p53 but not erbB-2 expression is associated with rapid tumor proliferation in urinary bladder cancer

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.

HER2 protein overexpression and gene amplification in upper urinary tract transitional cell carcinoma: systematic analysis applying tissue microarray technique

OBJECTIVES

To investigate HER2 (c-erbB-2) protein overexpression and HER2 gene amplification in upper urinary tract transitional cell carcinoma (TCC) with respect to its association with tumor grade and stage, as well as the prognostic significance.

METHODS

A total of 53 consecutive TCC specimens were analyzed immunohistochemically (HercepTest) and with fluorescence in situ hybridization applying a tissue microarray technique.

RESULTS

Overall, HER2 immunoreactivity (expression) was detected in 28 of 53 TCC specimens and tended to be stronger in high-stage (8 [36%] of 22 pT1 versus 20 [65%] of 31 pT2-T3; P = 0.06) and high-grade (11 [39%] of 28 low-grade versus 17 [68%] of 25 high-grade; P = 0.054) tumors. Weak overexpression (HercepTest score 2+) was seen in 9 cases (17%) and was associated with angioinvasion (P = 0.02) and had independent prognostic significance with respect to metastasis-free survival (risk ratio 9.6; P = 0.03). Low HER2 amplification was present in four TCC specimens (9%), with HER2/chromosome 17 ratios of 2.03, 2.77, 2.91, and 3.39, and polysomy of chromosome 17 was present in another 3 cases (7%). HER2 amplification and/or polysomy of chromosome 17 prevailed in high-stage (0 [0%] of 20 pT1 versus 7 [27%] of 26 pT2-T3; P = 0.01) and high-grade (1 [4%] of 24 low-grade versus 6 [27%] of 22 high-grade; P = 0.04) tumors, but lacked independent prognostic significance. Of nine TCC specimens with weak HER2 overexpression (HercepTest score 2+), 3 (33%) showed low HER2 amplification and two others had polysomy of chromosome 17.

CONCLUSIONS

HER2 overexpression and HER2 gene amplification were infrequent in our series. Thus, only a small number of patients with upper urinary tract TCC might benefit from HER2-targeted (Herceptin) cancer therapy.

Muscle invasive schistosomal squamous cell carcinoma of the urinary bladder: frequency and prognostic significance of p53, BCL-2, HER2/neu, and proliferation (MIB-1)

Muscle invasion is the usual presentation of schistosomal squamous cell carcinoma of the urinary bladder. It is unclear whether this invasive behavior is secondary to the aggressive nature of the disease or to delay in diagnosis. Fixed paraffin-embedded hematoxylin and eosin-stained sections of 15 cystectomy specimens from 15 patients (14 males, 1 female) (age range, 40 to 67 years), histologically confirmed as schistosomal squamous cell carcinoma, were assessed for grade (G1, n = 3; G2, n = 7; G3, n = 5) and pathological stage (PT category: PT2, n = 4; PT3a, n = 9; PT3b, n = 2). Immunostaining was performed for mutant p53, bcl-2, HER2/neu, and MIB-1 (proliferation), using steam antigen retrieval and an avidin-biotin complex method. Frequency of strong immunoreactivity was high for mutant p53 (73%) and MIB-1 (87% intermediate or high) but low for bcl-2 (20%) and HER2/neu (27%). There was no significant correlation of any of the four markers with either grade or stage. Hence, schistosomal bladder squamous cell carcinoma is felt to be an aggressive carcinoma de novo. The high frequency of mutant p53 expression (73%) and an intermediate to high proliferation index (87%) suggests this. The lack of correlation between histological grade and all four markers studied suggests that grading is not of prognostic value.

P53 protein expression in transitional cell carcinoma of the bladder - experience of the University of Malaya Medical Centre

OBJECTIVES

To study the incidence of p53 oncoprotein overexpression and its relationship to tumour grade, stage and clinical prognosis in a cohort of local Malaysian patients.

METHODS

All cases of transitional cell carcinoma (TCC) of the bladder diagnosed and treated at the University of Malaya Medical Centre from January 1995 to December 2000 were retrieved from the hospital records. Sections from paraffin-embedded tissues were retrieved and stained for p53 oncoprotein using immunohistochemistry techniques. P53 oncoprotein results were analyzed in relation to tumour grade, stage and clinical prognosis. Fisher's exact test was used to evaluate the relationship between categorical variables and the Kaplan-Meier procedure was used to assess survival outcomes. The Cox regression model was used for multivariate analysis.

RESULTS

A total of 64 cases were studied. The mean follow-up period was 23.7 months. The number of p53 positive cases was significantly higher in high-grade (G3) (p = 0.006) and muscle-invasive tumours ( summation operator T2, p = 0.035). The status of p53 expression had no significant association with recurrence-free (p = 0.594) or overall survival (p = 0.955). In multivariate analysis, a multiplicity of tumours at presentation (p = 0.004) and a history of cigarette smoking (p = 0.016) were independent predictors of recurrence. Tumour stage (p = 0.024) was the single independent predictor for poor overall survival.

CONCLUSIONS

Overexpression of p53 is associated with TCC of higher grade and tumour stage. It had no significant impact on prognosis in this cohort of TCC cases.

HER2 overexpression in muscle-invasive urothelial carcinoma of the bladder: prognostic implications

The HER2 (c-erbB-2) receptor is overexpressed in a variety of human malignant tumors and, in breast carcinoma, has been identified as a target for anti-HER2-directed therapy with the monoclonal antibody (MAb) trastuzumab. The aim of this retrospective study was to evaluate immunohistochemic HER2 expression in a large cohort of muscle-invasive urothelial cell carcinomas of the urinary bladder and to compare the results to pathologic characteristics and survival. Paraffin-embedded tumor specimens from 138 patients undergoing radical cystectomy for muscle-invasive bladder carcinoma were studied immunohistochemically with the Food and Drug Administration (FDA)-approved HercepTest (Dako, Glostrup, Denmark). HER2 overexpression was observed in 57 of 138 tumors (41%) and occurred more frequently in high-grade carcinomas than in low-grade carcinomas (p = 0.036). No significant relationship with HER2 overexpression was registered for tumor staging and lymph node status. Kaplan-Meier curves showed a significantly worse disease-related survival (p = 0.034) in patients with HER2-overexpressing tumors compared to those without HER2 overexpression. In addition to lymph node status (p = 0.0001; relative risk [RR] = 2.93), HER2 status (p = 0.020; RR = 2.22) was identified as an independent predictor for disease-related survival in a multivariate analysis. These results suggest that HER2 expression might provide additional prognostic information in patients with muscle-invasive bladder carcinomas. Because many of these patients harbor HER2-overexpressing tumors, clinical trials evaluating the efficacy of trastuzumab in bladder carcinoma are warranted.

Impact of p53 and Ki-67 in predicting recurrence and progression of superficial (pTa and pT1) urothelial cell carcinomas of urinary bladder

In predicting the aggressive behavior of bladder tumors, the histopathological characteristics of grade and invasive stage are of principal importance. However, for predicting tumor recurrence and progression, these are sufficient only to a limited extent, particularly in the case of superficial (pTa and pT1) urothelial cell carcinomas. New prognostic factors are therefore needed to avoid either insufficient or excessive treatment. In this retrospective study, we investigated the prognostic value of the p53 and Ki-67 immunoreactivity indices. The present study included 118 superficial urinary bladder tumors consisting of 58 recurrent and 60 non-recurrent cases. Twenty of the recurrent tumors progressed into a higher grade and/or invasive stage. Paraffin immunohistochemical analysis was carried out using anti-p53 and anti-Ki-67 antibodies on the initial tumor tissues. We concluded that there is a highly significant relationship between the p53 and Ki-67 immunoreactivities and the histological grade and pathological stage of the tumors (P < 0.0001). We observed a significant relationship between the presence of recurrence and progression and the p53 immunoreactivity index (P < 0.01 and P = 0.017, respectively) and Ki-67 immunoreactivity index (P < 0.0001 and P = 0.046, respectively). Positivity for p53 and Ki-67 can demonstrate the risk of recurrence (p53: sensitivity = 76%, specificity = 58%; Ki-67: sensitivity = 86%, specificity = 48%) and progression (p53: sensitivity = 80%, specificity = 46%; Ki-67: sensitivity = 85%, specificity = 36%; ). We believe that both of these immunohistochemical markers can be considered valuable in addition to classical histopathological prognostic parameters for predicting recurrence and progression risks.

Microarrays of bladder cancer tissue are highly representative of proliferation index and histological grade

The number of genes suggested to play a role in cancer biology is rapidly increasing. To be able to test a large number of molecular parameters in sufficiently large series of primary tumours, a tissue microarray (TMA) approach has been developed where samples from up to 1000 tumours can be simultaneously analysed on one glass slide. Because of the small size of the individual arrayed tissue samples (diameter 0.6 mm), the question arises of whether these specimens are representative of their donor tumours. To investigate how representative are the results obtained on TMAs, a set of 2317 bladder tumours that had been previously analysed for histological grade and Ki67 labelling index (LI) was used to construct four replica TMAs from different areas of each tumour. Clinical follow-up information was available from 1092 patients. The histological grade and the Ki67 LI were determined for every arrayed tumour sample (4x2317 analyses each). Despite discrepancies in individual cases, the grade and Ki67 information obtained on minute arrayed samples were highly similar to the data obtained on large sections (p<0.0001). Most importantly, every individual association between grade or Ki67 LI and tumour stage or prognosis (recurrence, progression, tumour-specific survival) that was observed in large section analysis could be fully reproduced on all four replica TMAs. These results show that intra-tumour heterogeneity does not significantly affect the ability to detect clinico-pathological correlations on TMAs, probably because of the large number of tumours that can be included in TMA studies. TMAs are a powerful tool for rapid identification of the biological or clinical significance of molecular alterations in bladder cancer and other tumour types.

Genetic alterations and biological pathways in human bladder cancer pathogenesis

Human bladder cancers are heterogeneous. For example, at first presentation papillary transitional cell carcinomas (TCCs) are typically superficial and often multifocal. Papillary TCCs frequently recur, but most never progress to invasive TCC. In contrast, bladder carcinoma in situ (CIS) usually presents as a solitary flat lesion and, if left untreated, invariably progresses to invasive TCC. Some TCC are already invasive at the time of presentation. Squamous cell carcinoma (SCC) tends to present at a later stage than most TCCs and has a relatively aggressive clinical course. Multiple genetic alterations have been identified in invasive human bladder cancers and are present in different combinations and in different frequencies in the different manifestations of bladder cancer described above. A high percentage ( approximately 67%) of superficial papillary TCCs show early losses involving chromosome 9q, while very few show either a TP53 or a CDKN2/16 mutation. Thus, loss of 9q may be the earliest event in initiation of papillary TCC. In contrast, bladder CIS and SCC show relatively low percentages of 9q loss. However, approximately 65% of bladder CIS contain a TP53 alteration and approximately 67% of bladder SCC contain a CDKN2/p16 alteration. Mutations in these two tumor suppressor genes have powerful implications for loss of genome stability and cell growth regulation, respectively, consistent with the aggressive phenotypes of these cancers. Thus, these data suggest a model of bladder cancer pathogenesis in which the predominant genetic alteration may be the "initiating event" in cancer pathogenesis and may play a role in determining the biological potential of the tumor.

p53 immunohistochemistry in bladder cancer. Combined analysis: a way to go?

Seven years after the initial reports of the potential prognostic value of p53 immunohistochemistry in bladder cancer, key questions remain unanswered. This is mainly due to conflicting results obtained through multiple retrospective trials mostly performed with small numbers of poorly defined patients. The aim of this article was to investigate the feasibility of a combined analysis of previously published data. Based on a MEDLINE search in 1997, papers reporting on the prognostic role of p53 alterations were identified and the respective groups were invited to participate. Twenty-six of 38 study centers approached contributed patient data sets according to the protocol requirements. Acceptance of the initiative was similar in Europe, North America, and Australasia. A total of 3,421 patients with bladder cancer from 25 centers are included in the further analysis. With regard to gender, age distribution, and tumor stage the patients contributed are comparable with a normal bladder cancer population. Considering tumor grade, G2 tumors appear to be over- represented while the amount of G1 tumors is smaller than expected. The reason for this is probably related to the low rate of p53 accumulation in G1 tumors. No significant differences between those groups initially approached and those that finally cooperated were noted. Therefore, it is concluded that a combined study is feasible, and the patient data collected are representative for the population presented in the published literature. The final analysis of the data is the subject of current investigation.

[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.

p53 mutations in bladder tumors inactivate the transactivation of the p21 and Bax genes, and have a predictive value for the clinical outcome after bacillus Calmette-Guerin therapy

PURPOSE

We analyze the relationship among p53 mutations, p21 and Bax activation as well as their clinical implication in clinical response to intravesical bacillus Calmette-Guerin (BCG) therapy in high grade bladder tumors.

MATERIALS AND METHODS

We analyzed a prospective series of 60 superficial bladder tumors using functional assays in yeast which test the transcriptional competence of p53 and can be used to identify p21 and Bax status. BCG instillations were given after initial tumor resection to 26 patients with a high risk of bladder invasive disease (pT1G3 tumors in 24 and carcinoma in situ in 2).

RESULTS

No p53 alteration was detected in cases of pTa tumors. In contrast, p53 mutations were detected in 16 of 24 patients (66%) with pT1 G3 tumors and in 2 with primary carcinoma in situ. These 18 mutant samples scored also mutant for transactivation of p21 and Bax reporter strain. In 26 bladder tumors treated with BCG instillations there was a statistical difference (p = 0.0075) in the response to BCG therapy between 18 tumors with and 8 without alterations using functional assays in yeast.

CONCLUSIONS

The p53 mutations, using functional assay in yeast, inactivate the transcription of p21 and Bax genes, and based on these preliminary results could have a useful predictive value for BCG therapy response in bladder cancer.

Cyclin D1 overexpression lacks prognostic significance in superficial urinary bladder cancer

The biological behaviour of urinary bladder neoplasms cannot be adequately predicted by histological criteria alone. Cyclin D1 is a cell-cycle regulating protein known to be overexpressed in a proportion of bladder carcinomas. To evaluate the prognostic significance of cyclin D1 expression and its relationship with tumour phenotype, 392 bladder carcinomas were analysed by immunohistochemistry. Clinical follow-up information was available in 337 patients with superficial bladder tumours (stages pTa/pT1). Cyclin D1 positivity was seen in 176 of 392 carcinomas. Cyclin D1 overexpression was strongly linked to papillary tumour growth, low stage, and low histological grade (p<0.005 each). Multivariate analysis showed that papillary tumour growth was the only parameter which was independently linked to cyclin D1 positivity. There was no significant difference in proliferative activity (Ki67 labelling index) between cyclin D1-negative and -positive tumours. Cyclin D1 positivity was not linked to the risk of recurrence or tumour progression, either in pTa or in pT1 carcinomas. It is concluded that cyclin D1 positivity distinguishes a large subgroup of papillary bladder tumours, but there is no evidence of prognostic significance for increased cyclin D1 expression.

Polyomavirus infection of renal allograft recipients: from latent infection to manifest disease

Polyomavirus (PV) exceptionally causes a morphologically manifest renal allograft infection. Five such cases were encountered in this study, and were followed between 40 and 330 d during persistent PV renal allograft infection. Transplant (Tx) control groups without PV graft infection were analyzed for comparison. Tissue and urine samples were evaluated by light microscopy, immunohistochemistry, electron microscopy, and PCR. The initial diagnosis of PV infection with the BK strain was made in biopsies 9+/-2 mo (mean +/- SD) post-Tx after prior rejection episodes and rescue therapy with tacrolimus. All subsequent biopsies showed persistent PV infection. Intranuclear viral inclusion bodies in epithelial cells along the entire nephron and the transitional cell layer were histologic hallmarks of infection. Affected tubular cells were enlarged and often necrotic. In two patients, small glomerular crescents were found. In 54% of biopsies, infection was associated with pronounced inflammation, which had features of cellular rejection. All patients were excreting PV-infected cells in the urine. PV infection was associated with 40% graft loss (2 of 5) and a serum creatinine of 484+/-326 micromol/L (mean +/- SD; 11 mo post-Tx). Tx control groups showed PV-infected cells in the urine in 5%. Control subjects had fewer rejection episodes (P<0.05) and stable graft function (P = 0.01). It is concluded that a manifest renal allograft infection with PV (BK strain) can persist in heavily immunosuppressed patients with recurrent rejection episodes. PV mainly affects tubular cells and causes necrosis, a major reason for functional deterioration. A biopsy is required for diagnosis. Urine cytology can serve as an adjunct diagnostic tool.

Can p53 nuclear over-expression, Bcl-2 accumulation and PCNA status be of prognostic significance in high-risk superficial and invasive bladder tumours?

AIMS

To evaluate p53 and Bcl-2 expression and proliferating status (PCNA) in subgroups of patients with high-risk superficial and invasive bladder cancer, with relation to cancer progression and death, and to correlate the results with established clinical prognostic factors.

METHODS

Paraffin-embedded sections from 42 high-risk superficial (T1G2,T1G3) and 33 invasive (T2-T4aG3 N0M0) tumours were investigated immunohistochemically for p53, Bcl-2 and PCNA. The median follow-up was 52 months.

RESULTS

In the cohort of superficial tumours, statistical analysis showed that p53 and PCNA positivity were significant prognostic factors (P-values: 0.008 and 0.006, respectively) for disease-specific death (DSD). When life expectancy was evaluated (log-rank test), p53(+) (P = 0.015) and PCNA(+) (P = 0.017) offered the most accurate prognosis compared to grade, tumour size and multiplicity. Bcl-2 status had no significant effect on patient survival. In the subset of muscle-invasive tumours we failed to demonstrate any important role of p53, Bcl-2 or PCNA positivity.

CONCLUSIONS

p53 and PCNA over-expression may offer valuable additional prognostic information in high-risk subgroups of superficial bladder tumours. From our results, Bcl-2 does not appear to contribute significantly to the prognosis of these patients. None of the studied markers offered prognostic information in muscle-invading disease.

Predictive value of molecular alterations for the prognosis of urothelial carcinoma

Accumulation of p53 and C-Myc overexpression are frequently found in advanced urothelial carcinomas. The prevalence and predictive value of both molecular alterations was investigated in 61 patients with superficial urothelial tumors. Distinct patterns of p53 accumulation and C-Myc overexpression were observed in superficial urothelial carcinoma of different stages. For instance, 67% of carcinomata in situ displayed accumulation of p53, but only 44% showed C-Myc overexpression, whereas in pT1 tumors the corresponding percentages were 25 and 75%. Similarly, while p53 accumulation was significantly (p = 0.02) associated with tumor grade, C-Myc overexpression did not correlate with grade. In multivariate analysis, p53 accumulation was found to be an independent predictor of tumor progression (p = 0.0096), whereas C-Myc overexpression did not correlate with the course of disease. Alterations in both markers together predicted neither tumor recurrence nor tumor progression better than p53 accumulation on its own. Sufficient expression of C-Myc may be a general requirement for proliferative competence in urothelial tumors, barring its use as a predictive marker. The predictive value of p53 accumulation for tumor progression was further underlined by the finding that in a distinct group of 52 patients with progressive urothelial carcinoma 73% of the recurrent tumors displayed p53 accumulation.

Prognostic factors in muscle-invasive bladder cancer treated with radiotherapy: an immunohistochemical study

OBJECTIVE

To determine the prognostic role of p53, Ki-67 and p21 for patients with muscle-invasive bladder cancer treated with curative intent by radiotherapy.

PATIENTS AND METHODS

The study included 131 patients (24 women and 107 men, median age 72 years, range 40-86) with transitional cell carcinoma (T2-T4) treated with external definitive pelvic radiotherapy between 1985 and 1994. Paraffin-embedded pretreatment biopsies from the patients were examined for the presence of p53, p21 and Ki-67, detected by immunohistochemistry, and related to tumour stage, grade and patient survival.

RESULTS

The expression of p53 protein correlated positively with the detection of Ki-67 (P < 0.05) but did not correlate with p21. None of the immunohistochemical variables (p53, p21 or Ki-67) correlated with T category and only Ki-67 correlated with histological grade. Patients with > 5% p21 expression tended to live longer than those with < 5% (P = 0.09). In a multivariate analysis, the T category (T2/T3 vs. T4), histological grade (2 vs. 3) and p21 expression (< or = 5% vs. > 5%) were independent prognostic factors for overall survival.

CONCLUSION

Further investigation is warranted in patients with muscle-invasive bladder cancer undergoing different types of treatment p21 seems to play an independent prognostic role in these patients, in addition to T category and grade.

Prognostic markers of intravesical bacillus Calmette-Guérin therapy for multiple, high-grade, stage T1 bladder cancers

BACKGROUND

Prediction of a response to intravesical bacillus Calmette-Guérin (BCG) therapy for bladder cancer is clinically important. We determined whether several molecular markers have prognostic value in intravesical BCG therapy for multiple, high-grade, stage T1 bladder cancers.

METHODS

The expressions of p53 (clone D07), bcl-2 (100-D5), cathepsin-D (C5), c-myc(9E11), c-erbB-2 (CB11) and Ki-67 (MM1) were determined by immunohistochemistry in paraffin-embedded tissues from 32 multiple, T1, grade II-III bladder cancer patients (15 BCG responders, 17 nonresponders) who had undergone a single course of BCG therapy (Pasteur strain, 5 x 10(8) CFU weekly for 6 weeks) after complete removal of the tumors. The association between the expression of these markers and the response to BCG was assessed by univariate and multivariate analyses.

RESULTS

There was no difference in patient and tumor characteristics between the 2 groups. Using multivariate analysis, the only useful marker was p53, with the overexpression of the p53 protein inversely related to the response to BCG therapy (P = 0.0182).

CONCLUSION

Our results suggest that the status of p53 expression offers significant clinical information and may be a useful tool in the selection of suitable candidates for BCG therapy in multiple, high-grade stage T1 bladder cancer patients.

Epidermal growth factor receptor expression is associated with rapid tumor cell proliferation in renal cell carcinoma

Epidermal growth factor receptor (EGF-r) expression and tumor cell proliferation rate have been proposed as potential prognostic parameters in renal cell carcinoma (RCC). In this study, immunohistochemical stains using antibodies to EGF-r and the cell proliferation marker Ki-67 (MIB-1) were used to study the relationship between EGF-r expression, tumor cell proliferation, and prognosis in 50 non-papillary RCC extending beyond the renal capsule (pT3). A high Ki-67 labeling index (LI) was associated with poor patient prognosis (P < .05). Thirty-eight cases (76%) expressed strong cell membrane immunoreactivity for EGF-r. There was a tendency toward a shortened survival for EGF-r-positive tumors (P = .08). Tumor growth fraction (Ki-67 LI) was significantly higher in EGF-r-positive tumors than in EGF-r-negative tumors (P < .05), suggesting that rapid tumor proliferation might be responsible for the poor prognosis associated with EGF-r-positive RCC.

p53 protein expression but not mdm-2 protein expression is associated with rapid tumor cell proliferation and prognosis in renal cell carcinoma

The clinical course of renal cell carcinoma (RCC) is highly variable. Overexpression of the p53 protein has been suggested as a possible prognostic parameter in RCC. Overexpression of the mdm-2 oncogene product has been shown to interact with the p53 function. To investigate the immunohistochemical overexpression of mdm-2 protein in comparison with that of p53 protein in RCC, 50 nonpapillary pT3 RCCs were immunostained for p53 protein (DO-7) and mdm-2 (IF2). Tumor growth fraction (Ki-67 labeling index; MIB-1) was determined by immunohistochemistry. p53 positivity was detected in 16% of tumors. mdm-2 overexpression was seen in 30% of RCCs. There was a significant association between p53 and mdm-2 immunostaining (P = 0.0006), suggesting that mdm-2 protein may contribute to p53 protein stabilization in RCC. p53 overexpression was associated with a high Ki-67 LI (P = 0.0002), suggesting that p53 overexpression is involved in growth control in RCC. Survival analysis showed that Ki-67 LI (P = 0.04) and p53 overexpression were associated with poor prognosis (P = 0.0021), whereas mdm-2 overexpression was not related to patient outcome (P = 0.73). A Cox regression analysis revealed tumor stage (P < 0.001) and p53 overexpression (P < 0.05) to be independent prognostic parameters. It is concluded that p53 but not mdm-2 may be of practical relevance in predicting patient prognosis in RCC.

Immunoreactivity of bcl-2, p53 and EGFr is associated with tumor stage, grade and cell proliferation in superficial bladder cancer. Finnbladder III Group

Immunoreactivity of bcl-2, p53, the epidermal growth factor (EGFr) and Ki-67 (MIB-1) proteins was assessed by immunohistochemistry in 185 patients with superficial bladder cancer (SBC) in order to evaluate their usefulness as indicators of tumor progression. Forty-one percent of the tumors were bcl-2 positive, 36% of them were positive for p53 (over 20% of nuclei), while 41% were positive for EGFr, and 30% of the tumors were MIB-1 positive (proliferation index > 15%). Immunoreactivity of all analyzed proteins was highly significantly related to tumor grade and stage. Tumors which were bcl-2, p53 or EGFr positive were also rapidly proliferative (MIB-1 score >15%). The obtained results suggest that all analyzed proteins may have prognostic significance in SBC. The prognostic value of the abnormal immunolabeling of the analyzed proteins will be established after an adequate follow-up period of this same cohort of patients.

Ki67 labelling index: an independent predictor of progression in prostate cancer treated by radical prostatectomy

The clinical course of prostate cancer is highly variable and cannot satisfactorily be predicted by histological criteria alone. Both tumour cell proliferation and neuroendocrine differentiation have been suggested as additional prognostic parameters, neuroendocrine differentiation being considered to enhance tumour cell proliferation. This study investigated the prognostic value of tumour cell proliferation [Ki67 labelling index (LI), MIB 1] and neuroendocrine differentiation and their relationship to each other. One hundred and thirty-seven paraffin-embedded radical prostatectomy specimens were examined. Neuroendocrine differentiation was found in 58 per cent of cases, but was not associated with pTN stage, Gleason score, Ki67 LI, or tumour progression. Ki67 LI was not significantly associated with pTN stage or with Gleason score. High grade (P = 0.0005), advanced local stage (P = 0.0004), positive lymph nodes (P = 0.02), and high Ki67 LI (P = 0.0203) were predictors of tumour progression if univariate analysis was performed, but Cox stepwise regression showed that only advanced local stage (P = 0.0025) and Ki67 LI (P = 0.0105) were independent predictors of tumour progression, the relative risk being 3.6 and 2.5, respectively. It is concluded that Ki67 is an important prognostic marker in prostate cancer with a potential for routine application.

Heterogeneity of chromosome 17 and erbB-2 gene copy number in primary and metastatic bladder cancer

To study the relationship of tumor genomic heterogeneity with bladder cancer phenotype and p53 gene alterations, 138 primary bladder tumors were examined by dual labeling fluorescence in situ hybridization (FISH) using probes for chromosome 17 centromere (p17H8) and p53 (17p13.1). The number of different aneusomic populations > 5% (and monosomic populations > 20%) of cells served as a marker for heterogeneity. Nuclear p53 overexpression and Ki67 labeling index (Ki67 LI) were determined by immunohistochemistry. The number of aneusomic populations was 0 in 53 tumors, 1 in 18, 2 in 47, 3 in 9, and > 3 in 11 tumors. Presence of aneusomy was associated with tumor grade and stage (P < 0.0001 each). Ki67 LI was low in disomic tumors (11.0 +/- 7.7), higher in tumors with 1-3 aneusomic populations (17.4 +/- 11.3), and highest in tumors with > 3 aneusomic populations (25.8 +/- 10.9; P = 0.02 for > 3 vs. 1-3 populations). Aneusomy and heterogeneity were associated with p53 alterations. Aneusomy was seen in 35% of tumors with neither p53 expression nor p53 deletion but in 97% of tumors with both p53 deletion and expression. Nine of 11 tumors with > 3 aneusomic populations exhibited both p53 deletion and overexpression. To study genomic heterogeneity in tumor progression, two recurrences and three metastases of a tumor with known erbB-2 amplification were examined for centromere 17 and erbB-2 copy number. A considerable heterogeneity in centromere 17 and erbB-2 gene copy number was found in both recurrences and metastases, indicating a marked genomic instability in these metastatic cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Chromosome-9 loss detected by fluorescence in situ hybridization in bladder cancer

A loss of chromosome-9 material is one of the most frequent genomic aberrations known in bladder cancer. In order to better understand the role of chromosome-9 losses in bladder cancer, 125 formalin-fixed and 37 unfixed bladder tumors were examined using fluorescence in situ hybridization (FISH). A repetitive probe for a pericentromeric region on 9q12 (pHUR98) was applied for chromosome-9 copy-number enumeration. Under-representation of chromosome 9 was found in 74 of 162 cases. There was no association between loss of chromosome 9 and increased grade or stage, papillary growth pattern, p53 protein expression, or tumor-cell proliferation (Ki-67). These data show that chromosome-9 loss is an early event in bladder-cancer development, occurring independently of p53 alterations. In order to determine the prevalence of large sub-regional chromosome-9 deletions, dual hybridizations with pHUR98 and cosmid probes for 9q34, 9q22, and 9p21 were performed. Partial deletion was detected in only 1 of 36 cases for 9q34 and in 1 of 24 cases for 9p21. Surprisingly, amplification of the interferon alpha locus on 9p21 was seen in 1 of 24 tumors. The finding of 9p amplification may indicate the site of an oncogene relevant for bladder cancer.