20th May 2019. All studies assessing the DTA of 5-ALA, HAL and NBI compared with WLC at patient and lesion-level were included. Relevant sensitivity analyses and risk of bias (RoB) assessment were undertaken. Results: 26 studies recruiting 3979 patients were eligible for inclusion. For patient-level analysis, NBI appeared to be the best (median sensitivity (SSY) 100%, median specificity (SPY) 68.45%, median positive predictive value (PPV) 90.75%, median negative predictive value (NPV) 100% and median false positive rate (FPR) 31.55%), showing better DTA outcomes than either HAL or 5-ALA. For lesion-level analysis, median SSY across NBI, HAL and 5-ALA were 93.08% (IQR 87.04-98.81%), 93.16% (IQR 91.48-97.04%) and 94.42% (IQR 82.37-95.73%) respectively. As for FPR, median values for NBI, HAL and 5-ALA were 20.40% (IQR 13.68-27.36%), 17.43% (IQR 12.79-22.40%) and 28.12% (IQR 22.08-42.39%), respectively. Sensitivity analyses based on studies with low to moderate RoB and studies with n>100 patients show similar findings. Conclusions: NBI appears to outperform 5-ALA and HAL in terms of diagnostic accuracy. All three modalities present high FPR, hence indicating the ability to detect additional cases and lesions beyond WLC.

Diagnostic performance of image technique based transurethral resection for non-muscle invasive bladder cancer: systematic review and diagnostic meta-analysis

OBJECTIVE

To explore the diagnostic performance of image technique based transurethral resection for bladder cancer, with white light-guided cystoscopy (WLC) as the reference standard.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

PubMed/MEDLINE, Web of Science, the Cochrane Library, Central Register of Controlled Trials and Embase from inception to 31 March 2018.

METHODS

Included studies reported the diagnostic performance of photodynamic diagnosis (PDD) with 5-aminolevulinic acid (5-ALA), PDD with hexaminolevulinic acid (HAL) or narrow band imaging (NBI), with WLC as the reference standard at the patient or lesion level. The studies' risk of bias (RoB) was assessed using Quality Assessment of Diagnostic Studies-2. Data were pooled using a random effect diagnostic meta-analysis, and subgroup analyses were performed.

RESULTS

Twenty-six studies comprising a total of 3979 patients were included in this diagnostic meta-analysis. Pooled sensitivity (SSY), specificity (SPY), diagnostic OR (DOR) and area under the receiver operating characteristic curve (AUROC) values were calculated per group for NBI, HAL and 5-ALA at the lesion or patient level. NBI showed significant diagnostic superiority compared with WLC at the lesion level (SSY 0.94, 95% CI 0.82 to 0.98; SPY 0.79, 95% CI 0.73 to 0.85; DOR 40.09, 95% CI 20.08 to 80.01; AUROC 0.88, 95% CI 0.85 to 0.91). NBI presented the highest DOR (358.71, 95% CI 44.50 to 2891.71) in the patient level. Subgroup analyses were performed on studies with low to moderate RoB and at least 100 patients at the lesion level. These results were consistent with those of the overall analysis.

CONCLUSIONS

Pooled data indicated that image technique based transurethral resection (NBI, HAL and 5-ALA) showed diagnostic superiority compared with WLC. Moreover, NBI is potentially the most promising diagnostic intervention, showing the best diagnostic performance outcomes. Further prognostic outcomes of novel imaging technologies compared with those WLC should be explored in addition to current diagnostic performance analysis.

Inflammatory cytokines in bladder cancer

The presence of inflammatory cells and their products in the tumor microenvironment plays a crucial role in the pathogenesis of a tumor. Releasing the cytokines from a host in response to infection and inflammation can inhibit tumor growth and progression. However, tumor cells can also respond to the host cytokines with increasing the growth/invasion/metastasis. Bladder cancer (BC) is one of the most common cancers in the world. The microenvironment of a bladder tumor has been indicated to be rich in growth factors/inflammatory cytokines that can induce the tumor growth/progression and also suppress the immune system. On the contrary, modulate of the cancer progression has been shown following upregulation of the cytokines-related pathways that suggested the cytokines as potential therapeutic targets. In this study, we provide a summary of cytokines that are involved in BC formation/regression with both inflammatory and anti-inflammatory properties. A more accurate understanding of tumor microenvironment creates favorable conditions for cytokines targeting to treat BC.

Four novel biomarkers for bladder cancer identified by weighted gene coexpression network analysis

Bladder cancer (BC) is one of the most malignancies in terms of incidence and recurrence worldwide. The aim of this study is to find out novel and prognostic biomarkers for patients with BC. First, we identified 258 differentially expressed genes by using GSE19915 from Gene Expression Omnibus database. Second, a total of 33 modules were identified by constructing a coexpression network by using weighted gene coexpression network analysis and yellow module was regarded as the key module. Furthermore, by constructing protein-protein interaction networks, we preliminarily picked out 13 genes. Among them, four hub genes (CCNB1, KIF4A, TPX2, and TRIP13) were eventually identified by using five different methods (survival analysis, one-way analysis of variance, the Spearman correlation analysis, receiver operating characteristic curve, and expression value comparison), which were significantly correlated with the prognosis of BC. The validation of transcriptional and translational levels made sense (based on Oncomine and The Human Protein Atlas database). Moreover, functional enrichment analysis suggested that all the hub genes played crucial roles in chromosome segregation, sister chromatid segregation, nuclear chromosome segregation, mitotic nuclear division, nuclear division, and organelle fission during cell mitosis. In addition, three of the hub genes (KIF4A, TPX2, and TRIP13) might be potential targets of cancer drugs according to the results of the genetical alteration. In conclusion, this study indicates that four hub genes have great predictive value for the prognosis of BC, and may contribute to the exploration of the further and more in-depth research of BC.

Cancer stem cells as a therapeutic target in bladder cancer

Bladder cancer is one of the most prevalent genitourinary cancers responsible for about 150,000 deaths per year worldwide. Currently, several treatments, such as endoscopic and open surgery, appended by local or systemic immunotherapy, chemotherapy, and radiotherapy are used to treat this malignancy. However, the differences in treatment outcome among patients suffering from bladder cancer are considered as one of the important challenges. In recent years, cancer stem cells, representing a population of undifferentiated cells with stem-cell like properties, have been eyed as a major culprit for the high recurrence rate in superficial papillary bladder cancer. Cancer stem cells have been reported to be resistant to conventional treatments, such as chemotherapy, radiation, and immunotherapy, which induce selective pressure on tumoral populations resulting in selection and growth of the resistant cells. Therefore, targeting the therapeutic aspects of cancer stem cells in bladder cancer may be promising. In this study, we briefly discuss the biology of bladder cancer and then address the possible relationship between molecular biology of bladder cancer and cancer stem cells. Subsequently, the mechanisms of resistance applied by cancer stem cells against the conventional therapeutic tools, especially chemotherapy, are discussed. Moreover, by emphasizing the biomarkers described for cancer stem cells in bladder cancer, we have provided, described, and proposed targets on cancer stem cells for therapeutic interventions and, finally, reviewed some immunotargeting strategies against bladder cancer stem cells.

Recent advances in optical imaging technologies for the detection of bladder cancer

White-light cystoscopy (WLC) is the diagnostic standard for the detection of bladder cancer (BC). However, the detection of small papillary and subtle flat carcinoma in situ lesions is not always possible with WLC. Several adjunctive optical imaging technologies have been developed to improve BC detection and resection. Photodynamic diagnosis, which requires the administering of a photoactive substance, has a higher detection rate than WLC for the detection of BC. Narrow-band imaging provides better visualization of tumors by contrast enhancement between normal mucosa and well-vascularized lesions. A technology called confocal laser endomicroscopy can be used to obtain detailed images of tissue structure. Optical coherence tomography is a high-resolution imaging process that enables noninvasive, real-time, and high-quality tissue images. Several other optical imaging technologies are also being developed to assist with the detection of BC. In this review, we provide an overview of the strengths and weaknesses of these imaging technologies for the detection of BC.

What is new in non-muscle-invasive bladder cancer in 2016?

Approximately 75% of bladder cancers are non-muscle-invasive bladder cancer (NMIBC), and 50% of NMIBC patients who are treated with transurethral resection (TUR) have a recurrence of the disease and 5-25% of these patients progressed to muscle-invasive disease after repeated recurrences. NMIBC patients receive various treatments aimed at reducing disease recurrence and progression. Although the recurrence rate of disease remains above target, thus increasing treatment cost, the true rate of recurrence after the primary surgery is controversial. Recurrences can be categorized as either true recurrence due to aggressive tumor biology and implantation of floating cancer cells or false recurrence such as small, flat, or carcinoma in situ lesions overlooked in the primary procedure. Here we discuss new diagnostic methods and treatment options to improve outcomes and reduce recurrence rates in NMIBC.

A meta-analysis of narrow band imaging for the diagnosis and therapeutic outcome of non-muscle invasive bladder cancer

Objectives

To assess the additional detection rate (ADR) of within-patient comparisons of Narrow band imaging (NBI) and white light cystoscopy (WLC) for non-muscle invasive bladder cancer (NMIBC) detection and compare the impact of NBI and WLC on bladder cancer recurrence risk.

Methods

We searched relevant studies from PubMed, Embase, Medline, Web of Science and the Cochrane Library database for all articles in English published beforeJuly26^th, 2016. Pooled ADR, diagnostic accuracy, relative risk (RR) and their 95% confidence intervals (CIs) were calculated.

Results

Twenty-five studies including 17 full texts and eight meeting abstracts were included for analysis. Compared to WLC, pooled ADR of NBI for NMIBC diagnosis was 9.9% (95% CI: 0.05–0.14) and 18.6% (95% CI: 0.15–0.25) in per-patient and per-lesion analysis, respectively. Pooled ADR of NBI for carcinoma in situ (CIS) diagnosis was 25.1% (95% CI: 0.09–0.42) and 31.1% (95% CI: 0.24–0.39) for per-patient and per-lesion analyses, respectively. The pooled sensitivity of NBI was significantly higher than WLC both at the per-patient (95.8% vs. 81.6%) and per-lesion levels (94.8% vs. 72.4%). In addition, NBI significantly reduced the recurrence rate of bladder cancer with a pooled RR value of 0.43 (95% CI: 0.23–0.79) and0.81 (95% CI: 0.69–0.95) at month three and twelve, respectively.

Conclusions

NBI is a valid technique that improves the diagnosis of NMIBC and CIS compared to standard WLC either at per-patient or per-lesion level. It can reduce the recurrence rate of bladder cancer accordingly.