Prognostic factors in bladder carcinoma: histologic parameters and expression of a cell cycle-related nuclear antigen (Ki-67)

The role of p53, MDM2 and c-erb B-2 oncoproteins, epidermal growth factor receptor and proliferation markers in the prognosis of urinary bladder cancer

The immunohistological expression of p53 and MDM2 oncoproteins was examined in paraffin embedded tissue from 106 patients with transitional cell carcinoma of the urinary bladder and was related to various clinicopathological features, the expression of proliferation associated markers (proliferating cell nuclear antigen - PCNA - and Ki-67), c-erb B-2 oncoprotein and epidermal growth factor receptor (EGFR), as well as to survival. MDM2 immunoreactivity was seen in 38% of our cases, and in 14% was accompanied by p53 positive immunohistochemistry. The rate of p53 positivity was associated with grade, stage and papillary status, whereas MDM2 immunopositivity increased with grade and stage (Ta VS T1), and MDM2 labeling index (LI) with stage. MDM2 expression was related to p53 expression and less strongly to proliferation rate (Ki-67 LI). The simultaneous p53 and MDM2 expression was more frequently observed in higher grade and stage tumours. C-erb B-2, EGFR and proliferation marker expression increased with grade, stage and non-papillary configuration. In univariate analysis high grade, solid growth pattern, advanced T-category, cystectomy, EGFR and Ki-67 expression were linked to shorter overall survival but only Ki-67 LI, along with T-category and type of therapy, had independent prognostic value. C-erb B-2 expression and stage were the two independent predictors of disease-free survival and Ki-67 LI and EGFR LI the independent predictors of post-relapse survival. For patients with superficial tumors PCNA LI emerged as the single independent determinator of survival. p53 and MDM2 expression did not appear to have any significant impact on survival, although the simultaneous expression of p53 and MDM2 turned out to be a highly significant parameter of shortened overall survival in univariate analysis.

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

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

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

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

Immunohistochemical study on the prognostic value of MIB-1 in gastric carcinoma

The prognostic significance of tumour cell proliferation was investigated in a series of 418 gastric carcinomas using the monoclonal antibody MIB-1. Owing to strong intratumoural heterogeneity of MIB-1 expression three different proliferation indices (PIs) were determined in all carcinomas: (1) PImax in areas of maximal tumour cell proliferation, (2) PIrand in areas randomly distributed over the whole tumour. (3) PIfront in areas exclusively located at the tumour invasion front. There was a strong intertumoral heterogeneity with PImax ranging from 4.9% to 92.2%, PIrand ranging from 3.4% to 81.4% and PIfront ranging from 4.2% to 87.1%. The mean values were 51.3% +/- 19.7 for PImax, 34.2% +/- 18.3 for PIrand and 37.2% +/- 19.5 for PIfront. Whereas no statistically significant correlation could be found between proliferative activity and the clinicopathological parameters depth of invasion, lymph node involvement or grade of tumour differentiation, there was a positive correlation between a high proliferation index at the tumour invasion front (PIfront) and the presence of blood or lymphatic vessel invasion. No significant correlation could be demonstrated between the different proliferation indices and survival, even when different subgroups of patients were analysed separately. The present results suggest that the immunohistochemical evaluation of the proliferation activity has no predictive value for the prognosis of gastric cancer patients or the identification of subgroups of patients who may be at higher risk.

Prognostic significance of nuclear DNA content and S-phase fraction by flow cytometry in primary papillary superficial bladder cancer

This study is aimed at determining the usefulness of nuclear DNA content and S-phase fraction (SPF) to predict tumor recurrence in papillary superficial bladder cancer. Tumor DNA content and SPF were measured by flow cytometry on formalin-fixed, paraffin-embedded tissue from 199 newly diagnosed pTa/pT1 transitional cell carcinomas of patients enrolled into a multicenter prospective study from 1990 to 1992. The follow-up extended up to March 1994, and, at last follow-up, 122 (61.3%) patients have experienced at least one recurrence. After exclusion of 34 cases, whose coefficient of variation exceeded 8%, 131 (79.4%) tumors were diploid, and 34 (20.6%) were aneuploid. There was no association between tumor DNA content and time to first recurrence. Diploid tumors with low SPF (< 11%) tended to have a longer recurrence-free survival (RFS) than those with high SPF, but this difference did not reach statistical significance (P = .2833). SPF in aneuploid tumors did not add any new information. Aneuploidy was associated with higher stage (P < .001), poorer grade (P < .002), multifocality (P = .028), Her-2/neu (P = .021), and p53 (P = .033) expression. High SPF correlated with higher stage (P = .066) and higher grade (P = .025). This study shows that DNA-ploidy and SPF measured on a single superficial bladder cancer specimen are not predictive of tumor recurrence. The frequent multifocality of the disease may explain, in part, these findings.

The proliferation index of MIB-1 as a prognostic factor for patients with transitional cell carcinoma of the upper urinary tract

BACKGROUND

Recently, several reports have shown that immunohistochemical analysis using MIB-1 antibody, which recognizes Ki-67 (a human nuclear antigen expressed of proliferating cells), is a useful method for determining the proliferative activity of various cancers. In this study, the authors evaluated the prognostic usefulness of the proliferation index using MIB-1 antibody in transitional cell carcinoma of the upper urinary tract.

METHODS

Proliferation activity was investigated immunohistochemically using monoclonal antibody MIB-1 in formalin fixed, paraffin embedded tissues obtained from 67 specimens of renal pelvic and ureteral cancer. The MIB-1 proliferation index values were calculated from each sample as the percentage of positive nuclei expressed in tumor cells and the clinicopathologic correlation evaluated.

RESULTS

The MIB-1 proliferation index values were correlated with prognostic parameters such as pathologic stage ( < or = pT1 vs. > or = pT2, P < 0.0005), histologic grade (G1 vs. G2, P < 0.01; G1 vs. G3, P < 0.0001; G2 vs. G3, P < 0.001), and prognosis (P < 0.0001). When patients were subgrouped using index values, patients with higher indices ( > or = 24%) had significantly poorer survival (P < 0.0001). This was especially observed in the G2 group, in which 9 of 10 patients in the higher indices subgroup had a high incidence of recurrence and died. In contrast, only 2 of 29 patients in the lower indices subgroup died. The higher indices subgroup had significantly worse cause specific survival (P < 0.0001). Furthermore, with regard to the muscle invasive tumors ( > or = pT2), the higher indices subgroup also had significantly worse cause specific survival (P < 0.0001).

CONCLUSIONS

The results of the evaluation of prognostic parameters indicate that the MIB-1 proliferation index is a useful prognostic factor and may enhance the accuracy of conventional morphologic grading and pathologic staging systems.

Ki-67 index in fine needle aspiration cytology specimens from primary and recurrent rectal cancer

A Ki-67 index was determined in 63 fine needle aspiration cytology (FNAC) specimens from patients with rectal cancer, 21 with primary cancers and 42 with local recurrences. Seventeen of the patients had received external irradiation before the examination. In primary cancers, in recurrences as well as in the post-irradiation cases, the mean percentage of Ki-67 positive cells was about 55% with a wide variation. The percentage of Ki-67 positive cells was independent of the length of the recurrence-free period. In conclusion, the Ki-67 antigen may well be studied in FNAC specimens. The presence of antigen did not correlate with development of recurrence, length of recurrence-free period or irradiation prior to the analysis.

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)

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.

Expansion of the Ki-67 proliferative compartment correlates with degree of dysplasia in Barrett's esophagus

BACKGROUND

Barrett's esophagus is a histologically defined premalignant lesion of the esophagus in which normal squamous epithelium is replaced by intestinalized columnar epithelium. In a multistep progression from Barrett's esophagus to fully developed carcinoma, accelerated proliferation may indicate or precede genomic instability and, therefore, may be an important factor in the pathogenesis and/or prediction of malignant transformation. Ki-67 is a nuclear antigen expressed in proliferating cells, (G1, S, G2, and M phases) but not in resting cells (G0 phase). This study was undertaken to determine if Ki-67 expression correlates with the degree of dysplasia and if Ki-67 expression can help to differentiate those patients with or without dysplasia.

METHODS

The Ki-67 proliferation fraction in 87 paraffin embedded esophageal biopsies from 43 patients with the Ki-67 antibody (MIB-1) was analyzed using immunohistochemistry. Using a computerized proliferation index program (QNA v2.54, Becton Dickinson Cellular Imaging Systems, Inc., Elmhurst, IL), a Ki-67 score was derived for the luminal surface, upper esophageal crypt, lower crypt, and underlying glandular zone of the columnar-lined esophagus.

RESULTS

Significant differences in Ki-67 scores were noted in each zone among different histologic categories: normal gastric ([NG] n = 17); Barrett's without dysplasia ([ND] n = 17); low grade dysplasia ([LG] n = 21); high grade dysplasia ([HG] n = 14); and adenocarcinoma ([CA] n = 5). The pattern of Ki-67 expression was associated strongly with each histologic category. The percentage of Ki-67 positive nuclei in each mucosal zone statistically separated high grade from low grade dysplasia (P < 0.001). In high grade dysplastic tissues, the Ki-67 positive nuclei were found predominantly on the surface epithelium and upper crypt zones, whereas in low grade dysplasia, the majority of Ki-67 positive nuclei were found in the lower crypt zone. The number of Ki-67 positive nuclei in each mucosal component also was significantly different in Barrett's esophagus without dysplasia when compared with Barrett's esophagus with low grade dysplastic tissues. (P < 0.001) Staining patterns of indefinite for dysplasia by H & E staining separated into several distinct patterns (five LG, seven ND, one NG) whereas six biopsies with low grade dysplasia had a Ki-67 expression pattern more consistent with that of high grade dysplasia.

CONCLUSION

The Ki-67 staining pattern correlated with histologic findings in Barrett's esophagus and may represent an additional parameter for differentiating patients with or without dysplasia.

Immunohistochemical Analysis of the Cell Cycle-Associated Antigens Ki-67 and Retinoblastoma Protein in Parathyroid Carcinomas and Adenomas

The morphologic distinction between parathyroid carcinoma and adenoma can be a difficult diagnostic problem. We analyzed nuclear immunoreactivity for the cell cycle-associated antigen Ki-67 with monoclonal antibody (MAb) MIB-1 and for retinoblastoma (RB) protein with two polyclonal antisera in 24 parathyroid carcinomas and 35 adenomas, which were formalin fixed and paraffin embedded to determine if these antibodies could assist in distinguishing between carcinomas and adenomas. In addition, 10 cases of parathyroid hyperplasia and 5 cases of normal parathyroids were examined as control tissues. The Ki-67 labeling index was significantly higher in parathyroid carcinomas compared to adenomas (7.1 +/- 1.0% vs 2.4 +/- 0.2%, p <0.001). No patient with a parathyroid adenoma, parathyroid hyperplasia, or normal parathyroid gland had a Ki-67 labeling index >5.3%. Analysis of the primary tumors from patients with recurrent carcinomas and from those with nonrecurrent carcinomas showed a higher mean Ki-67 labeling index (7.8 +/- 1.5% vs 5.2 +/- 1.1%) in the former group. Although these differences were not statistically significant, the RB protein immunoreactivity was not useful in distinguishing between parathyroid carcinomas and adenomas in paraffin-tissue sections. These results indicate that nuclear immunoreactivity for the cell cycle-associated antigen Ki-67 may be another useful method to assist in distinguishing parathyroid carcinomas from adenomas.

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

Tumor proliferation in bladder cancer is associated with tumor behavior. To assess the association between Ki-67 labeling index (LI), p53, and c-erbB-2 overexpression, formalin-fixed tissue samples of 160 patients with transitional cell carcinoma (TCC) of the urinary bladder were studied by immunohistochemistry. Ki-67 LI was strongly associated with tumor stage (P < .0001), tumor grade (P < .0001), and p53 status (P = .0014) but not with erbB-2 overexpression (P > .2). Ki-67 LI was higher in p53-positive tumors (19%) than in p53-negative tumors (14%) when all stages were compared. Ki-67 LI was independent of p53 expression in pTa tumors (p53-positive, 9%; p53-negative, 11%), showing that p53 overexpression alone is not sufficient to induce rapid tumor cell proliferation in pTa tumors. Ki-67 LI also was independent of p53 expression in pT2 to pT4 tumors (p53-positive, 20%; p53-negative, 23%), indicating that p53 expression is not necessary for rapid tumor cell proliferation in advanced stages. However, there was a striking difference in Ki-67 LI between p53-positive pT1 tumors (22.0% +/- 8.8 standard deviation [SD]; n = 20) and p53-negative pT1 tumors (9.7 +/- 8.3 SD; n = 22; P = .0001). These results suggest that increased proliferation in p53-positive pT1 tumors is caused by additional alterations that occur during tumor progression.

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

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

Prognostic value of Ki-67 expression in 182 soft tissue sarcomas. Proliferation--a marker of metastasis?

Soft tissue sarcomas (STS) are characterized by deregulated proliferation. Ki-67 is a cell cycle antigen which may be elevated in proliferative states. We analysed Ki-67 expression in fixed and embedded tissues from STS in order to examine associations between proliferation, primary tumour characteristics, and metastasis. One hundred and eighty-two adult patients with trunk wall or extremity STS were treated at our institution between 1980 and 1992 (35 developed local recurrence and 56 developed metastases). Median follow-up time for survivors was 6 years (1-13). We used a semiquantitative score to the assess percentage of Ki-67-positive cells: < or = 10% (n = 86), > 10-25% (n = 57), > 25-50% (n = 30), > 50-75% (n = 7), > 75-100% (n = 2). Increasing Ki-67 expression correlated positively with tumour size, malignancy grade, necrosis, vascular invasion, S-phase fraction, and metastasis. A Ki-67 index Ki-D < or = 10% (n = 86) and > 10% (n = 96) defined two groups who had 84% and 56% 3-year metastasis-free survival (p = 0.0001), respectively. Tumours with Ki-D > 10 were typically large, high grade, necrotic, DNA aneuploid, and had intravascular invasion and a higher S-phase fraction. Ki-67 expression may be helpful in predicting survival of patients with soft tissue sarcomas.

Prognostic significance of cell proliferation in mucoepidermoid carcinomas of the salivary gland: clinicopathological study using MIB 1 antibody in paraffin sections

Mucoepidermoid carcinomas of salivary gland origin have an uncertain clinical course not directly predictable by histomorphology. The MIB 1 antibody, which detects Ki-67 antigen in formalin-fixed, paraffin-embedded tissues, was used to study cell proliferation in these tumors. An MIB 1 index was developed to express the percentage of MIB 1-positive proliferating cells, and the results were compared with histomorphological tumor grade and clinical outcome. All patients with MIB 1 indices lower than 10% in their primary tumors had a favorable clinical outcome. Most patients with MIB 1 indices higher than 10% developed a recurrent or metastasizing disease. All patients who died of their tumor or who had persistent tumor had MIB 1 indices higher than 10%. Thus, the MIB 1 index defines two virtually nonoverlapping forms of the disease, an indolent one and an aggressive one. Cell proliferation in mucoepidermoid carcinomas, assessed with the MIB 1 antibody, thus represents a significant prognostic factor for improving the accuracy of conventional histological grading.

Cell proliferation correlates with prognosis in acinic cell carcinomas of salivary gland origin. Immunohistochemical study of 30 cases using the MIB 1 antibody in formalin-fixed paraffin sections

Immunohistochemical staining with the MIB 1 antibody was used to assess cell proliferation in 30 cases of acinic cell carcinoma of salivary glands. Until now, no prognostic factors have been available for these rare tumours. The MIB 1 monoclonal antibody recognizes the Ki-67 antigen in formalin-fixed, paraffin-embedded tissues. A MIB 1 index was developed as a means of expressing the percentage of MIB 1-positive tumour cell nuclei, and the tumours were scored without prior information of clinical behaviour. The staining results were then compared with the clinical outcome of the patients. All eight patients who developed tumour recurrences had MIB 1 indices higher than 5 per cent. Tumour recurrences could be predicted even in cases of bland morphology and low mitotic rate. Three patients died of their recurrent tumours, and had MIB 1 indices of 56.2, 12.7, 7.8 per cent in their primary tumours. Five of seven patients with MIB 1 indices higher than 10 per cent had unfavourable outcomes. None of the 17 patients with MIB 1 indices lower than 5 per cent developed recurrences during follow-up periods up to 30 years. The present results indicate that MIB 1 staining appears to be a significant prognostic factor in acinic cell carcinomas of salivary gland origin.

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.

Pseudomalignant spindle cell proliferations of the urinary bladder

Twelve cases of polypoid, nonrecurrent, pseudomalignant spindle cell proliferations of the urinary bladder (eight women and four men) were analyzed. Two patients had a simultaneous urinary bladder carcinoma. The lesions were characterized by proliferating spindle- or strap-shaped cells, which on electron microscopic examination (performed in all 12 cases) revealed characteristics of fibroblasts and myofibroblasts. The cells showed immunoreactivity for vimentin in all cases, for alpha-smooth muscle-specific and muscle-specific actin in six cases, for cytokeratins in five cases, and for CD 34 in one case. No immunoreactivity was observed for desmin, myoglobin, epithelial membrane antigen, S-100 protein, endothelial cell antigen (H and Y), CD 68, or factor VIII RAG. Immunoreactivity for Ki-67 and proliferating cell nuclear antigen was detected in up to 30% of the spindle cell nuclei. The static cytometric DNA analysis revealed a diploid, or in two cases a hyperdiploid, stem cell line. An awareness of this type of spindle cell lesion and its immunophenotypic characteristics and diversity is of importance to avoid an erroneous diagnosis of spindle cell sarcoma (in particular leiomyosarcoma and embryonal rhabdomyosarcoma) or spindle cell carcinoma.

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.

Cell proliferation in breast tumours: analysis of histological parameters Ki67 and PCNA expression

Ki67 and Proliferating Cell Nuclear Antigen (PCNA) are antigens expressed in the nucleus during various phases of cell division, which can be detected immunohistochemically using monoclonal antibodies. Thirteen fibroadenomas and 39 carcinomas were examined for expression of Ki67 and PCNA. A staining index was calculated for each tumour as the percentage of positive cells in the areas of highest density. The mean index for both antibodies was significantly lower in fibroadenomas than in malignant tumours. A wide range of proliferation rates was seen in the malignant group; the mean Ki67 index of Grade I carcinomas was 9% +/- 4.4 (mean +/- SD), of Grade II 14.3 +/- 8.7 and of Grade III 26.2 +/- 15.7. These differences are statistically significant. In malignant tumours there was a good correlation between the mitotic count and the Ki67 index (r = 0.61, p < 0.005) but none between the mitotic count and PCNA index. There was a weak correlation between the Ki67 and the PCNA indices (r = 0.38 p < 0.005), but no correlation was found between either index and oestrogen receptor status, patient age or tumour size. Ki67 immunohistochemistry is a convenient method for assessing cell proliferation, applicable in most laboratories. The validity of measuring proliferation in this way has yet to be established but the wide variation of expression even within the conventional grading categories may help to discriminate prognostically distinct subgroups. Expression of PCNA appears to correlate poorly with Ki67 expression in breast tumours and not with mitotic count; therefore its usefulness as a marker of proliferative activity, on current evidence, appears to be limited.

Evaluation of Ki-67 monoclonal antibody as prognostic indicator for prostatic carcinoma

Prostate tissue containing either primary adenocarcinoma (45 patients) or benign hyperplasia (15 patients) was immunostained with the monoclonal antibody Ki-67, which recognises a human nuclear antigen expressed by human cycling cells. The percentage of cells staining positive was considered a measure of proliferation. This derived Ki-67 index was higher for carcinomas than for hyperplastic glands. Within the group of carcinomas, Ki-67 indices in patients with metastatic disease were significantly higher than in those without and there was a trend towards increasing Ki-67 indices with increasing Gleason grade. When patients with prostate cancer were prospectively followed up, the Ki-67 index did not predict either disease progression or hormone responsiveness. Ki-67 immunostaining may define a group of patients with prostate cancer of poor prognosis.

Comparison of five histopathologic methods to assess cellular proliferation in transitional cell carcinoma of the urinary bladder

Transitional cell carcinomas of the urinary bladder vary in their biologic potential, which may be correlated with the grade and stage of the tumor. Cellular proliferation may prove to be another measure of predicting tumor biologic potential. We have compared five different methods to assess proliferation in 26 tumors and correlated these results with tumor grade and stage. A portion of each tumor was incubated in vitro with bromodeoxyuridine (BrdUrd). For each tumor this was compared with at least three of the following four other markers of proliferation: mitotic count, silver-stained nucleolar organizer regions, immunohistochemical staining with Ki67, and proliferating cell nuclear antigen. Statistical correlations were seen between tumor grade and stage and these markers. There were strong correlations between the BrdUrd labeling index (LI) and both the Ki67 LI and proliferating cell nuclear antigen LI. The correlation between the BrdUrd LI and mitotic count was more tenuous; no significant correlation was found between BrdUrd LI and silver-stained nucleolar organizer region count. The correlation between these measurements of proliferation and tumor grade and stage was less strong. Our data suggest that cellular proliferation of transitional cell carcinomas can be reliably assessed with several different markers and that most of these markers can be correlated with tumor grade but not with stage.