Computational Analysis Identifies Novel Biomarkers for High-Risk Bladder Cancer Patients

In the case of bladder cancer, carcinoma in situ (CIS) is known to have poor diagnosis. However, there are not enough studies that examine the biomarkers relevant to CIS development. Omics experiments generate data with tens of thousands of descriptive variables, e.g., gene expression levels. Often, many of these descriptive variables are identified as somehow relevant, resulting in hundreds or thousands of relevant variables for building models or for further data analysis. We analyze one such dataset describing patients with bladder cancer, mostly non-muscle-invasive (NMIBC), and propose a novel approach to feature selection. This approach returns high-quality features for prediction and yet allows interpretability as well as a certain level of insight into the analyzed data. As a result, we obtain a small set of seven of the most-useful biomarkers for diagnostics. They can also be used to build tests that avoid the costly and time-consuming existing methods. We summarize the current biological knowledge of the chosen biomarkers and contrast it with our findings.

Impact of clinical and pathological subtypes of carcinoma in situ (CIS) of the bladder: Lessons learned from long-term follow-up of a series of CIS patients treated with BCG

OBJECTIVE

Some attempts have previously been made to stratify patients with CIS for the purpose of risk-adapted clinical management and clinical trial design. In particular, two classification systems have been proposed: clinical classification, comprising primary (P-CIS), concomitant (C-CIS), and secondary (S-CIS) disease, and pathological classification, comprising P-CIS, cTa-CIS, and cT1-CIS. The aim of the present study was to assess the impact of both classifications on BCG response, recurrence-free survival (RFS), progression-free survival (PFS), overall survival (OS), and cancer-specific survival (CSS).

PATIENTS AND METHODS

We performed a retrospective analysis of 386 patients with bladder CIS, with or without associated cTa/cT1 disease, treated with BCG instillations between 2008 and 2015. Patients were stratified according to the two classification systems. Cox multivariate regression models were used to assess the impact of these subtypes on BCG response, RFS, PFS, OS, and CSS. We also performed a cumulative meta-analysis according to PRISMA guidelines.

RESULTS

The median follow-up was 70.5 months. According to the clinical classification, 34 (8.8%) patients had P-CIS, 81 (21%) S-CIS, and 271 (70.2%) C-CIS. The pathological classification showed 34 (8.8%) patients to have P-CIS, 190 (49.2%) cTa-CIS, and 162 (42%) cT1-CIS. In the overall cohort, BCG response was reported in 296 (76.7%); 159 (41.2%) had recurrence, 55 (14.2%) had progression, and 67 (17.4%) underwent radical cystectomy. Death from any cause was recorded in 135 (35%) and death from urothelial carcinoma in 38 (9.9%). Cox multivariate regression analysis showed that neither clinical classification nor pathological classification is an independent predictive factor for BCG response, RFS, PFS, OS, or CSS after adjusting for confounders. In the pooled meta-analysis, two studies and the present series were included for evidence synthesis, recruiting a total of 941 patients. We found no statistically significant difference across the groups for both classifications with respect to BCG response, RFS, PFS, and CSS.

CONCLUSIONS

Currently, the supporting evidence for an impact of clinical classification and pathological classification on oncological outcomes of CIS of the bladder is insufficient to justify their use to guide clinical management or follow-up.

Can random bladder biopsies be eliminated after bacillus Calmette-Guérin therapy against carcinoma in situ?

PURPOSE

Intravesical bacillus Calmette-Guérin (BCG) is the standard of care for bladder carcinoma in situ (CIS). The response to BCG therapy against CIS is generally assessed by random bladder biopsy (RBB). In this study, we examined the necessity of routine RBB after BCG therapy.

METHODS

We retrospectively identified 102 patients who were initially diagnosed with CIS with or without papillary tumor and received subsequent 6-8-week BCG therapy. Thereafter, all patients underwent voiding cytology analysis, cystoscopy, and RBB to evaluate the effects of BCG therapy. We evaluated the association between clinical parameters (voiding cytology and cystoscopy findings) and the final pathological results by RBB specimens.

RESULTS

According to the pathological results of RBB, 30 (29%) patients had BCG-unresponsive disease (remaining urothelial carcinoma was confirmed pathologically) and 20 were diagnosed with CIS. Positive/suspicious voiding cytology and positive cystoscopy findings were well observed in patients who had BCG-unresponsive disease compared with their counterparts (p = 0.116, and p < 0.001, respectively). The sensitivity (Sen.), specificity (Spe.), positive predictive value (PPV), and negative predictive value (NPV) of voiding cytology were 50%, 68%, 39%, and 77%, respectively. The values for cystoscopy findings were as follows: Sen.: 87%, Spe.: 57%, PPV: 46%, and NPV: 91%. The values for their combination (having either of them) were as follows: Sen.: 100%, Spe.: 44%, PPV: 43%, and NPV: 100%.

CONCLUSION

RBB after BCG therapy for patients with negative voiding cytology and negative cystoscopy may be omitted because their risk of BCG-unresponsive disease is significantly low (NPV: 100%).

Clinical outcomes and survival differences between primary, secondary and concomitants carcinoma in situ of urinary bladder treated with BCG immunotherapy

Background

The carcinoma in situ (CIS) of urinary bladder is a flat, high-grade and aggressive manifestation of urothelial cancer which carries a great risk for progression to muscle invasive disease and metastatic spread. The aim of the study was to analyse the clinical history and survival differences between primary, secondary and concomitants CIS of the bladder.

Methods

We analysed a database of 301 patients who were treated between 1998 and 2017 in university BCG outpatient department. Primary, secondary and concomitants CIS cases were included in the study with minimum follow-up of 12 months. Recurrence-free survival (RSF), progression-free survival (PFS) and cancer specific survival (CSS) were analysed by Kaplan–Meier curves and log-rank test. Additionally, Cox regression models were performed.

Results

Seventy-two patients with primary, 58 with secondary and 171 with CIS concomitants were analysed. The patients were followed from mean 61,9 months. RFS rates at 5-years follow-up were 54.9%, 55.3% and 60.4% for primary, concomitants and secondary CIS (P>0.05). PFS rates at 5-years follow-up were 65.8%, 72.1% and 77% for primary, concomitants and secondary CIS (P>0.05). CSS rates at 5-years follow-up were 83.1%, 81.9% and 90.1% for primary, concomitants and secondary CIS (P>0.05). There were no statistically significant differences between any CIS subtype in any of analysed endpoints in multivariate analysis. Female gender was associated with worse RFS and the instillation number was positively associated with all analysed survival rates. On contrary, age was not statistically related to RFS, PFS nor CSS.

Conclusions

In this study it was shown that when compared with secondary and concomitants CIS, primary CIS presented the worst RFS and PFS, however, the differences between subgroups were not statistically significant.

How well do we manage non-muscle invasive bladder tumors? A UK audit of real-life practices

OBJECTIVE

The aim of this study was to assess the quality of TURBT (transurethral resection of bladder tumor) using surrogate parameters and evaluate adherence to the guidelines regarding the management of bladder tumors.

MATERIALS AND METHODS

A clinical audit of all new diagnosis of bladder cancer was undertaken from January 2016 to January 2017. A total of 101 new bladder cancer cases were included. Surrogates of TURBT quality including presence of detrusor in the specimen, rate of re-TUR, presence of carcinoma in situ, and 3-month recurrence rates were analyzed. Adherence to guidelines regarding management of non-muscle invasive bladder cancer including time to re-TUR and utilization of single instillation chemotherapy was evaluated.

RESULTS

Absence of detrusor muscle in the specimen of the initial TURBT was noted in 22.8% of the cases. The chance of including muscle in the specimen was almost four-fold for tumors larger than 3 cm. A single instillation of intravesical chemotherapy following TURBT was administered in only 40% of eligible patients; 54.3% of patients had a re-TUR, the majority (61.3%) for high-grade non-muscle invasive bladder cancer on initial TURBT. Re-TUR was done on average 10 weeks after initial TURBT. The 3-month recurrence rate was 36.0% with larger tumors (>3 cm) being more prone to early recurrences. Early recurrences were not affected by intravesical instillations with bacillus Calmette-Guérin or mitomycin C although there was a positive association between the presence of carcinoma in situ on initial resection and early recurrences.

DISCUSSION AND CONCLUSION

One in two patients will have a re-TUR, and approximately one in two patients will have tumor on re-TUR. Single immediate chemotherapy instillations after TURBT are underutilized. The presence of carcinoma in situ on initial TURBT and tumor size were predictors of early recurrences.