Cell cycling in bladder carcinoma determined by monoclonal antibody Ki67

Prediction of neo-adjuvant chemotherapy response in bladder cancer: the impact of clinical parameters and routine biomarkers

PURPOSE

To investigate the role of clinical parameters and immunohistochemical (IHC) biomarkers in their feasibility to predict the effect of neo-adjuvant chemotherapy (NAC) in patients with muscle-invasive urothelial bladder cancer (MIBC).

MATERIALS AND METHODS

The first 76 consecutive patients with MIBC treated with NAC and radical cystectomy in two University hospitals in Finland between 2008 and 2013 were chosen for this study. After excluding patients with non-urothelial cancer, less than two cycles of chemotherapy, no tissue material for IHC analysis or non-muscle-invasive bladder cancer in re-review, 59 patients were included in the final analysis. A tissue microarray block was constructed from the transurethral resection samples and IHC stainings of Ki-67, p53, Her-2 and EGFR were made. The correlations between histological features in transurethral resection samples and immune-histochemical stainings were calculated. The associations of clinicopathological parameters and IHC stainings with NAC response were evaluated. Factors affecting survival were estimated.

RESULTS

The complete response rate after NAC was 44%. A higher number of chemotherapy cycles was associated with better response to neo-adjuvant chemotherapy. No response to neo-adjuvant chemotherapy and female gender was associated with decreased cancer-specific survival. The IHC stainings used failed to show an association with neo-adjuvant chemotherapy response and overall or cancer specific survival.

CONCLUSIONS

Patients who do not respond to neo-adjuvant chemotherapy do significantly worse than responders. This study could not find clinical tools to distinguish responders from non-responders. Further studies preferably with larger cohorts addressing this issue are warranted to improve the selection of patients for neo-adjuvant chemotherapy.

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.

Evaluation of hypoxia-inducible factor 1alpha overexpression as a predictor of tumour recurrence and progression in superficial urothelial bladder carcinoma

OBJECTIVES

To investigate the possible role of hypoxia-inducible factor 1alpha (HIF-1alpha, a transcription factor important in regulating O(2) homeostasis and physiological responses to oxygen deprivation) in the recurrence and progression of superficial urothelial bladder cancer, and to examine its expression in relation to proliferation status, apoptotic activity and intratumoral angiogenesis.

PATIENTS AND METHODS

Paraffin wax-embedded tissue from 140 patients with superficial primary urothelial bladder carcinoma was immunostained for HIF-1alpha, Ki-67, single-stranded DNA antibody for apoptotic cells, p53, bcl-2, vascular endothelial growth factor and CD31 antigen. We calculated the proliferative rate, the apoptotic index and the microvessel density (MVD). The mean (sem) follow-up was 46 (3.5) months, within which 86 patients relapsed while 18 progressed to a higher tumour stage and/or grade.

RESULTS

HIF-1alpha expression was more common in high-grade superficial urothelial carcinomas. The positivity was related to increased proliferative activity (P = 0.012), apoptotic rate (P = 0.006) and MVD (P < 0.001). HIF-1alpha overexpression had a marginal adverse influence on progression-free survival (P = 0.058; univariate analysis), but when combined with p53 overexpression, the unfavourable impact was statistically important (P = 0.028). In multivariate analysis, only grade and the high Ki-67 labelling index were significant predictors of recurrence-free survival, while T-stage and the HIF-1alpha+/p53+ phenotype emerged as the only independent variables of adverse prognostic significance for time to progression.

CONCLUSIONS

HIF-1alpha overexpression combined with aberrant mutant p53 nuclear protein accumulation seem to indicate an aggressive phenotype, suggesting a potential biological model predictive of future risk of disease progression in patients with superficial urothelial bladder carcinoma. These indicators may be helpful in clinical practice to discriminate superficial bladder cancer worth a more intensive follow-up, or more aggressive treatment.

Improving and predicting radiosensitivity in muscle invasive bladder cancer

PURPOSE

Muscle invasive bladder cancer is a common urological malignancy with a relatively poor prognosis and 5-year survival rates ranging from 20% to 90%. We review methods of improving the outcome of this condition, with particular emphasis on the principal bladder preserving treatment modality of radiation therapy.

MATERIALS AND METHODS

We performed a literature search using MEDLINE and the ISI Web of Science using the keywords radiotherapy, radiosensitization and bladder neoplasia to ascertain the current status of radiation therapy and radiosensitizing agents in the treatment of muscle invasive bladder cancer.

RESULTS

Several methods aimed at improving outcome following radiation therapy for muscle invasive bladder cancer are described. These methods range from modifications in the application of radiation therapy to use of conventional radiosensitizing agents, such as accelerated radiotherapy with carbon dioxide, oxygen and nicotinamide, and finally to use of more novel agents that interact with oncogenic products. The use of assays that predict tumor sensitivity on an individual basis represents an additional potential method to improve prognosis following radiation therapy.

CONCLUSIONS

The ability to predict tumor radiosensitivity and the subsequent implementation of radiosensitizing techniques are likely to improve the results of treatment centered on radiation therapy, suggesting that bladder sparing approaches will remain a treatment option for muscle invasive bladder cancer.

Biologic differences between noninvasive papillary urothelial neoplasms of low malignant potential and low-grade (grade 1) papillary carcinomas of the bladder

We investigated the expression of oncogenes p53, c-erbB-2, and bcl-2 and cell proliferative activity in 62 newly diagnosed superficial pTa papillary bladder tumors. Based on the 1998 World Health Organization/International Society of Urological Pathology (WHO/ISUP) and 1999 WHO classifications, 19 were urothelial neoplasias of low malignant potential (LMP) and 43 low-grade (grade 1) papillary carcinomas. All the patients underwent transurethral resection and were followed up to 97 months; 42 had recurrences. Initial biopsies were tested for p53, c-erbB-2, and bcl-2 proteins using DO7, CB11, and bcl-2 124 monoclonal antibodies. Cell proliferation was assessed by MIB-1 mAb and mitotic count. LMP had significantly lower MIB-1 (p = 0.002) and p53 immunopositivity (p = 0.03), mitotic count (p = 0.006), and recurrence rates (p = 0.04) than did grade 1 cases, whereas no difference was observed for c-erbB-2 and bcl-2 expression. The median disease-free survival for LMP was 76 months but only 15 months for grade 1 cases (p = 0.002). Although the cohort is small, the results indicate that the distinction between LMP and low-grade (grade 1) papillary urothelial neoplasias, as proposed by the 1998 WHO/ISUP and 1999 WHO classifications, reflects different biologic activity and clinical behavior; however, a long-term follow-up is advisable also for patients with LMP.

Improved objectivity of grading of T(A,1) transitional cell carcinomas of the urinary bladder by quantitative nuclear and proliferation related features

AIM

To analyse whether the mean nuclear area of the 10 largest nuclei (MNA-10), the mitotic activity index (MAI), and Ki-67 immunoquantitative features have additional value to discriminate different grades of T(A,1) transitional cell carcinoma (TCC) of the urinary bladder.

MATERIALS/METHODS

One hundred and fifty of 200 consecutive cases (75%) showing interobserver agreement on duplicate blind grade assessment by independent pathologists were studied. Using random numbers, the 150 cases were divided into sets for learning (n = 75) and testing (n = 75). Single and multivariate analyses were applied to discriminate the different grades in the learning set. The multivariate classifier developed in this way was evaluated in the test set (n = 75).

RESULTS

With the MNA-10 alone, using the classification MNA-10 < 80 microm(2) = grade 1, 80 microm(2) < MNA-10 < 130 microm(2) = grade 2, MNA-10 > 130 microm(2) = grade 3, 71% of all 150 cases were correctly classified (69% of grade 1 v grade 2 and 76% of grade 2 v grade 3). With multivariate analysis, the best discriminating features in the learning set (17 grade 1, 30 grade 2, and 28 grade 3) between grades 1 and 2 were MNA-10 and MAI, and between grades 2 and 3 MAI and Ki-67. With these features, 94% of grade 1 v grade 2 and 97% of grade 2 v grade 3 were correctly classified in the learning set (overall, 95% correct, none of the grade 3 cases misclassified). In the test set the classification results were similar. When the three grades were entered at the same time for discrimination, Ki-67 area % and MAI was the best discriminating combination, both in the sets for learning and testing. Overall correct classification results in the sets for learning and testing were slightly lower, but still 94% and 92%. Most importantly, none of the grade 3 cases was misclassified; the classification shifts all occurred between grades 1 and 2.

CONCLUSIONS

The combination of MNA-10, MAI, and Ki-67 gives much better discrimination between grades 1, 2, and 3 in T(A,1) TCC of the urinary bladder than MNA-10 alone. The similarity of the classification results of the learning set and test set are encouraging and this quantitative pathological grading model should be applied in a prospective study.

Immunohistochemical analysis of Ki-67, p21waf1/cip1 and apoptosis in marker lesions from patients with superficial bladder tumours treated with vinorelbine intravesical therapy in a preliminary phase I trial

OBJECTIVE

To investigate Ki-67 and p21Waf1/Cip1 expression and apoptosis, before and after treatment, in tumour biopsies obtained from patients with superficial bladder cancer who underwent vinorelbine intravesical therapy.

PATIENTS AND METHODS

Twenty patients with high-risk superficial bladder cancer (including one or more of the following parameters: tumour diameter > 3 cm, histological grade 3, or multicentric tumours) were treated 1-6 times (weekly) with intravesical vinorelbine (50 mg/mL) instillations. Transurethral tumour marker biopsies were obtained one week before the first instillation of the drug and one week after the last. The biopsies were immunostained for Ki-67 and p21Waf1/Cip1 with monoclonal antibodies, on tissue sections derived from paraffin-embedded samples obtained before and after vinorelbine treatments. In addition, apoptosis was determined using a terminal deoxynucleotidyl transferase-mediated dUTP biotin nick-end labelling (TUNEL) technique.

RESULTS

There were no significant differences in the cell proliferation marker Ki-67 in biopsies taken before or after treatment. However, p21Waf1/Cip1 showed significantly higher expression in biopsies obtained after vinorelbine treatment, with median (range) values of 40 (20-90)% before and 70 (50-80)% after (P < 0.001, paired nonparametric Wilcoxon test). The apoptotic index was significantly higher after vinorelbine therapy, with median (range) values of 0.89 (0.06-3.8)% before and 2.25 (0.17-18.7)% after treatment (P < 0.001, paired nonparametric Wilcoxon test). Despite the brief treatment and few patients there was a clinical response in nine patients, together with low toxicity in all.

CONCLUSION

The intravesical treatment of tumours with vinorelbine affects p21Waf1/Cip1 expression without blocking cell proliferation, although increasing apoptosis. The preliminary results suggest that vinorelbine may be useful for treating superficial bladder tumours, and thus a phase II study is warranted.

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.

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.

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.

[Prognostic factors of infiltrating bladder tumors]

In France, invasive bladder cancer is the most frequent urologic malignancy after prostate carcinoma. The standard treatment of bladder cancer is radical cystectomy. New therapeutic approaches such as chemoradiation combination for a conservative procedure, neoadjuvant or adjuvant chemotherapy are still in development. In this prospect, a rigorous selection of patients is needed. This selection is based on prognostic criteria which could be divided into four groups: 1) the volume of the tumour including the tumour infiltration depth, the nodal status, the presence or not of hydronephrosis and the residual tumour burden after transuretral resection; 2) the histologic aspects including histologic grading, the presence or not of an epidermoid metaplasia, of in situ carcinoma or of thrombi; 3) the expression of circulating tumour cell biological markers; 4) the biologic characteristics of the tumour such as ploidy, presence of cytogenetic abnormalities, expression of Ki67, expression of oncogenes or tumour suppressor genes, expression of telomerase, expression of tumour antigens or growth factor receptors. This paper reviews the prognostic value of these different parameters.

Cell proliferation, bcl-2, c-myc, p53 and apoptosis as indicators of different aggressiveness in small lymphocytic lymphoma (SLL)

Cell proliferation activity, by MIB1 mAb, expression of bcl-2, c-myc and p53 gene proteins and apoptotic index (AI) were assessed in 54 cases of SLL and compared to the morphological subtypes of this disorder, defined by Lennert on the basis of amount and distribution of small and larger activated lymphocytes as diffuse, tumor-forming and pseudofollicular subtypes (DS, TFS, PFS). MIB1 scores showed significant differences between DS, PFS and TFS (5.5%, 16.61% and 24.14%, respectively; p < 0.0001). Worth noting, the MIB1 score did not differ significantly when comparing DS with the diffuse areas of PFS, or TFS with the pseudofollicles of PFS. The mean bcl-2 gene protein score was displayed to a high extent in all subtypes, but less extensively by larger activated lymphocytes that, conversely, expressed c-myc. MIB1 score correlated negatively with bcl-2 and positively with c-myc protein scores. These findings suggest that lymphocytes protected from apoptosis by bcl-2 would be exponed to cell activation and growth acceleration provided by c-myc. This condition would account for a different aggressiveness of morphologically activated subtypes, such as TFS and PFS with larger pseudofollicles. The survival analysis, performed in 23 cases, showed a trend of association of cell proliferation and c-myc expression with a more aggressive progression of the disease. Overexpression of p53 and apoptosis were found only in a minority of cases, unrelated to the subtypes. In conclusion, cell growth fraction, bcl-2 and c-myc assessment may be of help in predicting the aggressiveness of different subtypes of SLL. This approach should be most conveniently applied to PFS, which represents a continuum between DS and TFS, in order to distinguish, in this heterogeneous subtype, more indolent from more aggressive disorders.

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.

Correlation of morphometry, nucleolar organizer regions, proliferating cell nuclear antigen and Ki67 antigen expression with grading and staging in urinary bladder carcinomas

OBJECTIVE

To investigate the correlation of four different indicators of proliferation--mean nuclear area (MNA) morphometry, nucleolar organizer region (NOR) count, proliferating cell nuclear antigen (PCNA) and Ki67 antigen expression--in specimens of invasive and non-invasive urinary bladder carcinomas with the grading and staging of the tumour and to determine which indicator is most suitable for discriminating between non-invasive and invasive carcinomas.

MATERIALS AND METHODS

Biopsies of 58 urinary bladder carcinomas of different grade and stage (38 invasive, 20 non-invasive) and 11 carcinomata in situ were included in the study. Ten specimens of normal bladder mucosa served as controls. Analysis of indicators was performed on sequential serial paraffin sections of the same tissue, applying each test once to one of four serial sections.

RESULTS

In comparison to normal bladder mucosa the values of the four indicators were significantly greater (P < 0.001) in all carcinomata in situ and in carcinomas. Values also increased from grade 1 to grade 3 carcinomas, but indicator values were similar for carcinomata in situ and grade 2 carcinomas. All indicators correlated with each other and allowed a significant discrimination between grade 1 and 2 or grade 2 and 3 carcinomas. Non-invasive carcinomas (Ta) showed a significantly lower proliferative activity (P < 0.001) than invasive carcinomas but there were overlapping values within the invasive carcinomas (T1,T2 and T3/4).

CONCLUSIONS

MNA, NOR count, PCNA index and Ki67 index could be correlated with tumour grade, but not with stage, of transitional bladder carcinoma. Of the indicators studied the Ki67 antigen was the most useful in differentiating between invasive and non-invasive carcinomas. This could be of prognostic relevance, especially for the heterogeneous group of grade 2 carcinomas.

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.

Expression of retinoblastoma gene product and p53 protein in bladder carcinoma: correlation with Ki67 index

OBJECTIVES

To determine whether loss of the tumour suppressor gene retinoblastoma (Rb) and increased expression of the p53 protein were associated with increased tumour cell growth fraction.

PATIENTS AND METHODS

Tumours from 105 patients (72 men, 33 women; median age 69 years, range 35-89) with newly diagnosed primary transitional cell bladder carcinoma were studied. Tumour samples were taken by means of cystoscopic resection. Expression of the retinoblastoma (Rb) and p53 gene products was assessed immunohistochemically in 98 of the carcinomas. The proportion of cells expressing the Ki67 antigen (Ki67 index which is a measure of growth fraction) was determined in 64 cases.

RESULTS

p53 protein was detectable in 50% and Rb protein in 82% of the tumours. Staining for p53 and lack of staining for Rb protein were associated with muscle-invasive growth and high tumour grade (G3). The Ki67 index varied over a wide range (1-47%), but there were significant differences between mean indices for poorly differentiated (G3) and well or moderately differentiated (G1/G2) tumours, and between indices for muscle-invasive and the remaining tumours. The mean Ki67 indices for Rb-negative tumours and p53-positive tumours were approximately twice those for Rb-positive and p53-negative tumours. Only 10% of the tumours expressed high levels of p53 protein and failed to express Rb.

CONCLUSION

These observations are consistent with the hypothesis that loss of Rb and mutation and overexpression of p53 are associated with an increased tumour cell growth fraction and that such changes may play a role in the de-regulation of cell proliferation in transitional cell carcinoma of the bladder.

Cell proliferation indices, morphometry and DNA flow cytometry provide objective criteria for distinguishing low and high grade bladder carcinomas

Argyrophilic nucleolar organizer region (Ag-NOR) analysis, proliferating cell nuclear antigen (PC-NA/PC10) and MIB-1 immunohistochemistry, nuclear morphometry and DNA flow cytometry have been performed on formalin-fixed, paraffin-embedded biopsies from 50 patients with transitional cell carcinoma of the urinary bladder. The mean AgNOR count was 6.01 for the 17 grade 1 (G1), 7.59 for the 21 G2 and 13.33 for the 12 G3 carcinomas (p < 0.001). The mean PCNA score was 15.03% for G1, 24.04% for G2 and 40.01% for G3 cases (p < 0.001). The mean MIB-1 score was 11.31% for G1, 17.09% for G2 and 34.47% for G3 carcinomas (p < 0.001). The mean nuclear area was 35.53 microns2 for G1, 38.65 microns2 for G2 and 83.62 microns2 for G3 cases (p < 0.001). Aneuploidy rates were significantly higher (91.7%) in G3 than in G2 (42.9%, p < 0.01) or G1 cases (47.1%, p < 0.05) but not different for G1 versus G2 cases (p = 0.94). While many overlaps of values were seen between G1 and G2 tumours, no overlaps were found between G3 and G1/G2 tumours. Significant differences of values were also found between pTa and invasive tumours (p < 0.0001 for AgNOR count and PCNA score; p < 0.001 for MIB-1 score and mean nuclear area; p < 0.01 for DNA ploidy); however many overlaps were seen. Our findings indicate that the quantitative parameters obtained with different methods are associated with histological grade of bladder urotheliomas and may improve the grading reproducibility. In addition, the absence of overlaps between G3 and G2/G1 carcinomas supports the tendency to classify bladder urotheliomas in only two categories of malignancy.

MIB-1, Ki67, and PCNA scores and DNA flow cytometry in intermediate grade malignant lymphomas

AIMS

To verify the correlation between MIB-1, Ki67, and proliferating cell nuclear antigen (PCNA-PC10) scores and S-phase fraction in intermediate grade non-Hodgkin's lymphomas (Working Formulation F); and their reliability in differently processed tissues.

METHODS

Forty one non-Hodgkin's lymphomas were classified as (F) intermediate grade malignant lymphomas according to the Working Formulation; mitotic counts and percentage of large cells were assessed for each case. Sections from formalin fixed, paraffin wax embedded tissues were stained with anti MIB-1 monoclonal antibody, after microwave oven processing, and anti-PCNA (PC10) monoclonal antibody using an avidin-biotin immunoperoxidase (ABC) method. One thousand cells from 10 representative fields were scored. Frozen sections from surgical specimens were stained with Ki67 monoclonal antibody using the ABC method; the fraction of Ki67 positive cells was calculated scoring 1000 cells. Flow cytometry analysis (FCM) was performed on cell suspensions from fresh tissues. Correlations between data were estimated using linear regression.

RESULTS

A linear correlation was found between MIB-1 and Ki67 scores (r = 0.92; p < 0.00001); between MIB-1 and PCNA scores (r = 0.79; p < 0.00001); and between MIB-1 score and S-phase fraction (r = 0.51; p = 0.0006). A linear correlation was also found between Ki67 and PCNA scores (r = 0.85; p < 0.00001); between Ki67 score and S-phase fraction (r = 0.6; p = 0.0002); and between PCNA score and S-phase fraction (r = 0.74; p < 0.00001). A correlation was found between mitotic counts and MIB-1 (r = 0.56; p = 0.0001), PCNA (r = 0.51; p = 0.0007), or Ki67 scores (r = 0.47; p = 0.002); between the percentage of large cells and MIB-1 (r = 0.49; p = 0.0009), PCNA (r = 0.6; p = 0.00003), and Ki67 scores (r = 0.53; p = 0.0003) and S-phase fraction (r = 0.55; p = 0.0002).

CONCLUSION

MIB-1, Ki67, and PCNA (PC10) scores and S-phase fraction are highly correlated and equally well represent the proliferative activity of intermediate grade non-Hodgkin's lymphomas in differently processed material. MIB-1 and PCNA stains can be applied even on small biopsy specimens. MIB-1 produces homogenous staining without background; it also strongly stains mitotic figures. It can be performed on routinely processed tissues, permitting the simultaneous evaluation of the morphology and tumour cell kinetics. The wide standard deviations of the proliferative indices found for intermediate grade NHL suggest that this category probably includes various degrees of malignancy.

Growth fractions in bladder cancer defined by Ki67: association with cancer grade, category and recurrence rate of superficial lesions

Predicting future tumour behaviour has always been a major task when treating bladder cancer. Ki67 monoclonal antibody has been reported to be a good marker of proliferative activity in a variety of tumours. We have studied the association of growth fractions defined by the monoclonal antibody with tumour grade, category and recurrence rate of superficial lesions in 34 patients with bladder cancer and 15 normal controls. Mean Ki67 indexes (% stained cells) were 0.07 +/- 0.02% in normal urothelium, 1.27 +/- 1.55% in grade 1, 12.23 +/- 8.32% in grade 2 and 16.42 +/- 11.82% in grade 3 tumours, while the values were 5.45 +/- 5.87%, 12.66 +/- 9.81% and 17.18 +/- 12.41% in categories pTa, pT1 and T2-T3 respectively. Recurrence and non-recurrence groups of patients showed indexes of 13.29 +/- 9.49% and 4.15 +/- 5.0% respectively. Statistically significant differences in Ki67 values between normal urothelium and tumour, between tumours of different grades and categories as well as between recurrence and non-recurrence groups of patients led to the conclusion that Ki67 monoclonal antibody is a good tool in defining tumour behaviour in bladder cancer.

Proliferative activity of normal and neoplastic urothelium and its relation to epidermal growth factor and transferrin receptors

AIMS

To investigate the proliferative activity (given by the Ki67 index) of the normal, atypical, and neoplastic urothelium and its relation to the cellular reactivity for the epidermal growth factor (EGFr) and transferrin (Tfr) receptors.

METHODS

The Ki67 index and the level of EGFr and Tfr reactivity were determined on frozen sections from 82 patients with urothelial cancer. Relevant clinical material was reviewed to establish correlations with the degree of atypia and invasion.

RESULTS

Morphologically normal urothelium, whether derived from controls or patients with cancer, exhibited a low Ki67 index (less than 0.1%) and weak receptor reactivity. In transitional cell carcinomas (TCCs) the Ki67 index was increased: it ranged between 0.7% and 10% in non-invasive and exceeded 10% in 88% of the invasive TCCs. Strong positive reactions for EGFr were seen only in invasive TCCs, but in 47% of invasive TCCs the EGFr was not "overexpressed" and did not match the Ki67 index. A better correlation was found between the Ki67 index and the Tfr which was positive in 26% of the non-invasive and in 71% of the invasive tumours. All three variables were increased in severe atypia but varied considerably in lesser degrees of atypia.

CONCLUSIONS

Despite the absence of a close correlation, accelerated growth and enhanced receptor expression were characteristic of invasive cancers. These results suggest that the growth rate in TCCs is not causally related to overexpression of growth factor receptors but that the latter is an abnormality which may accompany the malignant phenotype.

Proliferative state of the urothelium with benign and atypical changes. Correlation with transferrin and epidermal growth factor receptors and blood group antigens

We attempted to investigate how the proliferative state of the urothelium correlates with the reactivity for transferrin (Tf) and epidermal grown factor (EGF) receptors and the blood group (BG) antigen. We examined morphologically normal urothelium (34 cases), benign inflammatory and reactive conditions (24 cases), and atypical changes (20 cases) without exophytic or invasive neoplasia. The Ki67 nuclear antigen was used as the proliferation index and was complemented with the in vitro BrdU incorporation assay in 32 cases. The immunohistochemical reactions for Tf and EGF receptors and for the appropriate BG antigen were scored semi-quantitatively on frozen sections. We found that normal urothelium has very low Ki67 and BrdU indices as well as low reactivity for the two receptors and is almost invariably positive for the BG antigen. Benign conditions such as inflammation and metaplasia significantly augment the proliferation indices and the Tf receptor with little change in the EGF receptor and no significant effect on the BG antigen. Moderate atypia includes biologically heterogeneous cases which vary widely in proliferation and receptor expression. Severe atypia-carcinoma in situ is consistently associated with markedly elevated proliferation indices, strong Tf receptor reactivity, and depressed BG antigen. The reactivity for EGF receptor is less consistently increased. Cases with a combination of strong EGF receptor reactions and absence of the expected BG antigen have a poor prognosis with progression to invasive cancer.

Bromodeoxyuridine labelling of transitional cell carcinoma of the bladder--an index of recurrence?

Nineteen patients with newly diagnosed transitional cell carcinoma of the bladder consented to receive an intravenous bolus of bromodeoxyuridine (BrdUrd) 3 to 6 h prior to transurethral resection of bladder tumour. Routine paraffin embedded sections were stained with anti-BrdUrd monoclonal antibody in order to determine the S phase fraction of the bladder tumours and to correlate this with tumour grade, category and the development of recurrence during follow-up. BrdUrd labelling of nuclei was reliably detected in 100% of the tumours. The mean labelling index of Ta tumours (n = 8) was 3.14%; in T1 tumours (n = 7) it was 8.6% and in T2-3 tumours (n = 4) it was 16.4%. A similar correlation was found in association with tumour grade. The patients were followed up for a mean of 23 months (range 18-30). Seven of the 15 superficial tumours recurred during the period of follow-up. These tumours had a mean labelling index (at diagnosis) of 8.4%, whereas the tumours that did not recur had a mean labelling index of 3.4%. The in vivo determination of BrdUrd uptake in transitional cell carcinoma of the bladder may be useful in predicting which superficial tumours are likely to recur following resection and so rationalise both the time to follow-up and intravesical chemoprophylaxis.

Proliferative activity of urothelial neoplasms: comparison of BrdU incorporation, Ki67 expression, and nucleolar organiser regions

AIMS

To evaluate the proliferative activity of urothelial neoplasms, compare it with that of the normal urinary tract epithelium, and determine its relation to morphological grade and presence of invasion.

METHODS

Multiple biopsy specimens from 53 individuals--eight normal controls, five patients with severe urothelial atypia, and 40 with transitional cell carcinomas (TCCs)--were studied using in vitro bromodeoxyuridine (BrdU) incorporation, Ki67 antigen expression, and quantitation of the nucleolar organiser regions (NORs).

RESULTS

The percentage of nuclei labelled by BrdU (BrdU index) correlated well with the percentage of nuclei expressing the Ki67 antigen (Ki67 index). These proliferation indices were very low (less than 0.1% in 60% of samples) in the urothelium of normal controls and the morphologically unremarkable epithelium of patients with TCCs. Non-invasive TCCs had increased proliferation (BrdU index 6.32 (SD 0.8)%, Ki67 index 5.04 (0.6)% but lagged behind the invasive tumours (BrdU 20.9 (3.2)%, Ki67 18.6 (2.8)%). The average NOR count was 1.57 (0.03) in morphological normal epithelium, which increased progressively with grade in non-invasive TCCs, but varied greatly in invasive tumours and did not correlate with the proliferation indices. The spectrum of values for both proliferation indices and NORs was particularly wide in grade 2 TCCs. Severe atypias without exophytic growth had an increase in BrdU and Ki67 indices comparable with that found in grade 3-4 invasive TCCs; these also had the highest NORs per nucleus.

CONCLUSIONS

The growth potential of urothelial neoplasms is an important indicator of their aggressive course. In particular, growth indices over 10% are strongly associated with the presence of invasion. Papillary grade 2 TCCs show heterogeneity in their growth characteristics which may relate to their diverse clinical course. The mitotic count underestimates the growth potential of papillary TCCs and the addition of proliferation indices such as BrdU incorporation or the Ki67 index may enhance the prognostic accuracy of conventional morphological grading.

P53 and Ki-67 immunoreactivity in human prostate cancer and benign hyperplasia

Mutation of the p53 gene is one of the commonest genetic abnormalities found in solid human tumours. This gene is probably concerned with the control of cellular proliferation and in view of this we carried out a study of human prostate cancer and benign prostatic hyperplasia, comparing the expression of mutated p53 with measurement of growth fractions as assessed by staining with Ki-67. A series of 29 patients with prostate cancer (CaP) were compared with 34 men with benign hyperplasia (BPH); 22 of 29 prostate cancers (76%) contained Ki-67 immunoreactivity compared with 10 of 34 (29%) BPH. With respect to p53 staining, significantly more prostate cancers (17%) were stained than BPH (0%). The mean Ki-67 score in cancers positive for p53 (4.3%) was greater than that found in cancers negative for p53 (1.2%), but no statistically significant relationship was found between tumour grade and Ki-67 staining. The use of Ki-67 and p53 staining may allow identification of tumours with a higher rate of cell growth and may permit development of prognostic factors.