Abnormalities in p53 and DNA content in transitional cell carcinoma of the bladder

Accumulation of p53 protein in inverted transitional cell papilloma of the urinary bladder

Aims-To study the possible accumulation of p53 protein in inverted papilloma of the urinary bladder.Methods-Formalin fixed, paraffin wax embedded sections from 14 cases of inverted papilloma of the urinary bladder were studied retrospectively. Accumulation of p53 was detected by immunohistochemistry using a mouse monoclonal antibody directed against p53. p53 protein reactivity was scored as follows: 0 = 10%; 1 = 10% to <30%; 2 = 30% to <50%; and 3 = >50% of cells p53 positive.Results-The 14 sections were scored as follows: 3 in four cases; 2 in four cases; 1 in one case; and 0 in five cases. Overall, nine (64%) of the 14 cases were positive for p53 protein.Conclusions-The accumulation of p53 protein in inverted papilloma of the urinary bladder suggests that p53 may have has an important role in the neoplastic process of this tumour. However, the benign nature of inverted papillomas suggests that p53 protein accumulation is not related to tumour invasiveness and metastasis. p53 reactivity cannot be used as a marker of malignancy for urothelial neoplasia. Further studies are required to determine the role of p53 protein in the oncogenesis of urothelial neoplasms.

[Relationship between tumor recurrence and the expression of the p53 gene in primary superficial transitional carcinoma of the bladder]

Contribution of 60 patients with primary surface transitional cell tumours of the bladder where nuclear expression of p53 protein was prospectively studied and compared to known prognostic factors in an attempt to find out its role in the development of relapses. An statistically significant relationship was found between the protein expression and cytology, tumoral multifocality, stage, relapse development and tumoral progression. It can be concluded that expression of this protein can be of use as relapse predictor.

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.

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.

Grading of upper urinary tract transitional cell carcinoma by computed DNA content and p53 expression

OBJECTIVES

Transitional cell carcinomas of upper urinary tract (uttTCC) constitute 5% to 6% of all urothelial tumors. Ureteropyeloscopy has become the standard for clinical evaluation of uutTCC. Moreover, endoscopic treatments have been advocated as a conservative approach for low grade tumors or patients with intermediate grade tumors whose renal function is compromised. Therefore, grading has become the most predictive variable in defining therapeutic approach. In addition to morphologic evaluation, a series of biologic markers may be used to increase the accuracy of grading such as DNA analysis and p53 protein expression. In this study, we have evaluated these markers by means of cell image analysis with the SAMBA 400 system.

METHODS

Thirteen cases of uttTCC were studied with cytologic smear, cell block, and histologic confirmation. DNA analysis was performed on cytologic smear. Immunostaining was performed on cell blocks. A grade was assigned on the basis of DNA evaluation and p53 expression quantitation. These grades were combined for each case and compared with the initial cytologic grading and the final histologic grading.

RESULTS

Cytology alone diagnosed TCC in all but 1 case that was diagnosed atypical. Discrepancies were found in primary grading: cytologic grading concurred with histologic grading in 6 of the 13 cases.

CONCLUSIONS

These results, although in a limited but selected number of cases, show the potential of computerized evaluation of biologic markers as parameters for a more objective grading of tumors.

A comparison of different modes for the detection of p53 protein accumulation. A study of bladder cancer

The aim of the present study was to evaluate different techniques for the analysis of p53 protein accumulation in human bladder cancer. The accumulation was evaluated in 23 carcinomas by immunoblotting (IB), immunohistochemistry (IHC) and flow cytometry (FCM). The results revealed that six (26%), eight (35%) and ten (43%) of the tumours were p53 protein positive by IB, IHC and FCM, respectively. Mutation analysis of the TP53 gene confirmed mutations in 8 of 9 tumours which showed increased levels of p53 protein by FCM. Our results indicate that IHC could be applied for studies of p53 protein accumulation in archival formalin fixed, paraffin-embedded bladder tumours. However, FCM is a more sensitive and objective method for the detection of p53 protein than IHC and this should be taken into account when routinely evaluating the p53 protein accumulation by IHC.

Use of p53 in the diagnosis of upper-tract transitional cell carcinoma

OBJECTIVES

To assess the usefulness of p53 staining of cytology specimens obtained ureteroscopically in the diagnosis of upper-tract transitional cell carcinoma (TCC).

METHODS

We collected specimens from 43 patients undergoing a total of 50 ureteroscopic procedures for a variety of indications, including the diagnosis of TCC. Specimens were obtained by direct biopsy with forceps or basket whenever possible. We examined specimens for evidence of TCC by cytospin as well as cell block for any visible fragments. Each specimen was then stained for overexpression of p53 by immunohistochemical staining, and the degree of staining was graded. Eight patients subsequently underwent nephroureterectomy; the pathologic specimens were stained for p53 and compared with the cytology results.

RESULTS

Staining for p53 was positive in specimens from 36 of 50 procedures, including all 28 with ureteroscopic or cytologic evidence of TCC (P < 0.0001). By contrast, cytology accurately diagnosed only 23 of the 28. Specimens from all 14 procedures that were negative also stained negative for p53. Specimens from all 8 procedures with no tumor seen and atypical cytology stained positive for p53; 4 of 5 patients with adequate follow-up have had a tissue diagnosis of TCC at that site. Overall, 35 of the 36 specimens that stained positive for p53 were obtained from patients with some history of TCC (P < 0.0001). No significant association could be found between degree of staining and grade (P = 0.3034). The degree of staining of ureteroscopic biopsy specimens was identical to that of the nephroureterectomy specimen in 6 of 8 cases.

CONCLUSIONS

p53 nuclear protein staining of cytology specimens obtained ureteroscopically appears to correlate well with the presence of upper-tract urinary TCC. Further study is needed to determine if it can provide a definitive diagnosis in cases with indeterminate cytologic findings.

Correlation of nuclear p53 over-expression with clinical and histopathological features of transitional cell bladder cancer

Forty-four pathologic specimens of 39 bladder cancer patients were analyzed immunohistochemically with D07 monoclonal antibody to detect over-expression of mutant p53 gene. The findings were interpreted by correlating with patient age, sex, cigarette smoking, number and macroscopic appearance of tumour, histological tumour grade, muscular invasion, vascular invasion, necrosis and urothelial atypia or dysplasia. Mutant p53 gene was over-expressed in 8 (18.2%) specimens. Statistically significant correlation with grade, vascular invasion, necrosis and patient sex was found with p53 over-expression. Available follow-up data were insufficient to draw a conclusion about the prognostic role of p53 over-expression. Prospective studies with larger number of patients are needed to define the exact place of nuclear p53 over-expression in transitional cell bladder cancer.

P53 and ploidy assessed by flow cytometry in bladder washings

OBJECTIVE

To determine p53 expression in cells in bladder washings and to relate this to DNA content and clinical outcome.

PATIENTS AND METHODS

Washings from 102 patients (41 with newly diagnosed superficial tumours [pTa and pT1], 49 with recurrent superficial tumours and 12 with carcinoma invading bladder muscle) were studied. In 39 cases, the primary bladder tumour was also analysed. The rates of tumour recurrence and progression were determined for the new superficial tumours and related to both p53 expression and DNA content.

RESULTS

Cells positive for p53 were detected in 22 of 90 (24%) washings from patients with superficial bladder cancer. P53 expression correlated with tumour stage (P < 0.05), grade (P < 0.05) and abnormal DNA content (P < 0.05). The analysis of pure urothelial (cyto-keratin-positive) cells improved the detection of DNA abnormalities (P < 0.001). In 74% of cases where both washings and tumour were analysed, the results for DNA content agreed. Of 41 new superficial tumours, 27 (66%) recurred (11 were p53-positive, 16 were p53-negative, P = 0.221; 17 had abnormal DNA content, 10 were diploid, P = 0.069). Four patients progressed (one was p53-positive, P = 0.315 and all had abnormal DNA content, P = 0.072).

CONCLUSION

P53-positive cells can be detected in washings using flow cytometry and were more commonly detected in association with aneuploid tumours. At short-term follow-up, flow cytometric analysis of DNA content in washings had greater predictive value than had p53 expression. Few washings contained aneuploid cells when the primary tumour contained diploid cells, although the collection of washings is a convenient way of sampling tumour cells.

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.