Expression of cytokeratin 20 redefines urothelial papillomas of the bladder

The difference between cytokeratin 20 expression in high- and low-grade urothelial bladder carcinomas: A cross-sectional study

Background:

Bladder cancer is one of the most common cancers worldwide. Expression of cytokeratin 20 (CK 20) could be used as a biomarker in different epithelia to determine malignancy, especially in gastrointestinal, urinary tract, and Merkel cells. CK 20 could be detected in several urothelial carcinomas and was associated with bladder cancer recurrence. The study aimed to assess the utility of CK 20 expression for bladder cancer grading.

Materials and Methods:

This was a retrospective study assessing CK 20 expression in 73 bladder cancer patients who had transurethral resection of bladder tumor or cystectomy. The data were then collected and analyzed with SPSS Statistics version 20.0.

Results:

Fifty-six (76.7%) cases of high- and 17 (23.3%) cases of low-grade urothelial bladder cancer were examined for CK 20 expression. Positive expression was present in 57 (78.1%) samples. A significant difference (P = 0.034) in CK 20 expression was observed between low-grade and high-grade urothelial carcinomas. Positive expression was seen in 44 (77.2%) high-grade cases and only 13 (22.8%) low-grade cases.

Conclusion:

The difference in the CK 20 expression was found to be statistically significant among different grades of bladder cancer but not to metastatic bladder cancer. Further, studies are required to establish CK 20 as a diagnostic tool. We suggest a combination with several markers to compare which is superior.

A systematic review and meta-analysis of CK20, CD44, Ki67 and p53 as immunohistochemical markers in bladder carcinoma in situ

BACKGROUND

Urothelial dysplasia and carcinoma in situ (CIS) are related to recurrence and progression of urothelial carcinoma. Differentiating CIS and dysplasia from reactive atypia is often difficult based only on histological features. The integration of histological findings with immunohistochemistry is used in routine practice to make a diagnosis of CIS and, for this purpose, the immunohistochemical markers CK20, CD44, Ki67 and p53 are used to supplement histology. In this work, we aimed to assess CK20, CD44, Ki67 and p53 as immunohistochemical markers in patients with CIS through a systematic review and meta-analysis.

MATERIALS AND METHODS

A systematic review was performed by searching electronic databases for English-language studies published from January 2010 to April 2021. Studies were considered eligible if they evaluated the CK20, CD44, Ki67 and p53 expression in CIS.

RESULTS

In total, 15 references were suitable for quantitative review. The overall rate of CK20, CD44, Ki67 and p53 expression in CIS was 43%, 31%, 44%, 38%, respectively.

CONCLUSIONS

Our study supports the 2014 International Society of Urologic Pathology consensus that histological assessment remains the gold standard to diagnose urothelial CIS and suggests that a very close correlation between morphological, immunohistochemical and clinical data is essential to provide the best management for patients with bladder carcinoma.

Are We Ready to Implement Molecular Subtyping of Bladder Cancer in Clinical Practice? Part 1: General Issues and Marker Expression

Bladder cancer (BC) is a heterogeneous disease with highly variable clinical and pathological features, and resulting in different outcomes. Such heterogeneity ensues from distinct pathogenetic mechanisms and may consistently affect treatment responses in single patients. Thus, over the last few years, several groups have developed molecular classification schemes for BC, mainly based on their mRNA expression profiles. A “consensus” classification has recently been proposed to combine the published systems, agreeing on a six-cluster scheme with distinct prognostic and predictive features. In order to implement molecular subtyping as a risk-stratification tool in routine practice, immunohistochemistry (IHC) has been explored as a readily accessible, relatively inexpensive, standardized surrogate method, achieving promising results in different clinical settings. The first part of this review deals with the steps resulting in the development of a molecular subtyping of BC, its prognostic and predictive implications, and the main features of immunohistochemical markers used as surrogates to stratify BC into pre-defined molecular clusters.

Diagnostic roles of proliferative markers in pathological Grade of T1 Urothelial Bladder Cancer

The stage T1 urothelial bladder cancer (T1 UBC) tumor grade classification is important for prognosis and clinical management. However, the reproducibility of this two-grade classification system is limited in regards to pathological diagnosis, and there is lack of ideal, objective and easily detected markers for pathological diagnosis. In our study, bladder urothelial lesions from a total of 124 patients diagnosed pathologically after transurethral resection of the bladder tumor (TURBT) were collected, including non-cancerous lesions from 33 patients and lesions from 91 T1 UBC patients. A series of previous studies have suggested some common and valuable factors in the diagnosis and prognosis of UBC, but there are still some controversial factors, such as the mitotic figure (MF) of tumor cell, cell proliferation index Ki-67, graded differentiation marker CK20, P53, P504S and carcinogenesis associated telomerase reverse transcriptase (TERT) promoter mutations. The purpose of this study was to evaluate the value of these factors in the pathological grading diagnosis of T1 UBC. The results showed that gender, lesion size, mitotic index (MI), CK20, P53, Ki-67, P504S and TERT promoter hot spot mutations (C228T and C250T) were correlated with T1 UBC diagnosis (P<0.05). The MI, Ki-67 and P504S were correlated with the pathological grade of T1 UBC (P<0.05). Logistic regression analysis showed that the MI and Ki-67 were independent risk factors for high-grade (HG) of T1 UBC (P<0.05). The combined detection of the MI, Ki-67 and P504S in a multivariate diagnostic model improved the diagnostic accuracy of assigning the T1 UBC pathological grade (AUC=0.904, 95%CI: 0.824~0.956, P<0.05). In conclusion, MI and Ki-67, as important markers of histopathology and cell proliferation, can be easily measured and have good reproducibility. These markers may be meaningful parameters for assigning the pathological grade of UBC.

CK20 and CK5/6 Immunohistochemical Staining of Urothelial Neoplasms: A Perspective

Cytokeratins belong to the family of intermediate filaments. They are expressed in a highly specific manner in epithelial cells where they play a crucial role in the integrity and mechanical stability of the cells. Several types of cytokeratins have been described in normal as well as neoplastic urothelium. In the case of urothelial neoplasms expression of CK20 and CK5/6 has been shown in several studies to have diagnostic and prognostic implications. Thus, low-grade urothelial carcinoma manifests CK expression limited to the umbrella cells, while high-grade tumors usually have an expression in the entire thickness of the urothelium except for the basal layer. CK5/6 expression on the other hand is expressed in the basal cells in all low-grade and some high-grade urothelial carcinomas. Diffuse CK20 staining accompanied by loss of CK5/6-positive basal layer is usually associated with aggressive clinical behavior. Double staining of the slides for these cytokeratins may facilitate proper interpretation and correlation.

Diagnostic significance of dual immunocytochemical staining of p53/cytokeratin20 on liquid-based urine cytology to detect urothelial carcinoma

Background:

Urine cytology is a noninvasive and inexpensive method; however, it is limited in low sensitivity for detecting and monitoring urothelial carcinoma (UC). To overcome limitation of cytology, several tests using urine samples have been attempted that immunocytochemical staining is an inexpensive and easy to perform ancillary technique. Dual immunocytochemical staining for p53 and cytokeratin 20 (CK20) is assessed in liquid-based urine cytology slides.

Materials and Methods:

Liquid-based urine cytology samples collected between 2008 and 2013 and matched follow-up biopsy samples of high-grade UC (HGUC) (n = 44) and low-grade UC (LGUC) (n = 14) were analyzed.

Results:

Urine cytology showing atypical cells was subjected to dual-color immunostaining for p53 and CK20. The sensitivity of urine cytology combined with p53 and CK20 immunostaining was 77.3% in HGUC and 52.9% in LGUC. Of 20 cases diagnosed with atypia by urine cytology, 13 (65%) were positive for p53 or CK20. Dual immunocytochemical staining for p53/CK20 improved the diagnostic accuracy of urine cytology.

Conclusions:

The present results indicate that cytomorphology combined with p53/CK20 immunostaining is useful for the detection of HGUC and LGUC.

Diagnostic and prognostic roles of CK20 in the pathology of urothelial lesions. A systematic review

Cytokeratin 20 (CK20) is one of the most common immunohistochemical markers in the routine practice of a pathology lab, as biopsies from the urinary tract encompass a wide spectrum of lesions which may pose issues in their detection and classification. In this review, we aim to outline the diagnostic accuracy and prognostic value of CK20 in flat urothelial lesions, papillary non-invasive and invasive urothelial carcinoma, molecular subgroups and variant histology, and we briefly discuss its limitations and potential pitfalls.

Integrated Fourier Transform Infrared Imaging and Proteomics for Identification of a Candidate Histochemical Biomarker in Bladder Cancer

Histopathological differentiation between severe urocystitis with reactive urothelial atypia and carcinoma in situ (CIS) can be difficult, particularly after a treatment that deliberately induces an inflammatory reaction, such as intravesical instillation of Bacillus Calmette-Guèrin. However, precise grading in bladder cancer is critical for therapeutic decision making and thus requires reliable immunohistochemical biomarkers. Herein, an exemplary potential biomarker in bladder cancer was identified by the novel approach of Fourier transform infrared imaging for label-free tissue annotation of tissue thin sections. Identified regions of interest are collected by laser microdissection to provide homogeneous samples for liquid chromatography-tandem mass spectrometry-based proteomic analysis. This approach afforded label-free spatial classification with a high accuracy and without interobserver variability, along with the molecular resolution of the proteomic analysis. Cystitis and invasive high-grade urothelial carcinoma samples were analyzed. Three candidate biomarkers were identified and verified by immunohistochemistry in a small cohort, including low-grade urothelial carcinoma samples. The best-performing candidate AHNAK2 was further evaluated in a much larger independent verification cohort that also included CIS samples. Reactive urothelial atypia and CIS were distinguishable on the basis of the expression of this newly identified and verified immunohistochemical biomarker, with a sensitivity of 97% and a specificity of 69%. AHNAK2 can differentiate between reactive urothelial atypia in the setting of an acute or chronic cystitis and nonmuscle invasive-type CIS.

Diagnostic and Prognostic Implications of FGFR3high/Ki67high Papillary Bladder Cancers

Prognostic/therapeutic stratification of papillary urothelial cancers is solely based upon histology, despite activated FGFR3-signaling was found to be associated with low grade tumors and favorable outcome. However, there are FGFR3-overexpressing tumors showing high proliferation-a paradox of coexisting favorable and adverse features. Therefore, our study aimed to decipher the relevance of FGFR3-overexpression/proliferation for histopathological grading and risk stratification. N = 142 (n = 82 pTa, n = 42 pT1, n = 18 pT2-4) morphologically G1⁻G3 tumors were analyzed for immunohistochemical expression of FGFR3 and Ki67. Mutation analysis of FGFR3 and TP53 and FISH for FGFR3 amplification and rearrangement was performed. SPSS 23.0 was used for statistical analysis. Overall FGFR3high/Ki67high status (n = 58) resulted in a reduced ∆mean progression-free survival (PFS) (p < 0.01) of 63.92 months, and shorter progression-free survival (p < 0.01; mean PFS: 55.89 months) in pTa tumors (n = 50). FGFR3mut/TP53mut double mutations led to a reduced ∆mean PFS (p < 0.01) of 80.30 months in all tumors, and FGFR3mut/TP53mut pTa tumors presented a dramatically reduced PFS (p < 0.001; mean PFS: 5.00 months). Our results identified FGFR3high/Ki67high papillary pTa tumors as a subgroup with poor prognosis and encourage histological grading as high grade tumors. Tumor grading should possibly be augmented by immunohistochemical stainings and suitable clinical surveillance by endoscopy should be performed.

Evolving concepts and use of immunohistochemical biomarkers in flat non-neoplastic urothelial lesions: WHO 2016 classification update with diagnostic algorithm

CONTEXT

The classification of flat non-neoplastic urothelial lesions has been evolved through the years in the attempt to better define a spectrum of morphologic entities with somewhat overlapping features. Differentiating these lesions is important because of differences in patient management and clinical outcome. Materials and methods and objective: A systematic review of the literature has been carried out in order to (1) assess the most striking clinical features of each lesion and (2) identify those morphological traits and immunophenotypical markers which may aid in the differential diagnosis.

RESULTS AND CONCLUSION

Our results point out the importance of a proper definition of flat non-neoplastic urothelial lesions in order to predict clinical behaviour and allow tailored patient management; therefore, we attempted to construct a novel and "easy to use" algorithm for a clear, standardized and evidence-based pathological diagnosis.

Diagnostic difficulties in cases of papillary urothelial neoplasm of low malignant potential, urothelial proliferation of uncertain malignant potential, urothelial dysplasia and urothelial papilloma: A review of current literature

Tumours of the urinary tract are the fifth most frequent type of cancer. The most common types are urothelial tumours, among which, non-invasive urothelial neoplasms represent 45% of all cases. The 2016 WHO classification of urinary tract tumours introduced new classifications of non-invasive lesions. Besides urothelial papilloma (UP) and papillary urothelial neoplasm of low malignant potential (PUNLMP), as described in the former classification, the new classification also includes new entities such as urothelial proliferation of uncertain malignant potential (UPUMP) and urothelial dysplasia (UD). Of the aforementioned, UPUMP is the lesion that most commonly progresses, but solely to non-invasive carcinomas. UD is associated with a high risk of progression to invasive carcinoma. Understanding the biological character, and establishing the correct differential diagnosis in cases of non-invasive, non-cancerous lesions of the urinary bladder, will be of importance in establishing outcome predictions for future patients. A systematic review of the current literature allows us to systematize genetic, morphologic and prognostic factors of such lesions. Moreover, the collected data provide the basis for a proposed diagnostic algorithm which facilitates quick and effective differential diagnoses in cases of non-invasive non-cancerous urinary bladder lesions.

Increased Proliferation as Independent Predictor of Disease Recurrence in Initial Stage pTa Urothelial Bladder Cancer

Objectives:

To investigate the predictive impact of the proliferation biomarker Ki-67 on the clinical course of patients with initial stage pTa urothelial carcinoma of the bladder (UCB).

Methods:

We retrospectively analyzed all patients treated by transurethral resection of bladder tumors (TUR-B) for UCB between 1992–2004 in a single-center. Disease recurrence (≥pTa UCB) and absent tumor in histopathology, assessed by TUR-B with a non-malignant result for endoscopic suspect bladder lesion displayed endpoints. Immunohistochemical (IHC) analysis of formalin-fixed and paraffin-embedded tissue blocks was performed with an immunostainer using a primary antibody for Ki-67. Semiquantitative evaluation of Ki-67 was performed by three reviewers. Increased proliferation was defined with a cut-off value of ≥50%. Uni- and multivariable binary regression analyses were applied to address prediction of disease recurrence.

Results:

215 patients (84% male, median age 69 years at first diagnosis) were evaluable and included to the study. 89 patients stayed disease-free (41%), 126 patients showed recurrence (59%). Recurrence rates of patients with Ki-67 expression <10%, 10–24%, 25–49% and ≥50% were 14.8% vs. 30.8% vs. 63.9% and 80.7%, respectively (p < 0.001). In Kaplan-Meier analysis patients with increased proliferation ≥50% showed a statistically significant worse 10-year recurrence-free survival (19% vs. 57%, p < 0.001). Multivariable regression analysis revealed instillation treatment (p = 0.001) and high proliferation of Ki-67 (p < 0.001) to be independent predictors of recurrence in stage pTa UCB.

Conclusions:

High proliferation with Ki-67 expression ≥50% was strongly associated with worse recurrence-free survival in patients with initial stage pTa UCB. Stage pTa UCB patients with increased Ki-67 expression should undergo a strictly follow-up regime comparable to stage pT1 bladder carcinoma, while at least patients with Ki-67 expression <10% might be feasible for more liberate follow-up regime after evaluation of our data in randomized, prospective and multicenter studies.

Positive association of collagen type I with non-muscle invasive bladder cancer progression

PURPOSE

Non-muscle invasive bladder cancers (NMIBC) are generally curable, while ~15% progresses into muscle-invasive cancer with poor prognosis. While efforts have been made to identify genetic alternations associated with progression, the extracellular matrix (ECM) microenvironment remains largely unexplored. Type I collagen is a major component of the bladder ECM, and can be altered during cancer progression. We set out to explore the association of type I collagen with NMIBC progression.

EXPERIMENTAL DESIGN

The associations of COL1A1 and COL1A2 mRNA levels with progression were evaluated in a multi-center cohort of 189 patients with NMIBCs. Type I collagen protein expression and structure were evaluated in an independent single-center cohort of 80 patients with NMIBCs. Immunohistochemical analysis was performed and state-of-the-art multi-photon microscopy was used to evaluate collagen structure via second harmonic generation imaging. Progression to muscle invasion was the primary outcome. Kaplan-Meier method, Cox regression, and Wilcoxon rank-sum were used for statistical analysis.

RESULTS

There is a significant association of high COL1A1 and COL1A2 mRNA expression in patients with poor progression-free survival (P=0.0037 and P=0.011, respectively) and overall survival (P=0.024 and P=0.012, respectively). Additionally, immunohistochemistry analysis of type I collagen protein deposition revealed a significant association with progression (P=0.0145); Second-harmonic generation imaging revealed a significant lower collagen fiber curvature ratio in patients with invasive progression (P = 0.0018).

CONCLUSIONS

Alterations in the ECM microenvironment, particularly type I collagen, likely contributes to bladder cancer progression. These findings will open avenues to future functional studies to investigate ECM-tumor interaction as a potential therapeutic intervention to treat NMIBCs.

Immunohistochemical Expression of Cyclin D1, Cytokeratin 20, and Uroplakin III in Proliferative Urinary Bladder Lesions Induced by o-Nitroanisole in Fischer 344/N Rats

o-Nitroanisole is an intermediate in the manufacture of azo dyes. In a National Toxicology Program stop-exposure study,o-nitroanisole induced hyperplasia, papillomas, and papillary carcinomas in the urinary bladder of Fischer 344/N rats.o-Nitroanisole was investigated since occupational or environmental exposure to aniline and azo dyes is a risk factor for urinary bladder cancer in humans. The current study describes the morphology of urinary bladder neoplasms seen in rats with respect to those observed in humans. This study also evaluated immunohistochemical expression of the cell cycle-related proteins cyclin D1 and p53 and the differentiation markers cytokeratin 20 and uroplakin III in hyperplastic (n= 11) and neoplastic (n= 6 papillomas,n= 11 carcinomas) lesions of the urinary bladder epithelium from rats treated with o-nitroanisole and in normal (n= 6) urinary bladders from untreated rats. The tumors observed were more similar to the papillary type rather than the muscle-invasive type of urinary bladder cancer in humans. The preneoplastic and neoplastic lesions observed suggest progression from hyperplasia to papilloma to papillary carcinoma. With neoplastic progression (hyperplasia to papilloma to carcinoma), cyclin D1 immunoreactivity progressively increased in intensity, percentage of cells staining, and distribution. Overexpression of p53 was not found. Cytokeratin 20 staining decreased in superficial cells, while uroplakin III staining increased in intermediate and basal cells with progression from hyperplasia to carcinoma. The results are consistent with increased cell cycle dysregulation or proliferation (cyclin D1), decreased differentiation (cytokeratin 20), and abnormal differentiation (uroplakin III) as lesions progress toward malignancy.

Immunohistochemistry and Fluorescence In Situ Hybridization Can Inform the Differential Diagnosis of Low-Grade Noninvasive Urothelial Carcinoma with an Inverted Growth Pattern and Inverted Urothelial Papilloma

Urothelial carcinoma (UC) comprises a heterogeneous group of epithelial neoplasms with diverse biological behaviors and variable clinical outcomes. Distinguishing UC histological subtypes has become increasingly important because prognoses and therapy can dramatically differ among subtypes. In clinical work, overlapping morphological findings between low-grade noninvasive UC (LGNUC), which exhibits an inverted growth pattern, and inverted urothelial papilloma (IUP) can make subclassification difficult. We propose a combination of immunohistochemistry (IHC) and molecular cytogenetics for subtyping these clinical entities. In our study, tissue microarray immunohistochemical profiles of Ki-67, p53, cytokeratin 20 (CK20) and cyclinD1 were assessed. Molecular genetic alterations such as the gain of chromosomes 3, 7 or 17 or the homozygous loss of 9p21 were also assessed for their usefulness in differentiating these conditions. Based on our analysis, Ki-67 and CK20 may be useful for the differential diagnosis of these two tumor types. Fluorescence in situ hybridization (FISH) can also provide important data in cases in which the malignant nature of an inverted urothelial neoplasm is unclear. LGNUC with an inverted growth pattern that is negative for both Ki-67 and CK20 can be positively detected using FISH.

Long term outcome of primary urothelial papilloma: a single institution cohort

The aim of this study was to investigate the long term outcome of primary urothelial papilloma (UP). We retrieved 41 primary UP, diagnosed between January 2000 and December 2009. Follow-up was obtained by searching pathology and clinical electronic databases. Mean patient age was 57 years (range 30-84 years), with a male-to-female ratio of 1.9:1. Mean follow-up was 81 months (range 3-127 months). In 37 (90.2%) patients, no recurrence and/or progression were documented and no subsequent higher grade neoplasms were diagnosed. Three male patients were diagnosed with UP at 1, 31, and 43 months after the initial resection; the repeat diagnosis of UP at 1 month likely represented an incomplete resection. Thus, only two of 41 patients (4.9%) had a recurrent UP. One of these patients had a subsequent papillary urothelial neoplasm of low malignant potential (PUNLMP), 17 months after the recurrent UP (48 months after the initial UP). Only one additional male had a subsequent PUNLMP, 76 months after the initial UP. Thus, only two of 41 patients (4.9%) had a subsequent PUNLMP, both presenting with haematuria. Primary UP does not progress to UC when diagnosed using strict criteria, when no previous or concurrent neoplasms are documented, and when complete initial resection is performed.

Diagnostic utility of p53 and CK20 immunohistochemical expression grading urothelial malignancies

Introduction

Current grading system in application by WHO/ISUP divides urothelial malignancies in low and high grade by morphologic criteria while strict segregation may become cumbersome in limited tissue specimens. As grading these carcinomas are of utmost prognostic significance after depth of invasion, therefore we evaluated the role of immunohistochemical expression of p53 and cytokeratin 20 as an adjuctive tool in grading urothelial carcinoma.

Methods

The study was conducted in Aga khan university hospital, Histopathology section from December 2010 till June 2011 for duration of six months. It involved 95 cases of urothelial carcinomas diagnosed on trans-uretheral resection specimens of bladder growth. Immunohistochemical expression of p53 and cytokeratin 20 was performed according to standard protocols and correlated with grade and depth of invasion.

Results

There were 48 cases (50.5%) of low grade and 47 cases (49.5%) of high grade urothelial carcinoma included in the study. Male to female ratio was 4.3:1. Majority of patients (80%) were seen in 45 to 90 years age group. Diffuse positive expression of cytokerain 20 was noted in 33 cases (68.8%) of high grade and 19 (40.4%) low grade tumors. Strong positive expression of p53 was seen in 35 cases (72.9%) of high grade while only 17 cases (36.2%) of low grade tumors showed strong p53 expression.

Conclusion

Significant difference in expression of Cytokeratin 20 and p53 was found between low and high grade urothelial carcinoma. Therefore we suggest combined use of these markers may be helpful in assigning grade to urothelial carcinoma especially when histologic features are borderline.

Evaluation of a triple combination of cytokeratin 20, p53 and CD44 for improving detection of urothelial carcinoma in urine cytology specimens

Background:

Atypical urine cytology results trigger cystoscopy or molecular tests, both of which are costly, complex and difficult to perform tests. Several immunostains are being investigated to improve cancer detection; however, cytology material is limited and restricts the use of multiple immunostains. This study was designed to determine the utility of a cocktail of three stains, cytokeratin (CK20), p53 and CD44 in urine cytology samples for improving the detection of urothelial carcinoma.

Materials and Methods:

Urine cytology specimens with cell blocks containing adequate cytologic material between 2005 and 2010 and subsequent follow-up biopsy and/or Urovysion test (102 cases including 29 negative, 56 atypical and 17 malignant) were included in the study and evaluated with the triple stain. Results were first validated on the positive and negative cases and then applied to the atypical cases to determine the utility in the diagnosis of urothelial carcinoma.

Results:

Based on the validation and published literature, two distinct immunoprofiles were defined – malignant, characterized by at least five CK20 and/or p53 positive atypical cells and reactive, all other staining patterns. The malignant immunoprofile showed 88% sensitivity, 78% specificity, 74% positive predictive value (PPV) and 90% negative predictive value (NPV) for detecting urothelial carcinoma. These values improved to 95% sensitivity and 96% NPV when low-grade urothelial carcinoma cases were excluded.

Summary:

Our results indicate that the triple stain is an inexpensive, easy to perform test most useful for differentiating high-grade urothelial carcinoma from its mimics. However Inclusion of CD44 in the cocktail did not provide additional value and is best excluded.

Microsatellite instability status affects gene expression profiles in early onset colorectal cancer patients

BACKGROUND

The association between microsatellite instability (MSI) status and gene expression profiles in the early onset sporadic colorectal cancer (CRC) has not been clearly established. The aim of this study was to identify the altered gene expression patterns depending on the MSI status of early onset CRC and determine specific biomarkers that could provide novel therapeutic molecular targets in the Turkish population.

MATERIALS AND METHODS

MSI markers (BAT25, BAT26, D2S123, D5S346, and D17S250) were investigated in tumors from 36 early onset sporadic CRC patients in whom gene expression profiles were analyzed previously. The relationship between the gene expression profiles depending on MSI status was evaluated.

RESULTS

A total of 15 tumors (16.66%) were identified as having MSI and 21 tumors (58.33%) were identified as having microsatellite stability (MSS). CK20 and MAP3K8 upregulation, observed in MSS tumors, was significantly associated with lymph node metastasis, recurrence, and/or distant metastasis and a short median survival (P < 0.05). REG1A upregulation is also correlated with recurrence and/or distant metastasis and a short median survival in patients with MSI tumors (P < 0.05).

CONCLUSIONS

High expression levels of CK20 and MAP3K8 in MSS tumors and REG1A in MSI tumors correlated with a poor prognosis in CRC patients. Further studies and validations are required; these genes may provide novel therapeutic molecular targets for the development of anticancer drugs related to MSI status for early onset CRC treatment.

Overexpression of CK20, MAP3K8 and EIF5A correlates with poor prognosis in early-onset colorectal cancer patients

PURPOSE

Due to ethnic, genetic and environmental factors, the clinical and molecular characteristics of Turkish colorectal cancer (CRC) patients are different from those of Western populations. The aim of this study was to clarify the relevant alterations of gene expression associated with colorectal carcinogenesis in early-onset patients and to identify specific biomarkers that could provide novel therapeutic molecular targets in this population.

METHODS

The expression profiles of 114 different genes were evaluated using mRNA PCR arrays in 39 tumors and 20 surgical margin tissue samples from 39 sporadic CRC patients diagnosed at less than 50 years of age.

RESULTS

The expression levels of IMPDH2, CK20, MAP3K8 and EIF5A were strongly up-regulated in CRC tissues compared with normal colorectal tissues (p < 0.05). The highly significant expression ratios of CK20, MAP3K8 and EIF5A observed in the colorectal tumors of patients predicted recurrence (p < 0.05). The expression of IMPDH2, CK20, MAP3K8 and EIF5A was significantly higher in the tumors of patients with short median survival (log-rank p value < 0.05). Progression-free survival was also significantly increased in patients with low expression of the EIF5A gene compared with those who exhibited high expression of this gene (log-rank p value < 0.05).

CONCLUSION

We demonstrated that high CK20, MAP3K8 and EIF5A expression levels were significant prognostic factors for poor overall survival in CRC patients. Further studies and validations are required; these genes may provide novel therapeutic molecular targets for CRC treatment, as well as new directions for the development of anticancer drugs.

Combination of CK20 and Ki-67 immunostaining analysis predicts recurrence, progression, and cancer-specific survival in pT1 urothelial bladder cancer

BACKGROUND

The prognostic value of CK20, Ki-67, and p53 has been investigated for non-muscle-invasive urothelial bladder cancers but not for the distinct and clinically challenging subset of pT1 bladder cancers.

OBJECTIVE

To evaluate the prognostic value of CK20, Ki-67, and p53 within the largest series of pT1 urothelial bladder cancers.

DESIGN, SETTING, AND PARTICIPANTS

Data from 309 patients with pT1 urothelial bladder cancer from one single urologic centre were collected.

INTERVENTION

Adjuvant instillation of bacillus Calmette-Guérin was performed in each patient. A second resection was performed after 4-8 wk. A total of 76 patients underwent cystectomy.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We conducted histomorphologic analysis; immunohistochemistry for CK20, Ki-67, and p53; and univariate and multivariate Cox regression models including recurrence-free survival (RFS), progression-free survival (PFS), and cancer-specific survival (CSS).

RESULTS AND LIMITATIONS

At a median follow-up of 49 mo, we found recurrence and progression and disease-specific mortality rates of 22.7%, 20.1%, and 15.9%, respectively. CK20 expression was significantly correlated with RFS in multivariate analysis (hazard ratio [HR]: 5.89; 95% confidence interval [CI], 1.44-24.15; p=0.014). In multivariate analysis, Ki-67 was the only marker significantly correlated with PFS (HR: 2.80; 95% CI, 1.45-5.43, p=0.002). Ki-67 (HR: 3.83; 95% CI, 1.59-9.26; p=0.003), and CK20 (HR: 8.44; 95% CI,1.16-61.34; p=0.035) were significantly correlated with CSS in multivariate analysis. The combination of CK20 and Ki-67 showed significantly worse RFS (p=0.026), PFS (p=0.003), and CSS (p<0.001) in tumours with a high proliferation index and abnormal CK20 expression. A retrospective study design was the major limitation of this study.

CONCLUSIONS

Our present analysis of the largest series of patients with pT1 urothelial bladder cancer published to date found Ki-67 and CK20 to be potential prognostic markers improving the risk stratification of pT1 bladder tumours. They are reliable indicators of biologic aggressiveness and may contribute to decision making on therapeutic strategy for pT1 bladder carcinomas.

A molecular taxonomy for urothelial carcinoma

PURPOSE

Even though urothelial cancer is the fourth most common tumor type among males, progress in treatment has been scarce. A problem in day-to-day clinical practice is that precise assessment of individual tumors is still fairly uncertain; consequently efforts have been undertaken to complement tumor evaluation with molecular biomarkers. An extension of this approach would be to base tumor classification primarily on molecular features. Here, we present a molecular taxonomy for urothelial carcinoma based on integrated genomics.

EXPERIMENTAL DESIGN

We use gene expression profiles from 308 tumor cases to define five major urothelial carcinoma subtypes: urobasal A, genomically unstable, urobasal B, squamous cell carcinoma like, and an infiltrated class of tumors. Tumor subtypes were validated in three independent publically available data sets. The expression of 11 key genes was validated at the protein level by immunohistochemistry.

RESULTS

The subtypes show distinct clinical outcomes and differ with respect to expression of cell-cycle genes, receptor tyrosine kinases particularly FGFR3, ERBB2, and EGFR, cytokeratins, and cell adhesion genes, as well as with respect to FGFR3, PIK3CA, and TP53 mutation frequency. The molecular subtypes cut across pathologic classification, and class-defining gene signatures show coordinated expression irrespective of pathologic stage and grade, suggesting the molecular phenotypes as intrinsic properties of the tumors. Available data indicate that susceptibility to specific drugs is more likely to be associated with the molecular stratification than with pathologic classification.

CONCLUSIONS

We anticipate that the molecular taxonomy will be useful in future clinical investigations.

Immunocytochemical characterisation of cultures of human bladder mucosal cells

Background

The functional role of the bladder urothelium has been the focus of much recent research. The bladder mucosa contains two significant cell types: urothelial cells that line the bladder lumen and suburothelial interstitial cells or myofibroblasts. The aims of this study were to culture these cell populations from human bladder biopsies and to perform immunocytochemical characterisation.

Methods

Primary cell cultures were established from human bladder biopsies (n = 10). Individual populations of urothelial and myofibroblast-like cells were isolated using magnetic activated cell separation (MACS). Cells were slow growing, needing 3 to 5 weeks to attain confluence.

Results

Cytokeratin 20 positive cells (umbrella cells) were isolated at primary culture and also from patients' bladder washings but these did not proliferate. In primary culture, proliferating cells demonstrated positive immunocytochemical staining to cytokeratin markers (AE1/AE3 and A0575) as well fibroblasts (5B5) and smooth muscle (αSMA) markers. An unexpected finding was that populations of presumptive urothelial and myofibroblast-like cells, isolated using the MACS beads, stained for similar markers. In contrast, staining for cytokeratins and fibroblast or smooth muscle markers was not co-localised in full thickness bladder sections.

Conclusions

Our results suggest that, in culture, bladder mucosal cells may undergo differentiation into a myoepithelial cell phenotype indicating that urothelial cells have the capacity to respond to environmental changes. This may be important pathologically but also suggests that studies of the physiological function of these cells in culture may not give a reliable indicator of human physiology.

Different immunohistochemical and ultrastructural phenotypes of squamous differentiation in bladder cancer

Besides worse prognosis of bladder cancer with squamous differentiation (pure squamous cell carcinoma (SCC) or mixed urothelial carcinoma (UC/SCC)), high-grade non-keratinising squamous differentiation is difficult to identify in haematoxylin-eosin stainings. This study aims to validate routine immunohistochemical markers for squamous differentiation in a larger cohort of patients. Tissue microarrays of 89 pure SCCs and mixed UC/SCCs, 66 urothelial carcinomas (UC), precursor lesions and normal urothelium were stained for cytokeratin (CK) 5/6, CK 5/14, CK 7, CK 20 and uroplakin III. Electron microscopy was performed to confirm the differentiation. Pure SCCs displayed staining throughout the epithelium for CK 5/6 (76.6% (36/47)) and CK 5/14 (95.8% (46/48)), focal staining for CK 7 (28.9% (13/45)) and no staining for CK 20 and uroplakin III (both 0% (0/48)). UCs exhibited a basal or diffuse staining for CK 5/6 (30.2% (16/53)) and CK 5/14 (57.1% (32/56)), focal positivity for CK 7 (83.6% (46/55)), CK 20 (50.9% (29/57)) and uroplakin III (21.8% (12/55)). Each marker discriminated SCC and UC significantly (p < 0.01). A third subgroup rarely showed full epithelial staining for CK 5/6 (14.3% (1/7)) and CK 5/14 (28.6% (2/7)), focal staining for CK 7 (85.7% (6/7)) and no staining for CK 20 and uroplakin III (both 0% (0/7)). Electron microscopy could prove both, SCC and UC characteristics, revealing a transient type. A staining pattern with CK 5/6- and CK 5/14-positivity plus CK 20- and uroplakin III-negativity identified squamous differentiation in bladder tumours and revealed a third type of squamous transdifferentiation.

CK20 and Ki-67 as significant prognostic factors in human bladder carcinoma

Aberrant expression of CK20 and Ki-67 has been documented in many kinds of primary tumors and has proved useful as an ancillary diagnostic aid for those tumors. The aim of this study was to analyze the expression patterns of CK20 and Ki-67 in human bladder carcinomas (BCa) and to evaluate their clinical significance in the progression of BCa. CK20 and Ki-67 expression in BCa and normal bladder tissues were detected by immunohistochemical staining. The Spearman correlation was calculated between the expression of CK20 and Ki-67 in BCa tissues. The correlation of CK20 and Ki-67 expression with the clinicopathological characteristics and the prognosis of BCa were subsequently assessed. CK20 expression was positively expressed in 103/154 (66.9%) of BCa and 2/30 (6.67%) of normal bladder tissues, respectively. The positive expression rate of Ki-67 in BCa tissues was also significantly higher than those in normal bladder tissues (81.8 vs. 10%, p < 0.01). The Spearman analysis indicated that the expression level of CK20 has a significant positive correlation with that of Ki-67 (rs = 0.86, p = 0.02). Pathologic findings demonstrated that the intensity of CK20 and Ki-67 staining in cancerous tissues was associated significantly with tumor grades (p = 0.03, p < 0.01), distant metastasis (both p < 0.01) and TNM grades (p = 0.01, p = 0.03) of BCa. The progression-free survival of the patients with CK20 (+)/Ki-67 (+) expression was poorest (p < 0.01). The results suggest that the expression of CK20 and Ki-67 may be an important feature of BCa, and the detection of their co-expression may benefit the prediction of BCa prognosis.

Utility of a dual immunostain cocktail comprising of p53 and CK20 to aid in the diagnosis of non-neoplastic and neoplastic bladder biopsies

Background

Distinction between non-neoplastic and neoplastic bladder lesions is therapeutically and prognostically important. Our objective is to describe the use of double immunohistochemistry (DIHC) for p53+CK20 as a tool for diagnosing neoplasia in bladder biopsies.

Methods

p53+CK20 DIHC were examined in 38 reactive atypia, 10 dysplasia, 9 carcinoma in situ (CIS) and 7 invasive carcinoma (IC) cases. CK20 was evaluated according to distribution extent and degree of intensity whereas percentage of positive cells together with staining intensity was taken into account in the evaluation of p53.

Results

92% of reactive cases were either CK20(-) or (+) only in the upper 1/3 urothelium. In dysplastic cases CK20 staining distribution was as follows: 60% in 2/3 of the urothelium, 30% full thickness, 10% in the upper 1/3 urothelium. Among CIS cases, 89% had full thickness CK20 positivity, of which 62% were p53(+). 71% of IC cases exhibited strong and full thickness dual staining.

Conclusion

This is the first study in the literature to use DIHC of p53+CK20 in distinction of non-neoplastic and neoplastic bladder lesions. Dual staining by p53+CK20 cocktail allows for histologic correlation and diminishes the risk of losing the area of interest in limited biopsy specimens.

Detection of urothelial bladder cancer cells in voided urine can be improved by a combination of cytology and standardized microsatellite analysis

PURPOSE

To evaluate molecular and immunohistochemical markers to develop a molecular grading of urothelial bladder cancer and to test these markers in voided urine samples.

EXPERIMENTAL DESIGN

255 consecutive biopsies from primary bladder cancer patients were evaluated on a tissue microarray. The clinical parameters gender, age, adjacent carcinoma in situ, and multifocality were collected. UroVysion fluorescence in situ hybridization (FISH) was done. Expression of cytokeratin 20, MIB1, and TP53 was analyzed by immunohistochemistry. Fibroblast growth factor receptor 3 (FGFR3) status was studied by SNaPshot mutation detection. Results were correlated with clinical outcome by Cox regression analysis. To assess the predictive power of different predictor subsets to detect high grade and tumor invasion, logistic regression models were learned. Additionally, voided urine samples of 119 patients were investigated. After cytologic examination, urine samples were matched with their biopsies and analyzed for loss of heterozygosity (LOH), FGFR3 mutation, polysomy, and p16 deletion using UroVysion FISH. Receiver operator characteristic curves for various predictor subsets were plotted.

RESULTS

In biopsies, high grade and solid growth pattern were independent prognostic factors for overall survival. A model consisting of UroVysion FISH and FGFR3 status (FISH + FGFR3) predicted high grade significantly better compared with a recently proposed molecular grade (MIB1 + FGFR3). In voided urine, the combination of cytology with LOH analysis (CYTO + LOH) reached the highest diagnostic accuracy for the detection of bladder cancer cells and performed better than cytology alone (sensitivity of 88.2% and specificity of 97.1%).

CONCLUSIONS

The combination of cytology with LOH analysis could reduce unpleasant cystoscopies for bladder cancer patients.

REG1A predicts recurrence in stage Ta/T1 bladder cancer

AIMS

Stage Ta/T1 urothelial carcinoma of the bladder (Ta/T1 BC) has a marked tendency to recur. Regenerating protein 1 A (REG1A) has been reported to be expressed in human cancers, and it may be positively correlated with patient's prognosis. The aim of the present study was to evaluate the prognostic value of REG1A in Ta/T1 BC.

METHODS

Immunohistochemistry was done on 110 paraffin-embedded specimens of human Ta/T1 BC to detect the proteins REG1A, PCNA and MMP2. The relationships between REG1A expression and the clinical-pathological characteristics of Ta/T1 BC patients were evaluated.

RESULTS

Sixty-five out of 110 specimens were REG1A-positive. Grade and expression levels of MMP2 and REG1A were significantly correlated with the recurrence rate. REG1A expression (Hazard ratio: 3.1; 95% CI: 1.1-8.5; P=0.030) was an independent predictor of recurrence rate in multivariate Cox regression analysis. A significant association between REG1A expression and MMP2 expression (P=0.023) was also observed.

CONCLUSION

Expression of REG1A is an independent predictor of recurrence in Ta/T1 BC.

Urothelial carcinogenesis in the urinary bladder of rats treated with naveglitazar, a gamma-dominant PPAR alpha/gamma agonist: lack of evidence for urolithiasis as an inciting event

Naveglitazar, a gamma-dominant peroxisome proliferator-activated receptor (PPAR) alpha/gamma dual agonist, was tested for carcinogenicity in F344 rats in a 2-year study. Changes in urine composition and urothelial morphology were characterized in a companion 18-month investigative study. A significant increase in neoplasms of the bladder occurred only in females of the high-dose group (14/60) in the carcinogenicity study. Trends toward increased cell proliferation in the urothelium were noted in both sexes at all time points evaluated in the 18-month study. Group means for urothelial mitogenesis were increased statistically significantly only in high-dose females at 12 and 18 months. Urothelial hyperplasia occurred in high-dose females at 18 months. Morphologic changes in the urothelium at earlier time points were limited to hypertrophy and decreased immunolabeling of the superficial cells for cytokeratin 20 (a marker of terminal differentiation in urothelial cells) in both males and females. No treatment-related changes in urinary parameters, including urinary sediments, were associated with the occurrence of urothelial proliferation. Urinary pH was unaffected by treatment in both males and females, but expected diurnal changes were demonstrated. Collectively, these data indicate that naveglitazar was associated with hypertrophic and proliferative effects on the urothelium, but a link with changes in urinary parameters was not demonstrated.

Strong immunohistochemical expression of fibroblast growth factor receptor 3, superficial staining pattern of cytokeratin 20, and low proliferative activity define those papillary urothelial neoplasms of low malignant potential that do not recur

BACKGROUND

Papillary urothelial neoplasm of low malignant potential (PUNLMP) is a clinically significant lesion because recurrence occurs in approximately 35% of patients. To date, it is not possible to identify those cases that will recur based on conventional histopathologic assessment. The objective of the current study was to evaluate immunohistochemically tissue expression of fibroblast growth factor receptor 3 (FGFR3), cytokeratin 20 (CK20), and MIB-1 in nonrecurrent and recurrent PUNLMP.

METHODS

FGFR3, CK20, and MIB-1 were investigated by immunohistochemistry (IHC) in 80 PUNLMP cases (41 nonrecurrent and 39 recurrent), in 4 cases of normal urothelium (NU), and in 5 cases of muscle invasive pT2 urothelial carcinoma (UC). Statistics included discriminant analysis.

RESULTS

NU demonstrated a weak to moderate FRFG3 staining intensity, a superficial pattern of CK20 staining, and low proliferative activity. UC was found to have FGFR3 staining similar to NU, an abnormal CK20 expression, and high proliferative activity. The nonrecurrent PUNLMP group demonstrated strong FGFR3 intensity in 80.5% of the cases (vs 56.4% of the recurrent cases), a superficial CK20 staining pattern in 53.7% of the cases (vs 28.2% of the recurrent cases), and a percentage of MIB-1-positive nuclei below the median value of all the PUNLMP cases in 61% of the cases (35.9% in the recurrent cases). The differences were statistically significant. Discriminant analysis based on these 3 features demonstrated that 67.5% of cross-validated grouped PUNLMP cases were correctly allocated, with 73.2% of the nonrecurrent and 61.5% of the nonrecurrent cases being correctly classified. The specificity and sensitivity were 73.1% and 61.5%, respectively.

CONCLUSIONS

Strong immunohistochemical expression of FGFR3, a superficial staining pattern of CK20, and a low proliferative activity define those papillary urothelial neoplasms of low malignant potential that do not recur.

Diagnostic algorithm for papillary urothelial tumors in the urinary bladder

Papillary urothelial neoplasms with deceptively bland cytology cannot be easily classified. We aimed to design a new algorithm that could differentiate between these neoplasms based on a scoring system. We proposed a new scoring system that enables to reproducibly diagnose non-invasive papillary urothelial tumors. In this system, each lesion was given individual scores from 0 to 3 for mitosis and cellular thickness, from 0 to 2 for cellular atypia, and an additional score for papillary fusion. These scores were combined to form a summed score allowing the tumors to be ranked as follows: 0–1 = UP, 2–4 = low malignant potential (LMP), 5–7 = low-grade transitional cell carcinoma (TCC), and 8–9 = high-grade TCC. In addition to the scoring system, ancillary studies of MIB and p53 indexes with CK20 expression pattern analyses were compared together with clinical parameters. The MIB index was strongly correlated with disease progression. Four of the 22 LMP patients (18.2%) had late recurrences, two of these four (9.1%) had progression to low-grade carcinoma. The MIB index for LMP patients was strongly associated with recurrence (recurrence vs. non-recurrence, 16.5 vs. 8.1, p < 0.001). The proposed scoring system could enhance the reproducibility to distinguish papillary urothelial neoplasms.

Characterization of esophageal submucosal glands in pig tissue and cultures

The submucosal glands (SMGs) of the pig esophagus, like the human, secrete mucin and bicarbonate, which help in luminal acid clearance and epithelial protection. The aim of this study was to characterize histochemically the esophageal SMGs and a primary culture obtained from these glands. Tissues and cultures were stained with hematoxylin and eosin, periodic acid Schiff, Alcian blue, lectins, or cytokeratins. In the perfused esophagus, addition of carbachol increased mucin secretion by approximately 2-fold. The results indicate that [1] a method for culturing SMG cells was developed; [2] conventional staining indicates the presence of sulfated, acidic, and neutral mucopolysaccharides in glands and cultures; [3] lectin binding indicates the presence of N-acetyl glucosamine, N-acetyl neuraminic acid, N-acetyl galactosamine, and alpha-L: -fucose in mucous cells and cultures; [4] cytokeratin and lectin staining indicated similarities with Barrett epithelium (columnar metaplasia of the esophagus); and [5] cholinergic agonists enhance mucin secretion and this could play a significant role in esophageal protection.

Role of FGFR3 in urothelial cell carcinoma: biomarker and potential therapeutic target

Although non-invasive bladder tumours (pTa) are the most common group of bladder tumours at presentation, there has until recently been relatively little information on their molecular biology. Thus it was of great interest when mutations in the FGF receptor 3 (FGFR3) were identified in bladder tumours and it became apparent that these were most common in tumours of low grade and stage. Since the initial description of activating mutations of FGFR3, there have been numerous studies confirming the frequency and spectrum of these mutations in bladder cancers of all grades and stages. Mutation screening techniques have evolved and improved. FGFR3 mutation has been assessed as a predictive biomarker in tumour tissues and as a diagnostic biomarker in urine. Efforts have been made to understand the function of FGFR3 in urothelial and other cells. Although our understanding of FGFR3 function is incomplete, it is already apparent that this may represent an important therapeutic target not only in non-invasive bladder cancer but also in a significant number of invasive tumours. This review summarises the current state of knowledge of this interesting receptor in urothelial carcinoma (UC).

Low frequency of molecular changes and tumor recurrence in inverted papillomas of the urinary tract

AIM

Inverted papilloma (IP) of the urinary tract can be difficult to distinguish from noninvasive urothelial carcinoma with prominent inverted growth pattern (invNIUC). Ancillary markers may help to resolve such cases and clarify the reported malignant potential of some IPs.

METHODS

Eighty-nine urothelial lesions initially diagnosed as IP were reviewed by 4 experienced urologic pathologists and studied immunohistochemically (Ki67, p53, CK20, MSH2, MLH1, and MSH6). Mutations of the FGFR3 gene, deletions (loss of heterozygosity) of 9p, 9q, and 17p, microsatellite instability, and elevated microsatellite instability at selected tetranucleotides were also analyzed.

RESULTS

Considerable interobserver variability in histopathologic diagnoses was noticed. Only 62 (69.7%) initial diagnoses were confirmed by the review pathologists whereas 23 tumors (25.8%) were redefined as invNIUC. Molecular analyses revealed infrequent alterations in IPs, including microsatellite instability (1.8%), elevated microsatellite instability at selected tetranucleotides (13.2%), FGFR3 mutations (9.8%), 9p deletions (3.9%), 9q deletions (13.2%), 17p deletions (5.1%), nuclear p53 accumulation (18.9%), and aberrant immunostaining for MSH2 (5.8%), MLH1 (11.8%), and MSH6 (3.8%). IP and invNIUC differed in FGFR3 mutations and Ki-67 labeling index (P<0.001 each), and 9q loss of heterozygosity (P=0.03). There were fewer recurrences in IP (5.4%) compared with invNIUC (40.9%; P<0.0001).

CONCLUSIONS

IP is a benign lesion that lacks specific genetic alterations found in exophytic noninvasive papillary urothelial tumors. These lesions could be reactive in nature, perhaps secondary to chronic inflammation or a neoplastic process that lack specific genetic alterations. Nevertheless given the clinical and molecular data of this study a conservative clinical approach is appropriate.

Mcm2 predicts recurrence hazard in stage Ta/T1 bladder cancer more accurately than CK20, Ki67 and histological grade

Stage Ta/T1 urothelial carcinoma of the bladder (Ta/T1 BC) has a marked tendency to recur. Besides histopathology, markers such as CK20 expression and proliferation index (Ki67) have been shown to predict its clinical course. The replication-licensing factor minichromosome maintenance protein 2 (Mcm2) is a marker of proliferative potential shown to be a promising prognostic marker in various malignancies. The aim of the present study was to evaluate the prognostic value of Mcm2 in comparison to stage, grade, CK20 and Ki67. Initial sporadic Ta/T1 BC (n=71) were evaluated for their expression of CK20, Ki67 and Mcm2 by immunohistochemistry and tissue microarray technology. Prognostic power was analysed by univariate and multivariate Cox regression model for tumour recurrence rate. Median follow-up period was 39 months. A total of 35% patients experienced recurrence. While CK20 was not predictive, grade, Ki67 and Mcm2 were significantly related to recurrence rate in univariate Cox regression model. Only grade (HR 2.37; 95% CI 1.24-4.51; P=0.009) and Mcm2 expression with a cutoff > or = 40% (HR 5.81; 95% CI 2.41-14.00; P<0.001) were independent predictors of recurrence rate in multivariate Cox regression analysis. In addition to grade, expression of Mcm2 is an independent predictor of recurrence in Ta/T1 BC.

Genomic aberrations are rare in urothelial neoplasms of patients 19 years or younger

Urothelial neoplasms in patients 19 years of age or younger are rare, and the data regarding clinical outcome are conflicting. Molecular data are not available. Urothelial tumours from 14 patients aged 4 to 19 years were analysed, including FGFR3 and TP53 mutation screening, comparative genomic hybridization (CGH), UroVysion FISH analysis, polymerase chain reaction for human papillomavirus (HPV), microsatellite analysis using the NIH consensus panel for detection of microsatellite instability (MSI) and six markers for loss of heterozygosity on chromosome arms 9p, 9q, and 17p and immunohistochemistry for TP53, Ki-67, CK20 and the mismatch repair proteins (MRPs) hMSH2, hMLH1, and hMSH6. Based on the 2004 WHO classification, one urothelial papilloma, seven papillary urothelial neoplasms of low malignant potential (PUNLMPs), five low-grade, and one high-grade papillary urothelial carcinoma were included. No multifocal tumours were found and recurrence was seen in only one patient with a urothelial papilloma. All patients were alive with no evidence of disease at a median follow-up of 3.0 years. We found no mutations in FGFR3, deletions of chromosome arms 9p, 9q or 17p, MSI or MRP loss, or HPV positivity in any of the patients. Three cases showed chromosome alterations in CGH analyses, urothelial dedifferentiation with CK20 overexpression, or aneuploidy, and one TP53 mutation with TP53 overexpression was found. Urothelial neoplasms in people younger than 20 years are predominantly low grade and are associated with a favourable clinical outcome. Genetic alterations frequently seen in older adults are extremely rare in young patients. Urothelial neoplasms in children and young adults appear to be biologically distinct and lack genetic instability in most cases.

FGFR3 mutations and a normal CK20 staining pattern define low-grade noninvasive urothelial bladder tumours

OBJECTIVES

Molecular markers superior to conventional clinicopathologic parameters are needed to predict disease courses in bladder cancer patients. In this study, we investigated four markers (Ki-67, TP53, CK20, FGFR3) in primary urothelial bladder tumours and compared them with traditional pathologic features.

METHODS

Tissue microarrays were used to analyse CK20, TP53, and Ki-67 expression immunohistochemically in 255 unselected patients. FGFR3 mutations were detected by SNaPshot analysis.

RESULTS

Abnormal CK20 expression was strongly associated with higher tumour grades and stages (p < 0.001); however, 65% of pTa tumours revealed an abnormal CK20 pattern. In the group of pTaG1 tumours, 59% presented with an abnormal CK20 pattern, whereas 82% carried the FGFR3 mutation. In the group of bladder tumours with normal CK20 pattern, the FGFR3 gene was mutated in 89%, whereas a mutated FGFR3 gene was found in only 37% of cases with abnormal CK20 expression (p < 0.001). All markers proved to be strong predictors of disease-specific survival in univariate studies. However, in multivariate analyses they were not independent from classical pathologic parameters. None of the molecular markers was significantly associated with tumour recurrence.

CONCLUSIONS

Dysregulation of CK20 expression is an early event in the carcinogenesis of papillary noninvasive bladder cancer, but occurs later than FGFR3 mutations. The group of low-grade noninvasive papillary tumours is defined by the presence of an FGFR3 mutation and a normal CK20 expression pattern.

Cytokeratin 20 and Ki-67 to Distinguish Carcinoma In Situ From Flat Non-neoplastic Urothelium

Urothelial carcinoma in situ (CIS) is a high-grade neoplasm and an indicator of recurrence and progression that requires specific treatment. The distinction of CIS from flat non-neoplastic urothelium, in particular dysplasia, on the basis of histologic features is often difficult, and this study aims to validate cytokeratin 20 (CK20) and Ki-67 as discriminatory markers for this purpose. Immunostaining of these markers was applied to 26 cases of CIS, 14 atypia of unknown significance, 4 dysplasia, 6 normal, and 9 hyperplastic urothelium. CIS showed CK20 staining of deep urothelial cells in 23/26 CIS compared with restricted staining in surface cells in all non-neoplastic lesions. CIS had significantly increased Ki-67 index with a mean of 53.37% compared with that of non-neoplastic urothelium, which was <10% (P<0.0001). The proliferating cells were distributed randomly in CIS, whereas in non-neoplastic urothelium, staining was confined to the basal layer. Among the cases of atypia, 3/14 displayed deep staining for CK20 and 6/14 had elevated Ki-67 counts. In dysplasia similar findings were present in 1/4 and 2/4 cases, respectively. These findings suggest that CK20 and Ki-67 are objective markers to distinguish CIS from non-neoplastic urothelium. In cases of "atypia of unknown significance" and "dysplasia," positivity for both markers should raise the possibility of CIS or preneoplastic change and identify those cases for follow-up.

Papillary Urothelial Neoplasm of Low Malignant Potential: Evolving Terminology and Concepts

PURPOSE

The most controversial aspect of the new WHO 2004/ISUP classification system is the creation of the PUNLMP diagnostic category. We discuss PUNLMP tumors and the WHO 2004/ISUP classification system with an emphasis on tumor morphology and heterogeneity, recurrence and progression rates, tumor genetics, interobserver variability and the usefulness of biomarkers and molecular diagnostic techniques for grading bladder tumors.

MATERIALS AND METHODS

A literature search using PubMed was performed. All relevant literature concerning PUNLMP and the WHO 2004/ISUP grading system for urothelial neoplasms was reviewed.

RESULTS

The new WHO 2004/ISUP classification reflects work in progress. Low malignant potential terminology may not reflect the true biological behavior of these tumors. Additionally, interobserver variability in making a diagnosis of PUNLMP is high despite detailed histological criteria. Urine cytopathology in the context of the WHO 2004/ISUP classification does not appear to effectively discriminate PUNLMP from low grade carcinoma.

CONCLUSIONS

For practical purposes patients with PUNLMP should be treated similarly to patients with low grade, noninvasive urothelial carcinoma. It is our hope that recent advances in the molecular grading of these tumors may eventually supplant traditional morphological classification, allowing a more precise and objective assessment of the biological potential of these tumors.

Bladder tumor markers beyond cytology: International Consensus Panel on bladder tumor markers

This is the first of 2 articles that summarize the findings of the International Consensus Panel on cytology and bladder tumor markers. The objectives of our panel were to reach a consensus on the areas where markers are needed, to define the attributes of an ideal tumor marker, and to identify which marker(s) would be suitable for diagnosis and/or surveillance of bladder cancer. Our panel consisted of urologists and researchers from Europe, Asia, and the United States who reviewed original articles, reviews, and book chapters on individual bladder tumor markers published in the English language mainly using the PubMed search engine. Panel members also met during 3 international meetings to write recommendations regarding bladder tumor markers. The panel found that the most practical use of noninvasive tests is to monitor bladder cancer recurrence, thereby reducing the number of surveillance cystoscopies performed each year. Markers also may be useful in the screening of high-risk individuals for early detection of bladder cancer. However, more prospective studies are needed to strengthen this argument. Case-control and cohort studies show that several markers have a higher sensitivity to detect bladder cancer. However, cytology is the superior marker in terms of specificity, although some markers in limited numbers of studies have shown specificity equivalent to that of cytology. Our panel believes that several bladder tumor markers are more accurate in detecting bladder cancer than prostate-specific antigen (PSA) is in detecting prostate cancer. However, bladder tumor markers are held to a higher standard than PSA. Therefore, use of bladder tumor markers in the management of patients with bladder cancer will require the willingness of both urologists and clinicians to accept them.

Experimental models of human bladder carcinogenesis

Bladder cancer is the fifth most common cancer in the UK, yet human bladder carcinogenesis remains poorly understood and the response of bladder tumours to radio- and chemo-therapy is unpredictable. The aims of this article are to review human bladder carcinogenesis and appraise the different in vitro and in vivo approaches that have been developed to study the process. The review considers how in vitro models based on normal human urothelial (NHU) cells can be applied to human bladder cancer research. We conclude that recent advances in NHU cell culture offer novel approaches for defining urothelial tissue-specific responses to genotoxic and non-genotoxic carcinogens and elucidating the role of specific genes involved in the mechanisms of bladder carcinogenesis and malignant progression.