Noninvasive Papillary Tumors Research Articles

Abstract B018: KDM6A and MTAP expression loss enable identification of a large fraction of low grade non-invasive urothelial neoplasia of the urinary bladder

Abstract The identification of low-grade urothelial neoplasia in cytologic samples or in biopsies with dysplastic lesions poses a particular problem for pathologists in routine diagnostics. Improved diagnosis of low-grade urothelial neoplasia could help to reduce the number of cystoscopic follow-up examinations. KDM6A, also known as UTX (ubiquitously transcribed X chromosome tetratricopeptide repeat protein) is an epigenetic regulator which is frequently mutated in urothelial carcinoma. Because KDM6A is localized on chromosome Xp11.3, and because of the male predominance in bladder cancer, many KDM6A mutations should result in a complete loss of KDM6A protein expression and become detectable by immunohistochemistry (IHC). Similarly, S-methyl-5′-thioadenosine phosphorylase (MTAP), a critical enzyme for DNA and RNA synthesis, is co-deleted with the CDKN2A tumor suppressor located on chromosome 9p21 in about 25% of bladder cancers, resulting in reduced or lost protein expression. To study the prevalence and diagnostic potential of immunohistochemical loss of KDM6A and MTAP expression, 928 tumors were analyzed by IHC in a tissue microarray format. The cohort included 628 non-invasive papillary tumors (pTa) and 300 tumors from patients who underwent radical cystectomy for muscle-invasive disease (pT2-4). A complete KDM6A expression loss occurred in 35% of 342 pTa G2 low-grade, 23% of 150 pTa G2 high-grade, 17.8% of 90 pTa G3 tumors, and 20.1% of 243 interpretable muscle invasive (pT2-4) cancers (p<0.0001). Within pTa tumors, there was a strong correlation between KDM6A loss and low tumor grade (p=0.0003), whereas no significant difference was found between pT3 G3 and muscle invasive cancers (p=0.8828). Complete absence of MTAP expression occurred in 11% of 297 pTa G2 low-grade, 29.6% of 125 pTa G2 high-grade, 18.4% of 76 pTa G3 tumors, and 26.3% of 217 muscle invasive (pT2-4) cancers (p<0.0001). A combined analysis of 702 cancers with interpretable data for KDM6A and MTAP showed that 6.6% of tumors had expression loss of both KDM6A and MTAP, 20% had KDM6A loss only, and 13% had MTAP loss only. The rate of expression loss of KDM6A and/or MTAP was markedly higher in pTa G2 low (41.2%) and in pTa G2 high (40.3%) than in pTa G3 tumors (29%). In summary, our data demonstrate that about 40% of low-grade non-invasive urothelial neoplasias – which are usually not detected by urine cytology – had a completed expression loss of either KDM6A or MTAP. In patients with these alterations, follow-up could be potentially facilitated by immunohistochemistry. Citation Format: Florian Viehweger, Neele Heckmann, Natalia Gorbokon, Henning Plage, Sebastian Hofbauer, Sarah Weinberger, Florian Roßner, Simon Schallenberg, Sefer Elezkurtaj, Maximilian Lennartz, Tim Mandelkow, Elena Bady, Margit Fisch, Thorsten Ecke, Stefan Koch, Nico Adamini, Ronald Simon, Guido Sauter, Tobias Klatte, Thorsten Schlomm, David Horst, Henrik Zecha, Martina Kluth, Sarah Minner. KDM6A and MTAP expression loss enable identification of a large fraction of low grade non-invasive urothelial neoplasia of the urinary bladder [abstract]. In: Proceedings of the AACR Special Conference on Bladder Cancer: Transforming the Field; 2024 May 17-20; Charlotte, NC. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(10_Suppl):Abstract nr B018.

Multiparametric Classification of Non-Muscle Invasive Papillary Urothelial Neoplasms: Combining Morphological, Phenotypical, and Molecular Features for Improved Risk Stratification.

Diagnosis and grading of non-invasive papillary urothelial tumors according to the current WHO classification poses some challenges for pathologists. The diagnostic reproducibility of separating low-grade and high-grade lesions is low, which impacts their clinical management. Whereas papillary urothelial neoplasms with low malignant potential (PUN-LMP) and low-grade papillary non-invasive carcinoma (LG-PUC) are comparable and show frequent local recurrence but rarely metastasize, high-grade papillary non-invasive carcinoma (HG-PUC) has a poor prognosis. The main objective of this work is to develop a multiparametric classification to unambiguously distinguish low-grade and high-grade tumors, considering immunohistochemical stains for p53, FGFR3, CK20, MIB-1, p16, p21 and p-HH3, and pathogenic mutations in TP53, FGFR3, TP53, ERCC2, PIK3CA, PTEN and STAG2. We reviewed and analyzed the clinical and histological data of 45 patients with a consensus diagnosis of PUN-LMP (n = 8), non-invasive LG-PUC (n = 23), and HG-PUC (n = 14). The proliferation index and mitotic count assessed with MIB-1 and P-HH3 staining, respectively correlated with grading and clinical behavior. Targeted sequencing confirmed frequent FGFR3 mutations in non-invasive papillary tumors and identified mutations in TP53 as high-risk. Cluster analysis of the different immunohistochemical and molecular parameters allowed a clear separation in two different clusters: cluster 1 corresponding to PUN-LMP and LG-PUC (low MIB-1 and mitotic count/FGFR3 and STAG2 mutations) and cluster 2, HG-PUC (high MIB-1 and mitosis count/CK20 +++ expression, FGFR3 WT and TP53 mutation). Further analysis is required to validate and analyze the reproducibility of these clusters and their biological and clinical implication.

Targeting urothelial neoplasia using an investigational virus-like drug conjugate.

514 Background: Human papillomavirus virus-like particles (HPV VLP) preferentially target tumor cells via cell surface modified heparan-sulfate proteoglycans (HSPG). The investigational virus-like drug conjugate, belzupacap sarotalocan (AU-011), is currently in phase 2 clinical trials for treatment of primary choroidal melanoma. We previously demonstrated AU-011’s in vivo tumor acute cytotoxicity upon activation with near-infrared light (nIR), resulting in tumor-free survival for at least 100 days and protection from tumor re-challenge in the MB49 murine flank model of bladder cancer. Here we provide additional data supporting further clinical development in urothelial neoplasia as an additional oncology indication. Methods: We examined the cytotoxicity of AU-011 in a panel of six human bladder cancer cell lines in vitro and binding and distribution in human tumor biopsy samples ex vivo. Tumor distribution of AU-011 was also assessed in vivo after intravesical instillation in the orthotopic MB49 murine model. In consideration of the glycocalyx layer often found coating the interior of the bladder wall and the surface of bladder tumors, pre-treatment with hyauronidase was tested both on human biopsy samples and in the murine orthotopic model. Lastly, tumor distribution of AU-011 was evaluated when formulated with the polyamide Syn3. Results: When tested in vitro on a panel of human bladder tumor cell lines representing grades I-IV carcinomas, we found AU-011’s potency to be in the picomolar range (EC50 range 16.6 pM – 62.75 pM). We assessed the VLPs ability to bind ex vivo to a panel of human urothelial tumor biopsies and observed binding in samples representing both invasive T2 and non-invasive Ta papillary tumors. Tumor biopsy samples were pre-treated with hyaluronidase to break down the glycocalyx layer surrounding the tumor, and an increase in signal was observed in the Ta biopsy sample. Similarly, using the orthotopic MB49 murine tumor model with intravesical delivery of AU-011, we observed an enhancement of AU-011 distribution into the tumor when the bladders were pre-treated with hyaluronidase. Additionally, when formulated with Syn3, AU-011 distribution throughout the tumors was augmented without the need for hyaluronidase pre-treatment. Conclusions: We have demonstrated AU-011 targeted cytotoxicity in vitro using a panel of human bladder cancer cell lines indicating that its binding to bladder cancer cells is tumor grade and genetic mutation agnostic. Additionally, tumor binding and distribution was observed ex vivo using human bladder cancer biopsy samples and in vivo in the murine MB49 orthotopic model. Human and murine tumor distribution was improved with a pre-treatment of hyaluronidase or when formulated with Syn3. Collectively, these data support the further investigation of the use of AU-011 for the indication of uroepithelial cancer.

Genomic Landscape of Young-Onset Bladder Cancer and Its Prognostic Implications on Adult Bladder Cancer.

Due to the rare occurrence of young-onset bladder cancer (YBC), its genomic characteristics remain largely unknown. Twenty-nine biopsy-proven YBC cases were collected using a nation-wide search for bladder cancer diagnosed at 20 years or younger. Whole exome sequencing and RNA sequencing were carried out in 21 and 11 cases, respectively, and compared with those of adult bladder cancer (ABC) cases obtained from public databases. Almost all YBCs were low grade, non-invasive papillary tumors. YBC had a low mutation burden and less complex copy number alterations. All cases harbored putative driver mutations. Mutations were most commonly found in HRAS (10 cases), with a preference for exon 5. FGFR3 gene fusions were noted with various partner genes (7 cases). The alterations on HRAS and FGFR3 occurred in a mutually exclusive manner. Others included KRAS mutations (2 cases), chromosomes 4p and 10q arm-level deletions (1 case), and ERCC2 mutation (1 case). There were no point mutations in TP53 and FGFR3. The gene expression profiles of YBC were similar to those of the ABC group with good prognosis. None of the YBCs and ABCs with YBC-like mutations showed progression to muscle-invasive tumors. Our results suggest that bladder cancer with YBC-like mutations represents an indolent bladder tumor, regardless of age.

Cytohistologic Correlation of Urothelial Cancers– A study of 57 Cases

Transitional cell carcinoma (TCC) comprises about 90% of all primary tumors of urinary bladder. The accuracy of multiple voided urine cytology justifies its continued use as a first line diagnostic and detection technique, particularly for high grade invasive cancers and clinically unsuspected case of carcinoma particularly carcinoma in-situ. In this study 57 cases were taken to see correlation of cytology, histology, stage, morphological pattern and sensitivity and specificity of urothelial cancers. Out of 57, 53 (92.99)% were positive for malignancy and 4(7.01%) were negative. There were 14 (24.56%) non-invasive papillary tumors, 1(1.76%) carcinoma in-situ and 42 (76.68%) invasive carcinoma of all grades and types. Of 14 grade-II non-invasive papillary tumors, 12 (85.72%) were cytologically positive. With only two exceptions, out of 39 all of the invasive carcinomas of all grades and types were identified by cytology as cancerous. A 100% positive cytology was noted in the detection of flat carcinoma in-situ, papillary adenocarcinoma and squamous cell carcinoma of the urinary bladder. Of the total 57 cases of malignant lesions of urinary tract, 53 (92.99%) were positive on cytological examination. The two TCC of the renal pelvis also gave a 100% positive cytologic results. Among invasive carcinoma, stage B1 and B2 urothelial cancers yield highest positive cytologic diagnosis rather than stage 0 and stage A urothelial cancers. For all tumors the sensitivity was 92.99%. The specificity was 100% since there were no false positive cases. The diagnostic accuracy was 93% (approximately). Comparison with previously published data this study showed highest diagnostic accuracy, sensitivity, specificity of voided urine cytology, good correlation with cytology histology and stage of tumor. So voided urine cytology, a very cheap and purely non invasive technique, can be done as an effective method to diagnose urothelial cancers in a developing country like Bangladesh where facilities for other investigations are practically limited.TAJ 2017; 30(1): 1-10

Role of Non-Coding RNAs in the Etiology of Bladder Cancer.

According to data of the International Agency for Research on Cancer and the World Health Organization (Cancer Incidence in Five Continents, GLOBOCAN, and the World Health Organization Mortality), bladder is among the top ten body locations of cancer globally, with the highest incidence rates reported in Southern and Western Europe, North America, Northern Africa and Western Asia. Males (M) are more vulnerable to this disease than females (F), despite ample frequency variations in different countries, with a M:F ratio of 4.1:1 for incidence and 3.6:1 for mortality, worldwide. For a long time, bladder cancer was genetically classified through mutations of two genes, fibroblast growth factor receptor 3 (FGFR3, for low-grade, non-invasive papillary tumors) and tumor protein P53 (TP53, for high-grade, muscle-invasive tumors). However, more recently scientists have shown that this disease is far more complex, since genes directly involved are more than 150; so far, it has been described that altered gene expression (up- or down-regulation) may be present for up to 500 coding sequences in low-grade and up to 2300 in high-grade tumors. Non-coding RNAs are essential to explain, at least partially, this ample dysregulation. In this review, we summarize the present knowledge about long and short non-coding RNAs that have been linked to bladder cancer etiology.

Tumeurs urothéliales de l’enfant

Urothelial tumors are very rare in children (to date, only about 150cases have been reported worlwide). Only 20% occur before the age of ten. The aim of this study is to specify the clinicopathologic features of urothelial tumor in young patients, which require a slightly different approach to treatment. On the basis of the WHO/ISUP (World Health Organisation/International Society of Urological Pathology) consensus classification report, these lesions are usually low-grade lesions, non invasive, and rarely recurrent. The sex ratio is three boys to one girl. These tumors are located preferentially in the low urinary tract, especially in the bladder. The main symptom is the macroscopic hematuria, which requires ultrasound examination in all cases. Cystoscopy is indicated in case of lesion of the bladder wall, or in case of persistent or recurrent hematuria, to obtain definitive diagnosis and biopsies. The tumors are mainly located on the posterior or lateral bladder wall above the trigone or near the ureteral orifices. Treatment is based on the transurethral resection of the lesion. The subsequent monitoring is sparsely codified, due to the exceptional occurrence of these tumors in the paediatric age group. These patients are likely to have better outcome than older patients, but it is due to the predominance of noninvasive papillary urothelial tumors. Tumor recurrences are not uncommon. In case of invasive, high-grade urothelial carcinomas, metastases or even lethal outcome may occur in rare cases.

Simple and Efficient Stratification of Invasive Bladder Cancer Patients

Bladder cancer (BC) is the 4th most common cancer in men and the 11th most common in women (Kamat et al., 2016). The majority of bladder carcinomas (~ 90%) are non-invasive papillary tumors that are treated by transurethral resection followed by intravesical BCG installations or chemotherapy (Kiselyov et al., 2016). The superficial papillary tumors rarely progress to invasive carcinomas but they have a high propensity for recurrence. This necessitates a lifetime of invasive surveillance by repeated cystoscopy.

Expression of histone deacetylases 1, 2 and 3 in urothelial bladder cancer

BackgroundHistone deacetylases (HDACs) are known to be associated with an overexpression in different types of cancer such as colon and prostate cancer. In this study we aimed to evaluate the protein expression of class I HDACs in urothelial carcinoma of the bladder.MethodsA tissue microarray containing 348 tissuesamples from 174 patients with a primary urothelial carcinoma of the bladder was immunohistochemically stained for HDAC 1, 2 and 3. Intensity of staining was evaluated and the association with clinico-pathological features and prognosis was assessed.ResultsHigh HDAC expression levels were found in 40 to 60% of all investigated urothelial carcinomas (HDAC-1: 40%, HDAC-2: 42%, HDAC-3: 59%).HDAC-1 and HDAC-2 were significantly associated with higher tumour grades.Although all three markers could not predict progression in univariate analyses, high HDAC-1 expression was associated with a trend toward poorer prognosis. Patients with high-grade tumours and high expression levels of HDAC-1 were more likely to progress compared to all other patients (p < 0.05).ConclusionsHigh-grade noninvasive papillary bladder tumours are associated with high expression levels of HDAC-1 and HDAC-2. High grade tumours in combination with high expression of HDAC-1 showed a worse prognosis than the other tumours. The high expression levels of HDACs observed particularly in high grade urothelial bladder cancer clearly warrant subsequent studies on the potential use of HDAC inhibitors as a novel therapeutic approach.

Urothelial Tumors of the Urinary Bladder in Young Patients: A Clinicopathologic Study of 59 Cases

Urothelial tumors are rare in young patients. Because of their rarity, the natural history of the disease in young patients remains poorly understood. To understand the pathologic and clinical features of urothelial tumors of the urinary bladder in young patients. We identified 59 young patients with urothelial tumors of the urinary bladder treated at our institution and analyzed the tumors' pathologic features and the patients' clinical outcomes. All patients were 30 years or younger, with a mean age of 23.5 years (range, 4-30). Thirty-eight patients (64%) were male, and 21 (36%) were female. Most tumors were noninvasive, papillary urothelial tumors (49 of 59; 83%), including papillary urothelial neoplasms of low malignant potential (7 of 49; 14%), low-grade papillary urothelial carcinomas (38 of 49; 78%), and high-grade papillary urothelial carcinomas (4 of 49; 8%). Only a few (n=10) of the urothelial tumors were invasive, invading the lamina propria (n=5; 50%), muscularis propria (n=4; 40%), or perivesical soft tissue (n=1; 10%). Clinical follow-up information was available for 41 patients (69%), with a mean follow-up time of 77 months. Of 31 patients with noninvasive papillary urothelial tumors, only 1 patient (3%) later developed an invasive urothelial carcinoma and died of the disease, and 30 of these patients (97%) were alive at the end of follow-up, although 10 (32%) had local tumor recurrences. In the 10 patients with invasive urothelial carcinomas, 3 patients (30%) died of the disease and 5 others (50%) were alive with metastases (the other 2 [20%] were alive with no recurrence). Urothelial tumors in young patients are mostly noninvasive, papillary carcinomas and have an excellent prognosis; however, a small subset of patients may present with high-grade invasive urothelial carcinomas that result in poor clinical outcomes.

A case of intracystic apocrine papillary tumor: Diagnostic pitfalls for malignancy

Intraductal/intracystic papillary carcinoma (IPC) of the breast is defined as a malignant non-invasive papillary tumor arising from the ductal–lobular system. Based on the presence of myoepithelial cells in the cystic wall, IPC is distinguished from encapsulated papillary carcinoma (EPC). Here, we report a case of an intracystic apocrine papillary tumor in the breast of a 49-year-old woman. Histopathologic examination revealed that the entire papillary structures and cyst wall were comprised of apocrine cells, some of which showed nuclear atypia with macronucleoli. Immunohistochemical examination revealed a lack of myoepithelial cells in the papillary fronds and cyst wall. Although the dense proliferation of apocrine cells mimicked a cribriform pattern, detailed examination identified a delicately intermingled interstitium in the cribriform-like growth area in the present case. We judged the current case to be benign apocrine papilloma. Only a few apocrine variants of IPC or EPC have been reported to be malignant or potentially malignant. Since even benign apocrine lesions are known to lack myoepithelial cells, histopathologic evaluation regarding malignant potential requires caution in apocrine variants. The detection of clearly benign areas and knowledge of the “pseudo-cribriform” pattern should provide clues to distinguish between benign and malignant apocrine papillary tumors.

Multicenter Validation of Cyclin D1, MCM7, TRIM29, and UBE2C as Prognostic Protein Markers in Non-Muscle–Invasive Bladder Cancer

Transcripts from the four genes encoding cyclin D1, MCM7, TRIM29, and UBE2C have previously been included in gene expression signatures for outcome prediction in stage Ta/T1 urothelial carcinomas. We investigated the prognostic value of the protein expressions in Ta/T1 urothelial carcinomas patients. We used four different tissue microarrays (TMAs) with a total of 859 Ta/T1 urothelial carcinomas from Danish, Swedish, Spanish, and Taiwanese patient cohorts with long-term follow-up. Protein expression was measured by IHC, and antibody specificity was validated by Western blotting. We found the expression of cyclin D1, MCM7, TRIM29, and UBE2C to be significantly associated with progression to muscle-invasive bladder cancer (log-rank test; P < 0.001) in the Danish training cohort (n = 283). Multivariate Cox regression analysis identified cyclin D1 (P = 0.003), TRIM29 (P = 0.001), and UBE2C (P < 0.001) as independent prognostic markers. The prognostic value of the four proteins was validated in a joint validation cohort from Sweden, Spain, and Taiwan (n = 576). Computer-assisted image analysis of the prognostic markers produced results comparable to those obtained by manual scoring. Finally, a four-protein maximum-likelihood classifier was trained on the Danish training cohort and applied to the validation cohort. The four protein markers may help optimize treatment of patients with Ta/T1 bladder cancer. Additional prospective studies are needed for further validation of their clinical relevance.

Stat3 Activation in Urothelial Stem Cells Leads to Direct Progression to Invasive Bladder Cancer

Two subtypes of human bladder cancer, noninvasive papillary and muscle-invasive cancer, develop through independent pathologic and molecular pathways. Human invasive bladder cancer frequently develops without prior clinical evidence of a noninvasive tumor stage. However, an animal model that recapitulates this unique clinical progression of invasive bladder cancer has not yet been developed. In this study, we created a novel transgenic mouse model of invasive bladder cancer by targeting an active dimerized form of Stat3 to the basal cells of bladder epithelium. When exposed to the carcinogen nitrosamine, Stat3-transgenic mice developed invasive cancer directly from carcinoma in situ (CIS), bypassing the noninvasive papillary tumor stage. Remarkably, invasive bladder cancer driven by active Stat3 was predominantly composed of stem cells, which were characterized by cytokeratin 14 (CK14) staining and enhanced tumor sphere-forming ability. Active Stat3 was also shown to localize to the nucleus of human invasive bladder cancers that were primarily composed of CK14+ stem cells. Together, our findings show that Stat3-induced stem cell expansion plays a critical role in the unique clinical progression of invasive bladder cancer through the CIS pathway.

The Expression Pattern of Annexin A1 in Urinary Bladder Urothelial Carcinoma and Its Clinicopathologic Significance

Annexin A1 (ANXA1) is a 37-kDa protein with calcium and phospholipid binding properties. It is a member of the subfamily A of annexin (ANX), and presents in organisms from molds to mammals. ANX shares a conserved COOH-terminal with repeated domains and an N-terminal region, the variability of which confers specific annexin function. Its anti-inflammatory property is attributed to ANXA1 binding to surface receptors of granulocytes and macrophages, and its ability to inhibit phospholipase A2. It plays various roles in the regulation of apoptosis, intracellular signal transduction, differentiation, and proliferation. ANXA1 is also known to be involved in the carcinogenesis of many tumors. The expression of ANXA1 is increased in hairy cell leukemia, pancreatic cancers, and hepatocellular carcinoma. However, it is decreased in cancers of esophagus, larynx, prostate and B-cell lymphoma. ANX is known to be localized in the cytoplasm and moves to the membrane or the nucleus depending on calcium level and stimulation. Recent studies have shown that specific subcellular localization of ANXA1 is associated with epithelial differentiation and may be a prognostic factor in oral squamous cell carcinoma (SCC). Urothelial carcinoma (UC) of the urinary bladder is the seventh most common cancer worldwide, and comprises approximately 90% of all primary tumors of this organ. Development of UC is associated with chemical exposure, cigarette smoking, schistosomal infections, and genetic alterations. UC is known to progress along two divergent pathways: one is characterized by low grade non-invasive papillary tumors preceded by hyperplasia. The other is that of high grade invasive tumors, which progress from carcinoma in situ (CIS) or arise de novo. While low grade papillary tumors have frequent mutations of HRAS and fibroblast growth factor receptor 3 (FGFR3) genes activating the receptor tyrosine kinase-RAS pathway, high grade invasive tumors harbor defects in the p53 and/or the retinoblastoma protein (RB) pathways. Recently, ANXA1 emerges as a tumorrelated protein in UC, however, the significance of ANXA1 in bladder carcinogenesis is not yet fully understood and study results remain inconsistent. Cui et al. showed that ANXA1 expression was down-regulated in higher histologic grade of UC, but Li et al. reported contradictory outcome with their The Expression Pattern of Annexin A1 in Urinary Bladder Urothelial Carcinoma and Its Clinicopathologic Significance

Risk of urinary bladder cancer is associated with 8q24 variant rs9642880[T] in multiple racial/ethnic groups: results from the Los Angeles-Shanghai case-control study.

Multiple chromosome 8q24 genotypic variants are strongly implicated in several cancers. Recent genome-wide association studies of urinary bladder cancer report risk to be associated with the T allele of rs9642880 on 8q24 among individuals of European descent. We examined associations between bladder cancer risk and genotypes defined by rs9642880 and each of 8 additional 8q24 variants associated with risk of other cancers, in both high-risk non-Hispanic white and low-risk Chinese participants enrolled in a large population-based case-control study conducted in Los Angeles County and Shanghai. We confirmed association of rs9642880 T with bladder cancer risk not only among non-Hispanic whites but also among Chinese participants [overall per-allele relative risk estimate 1.32 (95% CI, 1.16-1.50; P = 0.000024)]. Subgroup analyses suggested that effects of rs9642880 are largely confined to nonsmokers and former smokers, and may be particularly important in the etiology of noninvasive papillary tumors. There was little indication that 8q24 SNPs associated with other cancer types--rs7008482, rs7000448, rs6983561, rs6983267, rs13281615, rs13254738, or rs10090154--are associated with bladder cancer risk. Bladder cancer risk is associated specifically with variation in the discrete 8q24 region containing rs9642880. Factors other than rs9642880 genotypes seem to underlie differences in bladder cancer risk between non-Hispanic whites and Chinese. Characterization of functional consequences of genetic variation in the discrete region including rs9642880 is needed to understand biological basis of this bladder cancer-specific 8q24 association in these racial/ethnic groups characterized by both high and low risk of bladder cancer.

Tumor Characteristics of Urothelial Carcinoma on Multidetector Computerized Tomography Urography

We investigated the relationship between tumor characteristics of urothelial carcinoma and detectability on multidetector computerized tomography urography. We retrospectively reviewed all adult consecutive patients with hematuria who underwent multidetector computerized tomography urography during a 23-month period at our hospital. Patients with a final diagnosis of urothelial carcinoma verified by histological examination of surgical specimens were included in the study. The presence and location of urothelial carcinomas on multidetector computerized tomography urography without knowledge of final diagnosis were recorded. Tumor characteristics (location, size, histological classification and stage) were recorded based mainly on histological findings. The association between tumor characteristics and urothelial carcinoma detectability on multidetector computerized tomography urography was analyzed. A total of 70 patients who underwent multidetector computerized tomography urography had 87 verified urothelial carcinomas. Of these carcinomas 6 (6.9%) were undetectable by multidetector computerized tomography urography, including 5 ureteral and 1 bladder urothelial carcinoma. Size of detectable and nondetectable tumors on multidetector computerized tomography urography differed significantly (3.05 +/- 1.79 vs 0.65 +/- 0.99 cm, respectively, p = 0.001). Tumor location (p = 0.009), tumor size 1 cm or larger (p = 0.003) and noncarcinoma in situ tumors (p = 0.001) were significantly associated with multidetector computerized tomography urography detectability. Conversely organ confined disease had no association with multidetector computerized tomography urography detectability. Multivariate analyses showed that noncarcinoma in situ tumor was a significant predictor of multidetector computerized tomography urography detectability (p = 0.001). Multidetector computerized tomography urography is useful for detecting nearly all urothelial carcinomas in adults with hematuria. Careful assessment by multidetector computerized tomography urography is needed to detect small (less than 1 cm) or ureteral urothelial carcinomas. It remains a challenge to detect carcinoma in situ tumors by multidetector computerized tomography urography. Thus, negative results of urothelial carcinomas on multidetector computerized tomography urography do not exclude the presence of carcinoma in situ tumors.

Papillary and muscle invasive bladder tumors with distinct genomic stability profiles have different DNA repair fidelity and KU DNA‐binding activities

Low-grade noninvasive papillary bladder tumors are genetically stable whereas muscle invasive bladder tumors display high levels of chromosomal aberrations. As cells deficient for nonhomologous end-joining (NHEJ) pathway components display increased genomic instability, we sought to determine the NHEJ repair characteristics of bladder tumors and correlate this with tumor stage and grade. A panel of 13 human bladder tumors of defined stage and grade were investigated for chromosomal aberrations by comparative genomic hybridization and for NHEJ repair fidelity and function. Repair assays were conducted with extracts made directly from bladder tumor specimens to avoid culture-induced phenotypic alterations and selection bias as only a minority of bladder tumors grow in culture. Four noninvasive bladder tumors (pTaG2), which were genetically stable, repaired a partially incompatible double-strand break (DSB) by NHEJ-dependent annealing of termini and fill-in of overhangs with minimal loss of nucleotides. In contrast, four muscle invasive bladder cancers (pT2-3G3), which displayed gross chromosomal rearrangements, repaired DSBs in an error-prone manner involving extensive resection and microhomology association. Four minimally invasive bladder cancers (pT1G3) had characteristics of both repair types. Error-prone repair in bladder tumors correlated with reduced KU DNA-binding and loss of TP53 function. In conclusion, there were distinct differences in DSB repair between noninvasive papillary tumors and higher stage/grade invasive cancers. End-joining fidelity correlated with stage and was increasingly error-prone as tumors became more invasive and KU binding activity reduced; these changes may underlie the different genomic profiles of these tumors.

Molecular pathogenesis of bladder cancer

Bladder tumors show widely differing histopathology and clinical behavior. This is reflected in the molecular genetic alterations they contain. Much information has accumulated on somatic genomic alterations in bladder tumors of all grades and stages and when this information is related to the common histopathological appearances, a model for the pathogenesis of two major groups of bladder tumors has emerged. This review summarizes the genetic alterations that have been reported in bladder cancer and relates these to the current two-pathway model for tumor development. The molecular pathogenesis of high-grade noninvasive papillary tumors and of T1 tumors is not yet clear and possibilities are discussed.

Loss of heterozygosity at 9q32–33 (DBC1 locus) in primary non‐invasive papillary urothelial neoplasm of low malignant potential and low‐grade urothelial carcinoma of the bladder and their associated normal urothelium

Tumour recurrence has a major impact on patients with non-invasive papillary urothelial tumours of the bladder. To explore the role of DBC1 (deleted in bladder cancer 1 locus), a candidate tumour suppressor gene located at 9q32-33, as prognostic marker we have performed loss of heterozygosity (LOH) testing in 49 patients with primary papillary urothelial tumours and associated normal urothelium. Data from the 38 tumours and 11 specimens of normal urothelium that were informative in the LOH study (D9S195 marker) showed that LOH in urothelium (45.4%) but not in non-invasive tumours (60.5%) was associated with tumour recurrence (p = 0.026) but not to grade or progression. Also, tumours whose normal urothelium had LOH were larger (p = 0.020) and showed cyclin D1 over-expression (p = 0.032). Non-significant increased expression of p53, p21Waf1, apoptotic index and tumour proliferation, and decreased expression of p27Kip1 or cyclin D3 also characterized tumours whose normal urothelium had LOH. The expression of these G1-S modulators, apoptotic index and tumour proliferation was more heterogeneous in papillary urothelial tumours, irrespective of having retained heterozygosity or LOH. Also, Bax expression decreased in papillary urothelial tumours having LOH (p = 0.0473), but Bcl-2 was unrelated to LOH status. In addition, FGFR3 protein expression decreased in LOH tumours (p = 0.036) and in those having LOH in their normal urothelium (p = 0.022). FGFR3 immunohistochemical expression was validated by western blot in selected cases. The survival analysis selected LOH in normal urothelium as a marker of disease-free survival (log-rank 5.32, p = 0.021), progression-free survival (log-rank 3.97, p = 0.046) and overall survival (log-rank 4.26, p = 0.038); LOH in tumours was significant in progression-free survival (log-rank 3.83, p = 0.042). It is concluded that LOH at the DBC1 locus in normal urothelium seems to be relevant in the prognosis of non-invasive papillary tumours of the bladder via selecting cases with increased proliferation, frequent alterations of the G1-S phase modulators, and decreased FGFR3 protein expression.

FGFR3 mutations and a normal CK20 staining pattern define low-grade noninvasive urothelial bladder tumors: van Oers JM, Wild PJ, Burger M, Denzinger S, Stoehr R, Rosskopf E, Hofstaedter F, Steyerberg EW, Klinkhammer-Schalke M, Zwarthoff EC, van der Kwast TH, Hartmann A, Department of Pathology, Erasmus MC, Rotterdam, The Netherlands.

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 tumors and compared them with traditional pathologic features. Methods Tissue microarrays were used to analyze 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 tumor grades and stages (P 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 tumors is defined by the presence of an FGFR3 mutation and a normal CK20 expression pattern.