Cell proliferation in prostatic carcinoma: comparative analysis of Ki-67, MIB-1 and PCNA

Effects of long-term cyclo-oxygenase 2 selective and acid inhibition on Barrett's oesophagus

BACKGROUND

There is an overexpression of cyclo-oxygenase 2 (COX-2) in Barrett's oesophagus (BO).

AIM

To determine the long-term effect of a COX-2 inhibitor on cellular mechanisms involved in BO.

METHODS

A randomized controlled trial was conducted in BO patients allocated to continue the usual proton pump inhibitor (PPI) alone treatment, or PPI combined with rofecoxib (25 mg/day) for 6 months. Cell proliferation index and COX-2 expression in BO glands was determined in biopsy specimens at baseline and after treatment. Cell apoptosis, cyclin D1, p53 and vascular endothelial growth factor (VEGF) expression was also explored in a subset of patients. Student-t test and the U-Mann-Whitney test were used for quantitative and ordinal variables.

RESULTS

Of 62 patients, 58 completed the study. A higher proportion of patients on rofecoxib + PPI exhibited a decrease in COX-2 expression compared to those treated with PPI alone, but cell proliferation index was not affected. Unlike PPI alone, rofecoxib + PPI was associated with an increase in the apoptotic cell index, a decrease in p53 cell staining and VEGF expression in mucosal vessels. No effect on low-grade dysplasia or cyclin D1 was observed.

CONCLUSIONS

The addition of rofecoxib to PPI therapy does not affect cell proliferation index in BO cells after 6 months of therapy, but does reduce COX-2 and VEGF expression and increases cell apoptosis.

Clinical validity of proliferating cell nuclear antigen as an objective marker for evaluating biologic features in patients with untreated prostate cancer

BACKGROUND

Although Gleason grading may be the most useful system for evaluating biological activity of untreated prostate cancer, lack of interobserver validity with Gleason scores (GS) is an unsolved issue. In this study, the proliferating cell nuclear antigen labeling index (PCNA LI) in untreated prostate cancer was investigated in order to clarify the usefulness of supplemental and objective markers for evaluating the biologic features of prostate cancer.

METHODS

Sixty cases of prostate cancer were randomly selected from the cancer registry in Gunma University Hospital for this study. PCNA LI were evaluated using paraffin-embedded biopsy cores taken at diagnosis. Correlation of PCNA LI with the Gleason grading system, clinical stage, serum prostate-specific antigen (PSA) levels and age were evaluated. Cumulative rates of freedom from cause-specific death were also evaluated stratified by various clinicopathologic features, including PCNA LI using Kaplan-Meier analysis.

RESULTS

Proliferating cell nuclear antigen labeling index was significantly higher in patients with PSA levels over 100 ng/mL, advanced clinical stage (>T4, N1 or M1 disease), higher Gleason grade or with a higher GS than in those with other clinicopathologic features. The 5-year cumulative rate of death from prostate cancer was significantly higher at 62% in patients with a PCNA LI of 20 or more than those with PCNA LI of less than 20, who accounted for 4%.

CONCLUSIONS

Proliferating cell nuclear antigen labeling index in combination with Gleason grading system may be of clinical value in evaluating biologic features and also in predicting cause specific survival of prostate cancer in an objective, reliable and reproducible manner.

Diagnostic utility of cell cycle and apoptosis regulatory proteins in verrucous squamous carcinoma

A major problem in the diagnosis of verrucous squamous cell carcinoma is the lack of readily reproducible objective criteria for distinguishing this malignant lesion from reactive epithelial hyperplasia. Both lesions are characterized by thickened (well-differentiated) squamous epithelium without cellular atypia and subjacent stroma densely infiltrated by lymphocytes and plasma cells. This study was carried out to evaluate the use of cell cycle and apoptosis-related regulatory proteins in the diagnosis of verrucous carcinoma. The study materials consisted of representative formalin-fixed and paraffin-embedded tissue blocks from 19 cases of verrucous carcinoma, 18 classic squamous cell carcinoma, and 14 squamous epithelial hyperplasia (acanthosis). The immunohistochemical expression of the following of cell cycle and apoptosis-related regulatory proteins was evaluated using avidin-biotin complex detection technique: p16, p21, p53, Ki67, and retinoblastoma gene product (RBGP) (also known as retinoblastoma protein [pRb]). Expression of Ki67 was detected only in the single basal layer of the epithelium in all 14 cases of acanthosis. In verrucous carcinoma, Ki67 was detected in basal and suprabasal cells in the lower third of the neoplastic epithelium in 19 of 19 cases (100%). In neoplastic squamous epithelium with frankly invasive squamous cell carcinoma, Ki67 was diffusely expressed throughout the entire thickness of the epithelium as well as in the underlying invasive tumor nests. The pattern of p53 expression was similar to that of Ki67 in all the experimental groups, with a Pearson correlation coefficient of 0.98. In addition, immunohistochemical expression of p53 in the hyperplastic squamous epithelium was very weak, in contrast to the more intense immunoreactivity observed in verrucous carcinoma and classic squamous cell carcinoma. There was an overlapping in the expression of p16, p21, and RGBP in all the experimental groups, being present in more than half the thickness of the epithelium in 50% to 100% cases in each study group. We therefore conclude that the pattern of Ki67 and p53 expression in verrucous carcinoma is readily reproducible and distinctly different from that observed in epithelial hyperplasia and that seen in invasive squamous cell carcinoma. Thus Ki67, and p53 immunostains are reliable adjuncts that may be helpful in resolving diagnostic problems associated with verrucous carcinoma.

Intratumor heterogeneity of biomarker expression in breast carcinomas

Small biopsy samples are used increasingly to assess the biomarker expression for prognostic information and for monitoring therapeutic responses prior to and during neoadjuvant therapy. The issue of intratumor heterogeneity of expression of biomarkers, however, has raised questions about the validity of the assessment of biomarker expression based on limited tissue samples. We examined immunohistochemically the expression of HER-2neu (p185erbB-2), epidermal growth factor receptor (EGFR), Bcl-2, p53, and proliferating cell nuclear antigen (PCNA) in 30 breast carcinomas using archived, paraffin embedded tissue and determined the extent of intratumor heterogeneity. Each section was divided into four randomly oriented discrete regions, each containing a portion of the infiltrating carcinoma. For each tumor, the entire lesion and four regions were analyzed for the expression of these markers. Scores of both membrane and cytoplasmic staining of HER-2neu and EGFR, scores of cytoplasmic staining of Bcl-2, and scores of nuclear staining of both p53 and PCNA were recorded. The intensity of staining and the proportion of immunostained cells were determined. A semiquantitative immunoscore was calculated by determining the sum of the products of the intensity and corresponding proportion of stained tumor cells. We analyzed both invasive (IDC) and in situ (DCIS) carcinomas. The Wilcoxon signed-rank test was used for paired comparisons between overall and regional immunoscores and between overall and regional percentages of stained cells. Spearman's correlation coefficients were used to assess the level of agreement of overall biomarker expression with each of the regions. Generalized linear models were used to assess overall and pair-wise differences in the absolute values of percent changes between overall and regional expression of biomarkers. For IDCs, there were no statistically significant differences in the expression of the biomarkers in terms of either the percentage of cells staining or the immunoscores when comparing the entire tumor with each region except for the lower EGFR expression of arbitrarily selected region 1 and lower p53 expression of region 1 compared to that of the entire tumor section. For DCIS, there were no statistically significant differences in the expression of the biomarkers between the entire tumor and each region except in PCNA of region 2 compared to that of entire tumor section. Positive correlation of immunoscores was observed between the entire tumor and each region as well as across all four regions for IDC. Similar observations were noted with DCIS except for HER-2neu and PCNA. No statistically significant differences were observed in the absolute values of percent changes of biomarker expression between overall and the four regions for both DCIS and IDC. Therefore, no significant intratumor heterogeneity in the expression of HER-2neu, Bcl-2, and PCNA was observed in IDC. Minor regional variations were observed for EGFR and p53 in IDC. Similarly, no significant regional variation in the expression of markers was observed in DCIS except for PCNA.

Primary human cells differ in their susceptibility to rAAV-2-mediated gene transfer and duration of reporter gene expression

The susceptibility of a variety of different primary tissues was examined to long-term transduction with recombinant adeno-associated virus type 2 (rAAV-2) and factors influencing the transduction efficiency. In contrast to others using cell lines and animal models, emphasis was placed on the use of primary human cells. Enhanced green fluorescent protein (EGFP) marker gene expression was examined using fluorescence-activated cell sorting analysis. The most effective target cells for rAAV-2-mediated gene transfer were bronchial epithelial, artery endothelial as well as smooth and skeletal muscle cells with mean transduction rates ranging from 34.3 to 81.6%. Lower transduction rates between 4.3 and 19.5% were found in chondrocytes, dermal papilla follicle epithelial cells and fibroblasts. No transduction was observed in melanocytes, granulocyte colony-stimulating factor (G-CSF)-mobilized CD34(+) cells or malignant CD19(+) cells from patients with chronic lymphocytic leukemia. A proportion of EGFP-expressing skeletal muscle and smooth muscle cells was maintained over a period of 6 weeks after transduction (42.7+/-5.4 and 67.1+/-0.9%, respectively). Interestingly, among hair follicle epithelial cells the proportion of transduced cells increased from 8+/-0.5 to 36+/-7.7% in the course of 6 weeks. In contrast, for endothelial cells, bronchial epithelial cells and fibroblasts, a rapid decline in the number of EGFP expressing cells were noted. An inverse relationship between the proportion of cells in G2/M phase of cell cycle and long-term gene expression was observed. All rAAV-2 susceptible primary cells expressed FGFR-1 and the alphaV integrin consistent with their role as co-receptors for AAV-2. In conclusion, AAV-2 is a suitable vector system for transduction and evaluation of functional effects of long-term gene expression in primary human muscle and hair follicle cells.

Prognostic factors in prostate cancer. College of American Pathologists Consensus Statement 1999

BACKGROUND

Under the auspices of the College of American Pathologists, a multidisciplinary group of clinicians, pathologists, and statisticians considered prognostic and predictive factors in prostate cancer and stratified them into categories reflecting the strength of published evidence and taking into account the expert opinions of the Prostate Working Group members.

MATERIALS AND METHODS

Factors were ranked according to the previous College of American Pathologists categorical rankings: category I, factors proven to be of prognostic importance and useful in clinical patient management; category II, factors that have been extensively studied biologically and clinically but whose importance remains to be validated in statistically robust studies; and category III, all other factors not sufficiently studied to demonstrate their prognostic value. Factors in categories I and II were considered with respect to variations in methods of analysis, interpretation of findings, reporting of data, and statistical evaluation. For each factor, detailed recommendations for improvement were made. Recommendations were based on the following aims: (1) increasing uniformity and completeness of pathologic evaluation of tumor specimens, (2) enhancing the quality of data collected pertaining to existing prognostic factors, and (3) improving patient care.

RESULTS AND CONCLUSIONS

Factors ranked in category I included preoperative serum prostate-specific antigen level, TNM stage grouping, histologic grade as Gleason score, and surgical margin status. Category II factors included tumor volume, histologic type, and DNA ploidy. Factors in category III included perineural invasion, neuroendocrine differentiation, microvessel density, nuclear roundness, chromatin texture, other karyometric factors, proliferation markers, prostate-specific antigen derivatives, and other factors (oncogenes, tumor suppressor genes, apoptosis genes, etc).

Predictability of PSA failure in prostate cancer by computerized cytometric assessment of tumoral cell proliferation

OBJECTIVES

To evaluate the relationship of DNA ploidy and cell proliferation (CP) with Gleason score (GS) and clinical outcome in prostate cancer.

METHODS

Sixteen patients with benign prostatic hyperplasia (BPH) and 65 patients with prostate cancer classified by GS (four groups: 2 to 4, 5 to 6, 7, and 8 to 10) were studied. All patients with carcinoma underwent prostatectomy and were separated into prostate-specific antigen (PSA) failure and nonfailure groups (failure if PSA 0.1 ng/mL or more three times after surgery). Tumoral CP (Ki-67 inmunostaining and SG2M phase) and DNA ploidy were evaluated by computerized cytometry.

RESULTS

BPH were diploid with low CP (8% SG2M cells or less). Carcinomas were either diploid with high CP (greater than 8% SG2M cells) or aneuploid. CP was significantly higher (P <0.001) in tumors with GS 7 or greater than in tumors with GS less than 7 (mean percent Ki-67 cells 18.3% versus 7.8%, respectively). PSA failure increased with GS (7.1% in GS 2 to 4, 21% in GS 5 to 6, 28.6% in GS 7, and 50% in GS 8 to 10), as well as with aneuploidy (18.5% in diploid tumors versus 72.7% in aneuploid tumors). Those experiencing PSA failure had significantly higher (P <0.001) CP than those not failing (mean percent Ki-67 cells 24% and mean percent SG2M 30.4% versus 8.7% and 13.5%, respectively). Cox regression analysis showed GS, DNA ploidy, Ki-67, and SG2M to each be univariately prognostic for time to PSA failure; however, Ki-67 and SG2M were more highly significant (P <0.0001 for both) than GS (P = 0.007) or DNA ploidy (P = 0.002). After adjusting for either SG2M or Ki-67 measures of CP, neither ploidy nor GS contained additional prognostic value.

CONCLUSIONS

Tumor CP and DNA ploidy can be reliably determined in prostate cancer by computerized cytometry. On the basis of our preliminary results, CP correlates well with GS and predicts PSA failure better than DNA ploidy or GS.

The prognostic significance of proliferation-associated nucleolar protein p120 expression in prostate adenocarcinoma: a comparison with cyclins A and B1, Ki-67, proliferating cell nuclear antigen, and p34cdc2

BACKGROUND

In this study, the authors evaluated the prognostic significance of the expression of nucleolar antigen p120, along with other cell proliferation-associated proteins, in prostate adenocarcinomas (PACs) and compared the results with previously reported data on p34cdc2 cyclin-dependent kinase (p34 cdk).

METHODS

Archival sections from 132 PACs were immunostained with monoclonal antibodies against p120, cyclin A, cyclin B1, Ki-67, and proliferating cell nuclear antigen (PCNA). The DNA content of each tumor was determined by the Feulgen method using image analysis. The immunohistochemistry (IHC) results were correlated with tumor grade, stage, margin positivity, metastasis, ploidy, and postsurgical disease recurrence.

RESULTS

The overall positivity for the various proteins follows: p120, 36%; cyclin A, 35%; cyclin B1, 43%; Ki-67, 46%; and PCNA, 32%. p120 correlated with grade (P = 0.004), stage (P = 0.01), ploidy (P = 0.02), margin positivity (P = 0.03), and metastasis (P = 0.004). Cyclin B1 correlated with ploidy (P = 0.04) and grade (P = 0.05), Ki-67 with grade (P = 0.02) and margins (P = 0.03), and PCNA with grade (P = 0.01). Significant coexpression among these proteins was noted, as was a significant association between the expression of these markers and that previously reported for p34 cdk. In univariate analysis, p120 (P = 0.01), cyclin A (P = 0.01) and p34 cdk (P = 0.002) correlated with disease recurrence. In multivariate analysis of all these proteins, only p34 cdk independently predicted postsurgical recurrence (P = 0.05).

CONCLUSIONS

Nucleolar antigen p120 expression appears to be an additional marker of aggressiveness in PACs. The significant coexpression of the various cell cycle regulatory proteins support their collective role in tumor cell proliferation, with p34 cdk positivity being an independent predictor of postsurgical recurrence.

Telomerase activity in gastrointestinal stromal tumors

BACKGROUND

Telomerase activity has been observed in 80-90% of carcinomas derived from various organs. However, to the authors' knowledge this report is the first assessment of telomerase activity in gastrointestinal stromal tumors (GISTs).

METHODS

Telomerase activity was analyzed by the telomerase repeat amplification protocol assay in 29 tumors from 26 patients (23 primary tumors from 22 patients, 1 pair of primary and metastatic tumors from 1 patient, and 4 metastatic tumors from 3 patients). Phenotypes, tumor cell proliferation, and overexpression of p53 protein were evaluated immunohistochemically.

RESULTS

Seven of 24 primary tumors (29%) and 5 of 5 metastatic tumors (100%) showed telomerase activity. Telomerase activity positive (+) GISTs were significantly larger (P < 0.05) and showed a significantly higher rate of proliferation than telomerase activity negative (-) tumors (P < 0.0001). All telomerase activity (+) GISTs were classified histologically as high risk tumors. Conversely, 15 of the 17 telomerase (-) GISTs were classified histologically as low risk tumors (P < 0.0001). With regard to p53 immunoreactivity, two and seven telomerase activity (+) tumors showed diffuse and sporadic positivity, respectively, whereas only five telomerase activity (-) tumors showed only focal or sporadic positivity. Telomerase activity was correlated significantly with poor prognosis (P < 0.05) in the patients in whom the primary GISTs were evaluated (n = 23).

CONCLUSIONS

Telomerase activity may be a useful marker for evaluating the malignant potential of GIST. A distinct subgroup of GISTs is a target for therapy with a telomerase inhibitor.

Tumor cell proliferation and survival in patients with prostate cancer followed expectantly

PURPOSE

Prostate cancers have different biological potentials, and aggressive tumors are difficult to identify when still localized. Tumor cell proliferation determined by MIB-1 expression has been suggested as an important predictor for outcome in several human cancers including the prostate. We test the possible prognostic value of tumor cellular proliferation in prostate cancer patients treated with no intent to cure.

MATERIALS AND METHODS

Formalin fixed, paraffin embedded tumor tissue obtained at the time of diagnosis from 221 patients originating from a well known complete Danish prostate cancer population was immunohistochemically investigated. The tumor cell proliferation rate was determined using the MIB-1 antibody. Tumors were clinically localized in 57% of the patients.

RESULTS

Tumor cell proliferation rate expressed by the MIB-1 score significantly correlated with tumor stage (p <0.001) and malignancy grade (p <0.001). The MIB-1 score, divided into low and high by the median value, showed significant association with disease specific survival in the entire study population (p <0.0001), as well as in the 125 patients suffering from clinically localized disease (p=0.018). Multivariate analyses showed that MIB-1 was a significant (p=0.0003) prognostic factor in the entire population, including advanced disease stages. However, in the theoretically curable clinically localized subpopulation MIB-1 was not significant (p=0.08) contrary to histopathological grade (p=0.02), erythrocyte sedimentation rate (p=0.02) and T classification (p=0.035).

CONCLUSIONS

Prostate tumor cell proliferation, expressed by MIB-1 immunoreactivity, demonstrated significant association with disease specific survival. However, MIB-1 is a close alternative to histopathological grade in describing the natural history of clinically localized prostate cancer. The additional prognostic value and the practical consequence of tumor cell proliferation remain to be clarified.

Significance of cell proliferation measurement in gastric cancer

Cell kinetic data may be important indicators of clinical behaviour in many types of cancer. Recently, several antibodies to cell-cycle associated antigens have been characterised. This overview summarises the advantages and disadvantages of different methods for the assessment of cell proliferation. Moreover, the prognostic value of proliferative activity in gastric cancer is discussed and suggestions for future research are given.

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

OBJECTIVE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

The prognostic significance of Ki-67 labeling indices for oligodendrogliomas

OBJECTIVE

The prognostic significance of quantitative measurement of tumor proliferative activity was evaluated for oligodendroglial tumors.

METHODS

Ki-67/MIB-1 immunochemistry was used to measure proliferative activity in 81 oligodendrogliomas and oligoastrocytomas. The relationship among survival, proliferation, histological features, and clinical variables were evaluated using a Cox proportional hazards analysis.

RESULTS

After stratifying by histological grade and adjusting for age at diagnosis, there was a significant association between the Ki-67/MIB-1 labeling index (LI) (percentage of positive cells) and survival (P = 0.04). This association was illustrated further by the significantly different survival of two groups based on LI ranges of less than or equal to 5 and greater than 5 (P < 0.0001).

CONCLUSION

The poor correlation between mitotic figures and survival in oligodendrogliomas that has been reported previously emphasizes the need for an accurate method to measure proliferative activity. Our study demonstrated the usefulness of the Ki-67/MIB-1 LI and demonstrated that LI ranges can be defined for clinical application.

Cell proliferation indexes: a biomarker in solid tumors

Clinical studies have shown that carcinogenesis is linked to the development of proliferative abnormalities. Proliferative activity has been found to have prognostic significance in a variety of human tumors. Because proliferative abnormalities can precede the occurrence of morphological abnormalities, their measurement could also serve as useful biomarkers for chemoprevention trials. The variety of techniques for measuring cell proliferation in routine sections include mitosis counting, AgNORs, DNA precursor uptake (bromodeoxyuridine), and immunohistochemical detection of cell cycle proteins (PCNA, Ki-67/MIB-1). It is essential that the virtues and limitations of these methods be examined to ensure collection of meaningful clinical data.

Proliferation and hypoxia in human squamous cell carcinoma of the cervix: first report of combined immunohistochemical assays

PURPOSE

To characterize the distribution of hypoxia and proliferation in human squamous cell carcinoma of the cervix via an immunohistochemical approach prior to initiation of therapy.

METHODS AND MATERIALS

Patients with primary squamous cell carcinoma of the cervix uteri received a single infusion of the 2-nitroimidazole, pimonidazole (0.5 g/m2 i.v.), and 24 h later punch biopsies of the primary tumor were taken. Tissue was formalin fixed, paraffin embedded, and sectioned for immunohistochemistry. Hypoxia was detected by monoclonal antibody binding to adducts of reductively activated pimonidazole in malignant cells. Staining for endogenous MIB-1 and PCNA was detected in tumor cells via commercially available monoclonal antibodies. Point counting was used to quantitate the fraction of tumor cells immunostained for MIB-1, PCNA, and hypoxia marker binding.

RESULTS

Immunostaining for pimonidazole binding was distant from blood vessels. There was no staining in necrotic regions, and only minimal nonspecific staining, mostly in keratin. In general, cells immunostaining for MIB-1 and PCNA did not immunostain for pimonidazole binding. Cells immunostaining for MIB-1 and PCNA showed no obvious geographic predilection such as proximity to vasculature. Quantitative comparison showed an inverse relationship between hypoxia marker binding and proliferation.

CONCLUSIONS

Immunohistochemical staining for pimonidazole binding is consistent with the presence of hypoxic cells in human tumors and may be useful for estimating tumor hypoxia prior to radiation therapy. Immunostaining for pimonidazole binding is an ideal complement to immunohistochemical assays for endogenous proliferation markers allowing for comparisons of tumor hypoxia with other physiological parameters. These parameters might be used to select patients for radiation protocols specifically designed to offset the negative impact of hypoxia and/or proliferation on therapy. The inverse relationship between pimonidazole binding and proliferation markers is a preliminary result requiring verification.

Immunohistochemical analysis of proliferating cell nuclear antigen, p53 protein and nm23 protein, and nuclear DNA content in transitional cell carcinoma of the bladder

BACKGROUND

Transitional cell carcinoma (TCC) of the bladder displays an unpredictable biologic behavior and the morphologic methods of grading tumor malignancy are often insufficient to predict the clinical outcome of patients with TCC of the bladder. Thus, the new indicator should reliably reflect prognosis. In this study, the authors determined the prognostic significance of proliferating cell nuclear antigen (PCNA), p53 protein, and nm23 protein, as well as nuclear DNA content in specimens with TCC of the bladder.

METHODS

Paraffin embedded materials taken from 77 patients with nonmetastatic untreated TCC of the bladder (classified as pTa-3b, NO, MO) treated with total cystectomy were employed in this study. PCNA expression, p53 protein and nm23 protein immunoreactivities, and the parameters for nuclear DNA content such as 2c deviation index (2cDI) and 5c exceeding rate (5cER) were evaluated using a computer-assisted image analyzer, and the results were compared with histologic findings and clinical outcome.

RESULTS

PCNA expression positively correlated with p53 protein and nm23 protein immunoreactivities, 2cDI value, and 5cER. In addition, histologic grade positively correlated with all of these five parameters. Similarly, pT category and disease progression positively correlated with all of the five parameters, except for nm23 protein immunoreactivity. In tumors with high genetic instability as judged by 2cDI and 5cER, both PCNA expression and p53 protein immunoreactivity were elevated, whereas nm23 protein immunoreactivity was not. However, the percent coefficient of variation in PCNA expression was smaller than that observed in p53 protein immunoreactivity in each group of genetic instabilities. In univariate analysis, prognostic potential was found with histologic grade, pT category, PCNA expression, p53 protein immunoreactivity, 2cDI value, and 5cER, but was not noted in nm23 protein immunoreactivity. Multivariate analysis indicated that quantity and intensity of PCNA expression (chi 2 = 8; P = 0.0047 for quantity and chi 2 = 8.71; P = 0.0032 for intensity) and 2cDI value (chi 2 = 5.52; P = 0.0019) were independent variables of histologic grade and pT category when predicting survival. However, p53 protein and nm23 protein immunoreactivities and 5cER were not of independent significance.

CONCLUSIONS

The tumor growth fraction as assessed by PCNA immunostaining is an independently significant predictor for survival of patients with TCC of the bladder.

Ki-67 expression in early prostate cancer and associated pathological lesions

AIM

To assess cell proliferation in early prostate cancer and associated pathological lesions.

METHODS

Using the Ki-67 antibody, the cell proliferation index was measured in early stage prostatic carcinoma in 37 incidental tumours diagnosed at transurethral prostatectomy (TURP) and in 20 low volume cancers treated by radical prostatectomy. Proliferation indexes have also been measured in areas of normal peripheral zone, transition zone hyperplasia, atrophic appearing lobules, and high grade prostatic intraepithelial neoplasia in the radical prostatectomy cases.

RESULTS

In the TURP series the proliferation index correlated with grade and stage. Logistic regression analysis, however, showed that Gleason grade was the most reliable predictor of biopsy proven residual disease and clinical progression. In the radical series transition zone carcinoma the proliferation index was half that of peripheral zone carcinoma. The atrophic lobules also showed a high proliferation index of the same order as seen in the peripheral zone carcinoma. Normal peripheral zone showed the lowest proliferation index and in hyperplastic transition zone it was also less than the other areas.

CONCLUSIONS

There is only limited support for the correlation of proliferation index with grade in early stage prostatic carcinoma. The findings do not suggest that proliferation index adds to the prognostic information given by grade and stage in pT1 disease. The significant difference in proliferation index in transition zone and peripheral zone carcinomas supports the morphological distinction of these tumour types and is consistent with differences in biological behaviour. The high proliferation index in lobules considered morphologically atrophic is reminiscent of previous observations in which carcinoma was spatially associated with atrophy.

Comparative analysis of mRNA and protein expression for epidermal growth factor receptor and ligands relative to the proliferative index in human prostate tissue

The expression of epidermal growth factor receptor (EGF-R), transforming growth factor alpha (TGFalpha), and epidermal growth factor (EGF) was evaluated in a series of prostate cancer (CaP; n = 55) and benign prostate hyperplasia (BPH; n = 44) specimens using immunocytochemistry (ICC) and Northern blotting. In situ hybridization (ISH), performed on a subgroup of these specimens, proved to be a more informative technique for the assessment of messenger RNA (mRNA) in this heterogeneous tissue. A comparative analysis was made in relation to the proliferative index, assessed using the MIB-1 antibody. Elevated levels of EGF-R and TGFalpha, mRNA, and protein were observed in carcinoma cells compared with benign, secretory epithelium using in situ hybridization and immunocytochemistry. In carcinoma specimens evidence of an autocrine growth loop is provided by a correlation between EGF-R and TGFalpha, mRNA (P < .0001), and protein expression (P < .01). A trend toward increased expression of EGF-R and TGFalpha protein with dedifferentiation and a similar trend in the growth fraction suggest a role in tumor progression. Although there was a correlation between EGF-R and the proliferative index (P < .01), no relationship was found between this latter parameter and TGFalpha immunoreactivity (P > .05), indicating that this growth factor may be linked with other aspects of malignant activity rather than directly stimulating proliferation.