Monoclonal antibody Ki-67 in the study of the proliferative activity of bladder carcinoma

Loss of Stromal Antigen 2 (STAG2) Expression in Upper Urinary Tract Carcinoma: Differential Prognostic Effect According to the Ki-67 Proliferating Index

BACKGROUND

Inactivating mutation and consequent expression loss of stromal antigen 2 (STAG2, also known as SA2), a component of the cohesion complex, is one of the most common genetic aberrations in urothelial carcinoma. However, the clinicopathologic or prognostic significance of STAG2 alterations in upper tract urothelial carcinoma (UTUC) is largely unknown.

METHODS

This study immunohistochemically examined the expression of STAG2 in 171 patients with UTUC. The correlations of STAG2 loss with clinicopathologic features and patients' prognoses were examined.

RESULTS

Loss of STAG2 expression was observed in 28 cases (16%). Loss of STAG2 was significantly correlated with histological low grade, papillary architecture, noninvasive tumors, absence of concomitant carcinoma in situ, and lower Ki-67 expression. Loss of STAG2 alone was not significantly associated with patients' prognoses in either the uni- or multivariate analysis. However, STAG2 loss was significantly associated with worse clinical outcome in UTUC with high Ki-67 proliferation indexes, but not in UTUC with low Ki-67 expression.

CONCLUSIONS

Loss of STAG2 was generally associated with less aggressive features in UTUC. However, the STAG2 loss was an ominous sign in the subpopulation with higher Ki-67 proliferation indexes. Examining both STAG2 and Ki-67 status may be useful for identifying aggressive clinical behavior of UTUC.

Role of morphometry and proliferative parameters in grading of urothelial neoplasms

INTRODUCTION

Mean nuclear area of 10 nuclei (MNA-10), mitotic activity index (MAI) and Ki-67 are highly reproducible and can be routinely used as adjuncts to histopathological grading in classifying tumors. Assays of these biomarkers are non-invasive, rapid, easy to perform, more objective and accurate, with high sensitivity and specificity, and correlate well with tumor grade.

MATERIAL AND METHODS

This study was conducted at the Department of Pathology PGIMS, Rohtak on 50 cases, of which 25 cases were high-grade, 15 low-grade, 6 Papillary Urothelial Neoplasm of Low Malignant Potentialand 4 reactive lesions as per the 2004 ISUP/WHO classification. MNA-10, MAI and Ki-67 immunoquantitation were performed on stained sections.

RESULTS

The age of the patients varied from 35 to 87 years. Male: female ratio was 3.5:1. The mean MNA-10 (μm(2)) for High Grade Malignant Potential was 104.52 ±25.64 μm(2), which was significantly higher than in PUNLMP (47.64 ±10.23) and LMP (51.57 ±15.66). MAI (/10 HPF) showed an increasing trend from reactive lesions to HMP, with a mean of (3 ±1.16)/10 HPF to (21.36 ±5.31)/10 HPF respectively. Ki-67 labelling index, a proliferative marker, revealed increasing trend lowest with reactive lesions (10 ±2.83%) and highest in high grade tumors (65.96 ±14.44). Spearman's correlation showed maximum correlation between MAI and Ki-67 and the increasing grade of tumor.

CONCLUSIONS

MNA-10 in combination with Ki-67 and MAI was found to be stronger than MNA-10 alone. MAI has high reproducibility in differentiating low and high grade, with simple assessment in paraffin embedded sections allowing adequate histopathological analysis and visualization of proliferating cells simultaneously. This multivariate grading model should be applied in routine grading to overcome interobserver variability and to increase reproducibility of grading.

Biomarkers in bladder cancer: translational and clinical implications

Bladder cancer is associated with high recurrence and mortality rates. These tumors show vast heterogeneity reflected by diverse morphologic manifestations and various molecular alterations associated with these disease phenotypes. Biomarkers that prospectively evaluate disease aggressiveness, progression risk, probability of recurrence and overall prognosis would improve patient care. Integration of molecular markers with conventional pathologic staging of bladder cancers may refine clinical decision making for the selection of adjuvant and salvage therapy. In the past decade, numerous bladder cancer biomarkers have been identified, including various tumor suppressor genes, oncogenes, growth factors, growth factor receptors, hormone receptors, proliferation and apoptosis markers, cell adhesion molecules, stromal factors, and oncoproteins. Recognition of two distinct pathways for urothelial carcinogenesis represents a major advance in the understanding and management of this disease. Nomograms for combining results from multiple biomarkers have been proposed to increase the accuracy of clinical predictions. The scope of this review is to summarize the major biomarker findings that may have translational and clinical implications.

Markers of bladder cancer State of the art

Biomarkers are increasingly being applied to the clinical management of patients with bladder cancer. The biomarkers in current clinical use focus on bladder cancer detection. Biomarkers for prognosis and as intermediate endpoints for chemoprevention are being evaluated in clinical trials. This review provides an overview of the performance characteristics of current clinical markers and other markers that are currently under evaluation.

Prognostic value of p53 and Ki-67 expression in intermediate-risk patients with nonmuscle-invasive bladder cancer receiving adjuvant intravesical mitomycin C therapy

OBJECTIVES

To analyze the prognostic values of p53 and Ki-67 expression in intermediate-risk patients with nonmuscle-invasive bladder cancer who were treated with adjuvant intravesical mitomycin C.

METHODS

From 2001 to 2006, 129 patients with nonmuscle-invasive bladder cancer who had undergone transurethral resection and adjuvant intravesical mitomycin C therapy. Patients with primary, single, Stage TaG1 lesions and those with T1G3 or carcinoma in situ lesions were excluded. The expression of p53 and Ki-67 was measured by immunohistochemistry on tissue sections after transurethral resection. The clinical and pathologic data were collected in a prospectively maintained bladder cancer database program.

RESULTS

The mean follow-up period was 48.6 months (range 6.1-96.0). Of the 129 patients, 61 (47.3%) developed recurrence and 15 (11.6%) developed progression to muscle-invasive disease. The expression of p53 was not associated with the patient outcomes, but Ki-67 overexpression was related to progression-free survival on univariate analysis (relative risk 4.38, 95% confidence interval 1.48-13.01, P = .006). On multivariate analysis, Ki-67 overexpression was significantly associated with progression-free survival (relative risk 3.40, 95% confidence interval 1.04-11.05, P = .042). In the patients with Ki-67 overexpression, the 1- and 5-year progression-free survival rate was 98.0% and 73.9%, respectively. When the combination of p53 and Ki-67 expression was assessed in the multivariate model, the simultaneous overexpression of p53 and Ki-67 did not predict for progression-free survival (adjusted relative risk 1.16; 95% confidence interval 0.21-6.20, P = .863).

CONCLUSIONS

These results suggest that Ki-67 expression can identify a subset of intermediate-risk patients with nonmuscle-invasive bladder cancer in whom intravesical mitomycin C therapy could be effective.

Detection of mutations in the cDNA of the proliferation marker Ki-67 protein in four tumor cell lines

The Ki-67 protein has an essential role in cell proliferation. It is present in all dividing cells of normal and tumor tissues, but absent in resting cells. At present, no data are available about any alterations in the gene of this protein that could contribute to its altered structure and function, resulting in tumor development. We therefore searched for mutations in the Ki-67 gene (MKI67). cDNAs from four tumor cell lines derived from carcinoma of the cervix (HeLa), colon (CXF94, SW480), and lung (A549) were prepared. Defined parts of the cDNA were amplified by specific primers, cloned into pCRII-Blunt-TOPO vector, and replicated in Escherichia coli. The sequence of the amplified products were determined by automated fluorescence sequencing. Eight different mutations were characterized in the four cell lines tested. One is a deletion of a single base at position 1496 causing a truncated protein, the second is a A433T exchange is a silent mutation, and the remaining six mutations result in an amino acid change that might alter the conformation of the protein. Our results show that several mutations exist within the Ki-67 protein's cDNA in four tumor cell lines. These mutations might provide a genetic basis for tumor development.

Immunohistochemical expression of CK20, p53, and Ki-67 as objective markers of urothelial dysplasia

Urothelial dysplasia and carcinoma in situ (CIS) are related to recurrence and progression of urothelial carcinoma. Distinguishing CIS and dysplasia from reactive atypia is often difficult on the basis of histological features alone. Cytokeratin 20 (CK20), p53, and Ki-67 are related either to neoplastic change or prognosis in urothelial proliferations. The objective of the present study was to establish the immunohistochemical pattern of these three antibodies in urothelial dysplasia and CIS. Three groups of patients were evaluated: 40 nonneoplastic urothelial samples, 50 cases with histologically incontrovertible CIS, and 30 samples with nonconclusive atypical changes (atypia of unknown significance). Monoclonal antibodies (MoAb) against CK20, p53, and Ki-67 (MIB-1) were used on paraffin-embedded samples. Nonneoplastic urothelium showed no reactivity to CK20 except for umbrella cells; p53 and Ki-67 were negative or weakly positive in <10% of basal cells. In the CIS group, 42% showed positivity for all three MoAb; 44%, for two; and 14%, only for one. CK20 was positive through the full thickness of the urothelium in 72% of cases, p53 was positive in 80% of cases, and Ki-67, in 94% of cases. In the third group, the suspected dysplastic cells showed strong positivity in scattered cells through the epithelium in 75% of cases. Aberrant CK20 expression in urothelial cells plus overexpression of p53 and Ki-67 are indicators of dysplastic change in urothelial mucosa. Thus, immunohistochemistry is a useful tool to confirm the diagnosis of CIS and could be helpful to distinguish dysplastic changes from reactive atypia.

Prognostic value of proliferative activity and nuclear morphometry for progression in TaT1 urothelial cell carcinomas of the urinary bladder

OBJECTIVES

To analyze the predictive power of Ki67 area% (Ki67), mitotic activity index (MAI), p53 area% (p53), and the mean area of the 10 largest nuclei (MNA10) for progression of stage in 195 primary consecutive TaT1 urothelial cell carcinomas of the urinary bladder.

METHODS

Ki67- and p53-positive versus negative nuclei, MAI, and MNA10 using motorized systematic random sampling morphometry were determined. Kaplan-Meier curves and multivariate survival analysis (Cox model) were used to assess the prognostic value of the quantitative and classic clinicopathologic risk factors (age, sex, stage, grade, carcinoma in situ, multicentricity).

RESULTS

Thirteen (6.7%) of the 195 patients had progression (0 [0%] of 36 low-risk, 1 [1.1%] of 85 intermediate-risk, and 12 [16.2%] of 74 high-risk patients). In univariate analysis (all variables), the strongest predictors with the highest hazard ratios were Ki67 (threshold 25.0%), MAI (threshold 30), and MNA10 (threshold 170 microm2). In multivariate analysis, the strongest independent combinations for progression--MNA10 (170 microm2) plus MAI (threshold 30) and MNA10 (threshold 170 microm2) plus Ki67 (threshold 25.0%)--overshadowed all other features. p53 was weaker but, combined with Ki67, still predicted progression fairly well. In the total group, the sensitivity, specificity, and positive and negative predictive values of MNA10-MAI and MNA10-Ki67 at the thresholds mentioned were 100%, 89%, 38%, and 100%, respectively. These feature combinations were also strongest prognostically in the high-risk treatment group.

CONCLUSIONS

The combined biomarkers MNA10-MAI or MNA10-Ki67 are accurate, well reproducible, and easy to assess progression predictors in all patients with TaT1 urothelial cell carcinomas, as well as in high-risk (bacille Calmette-Guérin-treated) patients.

Patterns of multiple recurrences of superficial (Ta/T1) transitional cell carcinoma of bladder and effects of clinicopathologic and biochemical factors

BACKGROUND

Although multiple sequential recurrences are one of the most important characteristics of superficial transitional cell carcinoma (TCC) of the bladder, few studies have examined multiple sequential recurrence patterns and the clinicopathologic and biochemical factors associated with these patterns.

METHODS

Two hundred seventy superficial TCC bladder carcinoma patients were followed. Clinical, pathologic, and tumor marker (p53, MIB-1, bcl-2, c-erb B-2, and epidermal growth factor receptor) data were collected at baseline and during followup. The Kaplan-Meier (KM) method was used to describe multiple recurrences. The Wei, Lin, and Weissfeld (WLW) marginal proportional hazards model was used to assess the effects of clinicopathologic and immunohistochemic factors on multiple recurrences.

RESULTS

Among the 270 patients, 126 (46.7%) had one or more recurrences, 38 (14.1%) had two or more recurrences, and 14 (5.2%) had three or more recurrences during the followup. The median times for the first, the second, and the third recurrences were 23 months, 15 months, and 13 months, respectively. In KM analysis, Stage T1, higher grades, and Ki-67 stain positivity were associated with the first recurrence, and p53 stain positivity was marginally significant. Other markers were not significant. For the second recurrence, only p53 stain positivity was significant. In multivariate analysis (WLW method), stage was significantly associated with the first recurrence (risk ratio [RR] = 2.03), and Ki-67 was marginally significant (RR = 1.49). For the second recurrence, only p53 positivity was statistically significant (RR = 2.73).

CONCLUSIONS

Among superficial TCC bladder carcinoma patients, multiple recurrences are common phenomena. The time for recurrence becomes shorter as the number of recurrences increases. In addition to tumor stage and grade, Ki-67 can be used to identify patients at high risk for a first recurrence; and p53 can be used to identify patients at high risk for a second recurrence.

[Prognostic value of P53, Ki67, and Rb protein in infiltrating bladder tumors]

OBJECTIVES

To determinate whether increased expression of the p53 and Ki67 and the of the tumour suppressor gene retinoblastoma (prot Rb), in an immunohistochemistry study, were associated with relapse in invasive bladder cancer.

MATERIALS AND METHODS

47 patients with invasive bladder cancer. 42 men and 5 women. Mean age 63 years old. Relapse in 19 patients (40%). Mean time until recurrence 8.5 months. p53 and Ki67 were study in 47 patients and prot Rb in 40 patients.

RESULTS

p53: Mean expression 41%. There were significant differences in the increased expression of p53 between patients with and without relapse (p = 0.03). A statistically significant association was then observed between patients with p53 > 20% (vs p53 < 20%) and adverse outcome of the disease (p = 0.04). Ki67 and prot Rb: There were no significant differences in relapse and progression free survival between Ki67 > 40% (vs Ki67 < 40%) and prot Rb < 10% (vs prot Rb > 10%). p53 expression showed a statistically significant correlation with Ki67 and prot Rb.

CONCLUSION

p53 is a good prognostic marker for the relapse and progression free survival in invasive bladder cancer.

Assessment of proliferative activity in colorectal carcinomas by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR)

The monoclonal antibody Ki-67 and the isospecific monoclonal antibody MIB-1 are routinely used in oncology to assess the proliferation index of tumor cells. A more objective and sensitive method is the determination of the of Ki-67 protein-specific mRNA by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). In 25 resected colorectal adenocarcinomas of different stages and grades we determined between 0.2 and 4.4 amol (10(-18) mol) Ki-67 protein-specific mRNA per microgram total RNA (median = 0.88 amol). The corresponding Ki-67 indices (expressing the percentage of Ki-67/MIB-I positive tumor cells) ranged from 41 to 81% (median = 61%). We found a good correlation between Ki-67 index and mRNA expression (r = 0.75), a significant correlation between both data and tumor stage (primary tumor, regional nodes, metastasis [pTNM] staging classification) (p < 0.001), but not between both data and tumor grade. Both Ki-67 indices (p = 0.05) and mRNA levels (p = 0.014) correlated significantly to the patients' survival. These results demonstrate that the Ki-67 protein-specific quantitative RT-PCR is a useful method for the characterization of tumor cell proliferation.

Correlation of Ki-67 and p53 with the new World Health Organization/International Society of Urological Pathology Classification System for Urothelial Neoplasia

OBJECTIVE

The present study examines p53 and Ki-67 staining patterns of the diagnostic entities included within the new World Health Organization/International Society of Urological Pathology (WHO/ISUP) classification of urothelial neoplasms.

DESIGN

We retrospectively studied 151 bladder biopsies from 81 patients with the following neoplasms: normal urothelium (n = 34 biopsies); low-grade intraurothelial neoplasia (LGIUN; n = 19); high-grade intraurothelial neoplasia (HGIUN; n = 20); papillary hyperplasia (n = 4); papilloma (n = 3); papillary neoplasm of low malignant potential (LMP; n = 12); low-grade papillary carcinoma (n = 28); and high-grade papillary carcinoma (n = 31). Sections were labeled immunohistochemically with antibodies to p53 and Ki-67 (MIB-1). Two hundred cells from each lesion were visually counted, and the percentage of positive cells was tabulated without knowledge of the WHO/ISUP diagnosis.

RESULTS

In flat lesions, p53 positivity was of limited diagnostic utility; the marker was present in 6 of 34 benign biopsies, 6 of 19 LGIUNs, and 10 of 20 HGIUNs. In one case in which HGIUN was present elsewhere in the bladder, 29% of the benign urothelial cells were p53 positive. In papillary lesions, p53 positivity was not seen in 4 of 4 cases of papillary hyperplasia, 3 of 3 papillomas, and 8 of 12 LMP tumors. In contrast, p53 was detected in 18 of 28 low-grade and 26 of 31 high-grade papillary urothelial carcinomas. A p53 labeling index (LI) greater than 30% was only seen in HGIUNs and high-grade papillary carcinomas. In flat lesions, an increased Ki-67 LI separated out benign urothelium (mean LI, 0.62%) from dysplasia (mean LI, 3.3%) and HGIUN (mean LI, 11.6%). In papillary lesions, Ki-67 positivity was as follows: papillary hyperplasia (mean LI, 1.1%); papilloma (mean LI, 4.3%); LMP tumors (mean LI, 2.5%), low-grade papillary carcinoma (mean LI, 7.3%); and high-grade carcinoma (mean LI, 15.7%). A Ki-67 LI greater than 10% was seen only in low- and high-grade papillary carcinomas, HGIUN, and single cases of LGIUN and papillary neoplasm of LMP.

CONCLUSIONS

An increased proliferative index as demonstrated by immunohistochemical staining for Ki-67 (MIB-1) is most often seen in papillary carcinoma and HGIUN. Marked p53 positivity is also characteristic of carcinoma but may be seen in benign-appearing urothelium, suggesting a "field effect" with occult molecular aberration.

EXPRESSÃO IMUNOHISTOQUÍMICA DO MIB-1 EM CARCINOMA DE CÉLULAS TRANSICIONAIS DE BEXIGA

A expressão do MIB-1 é um excelente marcador da atividade proliferativa e correlaciona-se com a agressividade biológica do carcinoma de células transicionais da bexiga.Correlacionamos a expressão do MIB-1 com a evolução dos pacientes. Revisamos 90 pacientes do HC-FMRP-USP entre 1980-2000, com idade entre 29 a 93 anos (média 71 anos);sendo 70 (77,8%) homens e 20 (22,2%) mulheres; e seguidos em média por 55 (2-231) meses. 45 (50%) tumores tinham grau I, 29 (32,2%) grau II e 16 (17,8%) grau III. Os tumores foram estadiados em pTA: 54 (60%), pT1: 8 (8,9%) e pT2-4: 28 (31,1%). Foi utilizado o anticorpo monoclonal anti-MIB-1 (Immunotech). Emprega-se o limite de 10% de núcleos corados como nível de corte para o MIB-1. Utilizamos para análise estatística os testes Mann-Whitney, Kaplan-Meier, e log rank, e nível de significância 5%. Expressaram MIB-1, 63 pacientes (70%) variando de 0 a 80%(mediana 5%, média 22,8%), com diferença significativa (P<0,05) entre tumores invasivos (pT2-4) e não invasivos (pT A-1) e entre os estádios pT A e pT1 (P=0,01). Houve associação com o grau dos tumores: significativa entre G1 e G2 (P<0,001) e G1 e G3 (P<0,001), e sem significância entre G2 e G3 (P=0,2). A relação do MIB-1 com o tamanho da lesão foi significante (P<0,02). As recidivas não foram preditas pelo índice MIB-1 (P=0,86), entretanto em pacientes MIB-1 positivos foi significantemente menor o intervalo livre de metástase (P=0.04), e a sobrevida entre tumores não invasivos (P=0.009) e na população total (P=0.0002), Há correlação entre a alta expressão do MIB-1 e os estádios invasivos, os graus avançados e os tumores maiores, contudo, não há diferença em tumores recidivados. O índice de positividade do MIB-1 não distinguiu os pacientes com menor tempo livre da doença, foi, contudo, significante para apontar aqueles com menor sobrevida e tempo livre de metástase.

[DNA ploidy determination with flow cytometry, Ki-67 index and overexpression of p53 protein in 121 T1 superficial bladder carcinomas. Retrospective studies. Part II: Prognostic value and usefulness in the indication for prophylactic treatment with BCG]

OBJECTIVE

Evaluate the utility of Ki-67 label index, p53 expression and flow cytometry-DNA ploidy in the selection of groups to be treated with prophylactic BCG and the prognostic value compared with the classic variables (grade, lymphatic permeation, multiplicity, volume, primary).

MATERIAL & METHOD

121 superficial bladder tumors T1. 10% Cut-off level for Ki-67 and p53. Aneuplody is defined as a tumor with DNA index different of 1 or more than 20% in G2-M phase. 71 (58.7%) received BCG.

RESULTS

In uni and multivariate analysis positivity to Ki-67 is correlated with recurrence. Progression is correlated with lymphatic permeation (p .0003), volume (p .016), ploidy (p .022) and positivity to p53 (p .007). In multivariate analysis, volume and positivity to p53 are independent variables. None were of utility to prevent recurrence, but Ki-67 positive or aneuploid treated tumors had less progression (p .025 and p .009 respectively). The p53 negative treated tumors had less progression too.

CONCLUSIONS

Only Ki-67 is correlated with tumoral recurrence. P53 and tumor volume are correlated with stage progression. If the results are confirmed with bigger series, the Ki-67 positive and/or aneuploid tumors would obtain benefits of prophylactic treatment with BCG.

Tumor proliferation in squamous cell carcinoma of the vulva

Tumor proliferation is of important prognostic significance for several neoplasms. The very few previous studies on this parameter in vulvar carcinoma have shown contradictory results. The aim of this study was to determine the prognostic significance of tumor proliferation in vulvar carcinoma. Paraffin-embedded tissue of 74 squamous cell carcinomas of the vulva was immunostained for MIB-1, detecting Ki-67, and analyzed for staining patterns and the percentage of positive cells. There were three general staining patterns: a diffuse distribution (diffuse type), a localized staining at the infiltrating tumor border (infiltrating type), and a localized staining in basal parts of infiltrating tumor cell aggregates (basal type). The percentage of positive cells was not correlated with morphologic or clinical parameters, nor was it correlated with disease-free and overall survival. MIB-1 staining types were correlated with tumor type and grading. Tumors of diffuse and infiltrating type seemed to have more frequent lymph node metastasis (p = 0.053) and shorter disease-free survival (p = 0.076). In these tumors, overall survival time was reduced significantly (p = 0.02). In multivariate analysis, MIB-1 staining types were the most important factor for overall survival with an odds ratio of 4.73. In conclusion, distribution and not the percentage of proliferating cells is of prognostic significance in squamous cell carcinoma of the vulva.

[Molecular biology in bladder cancer]

Progress of molecular biology with regard to etiopathogeny of tumours in general, and cancer of the bladder in particular, is taking place at such a vertiginous pace that practising urologists find themselves overwhelmed in terms of their ability to learn and keep updated in so complex a subject. The understanding of certain molecular factors with critical influence on the formation, growth and progression of a tumour of the bladder, is forcing us to make unbiased assessments on the role they will play in the evolution and survival of this neoplasia. It is anticipate they will be much more reliable than traditionally established morphological factors such as grade and stage. We also include a literature review with an analysis and elucidation of the role played by oncogenes, tumor suppressor genes, vascular density markers, telomerase etc., in the formation and growth of cancer of the bladder and their likely relationships with already established clinico-pathological factors.

Urinary markers of malignancy

Transitional cell carcinoma (TCC) is the second most common malignancy in the genitourinary tract. The majority of urothelial tumors are superficial when the patient first presents, but despite adequate resection of the primary lesion the recurrence rate is particularly high. In a small but significant group of patients the tumor is primary invasive or subsequently can progress and leads to death. Voided urine can be easily obtained and therefore diagnostic urine tests would be ideal for screening or follow up of TCC. Although many urinary markers have been described, none of them is used routinely in clinical practice. Promising tumor markers still need to be evaluated in multi-center clinical studies. Larger prospective trials are necessary in order to identify prognostic indicators that would help to predict disease progression or response to different treatment modalities (BCG, chemo-, radiotherapy, etc.). Hopefully, new diagnostic urine tests will allow to identify patients who will most benefit from early cystectomy with or without adjuvant treatment, bladder sparing protocols or systemic treatment. In this paper we have reviewed the literature and discuss, from the clinician's point of view, the current status of various diagnostic tests for urinary markers. [Lee SJ, Lee WE, Chang SG, Lee CH, Kim JI. A comparative study of telomerase, Lewis X, BTA, NMP22 and urinary cytology in bladder tumor. J Urol 1999;161(suppl):152.]

Current Concepts in Biomarker Technology for Bladder Cancers

Background: Transitional cell carcinoma of the bladder (TCC) is the second most common malignancy of the urinary tract. More than 70% of treated tumors recur, and 30% of recurrent tumors progress. Currently, pathologic staging and grading are valuable prognostic factors for detecting and monitoring TCC. Urinalysis, cystoscopy, and cytology are either invasive or lack sensitivity and specificity. The availability of a noninvasive, reliable, and simple test would greatly improve the detection and monitoring of patients with TCC. Several biomarkers for bladder cancer have been proposed, but no single marker has emerged as the test of choice.

Approach: We undertook a comprehensive literature search using Medline to identify all publications from 1980 to 1999. Articles that discussed potential biomarkers for TCC were screened. Only compounds that demonstrated high sensitivity or specificity, significant correlation with TCC diagnosis and staging, and extensive investigation were included in this review.

Content: Potential biomarkers of disease progression and prognosis include nuclear matrix protein, fibrin/fibrinogen product, bladder tumor antigen, blood group-related antigens, tumor-associated antigens, proliferating antigens, oncogenes, growth factors, cell adhesion molecules, and cell cycle regulatory proteins. The properties of the biomarkers and the methods for detecting or quantifying them are presented. Their sensitivities and specificities for detecting and monitoring disease were 54–100% and 61–97%, respectively, compared with 20–40% and 90% for urinalysis and cytology.

Summary: Although urine cytology and cystoscopy are still the standard of practice, many candidate biomarkers for TCC are emerging and being adopted into clinical practice. Further research and better understanding of the biology of bladder cancer, improved diagnostic techniques, and standardized interpretation are essential steps to develop reliable biomarkers. It is possible that using the current biomarkers as an adjuvant modality will improve our ability to diagnose and monitor bladder cancer.

Value of immunohistochemical Ki-67 and p53 determinations as predictive factors of outcome in renal cell carcinoma

OBJECTIVES

Nuclear grade and tumor stage are important prognostic factors in renal cell carcinoma, but tumors of similar stage and grade can exhibit a wide variation in biologic behavior and clinical outcome. In this retrospective study, we evaluated the immunologic markers, Ki-67 (MIB1) and p53, in 73 cases of conventional (clear cell) renal cell carcinoma and compared these markers with the accepted prognostic features of grade, stage, and tumor size in predicting outcome.

METHODS

Specimens of 73 renal cell carcinomas of different nuclear grade (20 Furhman I/II, 32 Fuhrman III, and 21 Fuhrman IV) and different stage (10 pT1, 23 pT2, 36 pT3, and 4 pT4) were immunostained with monoclonal antibodies against Ki-67 and p53.

RESULTS

Univariate statistical analysis showed that tumor size (P <0. 001), nuclear grade (P <0.01), tumor stage (P <0.01), Ki-67 index (P <0.001), and p53 immunostaining (P <0.03) correlated significantly with a poor prognosis. A Ki-67 index of 20% was a powerful predictor of survival in all patients (P <0.00001), with strong predictive values. On multivariate analysis, the Ki-67 index and metastases were significant independent prognostic factors (P <0.02 and <0.01, respectively).

CONCLUSIONS

Ki-67 immunostaining appeared to be an additional prognostic indicator of biologic aggressiveness in renal cell carcinoma. Immunohistochemical assessment of tumor antigens could be used to identify patients at high risk of tumor progression in addition to conventional prognostic factors.

The role of bcl-2, p53, and ki-67 index in predicting tumor recurrence for low grade superficial transitional cell bladder carcinoma

PURPOSE

We assess the prognostic significance of bcl-2 expression, p53 mutation and ki-67 index for low grade, superficial transitional cell bladder carcinoma.

MATERIALS AND METHODS

The medical records of 93 cases of primary, low grade (24 G1, 69 G2), superficial (70 pTa, 23 pT1) transitional cell carcinoma of the bladder were reviewed. Association of bcl-2, p53 and ki-67 index immunoreactivity with tumor grade and stage was examined. Prognostic significance of tumor grade, pathological stage, bcl-2 expression, p53 mutation and ki-67 index in predicting tumor recurrence was assessed.

RESULTS

Of the tumors 60 (70%) had p53 mutation and 9 (10.5%) expressed bcl-2. These 2 markers did not relate to tumor grade or pathological stage. Median ki-67 index was 10.9% and positively correlated with tumor grade. Recurrence was noted in 34.9% of patients with a median followup of 26 months (range 1 to 84). The ki-67 index was the only significant prognostic indicator in univariate and multivariate analyses. This marker can further distinguish grade 2 tumors with a favorable prognosis from those with an unfavorable outcome.

CONCLUSIONS

The ki-67 labeling index is an independent predictor of tumor recurrence for patients with primary superficial, low grade bladder cancers.

Prognostic value of the proliferative index determined by Ki-67 immunostaining in superficial bladder tumors

The biological behavior of urothelial carcinomas remains unpredictable. The objective of this study was to determine the prognostic value of Ki-67 index in superficial papillary bladder tumors and to correlate it with the S-phase fraction (SPF) measured by flow cytometry. Three hundred nineteen patients with newly diagnosed superficial (pTa, pT1) bladder tumors were included between September 1990 and April 1992. Patients with bladder carcinoma in situ alone were excluded. We observed 255 pTa tumors and 64 pT1 tumors, whereas 111 lesions were classified as grade G1 and 208 as grade G2-G3. Ki-67 immunostaining was performed on paraffin-embedded material using a 3-step immunoperoxidase procedure with the murine monoclonal antibody MiB1. The relation between Ki-67 expression and prognostic variables (stage, grade, tumor size, multifocality, age, and sex) was investigated by the chi-square test. Cox regression was used to describe the association between Ki-67 and tumor recurrence in 308 patients with follow-up while adjusting for potentially confounding prognostic variables. The frequency of high Ki-67 expression (> or =10%) increased with stage (P = .005) and grade (P = .001), but not with tumor size or multifocality. Two hundred one patients experienced tumor recurrence in a median follow-up of 68 months. Stage, grade, tumor size, and multifocality were all independent predictors of recurrence. Ki-67 index greater than 10% was found to be an independent predictor of tumor recurrence among patients with tumors larger than 3 cm in diameter (HR = 2.05, CI = 1.18-3.55), but not those with smaller size tumors. With regards to the DNA index, a significant but weak correlation was observed between Ki-67 expression and the SPF (Spearman's correlation coefficient = 0.23, P = .004). In addition, aneuploid tumors had significantly higher expression of Ki-67 (22.5%) than diploid tumors (10.1%) (P = .0006). Moreover, patients with DNA aneuploid bladder tumors were more likely to have more than 10% Ki-67-positive cells than those with diploid tumors. In patients with newly diagnosed pTa or pT1 bladder tumors, a Ki-67 index above 10% is an independent predictor of shorter time to recurrence only in those with tumors larger than 3 cm.

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.

Prognostic markers in bladder cancer: a contemporary review of the literature

PURPOSE

We provide a contemporary review of bladder tumor markers and summarize their role as prognostic indicators.

MATERIALS AND METHODS

A comprehensive review of the literature on prognostic markers for transitional cell carcinoma of the bladder was performed.

RESULTS

Intense research efforts are being made to identify and characterize better various bladder cancers and their true biological potential. The need to predict which superficial tumors will recur or progress and which invasive tumors will metastasize has led to the identification of a variety of potential prognostic markers. Blood group antigens, tumor associated antigens, proliferating antigens, oncogenes, peptide growth factors and their receptors, cell adhesion molecules, tumor angiogenesis and angiogenesis inhibitors, and cell cycle regulatory proteins have recently been identified. The potential clinical applications of these tumor markers are under active investigation. Recent attention has focused on which tumor markers may predict the responsiveness of a particular bladder cancer to systemic chemotherapy.

CONCLUSIONS

At present conventional histopathological evaluation of bladder cancer (tumor grade and stage) cannot predict accurately the behavior of most bladder tumors. With a better understanding of the cell cycle, and cell to cell and cell to extracellular matrix interactions as well as improved diagnostic techniques (immunohistochemistry), progress is being made to identify and characterize other potential prognostic markers for transitional cell carcinoma of the bladder. The ultimate goal is to develop reliable prognostic markers that will accurately predict not only the course but also the response of a tumor to therapy. This information may then be used to dictate more aggressive treatment for tumors that are likely to progress and less aggressive treatment for those that are unlikely to progress. In the future these biological markers may also be used in gene therapy for the treatment of bladder cancer.

Immunohistochemical analysis of Ki-67 antigen and Bcl-2 protein expression in prostate cancer: effect of neoadjuvant hormonal therapy

OBJECTIVE

To determine differences in the immunohistochemical (IHC) expression of Bcl-2 protein and Ki-67 antigen in patients with prostatic cancer who underwent radical prostatectomy with or without neoadjuvant hormonal therapy.

MATERIALS AND METHODS

Ki-67 antigen and Bcl-2 protein were detected by IHC using MIB-1 and Bcl-2 antibodies in prostatectomy specimens from 28 patients who received hormonal therapy before surgery (group 1) and 51 patients who did not (group 2).

RESULTS

In group 2, the mean MIB-1 index increased with increasing grade of tumour, from 11.6% in low-grade to 24.7% in high-grade tumours (P = 0.002). Bcl-2 expression did not correlate with either tumour grade or stage. In group 1, there were no correlations between Bcl-2 expression or MIB-1 index and tumour grade or stage. More tumours in group 1 were Bcl-2-positive (16 of 28, 57%) than were tumours in group 2 (11 of 51, 22%; P = 0.003). The mean (SD) MIB-1 index of tumours in group 2 [15.6 (14.4)%], was significantly greater than that of tumours in group 2 [6.8 (7.5)%; P = 0.004].

CONCLUSIONS

These results indicate that Bcl-2 positivity is increased by androgen ablation therapy and conversely, that the proliferative activity of cancer cells is significantly reduced. The expression of Bcl-2 protein may play a role in the ability of prostate cancer cells to survive in an androgen-deprived environment.

Prognostic significance of Ki-67 expression in transitional cell bladder carcinoma after radical cystectomy

We evaluated the prognostic significance of the Ki-67 labeling index (Ki-67 LI) in 75 patients with transitional cell carcinoma of the bladder who underwent radical cystectomy. Immunohistochemical staining of archival material was performed by the streptavidin-biotin method. Univariate survival analysis showed that Ki-67 LI (p < 0.001), histologic grade (p < 0.05), tumor stage (p < 0.001) and the number of positive lymph nodes (p < 0.001) significantly correlated with prognosis. Multivariate survival analysis indicated that the Ki-67 LI (p < 0.05), histologic grade (p < 0.01), tumor stage (p < 0.01), presence of lymph node metastases (p < 0.05) and use of neo-adjuvant therapy (p < 0.05) had independent prognostic value. The Ki-67 LI is an independent prognostic factor for patients with transitional cell bladder cancer treated by radical cystectomy.

Polyclonal Ki-67 expression in transitional cell carcinoma of the bladder

The proliferation kinetics of 101 cases of transitional cell carcinoma (TCC) and seven cases of transitional cell carcinoma-in-situ of the bladder were assessed following staining with polyclonal Ki-67 antibody (pKi-67). Labeling indices ranged from 49% to 60.2% with a mean value of 22.2% for all cases. A significant association between pKi-67 indices, tumor grade and tumor stage was observed, with significant differences between pKi-67 indices of Grade 1 and 3 tumors and Grade 2 and 3 tumors. Significant differences in labeling indices were also found between superficial (Ta) tumors and both musculoinvasive (T2/T3a) tumors and those infiltrating the perivesical fat (T3b). pKi-67 indices for carcinoma-in-situ were similar to those noted for Grade 1 TCC. No difference in pKi-67 index was found when tumors were classified according to the morphology of the tumor invasion front. It is concluded that pKi-67 index is a useful marker for tumor progression for vesical TCC and that this immunohistochemical stain may assist clinical assessment of the potential behaviour of tumors in individual cases.

Significance of conventional and new prognostic factors for locally confined renal cell carcinoma

BACKGROUND

The prognosis of patients with locally confined renal cell carcinoma is variable. To improve the prognostic knowledge and select patients at high risk, additional prognostic parameters are needed.

METHODS

The significance with respect to survival and tumor recurrence of "classic" and "new" prognostic parameters has been examined by following 41 patients with locally confined renal cell carcinoma after nephrectomy (mean follow-up, 5.2 years). The significance of histologic grade, tumor stage, Ki-67 index, proliferating cell nuclear antigen index, 3H-thymidine labeling index, tumor ploidy status, and tumor growth after xenotransplantation into nude mice (GAX range) was tested using the Kaplan-Meier plots by the log rank test or Tarone's test and also by the Cox multiple hazard regression analysis.

RESULTS

Tumor stage (P < 0.0025), histologic grade (P < 0.005), Ki-67 index (P < 0.006), and GAX range (P < 0.00004) were found to be significant prognostic parameters for survival and tumor recurrence using single-factor analysis. Applying the multivariate analysis, the combination of the "new" factors, GAX range and Ki-67 index, resulted in even a higher prognostic relevance than the combination of the "classic" prognostic factors, tumor stage and histologic grade. The calculated prognostic index based on the results of the Cox analysis, which, except for stage and grade, included the Ki-67 index, was shown to be highly correlated with survival (P = 0.00002) and tumor recurrence (P = 0.0004). Its prognostic validity was studied with the receiver operating characteristics procedure and was found to be considerably superior to that of the two conventional prognosticators.

CONCLUSIONS

The additional determination of the Ki-67 labeling index increases the prognostic assessment of patients with locally confined renal cell carcinoma.

Indici di proliferazione (Ki 67, TLI) ed espressione della p53. Introduzione: Proliferation indices (Ki 67, TLI) and p53 expression. Introduction

Histologic and pathologic findings are the most common and useful prognostic factors in transitional cell cancer of the bladder. Thus, clinicians know their peculiar limits very well. The Authors report the results of a literature review about an oncogenic-derivative protein (p53) and about indices of proliferation Ki 67 and TLI, which are frequently studied in bladder cancer.

Indici di proliferazione (Ki 67, TLI) ed espressione della p53. Esperienza personale: Proliferation indices (Ki 67, TLI) and p53 expression. Personal experience

The Authors report their experience on the study of urothelial bladder cancer by determining the overexpression of p53, DNA-content by flow-cytometry, Ki 67, TLI and cytofluorimetric S-phase in 81 patients. Ki 67, DNA content and p53 overexpression are statistically related with histologic grade, unlike TLI and S-phase. TLI, overexpression of p53 and Ki 67 are statistically related with stage, whereas ploidy and S-phase do not show any relation with stage. The Authors discuss these findings.

Proliferating cell nuclear antigen cyclin in human transitional cell carcinoma

OBJECTIVES

To confirm the value of the proliferating cell nuclear antigen (PCNA) labelling index in relation to histological grade, stage and prognosis.

MATERIALS AND METHODS

Tissue specimens from 56 patients (49 men, 7 women; mean age 65 years [range 34-86]) with newly diagnosed transitional cell carcinoma of the urinary bladder were stained by an avidin-biotin peroxidase method using an anti-PCNA monoclonal antibody. Immunohistochemical analysis was performed on ethanol-fixed, paraffin-embedded tissue sections obtained by endoscopic biopsy or transurethral resection (TUR). The PCNA labelling index was determined by counting the number of PCNA-labelled cells in the tissue sections.

RESULTS

Grade 1 tumours averaged 5.1 +/- 3.0% labelling versus 10.9 +/- 5.2% in grade 2 tumours, and grade 3 tumours had a PCNA labelling index of 21.8 +/- 10.4%. The average labelling indices for superficial tumour (37 patients) and invasive tumour (19 patients) were 7.5 +/- 5.3% and 20.8 +/- 10.0%, respectively. A distant metastatic bladder tumour showed an average labelling index of 42.3%. To analyse survival, tumours with PCNA indices above and below the median level (12%) were compared. Those patients with an index of < 12% (the mean of all of the PCNA values) had a worse prognosis than those with an index of > 12%. The mean PCNA labelling indices in recurrent and non-recurrent tumours were 6.4 +/- 0.7% and 8.2 +/- 1.7%, respectively, statistically not significant.

CONCLUSION

The higher PCNA labelling index may indicate biological malignancy. These results suggest that measurement of the PCNA labelling index in bladder cancer may prove to be an objective and quantitative assay of biological aggressiveness and provide significant prognostic information, though it does not help to select patients at high risk of recurrence in superficial tumours.

Usefulness of MIB1 monoclonal antibody in assessing the proliferative index in human bladder carcinoma: comparison with Ki-67 antibody

The reactivity of MIB1 antibody on routinely processed paraffin sections was compared with that of Ki-67 antibody on frozen sections of 80 transitional cell carcinomas of the bladder. The percentage of labelled cells was expressed as the labelling index. MIB1 labelling indices were higher than those of Ki-67 but for each case the two values were strongly correlated (r = 0.91). Ki-67 and MIB1 indices were also correlated to tumour grade and stage (P < or = 0.001). MIB1 indices determined after both formaldehyde and ethanol based Bouin's fluid fixatives did not show any significant difference. MIB1 antibody staining after microwave oven heating of tissue sections is a simple technique for assessing the proliferative fraction of bladder tumours on fixed material. The use of MIB1 antibody permits retrospective studies and should determine whether the proliferation index in bladder carcinoma has the same prognostic value as demonstrated in other types of neoplasms.

The cell proliferation-associated antigen of antibody Ki-67: a very large, ubiquitous nuclear protein with numerous repeated elements, representing a new kind of cell cycle-maintaining proteins

The antigen defined by mAb Ki-67 is a human nuclear protein the expression of which is strictly associated with cell proliferation and which is widely used in routine pathology as a "proliferation marker" to measure the growth fraction of cells in human tumors. Ki-67 detects a double band with apparent molecular weights of 395 and 345 kD in immunoblots of proteins from proliferating cells. We cloned and sequenced the full length cDNA, identified two differentially spliced isoforms of mRNA with open reading frames of 9,768 and 8,688 bp encoding for this cell proliferation-associated protein with calculated molecular weights of 358,761 D and 319,508 D, respectively. New mAbs against a bacterially expressed part and a synthetic polypeptide deduced from the isolated cDNA react with the native Ki-67 antigen, thus providing a circle of evidence that we have cloned the authentic Ki-67 antigen cDNA. The central part of the Ki-67 antigen cDNA contains a large 6,845-bp exon with 16 tandemly repeated 366-bp elements, the "Ki-67 repeats", each including a highly conserved new motif of 66 bp, the "Ki-67 motif", which encodes for the epitope detected by Ki-67. Computer analysis of the nucleic acid and the deduced amino acid sequence of the Ki-67 antigen confirmed that the cDNA encodes for a nuclear and short-lived protein without any significant homology to known sequences. Ki-67 antigen-specific antisense oligonucleotides inhibit the proliferation of IM-9 cell line cells, indicating that the Ki-67 antigen may be an absolute requirement for maintaining cell proliferation. We conclude that the Ki-67 antigen defines a new category of cell cycle-associated nuclear nonhistone proteins.

Prognostic value of Ki-67 immunolabelling in primary operable breast cancer

The prognostic value of Ki-67 immunohistochemical labelling was evaluated in 327 operable primary carcinomas of the breast. The follow-up time was up to 4 years (mean 2.7 years). The disease-free survival in Ki-67 positive patients was shorter than in Ki-67 negative patients (P < 0.005). By combining the Ki-67 expression with ER receptors and stage, subgroups with a different disease-free survival were identified. In stage II patients there was a significant difference (P < 0.005) in disease-free survival between Ki-67 positive/ER negative and Ki-67 negative/ER positive patients. In node negative patients there was no such difference. The disease-free survival according to different prognostic factors, stage, ER and node status, were separately examined using a Cox's proportional hazards model. ER (P < 0.0001), the Ki-67 (P < 0.02), tumour size (P < 0.0001) and nodal status (P < 0.006) were independent prognostic factors. We conclude that the potential value of Ki-67 labelling for prognostic evaluation of patients with breast carcinoma is good.