Cytogenetic investigation of transitional cell carcinomas of the upper urinary tract

[Carcinogenic pathways and natural history of upper tract urothelial carcinomas: state-of-the-art review for the yearly scientific report of the French National Association of Urology]

OBJECTIVE

To describe natural history and carcinogenesis of upper tract urothelial carcinoma (UTUC).

METHODS

A systematic review of the scientific literature was performed in the Medline database (Pubmed) using different associations of the following keywords: upper tract urothelial carcinoma; clonality; carcinogenesis; mutation; chromosomal instability; Lynch syndrome; genetic polymorphism.

RESULTS

Local development of UTUC is characterized by a highly prevalent multifocality that might be explained by the overlap of "field change" and "intraluminal seeding and implantation" theories. UTUC and bladder tumors share common carcinogenesis mechanisms such as mutations of FGFR3 and TP53 defining two distinct pathways of pathogenesis. Epigenetic alterations corresponding to the hypermethylation of different promoters regulating genes expression and chromosomal instability such as chromosome 9 deletions are also involved in UTUC carcinogenesis. Furthermore, specific genetic risk factors fro UTUC including Lynch syndrome and different polymorphisms might explain an individual susceptibility for developing these tumors.

CONCLUSIONS

Significant advances have been done in the field of basic research in UTUCs in recent years and have been of particular interest to provide better descriptions of their natural history. Despite these important findings however, some carcinogenic mechanisms remains not elucidated and unknown in the field of UTUC so far.

Identification of genetic alterations in upper urinary tract urothelial carcinoma in end-stage renal disease patients

Clinical presentations of end-stage renal disease (ESRD) patients on dialysis with upper urinary tract urothelial carcinoma (UUT-UC) are different from those with normal renal function. The pathogenesis remains unknown. We investigated the pathogenetic influence of chromosomal aberrations in patient on dialysis with UUT-UC. The chromosomal aberrations of UUT-UC specimens from seven dialysis patients were assessed by conventional comparative genomic hybridization (cCGH). Subsequently, we further investigated 20 cases by whole genome and fine-tiling oligonucleotide array-based CGH to demonstrate gains and losses, and compared with the clinicopathologic background. The chromosomal aberrations in UUT-UC specimens from dialysis patients were more complex than in bladder urothelial carcinoma (B-UC). Our data showed that gains at 5p, 7, 19q, and losses at 4q, 9p, and 15q are common in UUT-UC of ESRD patients. Gains in regions associated with DNA repair genes were noted in this study. High-stage and high-grade tumors displayed more copy number variants. In addition, female ESRD patients with UUT-UC had more frequent chromosomal aberrations than their male counterparts. In conclusion, unique chromosomal aberrations were indentified in UUT-UC in ESRD patients.

Cytogenetic alterations in renal tumors: a study of 38 Southeast Asian patients

Renal cell carcinoma (RCC) is the most common cancer of the kidney. Cytogenetic studies of renal cell carcinoma have provided valuable insight into the chromosomal abnormalities involved in the genesis and progression of the disease, and have also helped in the classification of these tumors. Our objectives were to identify nonrandom chromosome abnormalities in renal tumors in a Southeast Asian population and also to determine if they differ from those in Western populations. Structural rearrangements of 3p were specific for clear cell RCC, with the most consistent structural rearrangement being a translocation between 3p13 and 5q22. Gains of chromosomes 7 and 17 were observed in three and two cases of papillary RCC, respectively. All male patients with papillary RCC were noted to have loss of the Y chromosome. Gains of chromosomes 3 and 7, and structural aberration of chromosome 3, were observed in patients with transitional cell carcinoma of the renal pelvis (TCC). Chromosomal abnormalities in clear cell RCC, papillary RCC, and TCC did not differ between the Southeast Asian and Western populations. The aberrations seem to be common sporadic events, both geographically and racially.

The pathology of extrapulmonary small cell carcinoma

Extrapulmonary small cell carcinomas (EPSCCs) are uncommon malignant neoplasms with a reported incidence of 0.1% to 0.4% in the United States. Since their first description in 1930, they have been seen in nearly every organ system. Like their more common pulmonary counterparts, EPSCCs are thought to arise from a multipotential stem cell. However, there is recent molecular evidence that small cell elements may arise as a late-stage phenomenon in the genetic progression of more organ-typical carcinomas. The morphologic, immunohistochemical, and ultrastructural features are similar to those described in pulmonary small cell carcinomas (PSCCs). The differential diagnosis of EPSCC includes PSCC, other neuroendocrine tumors, small round blue cell tumors, metastatic melanoma, lymphoma, and poorly differentiated non-small cell carcinomas. Molecular alterations reported to occur in EPSCCs include abnormalities described in PSCC and changes found in carcinomas more typically encountered in the organ from which they arise. In this article we discuss the pathology of EPSCC with a review of theories of histogenesis, sites of occurrence, diagnostic features, differential diagnosis, molecular alterations, and clinical behavior.

Carcinomes urothéliaux de la voie excrétrice supérieure

Transitional cell carcinomas of the upper urinary tract (UUT-TCCs) are rare: they account for approximately 5% of all urothelial carcinomas. 30% of patients with UUT-TCC have a history of bladder TCC, but fewer than 2% of patients with bladder TCC have UUT-TCC. Tumor microsatellite instability (MSI) is an indicator of the clonal expansion of neoplasms; it was first identified in tumors from patients with hereditary non-polyposis colorectal carcinoma (HNPCC). UUT-TCC occurs in 5% of patients with HNPCC. High-frequency microsatellite instability is present in almost 20% of cases of sporadic UUT-TCC. In cases of UUT-TCC with high-frequency MSI, hereditary cancer must be sought, especially if the patient is younger than 60 years or has a personal or family history of an HNPCC-related cancer: such patients should undergo DNA sequencing for the MSH2 gene germline mutation. Invasive UUT-TCC has a poor prognosis. 5-year survival is less than 50% for stage T2-T3 tumors and less than 10% for T4 or N+/M+ tumors. The main prognostic factors are age and tumor stage and grade. High-frequency MSI is a positive prognostic factor, especially in patients younger than 70 years with T2/T3/N0-M0 tumors.

Promoter hypermethylation is associated with tumor location, stage, and subsequent progression in transitional cell carcinoma

PURPOSE

Transitional cell carcinoma (TCC) is a pan-urothelial disease characterized by multiplicity. Although little is known about the molecular events in upper-tract TCC, similar carcinogenic mechanisms are thought to occur throughout the urinary tract. However, we have previously shown that distinct patterns of microsatellite instability occur in upper and lower urinary tract TCC, suggesting biologic differences between these tumors. Here we investigate the extent of promoter hypermethylation in TCC throughout the urinary tract.

PATIENTS AND METHODS

Tissue was obtained from 280 patients (median follow-up, 56 months) whose tumors comprised 116 bladder and 164 upper-tract tumors (UTT). Analysis for hypermethylation at 11 CpG islands, using methylation-sensitive polymerase chain reaction and bisulfite sequencing, was performed for each sample and compared with the tumor's clinicopathologic details, microsatellite instability status, and subsequent behavior.

RESULTS

Promoter methylation was present in 86% of TCC and occurred both more frequently and more extensively in UTT (94%) than in bladder tumors (76%; P < .0001). Methylation was associated with advanced tumor stage (P = .0001) and higher tumor progression (P = .03) and mortality rates (P = .04), when compared with tumors without methylation. Multivariate analysis revealed that methylation at the RASSF1A and DAPK loci, in addition to tumor stage and grade, were associated with disease progression (P < .04).

CONCLUSION

Despite morphologic similarities, there are genetic and epigenetic differences between TCC in the upper and lower urinary tracts. Methylation occurs commonly in urinary tract tumors, may affect carcinogenic mechanisms, and is a prognostic marker and a potential therapeutic target.

"Proximal-type" and classic epithelioid sarcomas represent a clinicopathologic continuum: case report

We report a case of an epithelioid sarcoma that occurred in the right hand of a 14-year-old boy and had the "proximal-type" morphology and a complex, near-tetraploid karyotype. The tumor metastasized to the lungs, where the morphology was typical for the classic epithelioid sarcoma. Based on the morphologic and cytogenetic findings in this case, we suggest that the proximal-type and the classic epithelioid sarcomas are not distinct entities but represent a continuum.

Molecular cytogenetic characterization of proximal-type epithelioid sarcoma

Proximal-type epithelioid sarcoma is a recently described soft-tissue tumor that is distinguished from conventional-type epithelioid sarcoma by a far more aggressive clinical course, frequent location in the proximal anatomic regions, and variable rhabdoid morphology. Because of their rarity and peculiar morphology, proximal-type epithelioid sarcomas frequently pose serious diagnostic dilemmas, being easily misdiagnosed as a variety of other malignant neoplasms. To date, the information available on the genetic alterations associated with this tumor entity has been confined to single conventional cytogenetic reports. In this article, we present the results of a conventional and molecular cytogenetic analysis of six proximal-type epithelioid sarcomas. Spectral karyotyping analysis of these cases deciphered the characteristics of several marker chromosomes and complex translocations, leading to the recognition of recurrent rearrangements. The most frequently involved chromosome arm was 22q, and the identification of two cases with a similar translocation, t(10;22), suggests a role for one or more genes on chromosome 22 in the pathogenesis of this tumor and provides an opportunity for finely mapping the translocation-associated breakpoints. Chromosome arm 8q gain was also a frequent event and correlated with gain of MYC gene copy number, as demonstrated by fluorescence in situ hybridization. A review of both cases reported in the literature and those presented in this study reinforced the involvement of chromosomes 8 and 22 and also indicated frequent rearrangements of chromosomes 7, 14, 18, and 20.

Surveillance and management of recurrence for upper tract transitional cell carcinoma

Surveillance of treated upper tract TCC must be tailored to each patient based on individual tumor characteristics. Important risk factors include tumor stage, grade, and multifocality. Molecular markers for TCC may assist in future surveillance strategies, but for now remain experimental. Improvements in imaging eventually may provide the sensitivity needed to determine tumor stage, which would make both initial and recurrence management decisions much more accurate. Initial surgical treatment will influence surveillance when it pertains to superficial disease treated conservatively with either open segmental resection or, now more commonly, with endoscopic resection. Patients treated in this manner require vigilant surveillance of the ipsilateral ureter. Direct visualization in combination with cytology currently appears to be the most effective method, using the same timelines as those used for bladder TCC. Prospective studies concerning surveillance protocols for upper tract TCC would certainly provide more evidence for the current recommendations. However, the evidence does show that upper tract TCC behaves biologically much in the same fashion as does bladder TCC. In light of this fact, the current recommendations are meant to suggest following a patient after treatment for upper tract TCC in a manner similar to that used to follow a patient after treatment of bladder TCC, with individual strategies based on tumor characteristics. For superficial disease, the technology now exists to moniter a patient after endoscopic resection of an upper tract tumor in exactly the same manner used to follow a patient after endoscopic resection of a bladder tumor.

Microsatellite Instability in Urothelial Carcinoma of the Upper Urinary Tract

PURPOSE

Transitional cell carcinoma (TCC) of the upper urinary tract (TCC-UUT) may develop with high frequency in patients with hereditary nonpolyposis colorectal cancer syndrome. Tumors in patients with this syndrome show genomic lesions in DNA mismatch repair genes that are detectable as microsatellite instability (MSI). Because little is known about genetic lesions in TCC-UUT compared with bladder TCC, we determined the genetic profiles (MSI and allelic loss) in a series of 26 upper urinary tract tumors using 5 informative microsatellite markers.

MATERIALS AND METHODS

A total of 26 paraffin embedded samples from 24 patients with clinically diagnosed TCC-UUT (renal pelvis and/or ureter) were tested for loss of heterozygosity (LOH) and MSI with the dinucleotide markers D9S171 (9p21) and D5S346 (5q22), and the mononucleotide repeats BAT25 (4q12), BAT26 (2p16) and BAT40 (1p13.1).

RESULTS

MSI was detected at 1 or more microsatellite loci in 12 of the 26 tumors (46%). The markers BAT40, BAT25, BAT26, D9S171 and D5S346 showed instability in 7, 4, 4, 2 and 3 tumor samples, respectively. LOH at D9S171 was detected in 58% of the cases and 10 of the 14 tumors showing LOH were superficial. LOH at D5S346 occurred in 27% of the cases and it was a feature of invasive high grade TCC-UUT.

CONCLUSIONS

Frequent LOH at D9S171 in TCC-UUT confirms that LOH at 9p21 is not only observed in bladder TCC, but rather in whole urinary tract TCC. Furthermore, our study indicates a high level of MSI in TCC-UUT, although it is a rare event in bladder cancer. The establishment of distinct genetic profiles between upper and lower urinary tract tumors could provide an additional tool to improve diagnosis, disease monitoring and prediction of prognosis.

Transitional cell carcinoma of the ureter and renal pelvis

Transitional cell carcinoma (TCC) of ureter and renal pelvis is relatively uncommon. Smoking, occupational carcinogens, analgesic abuse, Balkan nephropathy are the risk factors. Cytogenetic studies revealed that the most frequent aberration is the partial or complete loss of chromosome 9. Approximately 20-50% of patients with upper urinary tract (UUT) TCC have bladder cancer at some point on their course, whereas the incidence of UUT TCC after primary bladder cancer is 0.7-4%. Excretory urography and retrograde pyelography are the conventional diagnostic tools; however, ureteropyeloscopy combined with cytology and biopsy is more accurate. Grade and stage of the disease have the most significant impact on survival. Nephroureterectomy with bladder cuff excision has been the mainstay of treatment. Local resection may be appropriate for distal ureteral lesions especially when the disease is low grade and stage. Advances in endourology have made it possible to treat many tumors conservatively. Ureteroscopic and to a certain extent percutaneous surgical approaches are widely used today especially in patients with low grade, low stage disease. Endoscopic close surveillance is mandatory for these patients. Adjuvant topical therapies appear to be safe but confirmation of any benefits awaits the results of further large studies. More recently, laparoscopic techniques have become a viable alternative to open surgery, but long term cancer control data are lacking. Aggressive surgical resection does not affect the outcome of patients with advanced disease. Adjuvant radiotherapy is ineffective, and systemic chemotherapy results in a low complete response rate for patients with metastases.

Renal cancer: cytogenetic and molecular genetic aspects

To date, much progress has been made in the fields of cytogenetics and molecular genetics of renal tumors. The previous and recent findings have delineated the characteristics of the various tumors, particularly the cytogenetic and molecular differences that exist between papillary and nonpapillary clear cell renal cell carcinomas (RCCs). At the same time, new cytogenetic subtypes have emerged [e.g., t(X;1)] in subtypes of RCC, while in others (e.g., Wilms tumors) several new cytogenetic abnormalities and consequent molecular involvement have been found. In addition to Wilms tumor, papillary RCC, and clear-cell RCC, cytogenetic and fluorescence in situ hybridization analyses have been performed on several other tumors of the kidney, including chromophobic carcinoma, metanephric adenoma, collecting duct carcinoma, transitional cell carcinoma, congenital mesoblastic nephroma, and malignant rhabdoid tumors of the kidney. This review is therefore intended to present a concise update on the cytogenetic and molecular data on renal tumors, focusing mainly on the clinical usefulness of the findings reported in the literature.

Spiradenocylindroma of the kidney: clinical and genetic findings suggesting a role of somatic mutation of the CYLD1 gene in the oncogenesis of an unusual renal neoplasm

We describe the morphology and comparative genomic hybridization findings in a tumor for which we propose the term "spiradenocylindroma" of the kidney. The tumor arose in the wall of a renal cyst in an otherwise healthy male patient who had a favorable clinical course after nephrectomy. Tumor cells formed either large nodules exhibiting a solid or trabecular architecture with conspicuous perivascular spaces or cylindromatous small tumor cell islands arranged in a jigsaw pattern. Focally, there were interspersed tubular structures and tumor cell rosettes with central deposits of periodic acid-Schiff-positive material. A minor tumor component showed epidermoid differentiation. The tumor cells were strongly positive for cytokeratins 5/6, high molecular weight cytokeratins 34betaE12 and AE1/3, and E-cadherin, but only weakly positive for cytokeratins 7, 8, 18, 19, and epithelial membrane antigen. Focal reactivity for actin, vimentin, and S-100 protein or lysozyme and alpha 1 -antichymotrypsin within tubular and cylindromatous areas suggested myoepithelial and apocrine differentiation, respectively. By comparative genomic hybridization, the only abnormality was loss of the long arm of chromosome 16 and gain of genetic material on the short arm of chromosome 16, suggesting isochromosome i(16p). This finding is unique among renal neoplasms and implies loss of heterozygosity at 16q12-13 of the CYLD1 gene that is critically involved in the oncogenesis of familial cylindromatosis and some sporadic spiradenocylindromas. We conclude that somatic mutation of the CYLD1 gene outside the skin can have a role in the oncogenesis of tumors with cylindromatous features.

Comparative genomic hybridization analysis of transitional cell carcinomas of the renal pelvis

We used comparative genomic hybridization to analyze 10 primary tumor samples from patients with transitional cell carcinoma of the renal pelvis. The most frequent loss was located at 9q, that is, in 50% of the tumors. Gains of DNA sequences were most frequently observed in chromosome regions 1q21 approximately q23, 2p23 approximately p25, 8q21.1 approximately q22 and in the whole chromosome 20. High level amplifications at 1q21 approximately q25, 6p22 approximately p23, 8q21 approximately q22, 8q22 approximately q24.1, 11q13, and 12q14 approximately q21 were detected. Most of these regions have previously been reported to be involved in transitional cell carcinoma of the bladder, thus confirming the importance of an increasing number of chromosome imbalances in the development and progression of this type of tumors.