Relationship between labeling indices of Ki-67 and BrdUrd in human malignant tumors

Effect of high fat diet on maternal behavior, brain-derived neurotrophic factor and neural stem cell proliferation in mice expressing human placental lactogen during pregnancy

Maternal obesity is a serious health concern because it increases risks of neurological disorders, including anxiety and peripartum depression. In mice, a high fat diet (HFD) in pregnancy can negatively affect placental structure and function as well as maternal behavior reflected by impaired nest building and pup-retrieval. In humans, maternal obesity in pregnancy is associated with reduced placental lactogen (PL) gene expression, which has been linked to a higher risk of depression. PL acting predominantly through the prolactin receptor maintains energy homeostasis and is a marker of placenta villous trophoblast differentiation during pregnancy. Impaired neurogenesis and low serum levels of brain-derived neurotrophic factor (BDNF) have also been implicated in depression. Augmented neurogenesis in brain during pregnancy was reported in the subventricular zone (SVZ) of mice at gestation day 7 and linked to increased prolactin receptor signaling. Here, we used transgenic CD-1 mice that express human (h) PL during pregnancy to investigate whether the negative effects of diet on maternal behavior are mitigated in these (CD-1[hGH/PL]) mice. Specifically, we examined the effect of a HFD on nest building prepartum and pup retrieval postpartum, as well as on brain BDNF levels and neurogenesis. In contrast to wild-type CD-1[WT]mice, CD-1[hGH/PL] mice displayed significantly less anxiety-like behavior, and showed no impairment in prepartum nest building or postpartum pup-retrieval when fed a HFD. Furthermore, the HFD decreased prepartum and increased postpartum BDNF levels in CD-1[WT] but not CD-1[hGH/PL] mice. Finally, neurogenesis in the SVZ as well as phosphorylated mitogen-activated protein kinase, indicative of lactogenic signaling, appeared unaffected by pregnancy and diet at gestation day 7 in CD-1[hGH/PL] mice. These observations indicate that CD-1[hGH/PL] mice are resistant to the negative effects of HFD reported for CD-1[WT] mice, including effects on maternal behaviors and BDNF levels, and potentially, neurogenesis. This difference probably reflects a direct or indirect effect of the products of the hGH/PL transgene.

The AT1 Receptor Blocker Telmisartan Reduces Intestinal Mucus Thickness in Obese Mice

The angiotensin II (type 1) (AT₁) receptor blocker telmisartan (TEL) is beneficial for the treatment of individuals suffering from metabolic syndrome. As we have shown that TEL has an impact on gut microbiota, we investigated here whether TEL influences gut barrier function. C57BL/6N mice were fed with chow or high-fat diet (HFD) and treated with vehicle or TEL (8 mg/kg/day). Mucus thickness was determined by immunohistochemistry. Periodic Acid-Schiff staining allowed the number of goblet cells to be counted. Using western blots, qPCR, and immunohistochemistry, factors related to mucus biosynthesis (Muc2, St6galnac), proliferation (Ki-67), or necroptosis (Rip3) were measured. The influence on cell viability was determined in vitro by using losartan, as the water solubility of TEL was too low for in vitro experiments. Upon HFD, mice developed obesity as well as leptin and insulin resistance, which were prevented by TEL. Mucus thickness upon HFD-feeding was diminished. Independent of feeding, TEL additionally reduced mucus thickness. Numbers of goblet cells were not affected by HFD-feeding and TEL. St6galnac expression was increased by TEL. Rip3 was increased in TEL-treated and HFD-fed mice, while Ki-67 decreased. Cell viability was diminished by using >1 mM losartan. The anti-obese effect of TEL was associated with a decrease in mucus thickness, which was likely not related to a lower expression of Muc2 and goblet cells. A decrease in Ki-67 and increase in Rip3 indicates lower cell proliferation and increased necroptosis upon TEL. However, direct cell toxic effects are ruled out, as in vivo concentrations are lower than 1 mM.

Recent Aspects in the Diagnosis and Prognosis of Bladder Cancer

Epidemiologic studies have stated the progressive increase of bladder tumors during the last decades. The aim of our review is to refer to factors implicated in bladder carcinogenesis (such as activated oncogenes, growth factors and chromosomal aberrations) and to resistance to drug uptake (i.e., multidrug resistance gene and P-glycoprotein). The review also provides information of diagnostic and prognostic significance, based on DNA analysis of transitional cancer cells. In addition to cytometric data, alternative counterings for estimation of the S-phase fraction, useful in indicating the biologic behavior of bladder cancer, are presented. Knowledge of such mechanisms results in a better approach to the diagnosis, prognosis and prevention of bladder carcinomas, especially those that do not respond to systemic intravesical chemotherapy. We have tried to mention all significant factors related to the development of bladder cancer. We conclude that the progress made in understanding the pathogenesis of bladder cancer has been significant. However, more studies are needed in order to introduce and adopt reliable criteria to accurately predict the clinical behavior.

Ki-67 antigen in lung neuroendocrine tumors: unraveling a role in clinical practice

Classification of lung neuroendocrine (NE) tumors is a step-wise process with four tumor categories being identified by morphology, namely typical carcinoid (TC), atypical carcinoid, large-cell NE carcinoma, and small-cell lung carcinoma (SCLC). Ki-67 antigen or protein (henceforth simply Ki-67) has been largely studied in these tumors, but the clinical implications are so far not clear. A well-defined role has regarded the diagnostic use in the separation of TC and AC from SCLC in nonsurgical specimens, with monoclonal antibody MIB-1 resulting in the most used reagent after antigen retrieval procedures. Uncertainties, however, have arisen in its assessment, usually expressed as Ki-67 labeling index, because of some variability in obtaining either value of the fraction. A diagnostic role is currently lacking, even though there are significant differences in most cases between TC and AC, less so between large-cell NE carcinoma and SCLC. In addition, the prognostic role of Ki-67 is debated, likely due to methodological and biological reasons. The last challenge would be to identify an effective lung-specific grading system based on Ki-67 labeling index. In this review article, five relevant issues to Ki-67 have been addressed by using a question-answer methodology, with relevant key points discussing major interpretation issues. The conclusion is that Ki-67 is a feasible and potentially meaningful marker in lung NE tumors, but more data are needed to determine its ideal function in this setting of tumors.

Difference between Luminal A and Luminal B Subtypes According to Ki-67, Tumor Size, and Progesterone Receptor Negativity Providing Prognostic Information

BACKGROUND

The St. Gallen International Expert Consensus of 2011 proposes a new classification system for breast cancer based on its division into five subgroups. The criteria to identify these subtypes were recently refined at the 2013 Conference. In this respect, the authors of this paper have conducted a retrospective analysis of breast cancer subtypes, related to Ki-67 and involvement of the axillary lymph nodes (ALNs). The analysis was performed only in the cases of invasive breast cancer in the pT2 stages. The research and results of the paper have shown that investigating the value of these parameters could be of great benefit in future treatment strategies of invasive breast cancer.

METHODS

A retrospective analysis of breast cancer subtypes, tumor nodal metastatic staging, and histopathological grading of 108 cases has been performed according to the methods recommended and provided by the St. Gallen International Expert Consensus Report, 2011. The estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor-2 (HER2), and Ki-67 of 108 tumor samples were all investigated by immunohistochemistry according to the methods used to classify breast cancer subtypes as proposed in the St. Gallen Consensus Report, 2011. Invasive breast cancers (n = 108) were immunohistochemically classified as follows: 28 (25.92%) as Luminal A, 51 (47.22%) as Luminal B (HER2 negative), 21 (19.44%) as Luminal B-like (HER2 negative), 2 (1.85%) as HER2 positive, and 6 (5.55%) as being a triple-negative subtype.

RESULTS

The conclusion was made that when Ki-67 was found to be higher, patients also showed a higher involvement in their ALNs. The chi-square test shows the difference to be significant (chi-square = 4.757; P = 0.029). Luminal B subtypes had the highest percentage (54.9%) of involvement of lymph nodes when compared to the other four subtypes. The Luminal B subtype had a higher percentage (51.4%) of involvement of lymph nodes than did Luminal A (10.7%). The chi-square test also shows the difference to be significant (P < 0.05).

CONCLUSION

A combination of the Ki-67 index, HER negative tumors, PR negativity, and a low value that can be used to segregate ER positive pT2 tumors into prognostically significantly different clinical outcomes may be utilized clinically to guide patient management in accordance with these tumor characteristics.

Luminal A and luminal B (HER2 negative) subtypes of breast cancer consist of a mixture of tumors with different genotype

Background

The St Gallen International Expert Consensus 2011 has proposed a new classification system for breast cancer. The purpose of this study was to elucidate the relationship between the breast cancer subtypes determined by the new classification system and genomic characteristics.

Methods

Invasive breast cancers (n = 363) were immunohistochemically classified as follows: 111 (30.6%) as luminal A, 95 (26.2%) as luminal B (HER2 negative), 69 (19.0%) as luminal B (HER2 positive), 41 (11.3%) as HER2, and 47 (12.9%) as basal-like subtypes.

Results

The high expression of Ki-67 antigen was detected in 236 tumors; no cases of luminal A subtype showed high expression of the Ki-67 antigen, but more than 85% of tumors of the other subtypes showed high expression. In addition, DNA ploidy and chromosomal instability (CIN) were assessed using imaging cytometry and FISH, respectively. In this series, 336 (92.6%) tumors consisted of 129 diploid/CIN- and 207 aneuploid/CIN + tumors. Diploid/CIN- and aneuploid/CIN+ features were detected in 64.9% and 27.9% of luminal A, 41.1% and 49.5% of luminal B (HER2-), 11.6% and 81.2% of luminal B (HER2+), 4.9% and 90.2% of HER2, and 17.0% and 76.6% of basal-like subtypes, respectively. Unlike the luminal B (HER2+), HER2 and basal-like subtypes, the luminal A and luminal B (HER2-) subtypes were heterogeneous in terms of DNA ploidy and CIN.

Conclusions

It is reasonable to propose that the luminal A and luminal B (HER2-) subtypes should be further divided into two subgroups, diploid/CIN- and aneuploid/CIN+, based on their underlying genomic status.

Prognostic markers in chondrosarcoma: evaluation of cell proliferation and of regulators of the cell cycle

Purpose. The prognosis, treatment principles and prediction of clinical outcome of patients with chondrosarcoma currently rest on histologic grading which is somewhat ambiguous due to difficulty in pathologic interpretation of this neoplasm. Immunohistochemistry, flow cytometry and oncogene/tumor suppressor gene expression have been examined as alternative indices to predict the biologic behavior of these tumors. Because of partial successes obtained with flow cytometry and because of the improvement in predicting recurrence offered by examining the S-phase fraction, we undertook the current study to determine if expression of specific regulators of the cell cycle would act as prognostic indicators for these patients.Subjects/methods. We examined archival pathologic specimens from 39 patients with at least 2 years' clinical follow-up for the presence of p53, Rb, src and MIB-1 by immunohistochemistry and correlated this with clinical histories and incidence of recurrence.Results. While Rb, p53 and src gene products were identified to a variable extent in these specimens, there was no prognostic significance to their expression. In contrast, MIB-1, an epitope expressed only during semiconservative replication and an accepted marker of cell proliferation, served as a significant prognostic indicator. MIB-1 staining was present in 14.5% of tumor cells in all specimens (range 0-59%). When MIB-1 staining was examined with respect to disease recurrence, there was a statistically significant association between staining and histologic grade (p < 0.05) as well as event-free survival (p < 0.02). Comparing survival curves stratified by MIB-1 expression, there was a significant decrease in event-free survival associated with increasing MIB-1 indices (p < 0.003). Covariates that were associated with event-free survival include histologic grade (p = 0.025) and stage (Musculoskeletal Tumor Society) (p = 0.014). There was no statistical association with patient age (p = 0.15), tumor size (p = 0.47), tumor histology (p = 0.62) or anatomic location (p = 0.316).Discussion. These results indicate that determination of the proliferation index by MIB-1 immunostaining may serve as a useful adjunct to current histopathologic classification. Patients with a high proliferation index may benefit from established adjuvant therapies or experimental approaches including immunotherapy or biologic modulation.

Accurate determination of S-phase fraction in proliferative cells by dual fluorescence and peroxidase immunohistochemistry with 5-bromo-2'-deoxyuridine (BrdU) and Ki67 antibodies

To ensure the maintenance of tissues in mammals, cell loss must be balanced with cell production, the proliferative activity being different from tissue to tissue. In this article, the authors propose a new method for the quantification of the proliferative activity, defined as the S-phase fraction of actively cycling cells, by dual labeling with fluorescence and peroxidase immunohistochemistry using BrdU (marker of S-phase) and Ki67 antibodies (marker of G(1)-, S-, G(2)-, and M-phases) after a one-step antigen retrieval. In the generative cell zones of fundic and pyloric glandular stomachs, where the majority of cells were cycling, the authors measured a proliferative activity of 31%. In the epithelium of the forestomach and the skin, where cycling cells are intermingled with G(0) and differentiated cells, proliferative activities were 21% and 13%, respectively. In the adrenal cortex, in which cycling cells were sparsely distributed, the proliferative activity reached 32%. During the regenerative process in the skin after a lesion, the proliferative activity increased in proximity to the wound. The present one-step dual-labeling method has revealed that the proliferative activity is different between tissues and depends on the physiological or pathological state.

Rapid cellular turnover in adipose tissue

It was recently shown that cellular turnover occurs within the human adipocyte population. Through three independent experimental approaches — dilution of an inducible histone 2B-green fluorescent protein (H2BGFP), labeling with the cell cycle marker Ki67 and incorporation of BrdU — we characterized the degree of cellular turnover in murine adipose tissue. We observed rapid turnover of the adipocyte population, finding that 4.8% of preadipocytes are replicating at any time and that between 1–5% of adipocytes are replaced each day. In light of these findings, we suggest that adipose tissue turnover represents a possible new avenue of therapeutic intervention against obesity.

Distant metastasis occurs late during the genetic evolution of pancreatic cancer

Metastasis, the dissemination and growth of neoplastic cells in an organ distinct from that in which they originated, is the most common cause of death in cancer patients. This is particularly true for pancreatic cancers, where most patients are diagnosed with metastatic disease and few show a sustained response to chemotherapy or radiation therapy. Whether the dismal prognosis of patients with pancreatic cancer compared to patients with other types of cancer is a result of late diagnosis or early dissemination of disease to distant organs is not known. Here we rely on data generated by sequencing the genomes of seven pancreatic cancer metastases to evaluate the clonal relationships among primary and metastatic cancers. We find that clonal populations that give rise to distant metastases are represented within the primary carcinoma, but these clones are genetically evolved from the original parental, non-metastatic clone. Thus, genetic heterogeneity of metastases reflects that within the primary carcinoma. A quantitative analysis of the timing of the genetic evolution of pancreatic cancer was performed, indicating at least a decade between the occurrence of the initiating mutation and the birth of the parental, non-metastatic founder cell. At least five more years are required for the acquisition of metastatic ability and patients die an average of two years thereafter. These data provide novel insights into the genetic features underlying pancreatic cancer progression and define a broad time window of opportunity for early detection to prevent deaths from metastatic disease.

Distant metastasis occurs late during the genetic evolution of pancreatic cancer

Metastasis, the dissemination and growth of neoplastic cells in an organ distinct from that in which they originated, is the most common cause of death in cancer patients. This is particularly true for pancreatic cancers, where most patients are diagnosed with metastatic disease and few show a sustained response to chemotherapy or radiation therapy. Whether the dismal prognosis of patients with pancreatic cancer compared to patients with other types of cancer is a result of late diagnosis or early dissemination of disease to distant organs is not known. Here we rely on data generated by sequencing the genomes of seven pancreatic cancer metastases to evaluate the clonal relationships among primary and metastatic cancers. We find that clonal populations that give rise to distant metastases are represented within the primary carcinoma, but these clones are genetically evolved from the original parental, non-metastatic clone. Thus, genetic heterogeneity of metastases reflects that within the primary carcinoma. A quantitative analysis of the timing of the genetic evolution of pancreatic cancer was performed, indicating at least a decade between the occurrence of the initiating mutation and the birth of the parental, non-metastatic founder cell. At least five more years are required for the acquisition of metastatic ability and patients die an average of two years thereafter. These data provide novel insights into the genetic features underlying pancreatic cancer progression and define a broad time window of opportunity for early detection to prevent deaths from metastatic disease.

A comparative study of cell proliferation markers in breast carcinomas

Aims-To investigate the tumour cell proliferative index obtained by immunostaining of paraffin wax sections of 30 cases of breast carcinoma with monoclonal antibodies MIB1, KiS1 and KiS5, and polyclonal Ki67 antisera to the Ki67 antigen and 19A2 and PC10 antibodies to proliferating cell nuclear antigen and the possible correlation between these indices and that of monoclonal Ki67 antibody in frozen sections of the same tumours.Methods-All tumour samples had been uniformly fixed and processed and sections were subjected to microwave antigen retrieval before immunostaining in all instances except for monoclonal Ki67 antibody which was used in cryostat sections. Tumour cell proliferative indices were evaluated by two independent examiners, each counting 500 tumour cells with the aid of a cross-hatched grid.Results-Proliferative indices obtained with MIB1, polyclonal Ki67, KiS1, and KiS5 correlated with those obtained with monoclonal Ki67 in frozen sections. Proliferative indices obtained with monoclonal 19A2 and PC10 showed no correlation with those of monoclonal Ki67 antibody. The staining obtained with MIB1 was the most intense and the easiest to read.Conclusions-Monoclonal antibodies MIB1, KiS1 and KiS5 and polyclonal Ki67 antiserum appear to be suitable substitutes for monoclonal antibody Ki67 in the assessment of tumour cell proliferative index. As these reagents are all immunoreactive in paraffin wax sections, they overcome the requirement for frozen tissue for immunostaining with monoclonal Ki67.

Ki-67 proliferative marker in lymph node aspirates of patients with non-Hodgkin's lymphoma

Proliferative activity of lymphoma cells was tested by immunocytochemical staining with Ki-67 monoclonal antibody in 63 aspirates of peripheral lymph nodes sampled from patients suffering from non-Hodgkin's lymphoma. Referring to the dominant cell population in nodal aspirates, a rising trend of Ki-67 proliferative marker was noted from the small cells (X = 13.20) and small cells with notched nucleus (X = 43.52) and large cells (X = 79.47) with histopathologic equivalents corresponding to aggressive lymphoma. Statistical testing of the difference in the Ki-67 proliferative marker against demographic and clinical-laboratory characteristics of the studied patients revealed the levels of significance for the performance status, bone marrow infiltration, and albumin serum value. Correlation of cytomorphological and immunocytochemical results was tested against International Prognostic Index (IPI). Statistically significant correlation of Ki-67 with cytomorphology and REAL-immunocytochemical classification of lymphoma was confirmed, but not with the IPI index. In order to determine the prognostic importance of Ki-67 marker, the patients were classified into those with low Ki-67 (<20% of proliferating cells), mean proliferation index Ki-67 (range 20-59%), and high proliferative index Ki-67 (positive in over 60% of lymphoma cells). Testing Ki-67 with survival we have found that the low proliferative index was associated with the longest survival, median about 36 mo; for proliferative marker values ranging between 20 and 59%, the median survival was 30.4 mo; and survival of patients with the high proliferative index was only 12.9 mo.

Proliferation marker Ki-67 in early breast cancer

Molecular markers have been extensively investigated with a view to providing early and accurate information on long-term outcome and prediction of response to treatment of early breast cancer. Proliferation is a key feature of the progression of tumors and is now widely estimated by the immunohistochemical assessment of the nuclear antigen Ki-67. The expression of Ki-67 correlates with other measurements of proliferation, including S-phase and bromodeoxyuridine uptake. High Ki-67 is a sign of poor prognosis associated with a good chance of clinical response to chemotherapy, but its independent significance is modest and does not merit measurements in most routine clinical scenarios. However, its application as a pharmacodynamic intermediate marker of the effectiveness of medical therapy holds great promise for rapid evaluation of new drugs.

Proliferative markers as prognostic and predictive tools in early breast cancer: where are we now?

In the last few decades, proliferative markers have been broadly evaluated as prognostic and predictive factors for early stage breast cancer patients. Several papers evaluating one or more markers have been published, often with contradictory results. As a consequence, there is still uncertainty about the role of these proliferative markers. The present paper critically reviews the current knowledge about the following markers: thymidine labeling index, S phase fraction/flow cytometry, Ki 67, thymidine kinase (TK), cyclins E, cyclin D, the cyclin inhibitors p27 and p21, and topoisomerase IIalpha. For each marker, the prognostic and predictive role was separately analyzed. Only papers published in English in peer-reviewed journals before June 2004 that include at least 100 evaluable patients were selected. In addition, the prognostic and predictive role of the proliferative markers had to be assessed through multivariate analyses. One hundred and thirty-two papers fulfilled these criteria and 159 516 patients were analyzed. Unfortunately, several methodological problems in the research to date prevent us from including any one of these proliferative markers among the standard prognostic and predictive factors. Early incorporation of translational research and new technologies with clinical trials are needed to prospectively validate biological markers and allow their use in clinical practice.

Extracorporeal irradiated autogenous osteochondral graft

We examined osteochondral autografts, obtained at a mean of 19.5 months (3 to 48) following extracorporeal irradiation and re-implantation to replace bone defects after removal of tumours. The specimens were obtained from six patients (mean age 13.3 years (10 to 18)) and consisted of articular cartilage (five), subchondral bone (five), external callus (one) and tendon (one). The tumour cells in the grafts were eradicated by a single radiation dose of 60 Gy. In three cartilage specimens, viable chondrocytes were detected. The survival of chondrocytes was confirmed with S-100 protein staining. Three specimens from the subchondral region and a tendon displayed features of regeneration. Callus was seen at the junction between host and irradiated bone.

Ki-67 expression in breast carcinoma: its association with grading systems, clinical parameters, and other prognostic factors--a surrogate marker?

BACKGROUND

The number of mitoses and, thus, the proliferative capacity of a tumor is one of the most crucial variables for tumor grading. The Ki-67 nuclear antigen may be considered as an alternative to mitotic counts in grading schemes and as a single parameter that can be used in fine-needle aspirates and small biopsies.

METHODS

Immunohistochemistry using the anti-Ki-67 antibody MIB-1 was performed on 434 breast carcinoma specimens from the International Breast Cancer Study Group (formerly Ludwig) Trial V. Three groups based on Ki-67 percent were used to replace the mitotic counts component in the Nottingham grade (NHG) to produce the Nottingham/Ki-67 grade (NKG) and to assess Ki-67 as a single parameter.

RESULTS

In both the lymph node positive subgroup and the lymph node negative subgroup, the NKG and Ki-67 group was correlated significantly with Bloom-Richardson grade (BRG), NHG, and Nottingham type. Tumor size in the lymph node negative cohort and estrogen receptor status, progesterone receptor status, and c-erbB-2 expression in the lymph node positive cohort also were correlated significantly with NKG. Ki-67 percentage was correlated significantly with c-erbB-2 expression in the lymph node positive cohort only. NKG was similar to BRG and NHG when it was evaluated for prognostic significance. Patients with higher categoric Ki-67 percentages had worse overall and disease free survival in all groups except for the untreated, lymph node negative group.

CONCLUSIONS

Ki-67 detection represents a valuable tool and is a good objective substitute for mitotic counts when used in a grading system. When it is used alone, Ki-67 detection provides valuable information, although it is necessary to combine this with other parameters in the study of core biopsies and fine-needle aspirates.

Cell proliferation in colorectal adenocarcinomas: comparison between Ki-67 immunostaining and bromodeoxyuridine uptake detected by immunohistochemistry and flow cytometry

We compared three different means of assaying tumor proliferative activity in 30 human colorectal adenocarcinomas labeled in vivo with bromodeoxyuridine (BrdUrd). The labeling indices (LI) of BrdUrd obtained both by flow cytometry (FCM) and immunohistochemistry (IH) were also compared with the labeling index of Ki-67. These methods were then related to tumor ploidy and pathological features. Flow cytometry was performed in accordance with Begg's method after intravenous infusion of BrdUrd four hours before surgery. Immunohistology was carried out on paraffin-embedded sections with monoclonal antibodies against BrdUrd and Ki-67. A positive correlation was found between BrdUrd LI obtained by both FMC and IH (p<0.0001), a finding that complies with the literature. However, we report on a correlation between Ki-67 LI and BrdUrd LIs in colorectal tumors (p=0.012). The results were valid for all tumors when they were subdivided into diploid and aneuploid groups. The labeling indices were significantly higher in the aneuploid tumor group than in the diploid group (p=0.047). No relationship between proliferation parameters and tumor stage or grade was found. To our knowledge, this is the first report on a positive correlation between tumor proliferation indices in BrdUrd LIs and Ki-67 in colorectal carcinomas. This finding validates the value of Ki-67 immunostaining, which, however, should be confirmed in a larger series under the same technical conditions.

Evidence of increased endothelial cell turnover in brain arteriovenous malformations

OBJECTIVE

We hypothesized that human brain arteriovenous malformations (BAVMs) are nonstatic vascular lesions with active angiogenesis or vascular remodeling. To test this hypothesis, we assessed endothelial cell turnover in BAVMs.

METHODS

We identified nonresting endothelial cells by use of immunohistochemistry for the Ki-67 antigen. From archived paraffin blocks, we selected BAVM vessels without intravascular thrombosis or embolic material in areas nonadjacent to the nidus edge. For controls, we used 50- to 100-microm diameter cortical vessels from temporal lobe cortex removed for epilepsy treatment. The Ki-67 index was calculated as a percentage of Ki-67-positive endothelial cells. The data were analyzed by the nonparametric Mann-Whitney test and reported as mean +/- standard deviation.

RESULTS

Thirty-seven specimens that met the above criteria were selected. There were 26 +/- 15 vessels counted in each BAVM specimen versus 18 +/- 5 in each control cortex (n = 5). The mean Ki-67 index was higher for BAVM vessels than control cortical vessels (0.7 +/- 0.6 versus 0.1 +/- 0.2%; P = 0.005), which represented an approximately seven-fold increase in the number of nonresting endothelial cells. In the BAVM group, there was a trend for younger patients to have a wider variation and higher Ki-67 index than older patients; no trend was evident in the control group.

CONCLUSION

Compared with control vessels, BAVM vessels have higher endothelial cell turnover, which suggests the presence of active angiogenesis or vascular remodeling in BAVMs.

Cell proliferation and apoptosis with BCL-2 expression in renal cell carcinoma

OBJECTIVES

To investigate cell proliferation, apoptosis, and bcl-2 immunoreactivity in renal cell carcinoma (RCC).

METHODS

Formalin-fixed and paraffin-embedded tissue blocks from 70 patients with RCC were studied. Cell proliferation activity was detected by Ki-67 immunostaining and the proliferation index (PI) was expressed as a percentage of the Ki-67-positive cells in the tumor cells. Apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL), and the apoptotic index (AI) was expressed as a percentage of the TUNEL-positive cells in the tumor cells. Immunoreactivity of bcl-2 was assessed immunohistochemically and coexpression of Ki-67 with bcl-2 was examined by double immunostaining.

RESULTS

The PI ranged from 5.0% to 44.0% (median 19.23%) and the AI from 0.9% to 3.4% (median 2.13%) in RCC. Statistical analysis revealed close associations between PI and tumor grade and stage, and a significant relationship between AI and the tumor grade of RCC. The expression of bcl-2 was detected in 24 (34.3%) of 70 RCCs. Coexpression of Ki-67 with bcl-2 was noted in 3 of the 24 RCCs with bcl-2 expression. The expression of bcl-2 was not related to PI, AI, or the clinicopathologic factors of RCC.

CONCLUSIONS

Our observations suggest that active cell proliferation may be accompanied by frequent apoptosis and that cell proliferation as reflected by Ki-67 staining may be the most important parameter of cell turnover in RCC.

Cultured human fibroblasts in agarose gel as a multi-functional control for immunohistochemistry. Standardization Of Ki67 (MIB1) assessment in routinely processed urinary bladder carcinoma tissue

Immunohistochemistry (IHC) in clinical practice is hampered by lack of standardization and by subjectivity in interpretation and quantitation. This study aimed to develop a control system for IHC in routinely fixed and histoprocessed tissues. Such a system should be easy to handle in clinical practice and should reflect variations in fixation time, section thickness, section storage conditions, and staining protocols. In addition, in image analysis quantitation of immunostained tissues, when using classifiers computed on IHC-control images, the control system should be very stable. Cultured human fibroblasts were suspended in agarose, transferred into a length of tubing and stored at 4 degrees C. Three pieces of the cellgel control were separately fixed, histoprocessed, and paraffin-embedded as external controls. One piece was prepared together with each of 18 bladder carcinoma biopsies as internal controls. Slides with sections from the biopsy and all types of cellgel controls were stored at different temperatures and then stained using three different IHC protocols. The fibroblasts were homogeneously distributed in the agarose gel. Variation in section thickness did not influence immunostaining as evaluated by the MIB1 labelling index (MIB1 LI). The external controls decreased notably in MIB1 LI with increased fixation time. This was not seen in the 18 internal controls that were each fixed with a fresh biopsy. However, section storage and immunostaining conditions influenced the MIB1 expression equally in all control types and to a similar degree to the biopsies. Furthermore, colour-based image analysis quantitation of MIB1 LI in biopsies proved stable and independent of the control type used to compute the classifier.

Differentiation of malignant lymphoma and non-lymphoma by an occlusive dressing method employing bromodeoxyuridine

Although lymphoma cells can proliferate in skin tissue, lymphocytes which have infiltrated the skin due to inflammatory changes are generally unable to do so. It may be possible to differentiate malignant lymphomas from benign lymphocytic infiltrations in skin tissue by detection of cell cycle-related antigens. We developed a novel in vivo method for studying the cell kinetics of human skin using bromodeoxyuridine (BrdU) with an occlusive dressing. Following the application of BrdU, BrdU-labeled lymphoid cells were counted in the dermis. The patients studied included 22 with various types of lymphomas (lymphoma group) and 22 with different forms of inflammatory skin disease (non-lymphoma group). Skin specimens were obtained after applying occlusive adhesive plasters containing 2% BrdU dissolved in 0.9% sodium chloride solution and were then immunostained with anti-BrdU monoclonal antibody. The average percentages of labeled cells were 15.9 +/- 7.6% for the lymphoma group and 4.7 +/- 2.6% for the non-lymphoma group. This difference was statistically significant (p < 0.0001). Using this method, malignant lymphomas and benign lymphocytic infiltrations of the skin could be differentiated by counting BrdU-labeled lymphoid cells, and this method could help in determining a prognosis.

Immunohistochemical detection of DNA topoisomerase type II alpha and Ki-67 in adenoid cystic carcinoma and pleomorphic adenoma of the salivary gland

Immunohistochemical detection of cell proliferation-associated antigens was investigated in 28 cases of adenoid cystic carcinoma (ACC) and 20 cases of pleomorphic adenoma (PA), using antibodies against DNA topoisomerase type II alpha (topo-II) (Ki-S1) and Ki-67 (MIB-1). The correlation of staining indices with clinicopathological data, histological features and prognosis was also studied. The topo-II value was significantly higher in ACC than in PA (P<0.0001), and highest in the solid growth pattern of ACC. In addition, significant relationships were found between topo-II values and clinical features such as local recurrence, surgical margins, and distant metastases. By log-rank test, the topo-II index was also correlated significantly with patient survival (P<0.01). The values of topo-II index paralleled those of Ki-67 index in ACC, and a correlation coefficient of 0.97 was obtained. Topo-II may be considered an additional marker for estimating the proliferating fraction of cells and for predicting the short-term prognosis for patients with salivary gland tumors.

Comparison of mitotic index, in vitro bromodeoxyuridine labeling, and MIB-1 assays to quantitate proliferation in breast cancer

PURPOSE

To investigate the hypothesis that in vitro bromodeoxyuridine (BrDu) labeling might be superior to MIB-1 immunostaining for prognostic value, because it more selectively labels cells during the S phase.

METHODS

Four hundred eighty-six patients with breast cancers (59% lymph node-negative, 41% lymph node-positive) surgically excised between 1988 and 1993 (median follow-up, 62 months) were evaluated for cellular proliferation using prospective in vitro BrDu uptake assays, retrospective mitotic indices, and MIB-1 labeling.

RESULTS

MIB-1, BrDu labeling, and mitotic index-derived proliferation data were highly correlated. Each was similarly associated with most other markers of prognosis, although these relationships were not identical. By univariate analysis, nodal status was the most significant prognostic variable for all patients. Higher BrDu labeling index, MIB-1 immunolabeling, and mitotic index were also associated with shortened disease-free survival (DFS) and disease-specific survival for the entire patient group, as well as for node-negative patients. The association between cellular proliferation and survival was much weaker for node-positive patients. Multivariate models confirmed that nodal status, tumor size, and proliferation data predicted survival in all patients as well as those with node-negative disease, although MIB-1 was somewhat more closely associated with outcome than mitotic index or in vitro BrDu data. For patients with T1NOMO disease (n = 172), the only significant predictors of DFS were proliferation rate (mitotic index or MIB-1) and tumor grade.

CONCLUSIONS

Proliferation rate predicts recurrence and survival in breast cancer. This effect is more pronounced in node-negative patients. In vitro BrDu data are not superior to MIB-1 and mitotic counting.

Expression of bcl-2-, p53, and Ki-67 and outcome of patients with primary nasopharyngeal carcinomas following DNA-damaging treatment

BACKGROUND

Recent studies suggest that apoptosis is important in the cell death induced by treatment that damages deoxyribonucleic acid (DNA). We assessed the correlation between the expression of the apoptosis-related proteins, p53 and bcl-2, and the clinical outcome of patients with nasopharyngeal carcinomas (NPCs) who were treated with both DNA-damaging treatments. We also assessed the level of Ki-67, a marker of cell proliferation, in these tumors.

METHODS

We evaluated statistically the relationships among the expression of p53, bcl-2, and Ki-67 and clinicopathologic factors, the sensitivity to radiation, the incidence of distant metastases, and survival.

RESULTS

The group that was positive for p53 tended to be resistant to radiotherapy and to have a significantly poorer prognosis (p = .05).

CONCLUSIONS

The enhanced expression of p53 may be a prognostic factor in patients with NPCs whose tumor is resistant to therapy that damages DNA.

Measurement of proliferation activities in human tumor models: a comparison of flow cytometric methods

Proliferating cells in tumors may be of considerable relevance in cancer therapy. Not only do such cells dictate the rate of tumor progression, but evidence exists that they may also play an important role in the diagnosis and prognosis of tumor regrowth. Consequently, the identification of this subset of cells in the overall neoplastic cell population is of considerable importance. The aim of the present investigations was to compare four flow cytometric methodologies commonly used to study cell proliferation. These included nuclear antigen Ki67 detection, acridine orange (AO) and bromodeoxyuridine (BrdUrd) staining, and percent S-phase determinations. Three human tumor cell lines (HEp3, A549, H226) were examined in various stages of growth. Further, a direct comparison was made of the proliferation activities of HEp3 cells grown in culture or as xenografts in nude mice. The results showed that of the techniques investigated, detection of the nuclear antigen Ki67 may be most useful for marking proliferating tumor cells and determining tumor growth fractions.

Long-term sequelae of experimental gastritis with Helicobacter pylori: a 5-year follow-up study

To investigate the long-term effects of Helicobacter pylori gastritis on the gastric mucosa, 13 wild Japanese monkeys (six H. pylori-infected and seven controls) were monitored for 5 years. Colonization with H. pylori, the presence of macroscopic and histological gastritis, pyloric glandular height, and epithelial cell kinetics were investigated, using Ki-67 immunostaining in the gastric mucosa. In the infected group, persistent colonization with H. pylori was demonstrated by culture and histopathologic examination. In this group, the gastritis scores were significantly higher than in controls. Simultaneously, a significant decrease in the height of antral glands and a significant increase in the length of Ki-67-positive cells between the highest and lowest cells were also demonstrated in the infected animals. These experimental results directly demonstrate the effect of H. pylori infection on the gastric mucosa and may explain the potential mechanism for its causal role in the chain of events leading to gastric carcinoma.

Increased cell proliferation activity and decreased cell death are associated with the emergence of hormone-refractory recurrent prostate cancer

The tumour growth kinetics (cell proliferation and apoptosis) of ten hormone-refractory locally recurrent prostate cancers were compared with their matched untreated primary tumour specimens. All recurrent tumours had a higher cell proliferation activity, as defined by Ki-67 immunohistochemistry, than corresponding primary tumours from the same patients. The mean cell proliferation activity in recurrences (13.5 +/- 3.8 per cent) was over two times higher (P < 0.0001) than that in primary tumours (5.5 +/- 2.4 per cent), suggesting that cell clones which progress during androgen withdrawal are actively stimulated to proliferate. The mean percentage of apoptotic cells, as estimated by the in situ end-labelling technique, was 5.4 +/- 4.7 per cent in untreated primary tumours, whereas it was 2.3 +/- 1.5 per cent in locally recurrent tumours (P = 0.05). In all but two cases, the apoptotic index was lower in recurrent than in corresponding primary tumours, suggesting that recurrent prostate carcinomas are able to avoid apoptosis in the androgen-deprived environment. In conclusion, the clinical progression of prostate cancer during androgen withdrawal is associated with increased cell proliferation and decreased apoptosis.

A comparison of proliferation indices in human anterior pituitary adenomas using formalin-fixed tissue and in vitro cell culture

The authors compared detection methods for cell proliferation in human anterior pituitary adenomas using histological sections and dispersed cell culture. After tumor cells had been grown for 4 days in dispersed culture, bromodeoxyuridine (BUdR), proliferating cell nuclear antigen (PCNA), and Ki-67 were compared by double immunostaining and contrasted with single staining of PCNA and Ki-67 indices in the corresponding histological sections from 12 human pituitary adenomas. In vitro, the BUdR labeling index was positive in six of 12 tumors (range < 0.1-5.1%), 10 of 12 tumors were PCNA-positive (range < 0.1-100%), and Ki-67 was positive in 10 of 12 adenomas (range < 0.1-8%). In vitro, BUdR and Ki-67 gave similar proliferative indices for 10 of 12 adenomas. In vivo, the PCNA labeling index was positive in 12 of 12 adenomas (range 0.9-95%) and Ki-67 was positive in 11 of 12 adenomas (range < 0.1-2%). Tumors with a labeling index less than 0.1% were considered to be negative for proliferation. High PCNA values were found in vitro and in vivo, whereas Ki-67 labeling indices were similar in vitro and in vivo for nine of 12 adenomas. It is concluded that Ki-67 proliferative indices in vivo reflect those found in vitro, at least after 4 days in dispersed culture, but that PCNA overestimates pituitary adenoma proliferation in histological sections as well as in dispersed culture.

Helicobacter pylori infection accelerates human gastric mucosal cell proliferation

Helicobacter pylori causes chronic atrophic gastritis and intestinal type gastric cancer arises against a background of atrophic gastritis. Increased proliferation of epithelial cells is an important indicator of increased risk for gastric adenocarcinoma. We investigated gastric mucosal cell proliferation in H. pylori-associated gastritis and the effect of eradication therapy on this proliferation in 45 patients endoscopically diagnosed (31 with persistent eradication and 14 in whom H. pylori) recurred. H. pylori status was determined by culture and histology in biopsied specimens from the gastric antrum and corpus. Eradication of the infection was defined as reversal to negative on both tests. In vitro Ki-67 immunostaining of endoscopic biopsy specimens was used to measure mucosal cell proliferation in H. pylori-associated gastritis before and after therapy. The proliferative zone was defined as the distance of Ki-67-positive gastric epithelial cells between the highest and the lowest cells. In patients in whom H. pylori was eradicated, cell proliferation in both the antral and corpus mucosa had decreased 4 weeks after completion of the eradication therapy (P < 0.01, P < 0.001), and 6 months later, it had markedly decreased (P < 0.05, P < 0.05) and returned to normal. In patients in whom H. pylori recurred, only antral epithelial cell proliferation was reduced 4 weeks after eradication therapy, but when H. pylori recurred, determined by culture and histology, cell proliferation level was the same as that before eradication. These results suggest that H. pylori infection accelerates cell proliferation in gastric mucosa and may play a causal role in the chain of events leading to gastric carcinoma.

Hepatic regeneration in humans with various liver disease as assessed by Ki-67 staining of formalin-fixed paraffin-embedded liver tissue

The ability to document nuclear proliferation in the liver is essential to our understanding of hepatic regeneration and hepatocellular carcinoma. While numerous tests are available to provide such information in experimental animals, few can be applied to patients with liver disease. Ki-67 is a proliferating nuclear antigen present in replicating cells. Recent data indicates that staining for Ki-67 reflects nuclear proliferation in these tissues. To date, the technique has had only limited application to human liver tissues in formalin-fixed paraffin embedded tissue. In the present study, we documented Ki-67 staining in archival liver tissue from patients with mild chronic hepatitis, severe chronic hepatitis, inactive cirrhosis, hepatocellular carcinoma, and in normal livers. We found that Ki-67 staining was increased in patients with mild chronic hepatitis (labelling index 29 +/- 25), severe chronic hepatitis (labelling index 41 +/- 40), and hepatocellular carcinoma (labelling index 71 +/- 61), when compared to patients with inactive cirrhosis, (labelling index 1.4 +/- 3.1), and normal livers (labelling index 2.5 +/- 3.2). In conclusion, Ki-67 maybe useful tool to assess hepatocyte proliferation in formalin-fixed paraffin-embedded human liver tissue.

Adenosquamous carcinoma arising in a mucinous cystadenoma of the pancreas

BACKGROUND

Approximately 500 cystic neoplasms of the pancreas have been reported, and among these the mucinous pancreatic cystadenomas are known to have malignant potential. We report a rare case of a mucinous cystadenoma containing adenosquamous carcinoma.

METHODS

We studied the histochemical and immunohistochemical staining characteristics of the tumor by staining with hematoxylin/eosin, Alcian Blue/Periodic Acid Schiff, and with immunoperoxidase-labelled antibodies against carcinoembryonic antigen, epithelial membrane antigen, low and high molecular weight cytokeratins, the proliferation antigen Ki-67, and the tumor suppressor antigen p-53. The K-ras oncogene was analyzed by direct sequencing.

RESULTS

This case illustrates the usual presentation and features of this unusual tumor-a middle aged woman with abdominal pain and no history of alcohol abuse or abdominal trauma. The mucinous cystic tumor of her pancreas was composed predominantly of benign epithelium with areas of a malignant component that were identified by thorough sampling.

CONCLUSION

We discuss the nomenclature of these neoplasms and suggest that continuing efforts to subclassify mucinous cystic pancreatic tumors histologically may not be necessary, since the tumors are all histologically similar and are malignant or have malignant potential, and for all, treatment should include resection.

Proliferation in Adrenocortical Tumors: Correlation with Clinical Outcome and p53 Status

There appears to be a relationship between mitotic activity and malignant behavior in adrenocortical tumors, and carcinomas with a high mitotic index may have a poorer prognosis. This has been investigated further by quantifying and comparing the Ki-67 index using antibody MIB-1 in a series of 14 adrenocortical adenomas and 40 carcinomas. The levels have been correlated with survival and disease-free survival in carcinomas and with evidence of abnormal p53 expression as detected by immunohistochemistry. Nevertheless, many carcinomas have a low level of proliferation that may reflect varying abnormalities within the regulation of both cell division and apoptosis. Expression of bcl-2 protein, an inhibitor of apoptosis has therefore also been examined. The Ki-67 index in carcinomas was significantly higher than in adenomas, but below 4% there was overlap. There was no significant difference in survival between carcinomas with MIB-1 index <3% and those greater, but the lower group had significantly longer disease-free survival (p = 0.02). There was no significant difference between p53 immunopositive and p53 immunonegative carcinomas. No tumor showed immunopositivity for bcl-2 protein. It is concluded that MIB-1 index may contribute additional prognostic information in adrenocortical tumors. Inhibition of apoptosis by bcl-2 does not appear to play a role in tumor growth.

The combination of p53 and age predict cancer specific death in advanced stage (FIGO Ic-IV) of endometrial carcinoma of endometrioid type. An immunohistochemical examination of growth fraction: Ki-67, MIB-1 and PC10; suppressor oncogene protein: p53; oncogene protein: p185 and age, hormone treatment, stage, and histologic grade

OBJECTIVE

Early surgical stage (FIGO Ia + b) is an excellent predictor of survival in endometrial carcinoma of endometrioid type (EC), in contrast to advanced stage which only predict cancer specific death (CSD) in approximately 20-30% of the patients. The value of growth fraction, p53 and p185 as predictor of CSD in EC was studied.

STUDY DESIGN

One hundred and eleven patients (45% hormone-users) with EC were entered prospectively and consecutively into an immunohistochemical study of growth fraction (Ki-67, MIB-1 and PC10), suppressor oncogene protein (p53) and oncogene protein (p185).

RESULTS

All markers except p185 intercorrelated significantly, although weakly, however, marked differences were found in median values of the markers of growth fraction (GF). It was shown that immunohistochemical demonstration of p53 and p185 proteins and stage correlates independently with CSD in EC.

CONCLUSION

The study indicates that the markers of GF do not give exact information about the proliferative compartment of the EC, and it is shown that p53 correlate to CSD, while stage indicate crude death.

Proliferation marker MIB-1 correlates well with proliferative activity evaluated by BrdU in breast cancer: an immunohistochemical study including correlation with PCNA, p53, c-erbB-2 and estrogen receptor status

The proliferative activity of 30 cases of non-treated invasive ductal breast carcinoma was evaluated by bromodeoxyuridine (BrdU), proliferation marker (MIB-1) and proliferating cell nuclear antigen (PCNA), and the relation between these proliferation markers and histological subtype and histological grade were investigated. In addition, the association of these proliferation markers with overexpression of p53 protein, c-erbB-2 oncoprotein, estrogen receptor (ER) status and clinicopathologic findings were also examined. The BrdU labeling index (LI), MIB-1 score and PCNA labeling rate (LR) correlated with the histological grade. However, there was no statistical difference in proliferative activity among the histological subtypes. A linear strong correlation was demonstrated between BrdU LI and MIB-1 score (r = 0.732). Significant correlation was also found between BrdU LI and PCNA LR (r = 0.446); however, the relation between MIB-1 score and PCNA LR was weak. BrdU LI and MIB-1 score correlated positively with tumor size, TNM stage and overexpression of p53, and negatively with the presence of ER. PCNA LR correlated only with p53. These results indicate that MIB-1 is closely associated with BrdU in clinicopathologic findings and is a more useful tool for evaluating cell proliferation than PCNA. However, it will be necessary to consider the clinical significance of MIB-1 immunohistochemistry cautiously until further widespread clinical and pathological studies are performed.

Enhanced cellular proliferation in intact stenotic lesions derived from human arteriovenous fistulas and peripheral bypass grafts. Does it correlate with flow parameters?

BACKGROUND

Vascular interventions are often complicated by the development of intimal thickening, leading to stenosis. Cellular proliferation is a key event in stenosis formation in animals, but the role of cell proliferation in intimal thickening in humans is still unclear. Furthermore, the relation between proliferation in human stenotic lesions and flow parameters has not been established.

METHODS AND RESULTS

We studied the proliferation patterns of 35 anatomically intact human stenotic lesions derived from either peripheral bypasses (normal flow) or hemodialysis AV fistulas (high flow) with the use of Ki-67, a cell proliferation marker. Local flow parameters were assessed with ultrasound. Proliferation patterns were similar in AV fistula and bypass stenoses. In the intima, proliferation was highest in the area just below the endothelium (AV fistulas, 3.6%; bypasses, 3.5%; P = NS). In adjacent nonstenotic vessel segments that were used as controls, proliferation rate in the intima was 0.3%. Double-labeling studies revealed that subendothelial-intimal proliferation consisted mainly (90%) of vascular smooth muscle cells, whereas proliferation in the other layers of the vessel wall also consisted of endothelial cells and macrophages. Blood flow velocity was negatively correlated with subendothelial-intimal proliferation (r = -.61, P < .05). The endothelial cell coverage of the lumen was positively correlated with proliferation (r = .85, P < .01).

CONCLUSIONS

These data suggest enhanced cellular proliferation in human stenotic tissue derived from AV fistulas and peripheral bypass grafts. Furthermore, high proliferation rates seem to be associated with endothelial cell coverage of the lumen and low local flow velocities.

Cyclin D1 overexpression in primary hypopharyngeal carcinomas

BACKGROUND

Hypopharyngeal squamous cell carcinomas (HPCS) are associated with an extremely poor prognosis. Generally, conventional clinicopathologic factors have only limited value as prognostic factors for this malignancy. It is therefore clinically important to identify new prognostic factors that accurately reflect the biologic aggressiveness of this malignancy. The amplification and overexpression of the cyclin D1 protooncogene have been reported in a variety of malignancies, and are thought to be related to tumor progression. Based on this phenomenon, the authors immunohistochemically evaluated overexpression of the cyclin D1 gene in 42 cases of primary HPCS. In addition, the immunohistochemical staining of the proliferation marker MIB-1 (Ki-67 antibody) was also performed.

METHODS

Formalin fixed, paraffin embedded biopsy specimens obtained prior to treatment were examined. Cyclin D1 and Ki-67 were detected using monoclonal antibodies by means of the streptavidin-biotin method. The relationship between cyclin D1 overexpression and the stage, histologic grade, presence of lymph node metastases, proliferation index, and survival was then statistically analyzed. The correlation between the proliferation index, other clinicopathologic factors, and survival was also evaluated.

RESULTS

Twenty-three (54.8%) HPCS specimens showed a 20% or greater immunoreactivity for cyclin D1. Cyclin D1 overexpression was related to cervical lymph node metastases (P = 0.037) but not to clinical stage, histologic grade, or the proliferation index. Cyclin D1 negative tumors were associated with a significantly better prognosis (P = 0.023), particularly in patients who underwent multimodality treatment. Finally, the MIB-1 labeling index showed no correlation with either the clinicopathologic parameters or overall survival.

CONCLUSIONS

Based on these findings, cyclin D1 immunohistochemical staining is considered to be useful, not only as a prognostic factor for HPCS, but also as a means of determining the optimum treatment for each individual patient. Conversely, the MIB-1 labeling index appears to have no clinical significance in HPCS.

Correlation of histology, cytogenetics and proliferation fraction (Ki-67 and PCNA) quantitated by image analysis in meningiomas

Sixty meningiomas were classified histologically according to the WHO criteria and analyzed cytogenetically. The Ki-67 and PCNA proliferation fractions (PRFs) were assessed by immunhistochemistry. The staining results were quantified by TV-image analysis (Miamed, Leica, Germany). Within meningiomas of WHO-grade II/III and those with complete or partial deletion of # 1p, we found a significantly higher mean and maximal Ki-67 PRFs than in those of WHO-grade I and those with all other karyotypes. This was not the case for PCNA PRFs. No differences in PRFs were detectable between histological subtypes. Although these results were obtained after measurement of five high power fields (HPFs) only, the heterogeneity of PRF distribution within the tumors was high. Even after the measurement of 100 HPFs, the 95% confidence intervals were in a range of 18% to 34.3% PRF. This finding seems to be responsible for the moderate interobserver reproducibility of image analytical determination of PRF (r = 0.74). Nevertheless, there was a good correlation between subjective and objective image analytical assessment of PRF (r = 0.83). The significance of the maximum Ki-67 PRF per specimen implies the possibility of selecting those areas which show the highest fraction of positively stained nuclei for measurement, avoiding the problem of intraslide heterogeneity. Thus the time needed for image analytical quantification may be reduced.

Colorectal cell kinetics

The assessment of cell proliferation in colorectal tissue may provide information with both prognostic and therapeutic implications. A variety of methods are available, including flow cytometric estimations of S phase fraction, immunohistochemical and autoradiographic visualization of exogenous and endogenous proliferation proteins, and morphological and stathmokinetic techniques. There is some correlation between Dukes stage and proliferation state features, and there is increased proliferative activity throughout the adenoma-carcinoma sequence. Data on cell proliferation rates are difficult to obtain. When correctly applied, the metaphase arrest technique remains the 'gold standard' of measuring proliferation, but its usefulness in clinical practice is limited. Recent studies have employed dual measurement flow cytometry and double labelling techniques to produce rate data.

Proliferative activities in conventional chordoma: a clinicopathologic, DNA flow cytometric, and immunohistochemical analysis of 17 specimens with special reference to anaplastic chordoma showing a diffuse proliferation and nuclear atypia

Chordoma shows various degrees of atypia histologically, however, the relationship between the histological features and the biological behavior still remains controversial. The authors subclassified 17 specimens with chordoma into two groups (ie, trabecular type showing a trabecular patterns and solid type mainly consisting of a diffuse proliferation of tumor cells). The histological grading was performed according to the degree of nuclear atypia on a scale of 1 to 3. Using DNA flow cytometric and immunohistochemical techniques, both the proliferative index (% S + G2 + M phase) and the MIB-1 labeling index (LI) of the tumor cells were estimated regarding their proliferative activities. In addition, p53 overexpression was also investigated using immunohistochemical techniques. There were eight (47.1%) specimens of trabecular type and nine (52.9%) of solid type. In nine specimens of solid type, those with higher nuclear atypia (grade 2 or 3) were significantly more frequent (five specimens, 55.6%) than in trabecular type in which all of the eight specimens were grade 1 (P = 0.44). The proliferative index was significantly higher in grade 2 or 3 lesions than in grade 1 lesions (P = .014), and the MIB-1 LI tended to be higher in solid type than in trabecular (P = .088). p53 overexpression was detected in two specimens of solid type, and the MIB-1 LI in these two specimens was significantly higher (P = .037) than that in the specimens without p53 overexpression. It was considered that the preceding anaplastic histological features, including either diffuse proliferation or high grade nuclear atypia, together with p53 overexpression, were thus closely related to the proliferative activities in chordomas.

Superficial bladder cancer: study of the proliferative nuclear fraction as a prognostic factor

The expression of the anti-proliferating cell nuclear antigen (PCNA) was examined in bladder specimens from 48 patients with superficial transitional carcinoma, with the use of the PC10 monoclonal antibody. In vesical tumours with good clinical behaviour, we found a median PCNA positivity of 7.1% with a range of 5-25%. In vesical tumours with high incidence of recurrence, the median was 36.6% with a range of 15-80%. In vesical tumours with a strong tendency to invasion, the median positivity for PCNA staining was 68% with a range of 40-92%. In conclusion, we believe that using PC10 immunostaining to determine a nuclear proliferative fraction is a quick and simple method of studying the prognosis of patients who have vesical tumours of low grade and low stage.

Proliferation Markers and Their Uses in the Study of Endocrine Tumors

A growing body of literature supports the view that the proliferative activity (PA) of tumor cells is an important prognostic indicator for a variety of different tumors. We examined the role of PA in diagnosis and prediction or malignancy of endocrine tumors (ETs) of pituitary gland, pancreas, thyroid, parathyroid glands, adrenal glands, paraganglia, gastroenteric tract, and lung. The data in the literature indicate that the assessment of PA is not a diagnostic indicator of malignancy especially at the individual case level, whereas it can be useful for identifying subsets of malignant tumors with different aggressiveness potential, as well as for choosing therapeutic options in metatstatic lesions. We hope that, in the near future, multiparametric approaches including PA markers, cell growth and differentiation factors, and oncogenes will yield valuable information for diagnosis and prognosis of ETs also in individual cases.

The correlation of Ki-67 staining indices with tumour doubling times in regrowing non-functioning pituitary adenomas

In order to improve our ability to predict the regrowth of nonfunctioning pituitary adenomas, we tried to assess the correlation between growth fractions with Ki-67 and PCNA (proliferating cell nuclear antigen) and tumour doubling times in regrowing tumours, and also to find out any difference of growth fractions between the regrowing and the cured cases. In 33 patients with non-functioning pituitary adenomas, 14 cases including 11 with cavernous sinus invasion showed residual tumour on MRI after the operation (regrowing group) and 19 cases had no tumour regrowth on MRI within 5 years after the operation (cured group). Immunocytochemical studies were done with monoclonal antibodies (anti-PCNA, anti-Ki-67: MIB-1). The growth fraction of each tumour was estimated by calculating the ratio of the positive nuclei to the total number of tumour cells with the aid of an image analyser (Mac SCOPE). The tumour doubling times were estimated from serial CT or MRI with the aid of the image analyser (NIH image). Ki-67 staining indices ranged from 0.2% to 1.5% (n = 14, 0.86 +/- 0.10%; mean +/- SEM) in the regrowing group, and from 0.1% to 0.5% (n = 19, 0.23 +/- 0.03%) in the cured group. PCNA staining indices of the regrowing group ranged from 0.6% to 24% (n = 14, 3.7 +/- 1.6%). In the regrowing group, the tumour doubling times ranged from 200 to 2550 days (930 +/- 180 days), and showed a significant inverse correlation with Ki-67 staining indices, but no correlation with PCNA staining indices. The regrowing group showed a significantly higher Ki-67 staining index (n = 14, 0.86 +/- 0.10%) than the cured group (n = 19, 0.23 +/- 0.03%) (p < 0.01). These results indicate that immunocytochemical studies using MIB-1 may be better than those with PCNA for the prediction of regrowth in non-functioning pituitary adenomas. Immunocytochemical study with MIB-1 could lead to the accurate prediction of the rapid regrowing lesions in non-functioning adenomas.