In cystectomy specimens with bladder cancer whole organ embedding increases the detection rate of histopathological parameters, but not of those with prognostic significance

Variation in cystectomy pathology reporting practice-results from an international survey of 212 pathologists

The pathological assessment of cystectomy specimens is important for accurate prognostic information and to inform adjuvant therapy decisions. However, there is limited evidence regarding the best approach to fixation, dissection, block selection and microscopic assessment of cystectomies. We report the results of an international survey of 212 pathologists and their approach to cystectomy pathology. There is variation at all stages of the specimen journey including in fixation and dissection techniques, and in the approach to evaluating residual tumour. This is particularly evident in the post-neoadjuvant chemotherapy setting where there is variable use of response scoring systems and differing approaches to sampling. We also find variation in the use of digital and molecular pathology in cystectomy specimens. Finally, we have suggested areas for future research in cystectomy pathological assessment.

Multiregion human bladder cancer sequencing reveals tumour evolution, bladder cancer phenotypes and implications for targeted therapy

We present an evolutionary analysis of the relative time of genetic events underlying tumorigenesis in human bladder cancers from 10 whole cystectomy specimens using multiregional whole-exome sequencing. We timed bladder cancer drivers, mutational signatures, ploidy and copy number alterations, provided evidence for kataegis and correlated alterations with tumour areas and histological phenotypes. We found that: (1) heterogeneous tumour areas/phenotypes had distinct driver mutations, (2) papillary-invasive tumours divided early into two parallel evolving branches and (3) parallel evolution of subclonal driver mutations occurred. APOBEC mutational signatures were found to be very early events, active in carcinoma in situ, and often remained a dominant source of mutations throughout tumour evolution. Genetic progression from carcinoma in situ followed driver mutations in NA13/FAT1, ZBTB7B or EP300/USP28/KMT2D. Our results point towards a more diverse mutational trajectory of bladder tumorigenesis and underpin the importance of timing of mutational processes and clonal architecture in bladder cancer as important aspects for successful prognostication and therapy. Copyright © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Concomitant carcinoma in situ may not be a prognostic factor for patients with bladder cancer following radical cystectomy: a PRISMA-compliant systematic review and meta-analysis

BACKGROUND

Numerous recent studies have shown that concomitant carcinoma in situ (CIS) can be closely associated with the prognosis of patients with bladder cancer (BCa). However, the prognostic value of CIS in BCa is still not conclusive. Hence, we performed a systematic review and meta-analysis to explore the association between CIS and clinicopathological features and the prognostic value for BCa following radical cystectomy.

METHODS

We performed this study in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Relevant studies were systematically collected from PubMed, EMBASE, and Web of Science, with an expiration date of August 2018. Hazard ratios and 95% confidence intervals (CIs) were pooled to assess the intensity of association. All data were analyzed by Stata 12.0. Moreover, heterogeneity and publication bias were determined, and sensitivity analysis was performed to examine whether the findings of the meta-analysis were robust.

RESULTS

A total of 18,845 patients from 24 studies were included in the analysis. Our results indicated that CIS has no significant correlation with cancer-specific mortality (CSM) (pooled HR = 0.97, 95% CI 0.93-1.00, p = 0.059), overall mortality (OM) (pooled HR = 0.93, 95% CI 0.85-1.01, p = 0.076), overall survival (OS) (pooled HR = 1.04, 95% CI 0.96-1.12, p = 0.386), cancer-specific survival (CSS) (pooled HR = 1.06, 95% CI 0.97-1.16, p = 0.186), recurrence-free survival (RFS) (HR = 1.05, 95% CI 0.99-1.11, p = 0.098) or recurrence (pooled HR = 1.04, 95% CI 0.98-1.11, p = 0.212) in BCa patients. In addition, CIS was not correlated with gender (male vs. female, OR = 1.00, 95% CI 0.74-1.34, p = 0.978), pathological stage (III/IV vs. I/II: OR = 0.74, 95% CI 0.50-1.10, p = 0.132), tumor grade (1/2 vs. 3: OR = 3.38, 95% CI 0.73-15.65, p = 0.119), soft tissue surgical margin (STSM) (+ vs. - : OR = 1.20, 95% CI 0.97-1.48, p = 0.093) or lymphovascular invasion (LVI) (+ vs. - : OR = 0.92, 95% CI 0.62-1.38, p = 0.702),but was closely related to adjuvant chemotherapy (ACT) (yes vs. no, OR = 1.17, 95% CI 1.03-1.32, p = 0.019). Furthermore, these findings were demonstrated to be reliable by our sensitivity and subgroup analysis.

CONCLUSIONS

The prognostic value of CIS in BCa remains inconclusive in patients submitted to RC. Our data indicated that CIS may have no significant correlation with the prognosis and clinicopathological parameters of BCa patients, and also may not be applied to risk stratification or individualized therapy in BCa patients. Further research should be conducted to confirm our findings.

[Tumorigenesis from a pathological perspective : Tumor spread and epigenetically regulated genes in bladder cancer]

The article describes the tumorigenesis of bladder cancer from a pathological perspective in three dimensions: morphology, genetics and epigenetics. Field cancerization and tumor cell migration/seeding are the two main hypotheses used for explaining synchronous and metachronous tumors in the urinary tract. By detailed histological mapping of completely embedded cystectomy specimens we found a single tumor focus in nearly 2/3 of the bladders accompanied by surrounding preinvasive carcinoma in situ. We substantiated our findings by studies analyzing TP53 mutations and loss of heterozygosity in various tumor sites. Identical TP53 mutations suggested a clonal relationship of the tumor foci. In situ lineage tracing via cytochrome C oxidase and succinate dehydrogenase enzyme histochemistry and subsequent mitochondrial DNA mutation analysis for definitive evidence of a clonal relationship in bladder tumors remained inconclusive. We found indications for both theories but intraurothelial migration/seeding was more prominent.A further mechanism in tumorigenesis is gene inactivation by epigenetic DNA methylation. We analyzed DNA methylation of various genes, which had previously been found by RNA expression analysis to be downregulated in bladder cancer. Most importantly, epigenetically silenced ITIH5 was associated with early relapse in pT1 high grade tumors and functionally showed an enhanced invasive metastatic phenotype in tumor cells, suggesting a putative tumor suppressive role. Thus, epigenetic gene silencing is an additional mechanism of tumorigenesis especially in tumor progression.