Bladder irrigation specimens assayed by fluorescence in situ hybridization to interphase nuclei

Exclusion of the uniform tetraploid cells significantly improves specificity of the urine FISH assay

The urine fluorescence in situ hybridization (FISH) assay (UroVysion™), with the current scoring criteria, has a higher sensitivity than routine cytopathology but a lower specificity. Among 215 urine FISH tests we performed, 45 had associated histopathology and clinical follow up. In this study, a cell with four signals for each probe was classified as a uniform tetraploid cell (UTC); a presumed reparative cell which is currently classified as an abnormal cell in the FDA approved assay. By using the existing criteria, the tests were scored as positive or negative before and after exclusion of the UTCs. Before the exclusion, 24 positive, 13 negative, seven false positive, and one false negative result were obtained with 96% sensitivity and 65% specificity. After the exclusion, the results changed to 22 positive, 19 negative, one false positive, and three false negatives resulting in a 88% sensitivity of 88% and a 95% specificity; a significant improvement in the specificity. We conclude that exclusion of the UTCs as abnormal cells would result in a more solid performance of the FISH assay.

Bladder cancer detection using FISH (UroVysion assay)

UroVysion is a fluorescence in situ hybridization assay that was developed for the detection of bladder cancer in urine specimens. It consists of fluorescently labeled DNA probes to the pericentromeric regions of chromosomes 3 (red), 7 (green), and 17 (aqua) and to the 9p21 band (gold) location of the P16 tumor suppressor gene. The UroVysion assay works by detecting urinary cells that have chromosomal abnormalities consistent with a diagnosis of bladder cancer. Studies have shown that UroVysion is more sensitive than urine cytology for the detection of all stages and grades of bladder cancer. UroVysion is Food and Drug Administration-approved for the detection of recurrent bladder cancer in voided urine specimens from patients with a history of bladder cancer and for the detection of bladder cancer in voided urine specimens from patients with gross or microscopic hematuria, but no previous history of bladder cancer. Recent studies also suggest that UroVysion may be useful for assessing superficial bladder cancer patients' response to bacillus Calmette-Guerin therapy and in detecting upper tract urothelial carcinoma.

Fluorescence in situ hybridization in diagnostic cytology

Fluorescence in situ hybridization (FISH) is a technique that uses fluorescently labeled DNA probes to detect chromosomal alterations in cells. FISH can detect various types of cytogenetic alterations including aneusomy (ie, abnormalities of chromosome copy number), duplication, amplification, deletion, and translocation. Because tumor cells generally contain chromosomal alterations, FISH is able to detect cells that have chromosomal abnormalities consistent with neoplasia in exfoliative and aspiration cytology specimens. This review will discuss the utility of FISH for the detection of bladder, lung, pancreatobiliary, and esophageal carcinoma in cytologic specimens.

Fluorescence in situ hybridization performed on exfoliated urothelial cells in patients with transitional cell carcinoma of the bladder

OBJECTIVES

To evaluate comparatively fluorescence in situ hybridization (FISH) and cytology performed on exfoliated urothelial cells obtained from voided urine and bladder washings as a method of diagnosis and follow-up in patients with transitional cell carcinoma (TCC) of the bladder.

METHODS

Thirty patients with confirmed bladder TCC, 10 patients enrolled in cystoscopy follow-up for previous bladder tumors, and 10 patients with bladders free of tumor without a previous history of bladder TCC underwent cytologic examination and FISH performed on voided urine and bladder washing specimens. The FISH probes were targeted to chromosomes 7 and 9.

RESULTS

FISH had a sensitivity of 92% for high-grade tumors in both voided urine and bladder washing specimens, significantly greater than that of cytology at a sensitivity of 64% in voided urine and 67% in the bladder washing specimens (P = 0.02). The sensitivity of FISH and cytology were both low and not significantly different statistically from each other for the low-grade tumors. Monosomy of chromosome 9 correlated with early tumor recurrence. Polysomy of chromosomes 7 and 9 correlated with high-grade tumors (80% and 92%, respectively).

CONCLUSIONS

According to our results, with the local cytopathology expertise, FISH performed on urothelial cells from voided urine has a sensitivity that supersedes that of cytology, making the former a valuable complementary method in the diagnosis and follow-up of patients with bladder TCC.

Vysis UroVysion for the detection of urothelial carcinoma

For decades, cystoscopy and urine cytology have been the mainstay for monitoring superficial urothelial carcinoma patients for tumor recurrence. However, urine cytology has poor sensitivity for urothelial carcinoma and, consequently, numerous investigators have been endeavoring to develop more sensitive assays for the detection of urothelial carcinoma. This article presents an overview of the types of new assays that have been developed for urothelial carcinoma detection but focuses primarily on the features and performance of a new fluorescence in situ hybridization assay for urothelial carcinoma detection known as Vysis UroVysion.

Evaluation of fluorescence in situ hybridization as an ancillary tool to urine cytology in diagnosing urothelial carcinoma

Our purpose was to evaluate the feasibility of performing fluorescence in situ hybridization (FISH) on routine urine samples and to compare the relative sensitivities of urine cytology and FISH for detecting urothelial carcinoma. Light microscopy (LM) using cytologic evaluation and FISH were used to study 121 consecutive urine samples. A mixture of fluorescent probes to chromosomes 3, 7, 17, and the 9p21 locus were used for detection of numerical chromosomal abnormalities (UroVysion, Vysis/Abbott). Biopsy specimens from patients in the study were reviewed if available. FISH analysis was performed without knowledge of cytology or biopsy findings. The urine cytology of 121 samples was interpreted as 59 negative, 41 reactive, 16 atypical, 2 suspicious and 3 insufficient cells for diagnosis. 85 samples were successfully analyzed by FISH. Thirty-one of these showed chromosomal abnormalities and these samples were initially regarded on the original cytology reading as follows: 10 negative, 10 reactive, 9 atypical, and 2 suspicious. FISH demonstrated chromosomal abnormalities in a significant number of cases (67%) that were initially diagnosed as normal or reactive by LM. Twenty-five patients were identified who had biopsy-proven TCC and successful FISH. Thirteen of the 25 patients (52%) were abnormal by FISH (cytology: 2 suspicious, 6 atypical, 4 reactive, 1 negative). One patient was atypical by cytology with normal FISH results but had TCC on biopsy. Hyperdiploidy for chromosomes 3 (77%) and 7 (67%) were seen consistently. Multiple chromosomal abnormalities were seen in 67% of these cases. We conclude that FISH has a greater sensitivity in detecting urothelial carcinoma when coupled with urine cytology. It is not entirely clear at this time whether a positive FISH may indicate frank neoplastic urothelial transformation or merely be an indicator of unstable urothelium capable of or primed for malignant transformation thus detecting patients at significant risk. The use of FISH in conjunction with urine cytology can potentially reduce urothelial carcinoma morbidity and mortality by diagnosing these tumors earlier.

Evaluation of chromosome 8 and 11 aneuploidies in washings and biopsy materials of bladder transitional cell carcinoma

We compared chromosome 8 and 11 aneuploidies on bladder biopsy tumor tissues and bladder washing samples of transitional cell carcinoma (TCC) and their relationship to tumor malignancy. Interphase fluorescence in situ hybridization (FISH) was applied to nuclei of washing material and biopsy samples of 17 patients with TCC. Incidence of cells having aneuploidy was clearly nonrandom from patient to patient. There was no significant difference in the incidence of aneuploid frequency for chromosomes 8 and 11 between biopsies of bladder tumors and bladder washing samples (P > 0.05). For chromosome 8, incidence of disomic cells (having two signals) in grade III tumors was significantly lower than in grade II tumors of both washing samples (P = 0.004) and biopsy materials (P = 0.005), indicating a high frequency of aneuploidy. The incidence of nuclei with four or more than four signals of chromosome 8 was significantly higher in grade III tumors than in grade II tumors in washing samples (P = 0.031 and 0.003, respectively). Similarly, in biopsy material, the incidence of nuclei with more than four signals of chromosome 8 was significantly higher in grade III tumors than in grade II tumors (P = 0.004). For chromosome 11, in both washing samples and biopsy materials, the incidence of disomic cells (having two signals) in grade III tumors was significantly lower than that detected in grade II tumors (P = 0.031 and 0.014, respectively), indicating a high frequency of aneuploidy. In biopsy materials, the incidence of nuclei with three or four signals was significantly higher than that in grade II tumors (P = 0.014 and 0.012, respectively). These findings suggest that FISH analysis of bladder washing samples can be effectively detected as genetic changes of bladder tumors. It might predict genetic progression of these tumors, which might be related to tumor stage, because higher stages of tumors showed a higher incidence of aneuploidies of chromosomes 8 and 11.

DNA image cytometry and fluorescence in situ hybridization for noninvasive detection of urothelial tumors in voided urine

BACKGROUND

Cystoscopy and histologic examination remain the standard methods for initial tumor diagnosis and monitoring for early detection of recurrences, since the sensitivity of conventional urinary cytology for the detection of urothelial tumors in urinary specimens is low. DNA image cytometry (ICM) and fluorescence in situ hybridization (FISH) have been suggested as ancillary tools. The goal of the current study was to compare the diagnostic value of DNA image cytometry and FISH for the noninvasive detection of urothelial tumors in voided urine.

METHODS

Cytospin preparations were prepared from voided urine collected prior to the resection of 26 noninvasive (pTa) and 11 invasive (pT1-2) tumors. Specimens from 14 patients with benign prostatic hyperplasia were used as negative controls. DNA ICM was performed using the AUTOCYTE trade mark cell analytical system on Feulgen-stained cytospin specimens. The commercially available UroVysion trade mark FISH multiprobe was used to analyze chromosomes 3, 7, and 17, and 9p21.

RESULTS

The overall sensitivity of cytology improved from 24% to 54% and to 78% if supplemented by ICM or FISH, respectively. Image cytometry detected all invasive tumors (pT1-2), while FISH missed one; FISH identified 19 of 26 (73%) pTa tumors, while only 9 (35%) of these tumors were aneuploid by ICM. The results of ICM and FISH were concordant in 37 of 51 (72%) cases.

CONCLUSIONS

The current study shows that both FISH and ICM can successfully be used as supplementary methods to detect the clinically most relevant group of invasive bladder carcinomas. However, UroVysion FISH is more sensitive in the detection of pTa tumors than ICM, as it recognizes individual chromosomal alterations that frequently prevail in urothelial tumors.

Clinical evaluation of a multi-target fluorescent in situ hybridization assay for detection of bladder cancer

PURPOSE

The UroVysion fluorescence in situ hybridization assay (UroVysion Bladder Cancer Recurrence Kit, Vysis, Inc., Downers Grove, Illinois) is a multi-target assay that detects aneuploidy of chromosomes 3, 7 and 17, and loss of the 9p21 band in exfoliated cells in urine from patients with transitional cell carcinoma. We performed 2 multicenter trials. In 1 trial we compared the sensitivity of the FISH assay to the BTA Stat test (Bion Scientific, Redmond, Washington) and voided cytology in the detection of transitional cell carcinoma. In a separate study of healthy volunteers and patients with other (nontransitional cell carcinoma) conditions we determined the specificity of the FISH assay.

MATERIALS AND METHODS

A total of 176 patients with transitional cell carcinoma in the previous 9 months provided voided urine before cystoscopy. Each specimen was split, preserved and shipped to a central laboratory where all 3 tests were performed. All sites were blinded to results. Sensitivity calculations were based on central pathology review of resected tissue. Specificity was determined by testing 275 volunteers who were healthy and with nontransitional cell carcinoma conditions.

RESULTS

The 21 sites enrolled 176 patients with a history of transitional cell carcinoma, with 62 recurrences while undergoing surveillance. Overall sensitivities (with 95% CI) were FISH 71% (95% CI 58 to 82), BTA Stat test 50% (37 to 63) and cytology 26% (16 to 39). FISH was negative in 260 of the 275 healthy volunteers or patients with no history of transitional cell carcinoma (specificity 94.5%).

CONCLUSIONS

Sensitivity of the FISH assay is superior to that of cytology and at least equivalent to the BTA Stat test in detecting recurrent transitional cell carcinoma. Its specificity approaches that of cytology. Further testing of its clinical use is warranted.

Novel chromosome findings in bladder cancer cell lines detected with multiplex fluorescence in situ hybridization

Bladder cancer is a common neoplasm worldwide, consisting mainly of transitional cell carcinomas, while squamous, adenocarcinoma, and sarcomatoid bladder cancers account for the remaining cases. In the present study, multiplex fluorescence in situ hybridization (M-FISH) has been used to characterize chromosome rearrangements in eight transitional and one squamous cell carcinoma cell line, RT112, of UMUC-3, 5637, CAT(wil), FGEN, EJ28, J82, 253J, and SCaBER. Alterations of chromosome 9 are the most frequent cytogenetic and molecular findings in transitional cell carcinomas of all grades and stages, while changes of chromosomes 3, 4, 8, 9, 11, 14, and 17 are also frequently observed. In the present study, alterations previously described, including del(8)(p10), del(9)(p10), del(17)(p10), and overrepresentation of chromosome 20, as well as several novel findings, were observed. These novel findings were a del(15)(q15) and isochromosome 14q, both occurring in three of nine cell lines examined. These abnormalities may reflect changes in bladder tumor biology. M-FISH represents an effective preliminary screening tool for the characterization of complex tumor karyotypes.

Numerical aberrations of chromosome 9 in bladder cancer. A possible prognostic marker for early tumor recurrence

To investigate whether nonrandom aberrations of chromosomal numbers could predict tumor recurrence in patients with bladder cancer, archival urine cytology specimens (Giemsa-stained) from patients previously treated for transitional cell carcinoma of the urinary bladder were studied retrospectively by fluorescence in situ hybridization. A total of 48 patients (pTis, 6; pTa, 2: pT1, 32; and pT2-4, 8) were consecutively enrolled in this study, and numerical aberrations of chromosomes 9 and 17 were investigated. Cytology was diagnosed as negative for malignancy in 18 patients and positive in 30 patients. Twenty-seven of the 48 patients (56%) had one or more chromosomal aberrations. The frequency of numerical aberrations of chromosome 17 was correlated with increasing stage and grade, whereas loss of copies of chromosome 9 (monosomy) was frequently observed at a lower stage and grade. Chromosomal aberrations were detected in 9 (50%) of 18 patients with negative or equivocal cytology (class I, II, or III) by the Papanicolaou classification. Of eight patients with negative or equivocal cytology who developed tumor recurrence, four (50%) showed monosomy 9 and one (14%) showed a numerical aberration of chromosome 17. All six patients who showed monosomy of chromosome 9 developed tumor recurrence within 12 months, whereas four of the nine patients who did not show monosomy of this chromosome developed recurrence within 12 months (P<0.05, Fisher test). These results suggest that monosomy of chromosome 9 might be a prognostic marker for early tumor recurrence in patients with negative or equivocal cytology specimens.

The relationship of BRMS1 and RhoGDI2 gene expression to metastatic potential in lineage related human bladder cancer cell lines

We have recently characterized a human bladder cancer cell line T24 and a more aggressive lineage related variant of it, T24T. To gain further insights, we have studied their metastatic ability in an in vivo model system. Results show that T24 forms significantly fewer [4/12 (1/11) mice had metastases with 1-2 lesions/mouse] metastasis in SCID/bg mice than T24T [14/14 (6/6) mice had metastases with a mean of 24-28 lesions/mouse]. To begin exploring the mechanisms underlying this difference, we evaluated the mRNA and protein expression levels of metastasis-suppressor genes, known to be important in the progression of other cancers, in our model of bladder cancer progression. A higher mRNA expression of BRMS1, a metastasis suppressor in breast cancer, was observed in T24 cells. In addition, RhoGDI2 mRNA expression was only observed in T24 when compared to T24T, suggesting that Rho activation might play a significant role in the metastatic cascade. However, a basal level mRNA expression of KISS1, described as metastasis suppressor in melanoma and breast, was observed in both the lines and had slightly higher expression in T24T. No difference of Nm23-H1, KAI1, MKK4/SEK1 and E-Cadherin protein levels were noted between these two lines. In summary, it appears that the T24/T24T paired cell lines constitute a useful model for the study of human bladder cancer metastasis that will allow both the discovery and mechanistic evaluation of genes potentially involved in this process.

Chromosome 9 aberrations by fluorescence in situ hybridisation in bladder transitional cell carcinoma

To investigate the role of the monosomy 9 in bladder carcinogenesis, 96 cases of superficial bladder transitional cell carcinoma (TCC) were studied and followed periodically for around 3 years (mean+/-standard error of the mean (SEM); 3.46+/-0.34 years). Samples from bladder washings were analysed by fluorescent in situ hybridisation (FISH) to detect numerical anomalies of chromosome 9. Moreover, to evaluate the relative under representation of this chromosome, we detected numerical changes of chromosome 8 and DNA ploidy by flow cytometric analysis (FCM). Chromosome 8 copy number were related to FCM DNA ploidy and both were related with tumour grade. Monosomy 9 did not correlate with tumour grade, stage, chromosome 8 aneuploidies and abnormal DNA content, but correlated with tumour progression. Comparing the results in the primary and subsequent tumours, we observed an increase in the frequency of aneuploidies by FCM, associated with an increase of chromosome 8 polysomies. The mean chromosome 9 copy number/nucleus remained nearly the same in most of the primary and invasive tumours. Our results confirm that monosomy 9 is an early event and that it is retained during tumour progression and invasion and that the loss occurs before the tetraploidisation process. The relationship between the presence of a sub-population with monosomy 9 and tumour progression suggests the presence of a region that could have a role in the progression of superficial bladder TCC.

Noninvasive detection and prediction of bladder cancer by fluorescence in situ hybridization analysis of exfoliated urothelial cells in voided urine

OBJECTIVES

To investigate the clinical utility of fluorescence in situ hybridization (FISH) of voided urine in the detection of bladder cancer and the prediction of its recurrence.

METHODS

FISH with centromere-specific probes for chromosomes 9 and 17 was performed to evaluate the chromosomal alterations of exfoliated urothelial cells in voided urine obtained from 44 patients with bladder cancer and 20 controls. The analysis was also performed in 17 patients with bladder cancer after complete transurethral resection to prospectively determine whether FISH can predict tumor recurrence.

RESULTS

The sensitivity to detect bladder cancer by FISH analysis (85%) was significantly higher than that by urine cytologic examination (32%) and by the bladder tumor antigen test (64%) (P <0.0001 and P = 0.026, respectively). The specificity of FISH, cytologic analysis, and the bladder tumor antigen test was 95%, 100%, and 80%, respectively. Among the 17 patients tested after transurethral resection, 7 of 13 FISH-positive patients developed tumor recurrence within the 27-month follow-up period; none of 4 FISH-negative patients developed recurrence during the same period. The recurrence rate in patients with the loss of chromosome 17 was 100%, significantly higher than the 23% for patients without this alteration (P = 0.015).

CONCLUSIONS

These findings suggest that FISH analysis of exfoliated urothelial cells in voided urine can efficiently detect bladder cancer and predict its recurrence.

Biomarkers in monitoring for efficacy of immunotherapy and chemoprevention of bladder cancer with dimethylsulfoxide

This study correlated biomarkers expressed in tumor and epithelial field with clinical response and recurrence. Of 25 bladder cancer patients, 11 received 6 weeks of intravesical Bacille Calmette-Guerin (BCG), and 14 were treated weekly with intravesical dimethylsulfoxide (DMSO) for 4 weeks to further modulate biomarker expression. G-actin, DNA aneuploidy, and p300 tumor antigen were evaluated by quantitative fluorescence image analysis on uroepithelial cells from bladder wash samples prior to and immediately following treatment. Excluding patients who did not respond to BCG (and who had persistently abnormal p300 and DNA markers), recurrence correlated with persistent abnormal G-actin findings. Of patients who were G-actin negative following therapy, only 25% recurred during follow-up in contrast to 67% in patients who were positive (p < 0.03 by Fisher's exact test). The odds ratio for recurrence was 6.00 (95% confidence interval: 1.3-28.6). Cytosolic G-actin levels can be an important intermediate end point marker for chemoprevention.

Genetic and molecular markers of urothelial premalignancy and malignancy

The molecular genetic changes reported in bladder tumors can be classified as primary and secondary aberrations. Primary molecular alterations may be defined as those directly related to the genesis of cancer. These are frequently found as the sole abnormality and are often associated with particular tumors. There are characteristic primary abnormalities involved in th production of low-grade/well-differentiated neoplasms, which destabilize cellular proliferation but have little effect on cellula "social" interactions or differentiation, as well as the rate of cell death or apoptosis. Other molecular events lead to high-grad neoplasms which disrupt growth control, including the cell cycle and apoptosis, and which have a major impact on biological behavior. A primary target leading to low-grade papillary superficial bladder tumors resides on chromosome 9, while p53 gene alterations are commonly seen in flat carcinoma in situ. Other molecular alterations must be elucidated, as many non-invasive neoplasms have neither chromosome 9 nor p53 alterations. Novel approaches utilizing tissue microdissection techniques an molecular genetic assays are needed to shed further light on this subject. Secondary genetic or epigenetic abnormalities may be fortuitous, or may determine the biological behavior of the tumor. Multiple molecular abnormalities are identified in most human cancers studied, including bladder neoplasms. The accumulation, rather than the order, of these genetic alterations may be the critical factor that grants synergistic activity. In this regard, it is noteworthy that many of the genes that are altered act upon the two recognized critical growth and senescenc pathways, TP53 and RB. These particular molecular aberrations may be especially important to evaluate for their use in the management of bladder cancer because of their commonality in progressive forms of the disease. Thus, clinical trials are underway to explore their use in specific situations, particularly in the surgical management of locally advanced disease, and to determine whether adjuvant chemotherapy in such patients may be of benefit. The use of molecular alterations in the management of non-invasive bladder neoplasms remains to be firmly established. Our knowledge of molecular alterations important in bladder cancer progression is far from complete, and further study is necessary to further elucidate cruci pathways involved in progression and therapeutic response. As per preneoplastic conditions, difficulties in identifying and interpreting the significance of phenotypic changes have imposed certain limitations, as has an evolving nomenclature and issues of reproducibility in interpreting morphologica criteria. Nevertheless, molecular alterations involving chromosome 9q and the INK4A locus in papillary superficial tumors vs changes in chromosomes 14q and 8q, p53 and RB in flat carcinoma in situ lesions may indicate a molecular basis for early events that lead to varying pathways in urothelial tumorigenesis. Studies aimed at revealing the clinical relevance of genet instability, as well as molecular or epigenetic alterations, in urothelium and preneoplastic lesions of otherwise morphologicall normal appearance are needed to further advance knowledge in the field. Clinical advances in bladder cancer will be facilitated by novel animal models paralleling the human disease. Molecular diagnostics, particularly specific antigen expression, fluorescence in situ hybridization and microsatellite analyses, have show great promise as screening and follow-up methodologies, and may supplement urine cytology in the diagnosis and characterization of new and recurrent disease. In addition, the use of high-throughput genomic/proteomic assays, linked to comprehensive databases, and coupled with robust bioinformatics will be key elements in elucidating the components of regulatory and signaling pathways involved in bladder tumorigenesis and cancer progression.

The development of a multitarget, multicolor fluorescence in situ hybridization assay for the detection of urothelial carcinoma in urine

The purpose of this study was to develop a multitarget, multicolor fluorescence in situ hybridization (FISH) assay for the detection of urothelial carcinoma (UC) in urine specimens. Urinary cells obtained from voided urine specimens of 21 patients with UC and 9 normal donors were analyzed with nine different centromere enumeration probes and a single locus-specific indicator probe to determine an optimal set of FISH probes for UC detection. The four probes with the greatest sensitivity for UC detection were then labeled with a unique fluorophore and combined into a single probe set. The probes with the greatest combined sensitivity for UC detection were CEP3, CEP7, CEP17, and the 9p21 (P16) LSI. This probe set was used to evaluate urine specimens acquired from 179 patients for prospective testing (46 with biopsy-proven UC). FISH slides were evaluated by scanning the slide for cells with nuclear features suggestive of malignancy and assessing the FISH signal pattern of these cells for polysomy (ie, gains of two or more different chromosomes). A receiver operator characteristic curve revealed that a cutoff of 5 cells with polysomy as the positive criterion for cancer resulted in an overall sensitivity of 84.2% for patients with biopsy-proven UC and a specificity of 91.8% among patients with genitourinary disorders but no evidence of UC. This study demonstrates that a multitarget, multicolor FISH assay containing centromeric probes to chromosomes 3, 7, and 17 and a locus-specific probe to band 9p21 has high sensitivity and specificity for the detection of UC in voided urine specimens.

Treatment of leptomeningeal metastases evaluated by interphase cytogenetics

PURPOSE

Although cytologic examination of CSF is the primary method for the evaluation of response to therapy for leptomeningeal metastases (LMMs), the procedure's sensitivity decreases throughout the course of protracted therapy. We studied whether this response could be monitored more accurately through the detection of numerical chromosomal aberrations by interphase cytogenetics, using fluorescence in situ hybridization (FISH).

PATIENTS AND METHODS

Seven patients treated for LMMs and with a known numerical aberration for chromosome 1 in their pretreatment CSF were included in this study. Up to 16 consecutive CSF samples were analyzed by means of the fluorescence in situ hybridization (FISH) technique for cells with aberrant chromosome 1 content. The results of routine cytology and FISH analyses were compared and were correlated with each patient's neurologic status.

RESULTS

Routine cytology detected malignancies in only 24 of the 76 samples, all of which were classified as chromosomally abnormal by FISH (except for two samples that could not be evaluated). Moreover, FISH demonstrated aneusomic cells in 32 additional samples, which could therefore be classified as malignant. The FISH results correlated better with patient neurologic status in that more malignant cells were detected in the CSF of neurologically deteriorating patients.

CONCLUSION

Using FISH in addition to performing routine cytologic examination of CSF led to a more accurate evaluation of response to treatment in patients treated for LMMs.

Genetic and phenotypic changes associated with the acquisition of tumorigenicity in human bladder cancer

There has been a general lack of human paired cell lines that both reproduce the in vivo spectrum of tumor progression of bladder cancer and have some of the genetic changes associated with progression in human tumor tissue. T24, a cell line established from an invasive human transitional cell carcinoma (TCC) of the bladder, has been used extensively in bladder cancer research. However, a significant limitation of this cell line is its lack of tumorigenicity when injected into immunocompromised mice. This characteristic was used to our advantage as we sought to characterize T24T, a highly tumorigenic variant that could then be used to elucidate the genes responsible for human bladder tumor progression. In culture, T24T has a faster doubling time, reaches a higher cell density in monolayer culture, and is more motile than T24 at higher cell densities. T24T is able to form colonies in soft agar, whereas T24 is not, and expresses HRAS, a gene associated with increased aggressiveness in human TCC, at higher levels than T24. Most importantly, T24T forms solid tumors when injected subcutaneously in SCID mice both with and without Matrigel (Sigma, St. Louis, MO), whereas T24 does not. Cytogenetically, the 2 cell lines contain at least 5 shared structural anomalies, as determined by detailed karyotyping. Interestingly, T24T has acquired 4 new structural changes, 3 of which [add(10)(p12), i(10)(q10), -15] have been observed in loss of heterozygosity (LOH) studies of tumor progression in human TCC. It appears that the T24/T24T model may be an excellent tool for the study of human TCC progression because of its relationship with known karyotypic changes associated with human bladder cancer progression. We are currently taking advantage of these paired cell lines to identify genes involved in human TCC progression. Genes Chromosomes Cancer 27:252-263, 2000.

Mutation of cell cycle regulators and their impact on superficial bladder cancer

Early cytogenetic studies in bladder cancer identify regions of chromosomal gain or loss that can be candidate loci for oncogenes and tumor suppressor genes. Oncogenes with potential prognostic significance identified in bladder cancer the RAS family, epidermal growth factor receptor, ERBB-2, MDM2, and cyclin D1. The TP53 gene has been the most thoroughly characterized tumor suppressor gene in bladder cancer, with correlation of TP53 alterations with type of carcinogenic exposure, tumor stage and grade, as well as prognosis. Studies evaluating alterations of the retinoblastoma pathway have identified the retinoblastoma gene, RB, p161NK4A/CDKN2, and E2F-1 as tumor suppressor genes with potential prognostic significance in patients with bladder cancer. Better understanding of the genetic mechanisms underlying bladder tumor development and progression will allow better prevention, diagnosis, and treatment strategies.

Chromosome 9 monosomy by fluorescence in situ hybridization of bladder irrigation specimens is predictive of tumor recurrence

PURPOSE

Bladder irrigation specimens are effective for sampling the urothelium for detection of recurrent bladder cancer. These specimens can be evaluated by cytology or quantitative techniques. Proliferation and ploidy changes are readily detected using deoxyribonucleic acid (DNA) cytometry. Tumor associated chromosomal aberrations can be assayed using fluorescence in situ hybridization (FISH). The prognostic values of DNA cytometry, and chromosome 9 and 9p21 FISH on exfoliated cells from bladder irrigation specimens from 61 bladder cancer patients were evaluated.

MATERIALS AND METHODS

A total of 61 consecutive bladder irrigation specimens were obtained during cystoscopy. DNA cytometry was performed by image analysis. FISH was performed using a centromeric chromosome 9 probe and a cosmid contig (COSp16) probe to the CDKN2A/p16 tumor suppressor region of 9p21. Proportional hazards regression analysis was performed with statistical software to test the predictor variables of initial patient status (presence of tumor), COSp16 fraction (the proportion of COSp16 signals relative to centromeric probe signals), monosomic and hyperdisomic fractions of the chromosome 9 probe, and hyperdiploid fraction from DNA cytometry. Median time to recurrence was calculated using statistical software survival analysis.

RESULTS

Initial patient status and monosomy of chromosome 9 were predictive of bladder cancer recurrence (p <0.0001 and p = 0.0073, respectively). The 11 patients with chromosome 9 monosomy fractions greater than 15% and a visible tumor had a median time to recurrence of 105 days. In contrast, only 8 of the 25 patients with chromosome 9 monosomy fractions less than 15% and no visible tumor had recurrence within 560 days. Median time to recurrence was 185 days for 6 patients with chromosome 9 monosomy fractions greater than 15% and no visible tumor, and 225 for 19 with chromosome 9 monosomy fractions less than 15% and a visible tumor. Hyperdiploid fraction was suggestive but not predictive of bladder cancer recurrence (p = 0.078). COSp16 and hyperdisomic fractions were not predictive of bladder tumor recurrence (p = 0.11 and p = 0.30, respectively).

CONCLUSIONS

Chromosome 9 monosomy by FISH was predictive of bladder tumor recurrence. Furthermore, our findings support the hypothesis that losses of tumor suppressor genes on chromosome 9 are critical, perhaps initiating genetic events in bladder cancer.

Numerical chromosomal aberrations in muscle invasive squamous cell and transitional cell cancer of the urinary bladder: an alternative to classic prognostic indicators?

OBJECTIVES

To evaluate the prognostic value of chromosomal aberrations in muscle invasive bladder cancer, because they are of diagnostic and prognostic significance in superficial bladder cancer.

METHODS

One hundred ninety patients, who underwent radical cystectomy because of squamous cell carcinoma (SCC) of the urinary bladder in 94 cases and transitional cell carcinoma (TCC) in 96 cases, were studied retrospectively. Numerical aberrations of chromosomes 7, 9, and 17, p53 positivity, histologic stage and grade, histologic tumor type, lymph node status, and the presence of bilharzial eggs were investigated as possible prognostic factors.

RESULTS

Univariate analysis demonstrated the prognostic significance of all parameters analyzed, excluding chromosome 9. Multivariate analysis revealed only T category (P = 0.01095266), lymph node involvement (P = 0.00054877), and p53 positivity (P = 0.0316974) to be independent prognostic factors in muscle invasive SCC and TCC.

CONCLUSIONS

Although chromosomal aberrations are associated with progression-free survival, they are not independent prognostic factors and give the clinician no additional information on patients with muscle invasive bladder cancer.

Multifocality of transitional cell carcinoma results from genetic instability of entire transitional epithelium

OBJECTIVES

Multifocality of transitional cell carcinoma (TCC) has been attributed to seeding of exfoliated tumor cells or to a general sensitivity of the entire urothelium to carcinogenic stimuli. By contrast, TCC has been shown to evolve as a consequence of genetic defects and chromosomal instability. We analyzed chromosomal patterns, total DNA content, and p53 and Ki67 expression in malignant and normal transitional cells to evaluate their relationship to the development of multifocal TCC.

METHODS

Included in the study were 47 patients, 16 women and 31 men, with a mean age of 70.04 years (range 37 to 83). Of 47 patients, 45 had TCC of the urinary bladder and 7 of those had synchronous ureteral involvement. Two patients had ureteral TCC and a history of TCC of the bladder. Using fluorescence in situ hybridization, numerical aberrations of chromosomes 7, 9, and 17 were detected in imprint specimens of histologically verified tumor and "normal" urothelium and were compared with static ploidy and p53 and Ki67 expression.

RESULTS

Chromosome 7 was altered in 93.6%, chromosome 9 in 63.8% (including monosomy), and chromosome 17 in 87.2% of the 47 analyzed tumor and normal imprints. Differences between tumor and normal epithelium were observed in aberrational frequencies (number of cells showing chromosomal aberrations calculated on 200 cells counted, given in percentages). DNA content was aneuploid in all tumor specimens, but diploid in 20 (42.5%) of 47 normal specimens, according to lower aberration frequencies in these patients. p53 detection was positive in 82.9% of the tumor specimens and 76.6% of the normal specimens. Ki67 was positive in 87.2% of the tumor imprints and in 72.3% of the normal specimens.

CONCLUSIONS

These data suggest a general genetic instability as a reason for multifocality in the entire transitional epithelium.

Nephrogenic adenoma in renal transplant recipients: a truly benign lesion?

OBJECTIVES

Nephrogenic adenoma is a benign metaplastic lesion of the urinary bladder, reported to occur as a response to inflammation, trauma, intravesical therapies, and after renal transplantation. The aim of this study was to evaluate on the basis of chromosomal analysis whether nephrogenic adenoma really is benign.

METHODS

Twelve renal transplant recipients with histologically verified nephrogenic adenoma were analyzed for numerical aberrations of chromosomes 7, 9, and 17. Results were related to total DNA content, p53 and Ki-67 positivity, and clinical outcome. Ten patients with superficial bladder cancer and 10 healthy renal transplant recipients formed the control groups.

RESULTS

All 12 patients with nephrogenic adenoma had monosomy 9 in a mean of 24.3% (range 20% to 30%) of the evaluated cells; 3 patients had an additional trisomy 7 in a mean of 8% (range 6% to 10%) of the counted cells. Chromosome 1 7 was disomic in all patients. DNA histograms were diploid in 11 of the 12 patients and aneuploid in 1 patient. No p53 and Ki-67 positivity was present in this group. All patients with superficial bladder cancer had monosomy 9 in a mean of 79.8% (range 75% to 85%) of the counted cells. Two patients were found to have an additional trisomy 7 in 50% and 65% of the cells, respectively. The latter had an aneuploid histogram; the others had haploid/diploid histograms. p53 was negative in all specimens. Ki-67 positivity was present in 70% of these patients. All healthy transplant recipients had disomic chromosomal patterns according to diploid DNA histograms and negative immunocytochemical results.

CONCLUSIONS

Even if in a lower percentage of cells, aberrations of chromosome 7 and 9 were detected in nephrogenic adenoma. It therefore cannot be excluded that nephrogenic adenomas in immunosuppressed renal transplant recipients may develop into malignant lesions.

Numerical aberrations of chromosomes 7, 9 and 17 in squamous cell and transitional cell cancer of the bladder: a comparative study performed by fluorescence in situ hybridization

PURPOSE

Since squamous cell differs from transitional cell cancer regarding histopathology, clinical outcome and etiology, the underlying genetic effects of these 2 tumor types may also be different. We compared numerical aberrations of chromosomes 7, 9 and 17 in bilharzial squamous cell carcinoma, and bilharzial and nonbilharzial transitional cell carcinoma by fluorescence in situ hybridization, and correlated the findings to p53 positivity of the 3 tumor types.

MATERIALS AND METHODS

Cystectomy for invasive bladder cancer was performed in 169 men and 51 women with a mean age of 54.8 years (range 28 to 83). Of the 220 patients 100 (45.4%) had histologically verified bilharzial squamous cell carcinoma, 61 (27.7%) bilharzial transitional cell carcinoma and 59 (26.8%) nonbilharzial transitional cell carcinoma. Using fluorescence in situ hybridization cystectomy specimens were evaluated for numerical aberrations of chromosomes 7, 9 and 17, and p53 detection was performed by immunohistochemistry.

RESULTS

Aberrations of chromosome 7 were observed in 79% of the bilharzial squamous cell carcinoma specimens, and 100% and 93.2% of bilharzial and nonbilharzial transitional cell carcinoma specimens, respectively (p = 0.00011). Aberrations of chromosome 9 were seen in 92% of squamous cell carcinoma specimens but in only 52.4% and 60.9% of bilharzial and nonbilharzial transitional cell carcinoma, respectively (p < 0.00001). Aberrations of chromosome 17 were found in only 29% of squamous cell carcinoma specimens, compared to 83.6% and 84.7% aberrations of chromosome 17 in both transitional cell carcinoma groups, respectively (p < 0.00001). The p53 over expression was similar in all 3 tumor types with 82% for squamous cell carcinoma, and 73.7% for bilharzial and 81.3% for nonbilharzial transitional cell carcinoma (not significant, p = 0.5285).

CONCLUSIONS

Our data show clear differences between chromosomal patterns of invasive bilharzial squamous cell carcinoma and invasive bilharzial or nonbilharzial transitional cell carcinoma but similar frequencies of p53 over expression in all 3 tumor types. However, aberrations of chromosome 9 were observed in all analyzed groups, which confirms the 2 pathways in the oncogenesis of squamous cell and transitional cell carcinoma at the cytogenetic level as suggested by molecular studies.

DNA cytometry and chromosome 9 aberrations by fluorescence in situ hybridization of irrigation specimens from bladder cancer patients

OBJECTIVES

To determine the sensitivity and specificity of combining fluorescence in situ hybridization (FISH) measurement of chromosome 9 and DNA cytometry of bladder irrigation specimens in the detection of bladder cancer.

METHODS

Bladder irrigation specimens were obtained from 37 normal control patients and 317 bladder cancer patients during cystoscopic examinations. Bladder cancer patients were sampled in the absence of observable tumor (256 specimens) and concurrently with tumor (204 specimens). Chromosome 9 copy number was determined on a cellular basis by FISH, and cellular DNA content was determined by Feulgen DNA staining and image cytometry.

RESULTS

Sensitivity of chromosome 9 FISH was 42% for all tumors and was not correlated to transitional cell carcinoma tumor grade, while the sensitivity of DNA cytometry was 55% and improved with increasing grade from 38% for grade 1 to 90% for grade 3 tumors. The results of FISH and DNA cytometry were combined, resulting in specificity of 92% and sensitivity of 69% for grade 1, 76% for grade 2, and 97% for grade 3 tumors.

CONCLUSIONS

The lack of increase with grade in the percentage of positive specimens by FISH supports the hypothesis that chromosome 9 aberrations are critical events in bladder tumorigenesis for many patients. These data demonstrate the presence of cells in irrigation specimens with specific genomic lesions of chromosome 9 and DNA content. Combining FISH on chromosome 9 and DNA cytometry provides an increase in sensitivity to transitional cell carcinoma over either test alone.

Loss of heterozygosity on chromosome 9 and loss of chromosome 9 copy number are separate events in the pathogenesis of transitional cell carcinoma of the bladder

The most frequent genetic aberration found in transitional cell carcinoma (TCC) of the bladder involves chromosome 9. Loss of heterozygosity (LOH) analyses show deletions of both chromosome 9p and 9q, while in situ hybridization studies suggest a significant percentage of tumours with monosomy 9. To investigate the types of chromosome 9 losses that occur in bladder cancer, we have studied 40 tumours with different techniques such as in situ hybridization (ISH), flow cytometry and LOH analysis. LOH for one or more markers was found in 43% of the tumours. This percentage does not differ from previous reports. With ISH, complete monosomy for chromosome 9 was observed in only 1 of the 40 tumours. Four other tumours had monosomic subpopulations, representing 23-40% of the cells. In 18 cases, an underrepresentation of the chromosome 9 centromere relative to chromosome 6 or to the ploidy of the tumour was observed, including the cases with monosomy. In 5 of these 18 cases, the relative loss could not be confirmed by LOH. In addition, when LOH and a relative underrepresentation were observed in the same tumour, the extent of LOH as measured by the intensity of allele loss, was often not related to the extent of underrepresentation. We therefore conclude that complete monosomy of chromosome 9 is rare in TCCs of the bladder and that a relative loss of centromere signal may not be related to a loss compatible with inactivation of a tumour suppressor gene. LOH was found in TCCs of all stages and grades. Our results suggest that loss of tumour suppressor genes on chromosome 9 is an early event in the pathogenesis of bladder cancer.

Loss of the CDKN2A/p16 locus detected in bladder irrigation specimens by fluorescence in situ hybridization

PURPOSE

We measured the CDKN2A/p16 tumor suppressor gene locus in bladder irrigation specimens and correlated the measurement with the clinical status of patients with bladder cancer.

MATERIALS AND METHODS

Irrigation specimens were obtained at cystoscopy from 10 normal controls, 21 patients with bladder cancer in whom no concurrent bladder tumor was seen and 23 patients with bladder tumors. Deoxyribonucleic cytometry and fluorescence in situ hybridization measurements were made. One fluorescence in situ hybridization probe was specific to the chromosome 9 centromere and the other, COSp16, targeted the CDKN2A/p16 region on chromosome 9p21. Three rates were calculated, including the hyperdiploid fraction from deoxyribonucleic acid cytometry, disomic fraction from the 9 centromere count and COSp16F, the frequency of COSp16 in association with 9 centromere. Specimens were classified as positive or negative for each of these rates using cutoff points based on previous studies and the distribution of values obtained for the normal control specimens.

RESULTS

Hyperdiploid fraction values were positive (greater than 8%) in 1 normal and 1 nontumor specimen. Ten specimens from patients with tumor showed elevated hyperdiploid fraction values. In 4 nontumor and 13 tumor irrigation specimens the chromosome 9 disomic fraction values were positive (less than 80%). COSp16F was positive (less than 83%) for 18 nontumor irrigation specimens and 18 tumor irrigation specimens. One normal, and 39 of 44 nontumor and tumor irrigation specimens were positive by at least 1 test.

CONCLUSIONS

COSp16 loss is measurable in irrigation specimens and it correlates with clinical status. This assay may prove useful in screening for and managing bladder cancer.

Bladder cancer: natural history, tumor markers, and early detection strategies

Transitional cell bladder carcinoma is characterized by a dichotomous, multichronotopic natural history. Low and moderate grade Ta lesions frequently recur, yet rarely invade, and carry an excellent prognosis with currently available treatments. High grade Ta lesions, tumors with lamina propria invasion (T1), and carcinoma in situ often progress to invasive disease, at which time overall prognosis is significantly decreased, despite various treatment alternatives. Although early detection of bladder tumors, prior to muscle invasion, should vastly improve our ability to save both bladders and lives, current methods of detection are neither sufficiently sensitive nor specific. Tumor marker analysis is an exciting new frontier in bladder cancer evaluation, and may have important applications to early detection strategies, in combination with simple hematuria testing and other selected noninvasive screening methods.

Genetic studies and molecular markers of bladder cancer

Target genes implicated in cellular transformation and tumor progression have been divided into two categories: proto-oncogenes which, when activated, become dominant events characterized by the gain of function, and tumor suppressor genes which become recessive events characterized by the loss of function. Alterations in proto-oncogenes and tumor suppressor genes seem equally prevalent among human cancers. Multiple mutations appear to be required to conform the malignant phenotype. Proto-oncogenes are activated mainly by point mutations; however, amplification and translocation events are also common. Tumor suppressor genes are inactivated by an allelic loss followed by a point mutation of the remaining allele. The prototype suppressor genes are the retinoblastoma (RB) gene and the TP53 (also known as p53) genes. Recent studies have shown that inactivation of TP53 and RB occur in bladder tumors that have a more aggressive clinical outcome and poor prognosis. We will review the molecular abnormalities associated with both oncogenes and tumor suppressor genes in bladder tumors, and also discuss the potential clinical use of their detection. The implementation of objective predictive assays to identify these alterations in clinical material will enhance our ability to assess tumor biological activities and to design effective treatment regimes.

Interlaboratory variability in fluorescence in situ hybridization analysis. The NCI Bladder Tumor Marker Network

Reliable interpretation of fluorescence in situ hybridization (FISH) data, especially data that have been generated in more than one laboratory, requires knowledge of the sources of variability inherent in FISH analysis. Possible sources of variation may derive from differences in sample preparation, probes used, intrasample heterogeneity, hybridization protocols, counting criteria within and between scorers, fluorescence microscopes, and filters. This study characterized the relative weight of some of these factors in order to determine the degree to which FISH results are comparable between laboratories. We used a hierarchical partitioned chi 2 analysis to measure sources of variation. We found that replicate counts varied no more than expected based on counting statistics (i.e., multinomial variation). However, with replicate hybridizations done in two separate laboratories, the variability increased significantly. Thus, care must be taken when interpreting FISH data that are derived from more than one institution. Previously agreed upon counting criteria as well as standardized FISH hybridization protocols may decrease this variability.

Molecular detection of primary bladder cancer by microsatellite analysis

Microsatellite DNA markers have been widely used as a tool for the detection of loss of heterozygosity and genomic instability in primary tumors. In a blinded study, urine samples from 25 patients with suspicious bladder lesions that had been identified cystoscopically were analyzed by this molecular method and by conventional cytology. Microsatellite changes matching those in the tumor were detected in the urine sediment of 19 of the 20 patients (95 percent) who were diagnosed with bladder cancer, whereas urine cytology detected cancer cells in 9 of 18 (50 percent) of the samples. These results suggest that microsatellite analysis, which in principle can be performed at about one-third the cost of cytology, may be a useful addition to current screening methods for detecting bladder cancer.