Percentage Of Ki-67 Positive Cells Research Articles

The Syk Inhibitor R788 (FosD) Inhibits Tumor Growth in the TCL1 Transgenic Mouse Model of CLL by Blocking Antigen-Dependent BCR Signaling.

Abstract 887CLL B-cells depend on various signals from the microenvironment for survival and proliferation. Among these, antigenic stimuli that are propagated through the B-cell receptor (BCR) are considered particularly important for the development and progression of CLL, suggesting that the BCR signaling pathway could be an important target for therapeutic intervention. We have previously characterized some of the critical components of the signaling pathway downstream of the BCR in CLL B cells and identified the protein tyrosine kinase Syk as a promising therapeutic target. In a recent study we showed that CLL B-cells frequently have increased basal/constitutive Syk activity and are moderately sensitive to the cytotoxic effect of the selective Syk inhibitor R406 [Gobessi et al, Leukemia 2009]. More importantly, the survival signal induced by sustained BCR engagement was completely abolished by R406, suggesting that this compound may exert an even greater effect in vivo by inhibiting antigen-dependent Syk activation. We have now tested this possibility in the Eμ-TCL1 transgenic mouse model of CLL. Aged Eμ-TCL1 mice develop CD5+ B-cell leukemias that, similar to aggressive human CLL, show features of an antigen-driven process, including expression of stereotyped BCRs and reactivity with common autoantigens and microbial agents [Yan et al, Proc Natl Acad Sci USA 2006]. For our experiments we used a TCL1 leukemia (TCL1-002) that does not grow in vitro, but can be propagated in syngeneic recipients in vivo. TCL1-002 cells express an unmutated stereotyped BCR encoded by the VH12/VK4 combination, which reacts with phosphatidylcholine, an autoantigen exposed on the surface of senescent erythrocytes.In vitro experiments showed that R406 is not cytotoxic for TCL1-002 cells, although it completely inhibited both the basal and BCR-induced activation of signaling pathways downstream of Syk. The absence of a direct cytotoxic effect provided a unique opportunity to investigate whether inhibition of BCR signaling will affect leukemia growth in vivo. For this purpose, 1×107 TCL1-002 cells were injected intraperitoneally in 18 syngeneic mouse recipients. Three days later treatment was started in 8 mice with R788, which is the water-soluble prodrug of R406, at a daily dose of 80mg/kg during 18 consecutive days. Because of the rapid clearance of the drug (serum half-life <2 hours) R788 was administered in 3 divided doses at 4 hour intervals. Two weeks after the end of treatment leukemia developed in all mice from the control group (median WBC counts 131×106/ml, range 12-300×106/ml), whereas all R788-treated mice showed normal WBC numbers (median 6×106/ml, range 3-8×106/ml, P<0.001). Three weeks later all mice in the control group had died (median survival 46 days), whereas all mice in the R788 group were still alive and only two of them had detectable leukemic cells. R788 also showed some efficacy in the treatment of mice with overt TCL1-002 leukemias (WBC >50×106/ml). Whereas all mice from the control group (n=9) died between 6 and 18 days from the beginning of therapy, 4 out of 9 mice from the R788 group survived for more than 33 days. The mechanism of R788 activity was primarily related to inhibition of leukemic cell proliferation, as evidenced by a substantial decrease in the percentage of Ki67-positive cells after 7 days of treatment (30% before, 5% after therapy, P<0.001).To investigate whether R788 will also be effective against other TCL1 tumors we treated five TCL1 mice with preleukemic mono- or oligoclonal B-cell expansions during a four week period. R788 reduced the percentage of CD5+/B220+ cells in 2 cases, whereas in 2 other cases the percentage increased. Interestingly, the pattern of clonal Ig gene rearrangements changed during therapy, suggesting that only certain TCL1 clones are sensitive to R788 treatment. In summary, this study shows that R788 can effectively inhibit the growth of certain TCL1 tumors and provides the first in vivo experimental evidence suggesting that inhibition of antigen-dependent BCR signaling could be an effective therapeutic approach in CLL. Disclosures:No relevant conflicts of interest to declare.

A case of recurrent type 1 diabetes mellitus with insulitis of transplanted pancreas in simultaneous pancreas–kidney transplantation from cardiac death donor

A 41-year-old woman undergoing simultaneous pancreas-kidney transplantation from an HLA-mismatched cardiac death donor abruptly developed overt hyperglycaemia under standard immunosuppressive therapy at 48 months after transplantation. Unexpectedly, we found insulitis in the transplanted pancreas and characterised the insulitis. Pancreas graft biopsies were performed 3 years before and after the development of hyperglycaemia and the specimens were examined histologically. Insulitis was absent in the first biopsy, although oxidative DNA changes revealed by 8-hydroxy-2'-deoxyguanosine (8-OHdG) staining were diffusely present both in islet cells and exocrine cells. No Ki67-positive proliferating cells were seen in the islets. Anti-glutamic acid decarboxylase antibody was undetectable 6 months earlier but increased to 6.3 U/l at the development of hyperglycaemia. The level of anti-insulinoma-associated protein 2 antibody was 18.5 U/l. Insulin secretion was severely suppressed and insulin therapy was resumed. In the second biopsy, although acute allograft rejection was minimal, insulin-positive beta cells were markedly reduced, and glucagon-positive alpha cells predominated. CD3-positive T lymphocytes, CD8-positive cytotoxic T lymphocytes and CD68-positive macrophages infiltrated around and into islets. The infiltrating cells expressed Fas ligand as well as granzyme B. More than 80% of islets were affected by insulitis. 8-OHdG-positive cells were also present in islets and exocrine tissue. The percentage of Ki67-positive cells in total islet cells was 1.5%. There were no TUNEL-positive apoptotic cells in the islet cells. The histological features of insulitis in transplanted pancreas were consistent with common type 1 diabetes mellitus, but the clinical course of the recurrence appeared to be more rapid.

Chordoid Glioma: A Case Report and Molecular Characterization of Five Cases

Chordoid gliomas are rare, slow-growing neoplasms of the anterior third ventricle. We reported a case of chordoid glioma in a 41-year-old man with obstructive hydrocephalus. Histologically, the tumor consisted of polygonal epithelioid cells admixed with elongated cells in a myxoid stroma. A prominent lymphoplasmacytic infiltrate was present. The tumor cells expressed glial fibrillary acidic protein (GFAP), epithelial membrane antigen (EMA), vimentin, CD31, CD34, epidermal growth factor receptor (EGFR) and S100 but were negative for pankeratin and E-cadherin. The percentage of Ki67 positive cells was approximately 3%. Weak p53 immunoreactivity was seen in less than 10% of the cells. Array comparative genomic hybridization performed on this case, as well as on four other archived cases, showed losses at several loci. Fluorescence in situ hybridization (FISH) confirmed consistent genetic alterations at 9p21 and 11q13. These are the fifth through ninth reported cases of chordoid gliomas with molecular characterization suggesting a distinct genetic origin from other gliomas.

Immunohistochemical markers of proliferation and vascularisation in preneoplastic bronchial lesions and invasive non-small cell lung cancer

Autofluorescence bronchoscopy (AFB) has been shown to be sensitive to detect preneoplastic lesions in central lung airways system. In early stages of carcinogenesis, up-regulation of cyclooxygenase (COX)-2, Ki67 and/or increased angiogenesis may play a role by promoting the proliferation of tumoral cells and their resistance to apoptosis, as well as angiogenesis, tumor cell invasion and setting up of the metastatic process. The present study compared the expression of proliferative (COX-2, Ki67 and PCNA) and angiogenic markers (CD34 and NG2) between preneoplastic bronchial squamous dysplasia lesions and invasive squamous cell carcinoma. Biopsies obtained during AFB [preneoplastic lesions: low-grade (lesions up to moderate dysplasia), n=13; high-grade lesions (severe dysplasia), n=12] and surgical specimens (resections of bronchogenic carcinoma, n=11) were stained with COX-2, Ki67, PCNA, CD34 and NG2 monoclonal antibodies. Microvessel density (MVD) was analysed based on anti-CD34 immunostaining. Lesions were positive for COX-2 in 12 out of 25 preneoplastic lesions, and in 10 out of 11 invasive carcinomas (p=0.025). In preneoplastic lesions, the mean percentage of Ki67 positive cells was lower compared to invasive carcinomas (37.4+/-5.8 versus 58.6+/-8.4%, p=0.043). In addition, significant differences in MVD were observed between preneoplastic and NSCLC specimen [35.3 (25.9, 61.9) versus 22.1 (20.1, 32.6), p=0.016]. No differences were observed in the mean percentage of PCNA or NG2 positive cells between preneoplastic lesions and invasive carcinomas. Findings of the present study indicate that increases in COX-2 and Ki67 expression may be associated with the development of bronchogenic carcinomas and possibly with acquisition of an invasive phenotype. In contrast, increased CD34 expression in preneoplastic lesions suggests that increased MVD may represent an early marker of lung carcinogenesis.

The Effect of Smoking on Epithelial Proliferation in Healthy and Periodontally Diseased Marginal Gingival Epithelium

Smoking causes an increase in the thickness of gingival epithelium, which is the outcome of increased keratinocyte proliferation or loss. Smoking-related changes in the proliferative activity of the gingival epithelium are largely uncharacterized for periodontal diseases. The aim of the present study was to determine the effects of smoking on the proliferation of the epithelium in periodontally diseased marginal gingiva by comparing the expression patterns of two different proliferation markers. Gingival biopsies (N=60) were obtained from smokers who had clinically healthy gingiva (n=10), smokers with gingivitis (n=10), smokers with periodontitis (n=10), non-smokers with clinically healthy gingiva (n=10), non-smokers with gingivitis (n=10), and non-smokers with periodontitis (n=10). The quantitative measurement of maximum epithelial thickness was performed on hematoxylin and eosin-stained sections. The expression patterns for proliferating cell nuclear antigen (PCNA) and Ki67 were evaluated immunohistochemically. The percentage of PCNA-positive cells was higher than the percentage of Ki67-positive cells in all groups (P<0.001). When the mean values of PCNA and Ki67 were compared in each group, a statistically significant difference was observed only in the healthy smoker group (P=0.003). Significant differences in PCNA proliferation indices were only found between the smoker group and the non-smoker healthy group (P=0.015). Smoking had an affect on the proliferation of cells in the oral gingival epithelium, regardless of periodontal status. The increase in thickness of the epithelium was not associated with smoking; periodontal status and inflammation seemed to be more important factors. Smoking induced the replication activity of gingival epithelium and induced DNA repair.

Clinical response after two cycles compared to HER2, Ki-67, p53, and bcl-2 in independently predicting a pathological complete response after preoperative chemotherapy in patients with operable carcinoma of the breast

IntroductionTo investigate the predictive value of clinical and biological markers for a pathological complete remission after a preoperative dose-dense regimen of doxorubicin and docetaxel, with or without tamoxifen, in primary operable breast cancer.MethodsPatients with a histologically confirmed diagnosis of previously untreated, operable, and measurable primary breast cancer (tumour (T), nodes (N) and metastases (M) score: T2-3(≥ 3 cm) N0-2 M0) were treated in a prospectively randomised trial with four cycles of dose-dense (bi-weekly) doxorubicin and docetaxel (ddAT) chemotherapy, with or without tamoxifen, prior to surgery. Clinical and pathological parameters (menopausal status, clinical tumour size and nodal status, grade, and clinical response after two cycles) and a panel of biomarkers (oestrogen and progesterone receptors, Ki-67, human epidermal growth factor receptor 2 (HER2), p53, bcl-2, all detected by immunohistochemistry) were correlated with the detection of a pathological complete response (pCR).ResultsA pCR was observed in 9.7% in 248 patients randomised in the study and in 8.6% in the subset of 196 patients with available tumour tissue. Clinically negative axillary lymph nodes, poor tumour differentiation, negative oestrogen receptor status, negative progesterone receptor status, and loss of bcl-2 were significantly predictive for a pCR in a univariate logistic regression model, whereas in a multivariate analysis only the clinical nodal status and hormonal receptor status provided significantly independent information. Backward stepwise logistic regression revealed a response after two cycles, with hormone receptor status and lymph-node status as significant predictors. Patients with a low percentage of cells stained positive for Ki-67 showed a better response when treated with tamoxifen, whereas patients with a high percentage of Ki-67 positive cells did not have an additional benefit when treated with tamoxifen. Tumours overexpressing HER2 showed a similar response to that in HER2-negative patients when treated without tamoxifen, but when HER2-positive tumours were treated with tamoxifen, no pCR was observed.ConclusionReliable prediction of a pathological complete response after preoperative chemotherapy is not possible with clinical and biological factors routinely determined before start of treatment. The response after two cycles of chemotherapy is a strong but dependent predictor. The only independent factor in this subset of patients was bcl-2.Trial registration numberNCT00543829

Argyrophilic Nucleolar Organizing Regions and Ki67 Equally Reflect Proliferation in Fine Needle Aspirates of Normal, Hyperplastic, Inflamed, and Neoplastic Canine Lymph Nodes (n = 101)

Background: The count of argyrophilic nucleolar organizing regions (AgNOR) has been considered a useful variable that reflects cellular proliferation in canine lymph nodes, but it has not been compared with other markers of proliferation. Hypothesis: Ki67 and AgNORs are equally useful as markers of tissue proliferation in fine needle aspirates of canine lymph nodes. Animals: A total of 101 dogs.Material and Methods: Prospective, observational study of a convenience sample of dogs. Two smears were prepared for a May‐Gruenwald‐Giemsa stain and a Ki67/AgNOR double stain. In addition, CD3/CD79a immunostaining was performed when cytologic examination revealed a lymphoma. The dogs were grouped as normal (n = 26), reactive hyperplasia (n = 25), lymphadenitis (n = 31), and lymphoma (n = 19), based on the physical examination and the cytologic findings. The AgNOR count/cell, AgNOR area/cell and the percentage of cells staining positive for Ki67 were evaluated in 100–167 cells (median, 113 cells) by using automatic image analysis. Results: Mean (SD) AgNOR counts/cell were 1.36 6 0.19 in normal dogs, 1.55 ± 0.26 in lymphadenitis, 1.65 ± 0.32 in reactive hyperplasia, and 3.67 ± 1.08 in lymphoma. The percentage of Ki67 positive cells was 2.67 ± 0.99% in normal lymph nodes, 5.04 ± 3.34% in lymphadenitis, 5.36 ± 2.14% in reactive hyperplasia, and 30.2 ± 10.8% in lymphoma. All variables were significantly higher in dogs with lymphoma compared with the other groups (P &lt; .0001). The sensitivity and the specificity of the AgNOR count for diagnosing lymphoma were 95 and 96% at a cutoff value of .2.04 AgNORs/cell. The cutoff value for the Ki67 positive cells was .10.40% (sensitivity, 95%; specificity, 98%).Conclusion and Clinical Importance: The results indicated that both AgNOR and Ki67 counts were good diagnostic tools for assessment of proliferation in aspirates of canine lymph nodes.

Expression of oligodendroglial differentiation markers in pilocytic astrocytomas identifies two clinical subsets and shows a significant correlation with proliferation index and progression free survival

The growth pattern of pilocytic astrocytoma (PAs) is unpredictable. Gene expression profiling has recently demonstrated an inverse relationship between myelin basic protein (MBP) expression and progression free survival (PFS) in PAs. We present here the pattern of expression of oligodendroglial differentiation markers (ODMs) in PAs by immunohistochemistry and their correlation with PI and PFS. Sixty-four cases of PA were reviewed and representative sections were stained for Ki-67 and ODMs, including MBP, platelet-derived growth factor receptor-alpha (PDGFR-alpha), Olig-1, and Olig-2. Sections were graded semi-quantitatively for intensity (I: 0-3+) and extent (E: 0-4+) of staining. PI was expressed as a percentage of Ki-67 positive cells. Immunoreactivity of MBP, PDGFR-alpha, Olig-1, and Olig-2 was observed in 84, 56, 97, and 75% of cases, respectively. There was a statistically significant inverse correlation between MBP expression and PI (r (2) = .696, p = .014). A positive correlation was observed between PDGFR-alpha and PI (r (2) = .727, p = .011). Further analysis showed a significant difference in PFS between low expressors [I + E score < or = 3] and high expressors (I + E score > or = 4) for PDGFR-alpha with p < .001. Notably, there was a significant difference in PFS between high expressors of MBP and high expressors of PDGFR-alpha with p < .001. These results suggest that expression of ODMs, especially MBP and PDGFR-alpha, may identify two clinical subsets of PA. In addition, we have shown the expression of 4 different ODMs in PAs, which may support the possibility that PAs arise from oligodendrocyte progenitor/precursor cells probably similar to the O2A progenitor cells in the mouse.

The relationship between FDG uptake in PET scans and biological behavior in breast cancer

Positron emission tomography (PET) is a non-invasive imaging modality used in the diagnosis and staging of breast cancer. However, several factors can affect fluoro-deoxyglucose (FDG) uptake by a tumor. To clarify the parameters that most affect FDG accumulation in tumors, the relationship between standardized uptake values (SUVs) and clinicopathological factors and immunohistopathological analysis was investigated in breast cancer. PET studies were performed preoperatively on 37 patients with breast carcinoma. SUVs were counted at one hour (early phase) and at two hours (delayed phase) after FDG injection. The relationships between SUVs and 13 clinical, pathological and immunohistchemical factors were studied. A significant association was found between FDG accumulation and early and delayed phase mitotic counts (p=0.0018 and 0.0010, respectively), Ki67 positive cell percentage (p=0.0098 and 0.0062, respectively), and nuclear grade (p=0.0232 and 0.0195, respectively). On the other hand, nodal status weakly correlated with the delayed phase (p=0.0907). However, other clinicopathological parameters and immunohistopathological status, which included tumor size, age, histology, estrogen receptor, progesterone receptor and Her2/neu overexpression, did not correlate significantly with FDG uptake. Mitotic count and Ki67 reflect cellular aggressiveness. These parameters were strongly correlated with tracer uptake. Thus our data suggested that the biological behavior of breast cancer is reflected in the variation of FDG uptake by the tumor. However, whether FDG uptake is a true prognostic and predictive factor remains to be confirmed in larger studies over an extended period of time.

Argyrophilic Nucleolar Organizing Regions and Ki67 Equally Reflect Proliferation in Fine Needle Aspirates of Normal, Hyperplastic, Inflamed, and Neoplastic Canine Lymph Nodes (n &amp;hairsp;=&amp;hairsp; 101)

The count of argyrophilic nucleolar organizing regions (AgNOR) has been considered a useful variable that reflects cellular proliferation in canine lymph nodes, but it has not been compared with other markers of proliferation. Ki67 and AgNORs are equally useful as markers of tissue proliferation in fine needle aspirates of canine lymph nodes. A total of 101 dogs. Prospective, observational study of a convenience sample of dogs. Two smears were prepared for a May-Gruenwald-Giemsa stain and a Ki67/AgNOR double stain. In addition, CD3/CD79a immunostaining was performed when cytologic examination revealed a lymphoma. The dogs were grouped as normal (n = 26), reactive hyperplasia (n = 25), lymphadenitis (n = 31), and lymphoma (n = 19), based on the physical examination and the cytologic findings. The AgNOR count/cell, AgNOR area/cell and the percentage of cells staining positive for Ki67 were evaluated in 100-167 cells (median, 113 cells) by using automatic image analysis. Mean (SD) AgNOR counts/cell were 1.36 +/- 0.19 in normal dogs, 1.55 +/- 0.26 in lymphadenitis, 1.65 +/- 0.32 in reactive hyperplasia, and 3.67 +/- 1.08 in lymphoma. The percentage of Ki67 positive cells was 2.67 +/- 0.99% in normal lymph nodes, 5.04 +/- 3.34% in lymphadenitis, 5.36 +/- 2.14% in reactive hyperplasia, and 30.2 +/- 10.8% in lymphoma. All variables were significantly higher in dogs with lymphoma compared with the other groups (P < .0001). The sensitivity and the specificity of the AgNOR count for diagnosing lymphoma were 95 and 96% at a cutoff value of >2.04 AgNORs/cell. The cutoff value for the Ki67 positive cells was >10.40% (sensitivity, 95%; specificity, 98%). The results indicated that both AgNOR and Ki67 counts were good diagnostic tools for assessment of proliferation in aspirates of canine lymph nodes.

Developmental expression of cell cycle regulators in the baboon fetal adrenal gland

Although the human and the nonhuman primate fetal adrenal glands undergo a highly unique pattern of cortical zone-specific intrauterine growth and development, studies of the regulatory components of the cell cycle responsible for this growth have not been conducted. Therefore, the present study determined expression of the cell cycle regulators, cyclin D1 and cyclin E, and their cyclin-dependent kinases, Cdk2, Cdk4, and Cdk6, and Ki67 a marker of cell proliferation within the baboon fetal adrenal cortex during advancing stages of gestation. Fetal adrenal glands were obtained on days 60 (early), 100 (mid), and 160-170 (late) of gestation (term = 184 days). Mean (+/- s.e.) cyclin D1 mRNA levels, determined by RT-PCR and expressed relative to 18S rRNA, were similar at early (0.85 +/- 0.09) and mid (1.04 +/- 0.08) gestation, then decreased (P < 0.001, ANOVA) approximately 50% by late gestation (0.57 +/- 0.04). Cyclin E mRNA levels were also similar at early (2.03 +/- 0.07) and mid (1.63 +/- 0.31) gestation, and decreased by 70% (P < 0.001) in late gestation (0.53 +/- 0.09). Coinciding with the decrease in cyclin D1 and cyclin E, the percentage of Ki67 positive cells in the definitive zone decreased twofold (P < 0.01) between mid (28.2 +/- 3.6) and late (13.8 +/- 1.7) gestation. The cyclin D1 and cyclin E proteins, determined by immunocytochemistry, were expressed at high levels in the definitive zone of baboon fetal adrenal gland, where they decreased between mid- and late gestation. In contrast, immunocytochemical expression of the functionally important steroidogenic enzyme Delta(5)-3beta-hydroxysteroid dehydrogenase (3beta-HSD) became abundant in the definitive and transitional zones with advancing pregnancy. However, fetal adrenal Cdk2, Cdk4, and Cdk6 mRNA levels and protein immunoexpression were similar in the baboon fetal adrenal at early-, mid-, and late gestation. In summary, expression of cyclin D1, cyclin E, and Ki67 decreased, while 3beta-HSD expression increased, in the fetal adrenal cortex, particularly in the definitive zone, between mid- and late-baboon gestation. We propose that a developmental decline in cellular proliferation permits functional differentiation of fetal adrenal cortical cells, leading to increased production of steroid hormones important for placental estrogen synthesis and maturation of organ systems within the developing fetus.

Immunohistochemiczna ocena molekuły Ki67 w tkance polipów nosa

Immunohistochemical assessment of proliferation marker--Ki67 in nasal polyps tissue and in healthy nasal mucosa was performed. There was no statistical significance difference between percentage of Ki67 positive cells in nasal polyps and nasal mucosa. These cells were observed mainly in epithelial layer and few in subepithelial layer. In examined group Ki67 expression was higher in planoepithelial metaplasia. Assessment of cells proliferation processes could be sensitive and early indicator of neoplasmatic transformation. Examined subgroup in witch Ki67 expression was also higher, was subgroup with eosinophilic infiltrations. Cells proliferation processes in nasal polyps tissue are very important occurrence and require further examinations.

Ki-67 Expression Level Is Not a Significant Prognostic Factor in Korean Diffuse Large B-Cell Lymphoma.

The cell proliferation rate of tumors from patients with non-Hodgkin's lymphomas has been shown to correlate with survival in previous studies. The aim of this study was to evaluate the independent prognostic value of Ki-67 expression level and the significance of cell proliferation rate as an outcome predictor. To this end, we reviewed the hospital case records and histopathological materials of 92 patients diagnosed with diffuse large B-cell lymphoma in a single center. The cell proliferative rate was expressed as percentage of Ki-67 positive cells (Ki-67 labeling index). All patients were available Ki-67 expression level. High Ki-67 labeling index was defined as nuclear Ki-67 expression in ≥ 70% of malignant cells. A cutoff point of 70% was used because this divided the group of cases into two subgroups of similar size (Ki-67 labeling index < 70, n = 46, Ki-67 labeling index ≥ 70, n = 46). The median age was 57 years (range, 15 to 83 years). The median follow-up time was 14 months. Sixty-nine (75%) patients were treated R-CHOP regimen initially and 13 (14%) patients were CHOP regimen. In a univariate analysis, age (p =.003), performance (p =.001), serum LDH (p =.020) were significant prognostic factors for overall survival. But Ki-67 had no statistical significance (p =.554). Multivariate analysis used Cox's multivariate regression model revealed that serum LDH (relative risk estimate 6.7; 95% confidence interval, 1.5, 30.5), age (relative risk estimate 7.0; 95% confidence interval, 1.9, 26.4) were independent prognostic factors for overall survival. Taking all the results into consideration, it seems that Ki-67 expression level has no significance as outcome predictor in Korean diffuse large B-cell lymphoma.

Cell proliferation and p53 expression in pseudoepitheliomatous hyperplasia of oral paracoccidioidomycosis

Paracoccidioidomycosis (PCMycosis) is a systemic mycosis frequently found in many regions of Latin America. Microscopically, it is characterised by granulomatous inflammation and pseudoepitheliomatous hyperplasia (PEH). This work describes the proliferation index and p53 expression by immunohistochemistry in PEH of PCMycosis, normal oral mucosa (NOM) and mild oral epithelial dysplasia (ED). Ki67 positive cells were present in the basal and parabasal layers in NOM and PEH, while in ED it was also observed in the spinous layer. Percentage of ki67 positive cells was 7.7, 28.2 and 46.0 in NOM, PEH and ED respectively. p53 was negative in NOM and in PEH it was expressed by few cells in the basal layer of only three cases. However, it was expressed in all cases of ED, in basal and parabasal layers. Although histologically PEH mimics well-differentiated squamous cell carcinoma, its proliferative pattern and p53 expression are more similar to NOM than to dysplasia. These findings, confirm PEH as a reactive process probably associated with the underlying chronic inflammation.

Cyclooxygenase-2 expression in astrocytomas. Relationship with microvascular parameters, angiogenic factors expression and survival

Cyclooxygenase-2 (COX-2) is the enzyme isoform involved in the synthesis of prostaglandins (PGs) and thromboxane from arachidonic acid. The role of the up-regulation of COX-2 in the formation and progression of gliomas has been dealt with in earlier reports, which describe increased levels of PGs within gliomas. In the present study, we examined the expression of COX-2 in diffuse gliomas of astrocytic origin in relation to microvascular parameters, angiogenic factors and survival. A total of 83 cases of diffuse astrocytomas (grade II-IV) were analyzed by immunohistochemistry for the presence of COX-2. COX-2 expression was detected in 79 cases (95%) with an increased expression in grade IV as compared to grades II/III (p=0.024). A positive correlation occurred between COX-2 and angiogenic factors such as vascular endothelial growth factor (VEGF) (p<0.0001) and hypoxia inducible factor (HIF)-1alpha (p=0.005), as well as the tumours' proliferative activity (expressed as the percentage of Ki-67 positive cells) (p=0.032), and total vascular area (TVA) (p=0.040). In univariate analysis, COX-2 was associated with shortened survival (p = 0.050). Multivariate survival analysis showed that the interaction model of COX-2 with grade along with age were the only significant prognostic indicators. These results implicate COX-2 in the angiogenesis and biological aggressiveness of diffuse astrocytomas, and suggest that it would be worthwhile to examine how the inhibition of COX-2 expression may influence astrocytoma patients' survival.

Ki67 Predicts Progression in Early CIN: Validation of a Multivariate Progression-Risk Model

A recent work by Kruse et al. [1], carried out to verify whether CIN 3 lesions are a “matter of co-existence or true progression”, demonstrated a higher prognostic accuracy of Ki67 quantitation over the histopathological classification of uterine cervix intraepithelial neoplasia. The authors specify that the prognostic value consists in the prediction of progression of CIN 1 and 2 lesions to CIN 3. Prognostic marker evaluations are carried out with an automated interactive image analysis system, which permits the quantitation of “Ki67 features”. Two different types of Ki67 evaluations, the 90th percentile of the stratification index and the percentage of Ki67 positive cells in the middle third layer of the epithelium were combined together in a progression risk model that permits the classification of patients with CIN 1 and 2 lesions into two subgroups at high and low risk. This method appears somewhat complicated and at the very least requires rigorous quality controls on determination intra-reproducibility because of the immunoperoxidase staining used and possible background biases. Moreover, I wonder how diffuse the analysis system is in Pathology Units. Having said that, it must be recognised that the negative predictive value of the model was 100%, that is, none of the CIN 1 or 2 “Ki67 model low-risk” cases progressed to CIN 3 during a mean follow-up of 3.4 years. However, as stated by the Authors themselves, the progression rates from CIN 1/CIN 2 to higher grade lesions are fairly low and it would therefore be important to identify lesions that will definitely progress rather than those that will not. Unfortunately, the positive predictive value for Ki67 model is only 30%, that is less than one third of low-grade “Ki67 model high-risk” lesions which actually progressed to higher grade lesions. Doesn’t this mean that 70% of low-grade “Ki67 model high-risk” lesions are actually “over-diagnosed” by the proposed prognostic model? If the Authors’ goal was to predict low-grade CIN progression, I wonder how, with such a low predictive capacity, Ki67 quantitation could possibly modify the current clinical follow-up of these patients.

C-Myc Amplification in Non Hodgkin's-Lymphomas with Burkitt-Like Features Is Associated with a Poor Prognosis.

We retrospectively studied 15 newly diagnosed patients presenting with NHL and Burkitt-like cells (BLCs) after morphological examination and histology review (lymph-nodes: 7 cases, peripheral blood: 5 cases, bone marrow: 3 cases and spleen: 1 patient). Conventional cytogenetic analyses were performed at diagnosis on lymph nodes biopsies (n=6), peripheral blood lymphocytes (n=4), bone marrow (n=4) or spleen (n=1). FISH studies used commercially available probes: IGH/c-MYC fusion signals probes, IGH/Bcl-1 fusion signals probes, IGH/Bcl-2 fusion signals probes and c-Myc 8q24 probe to detect t(8;14)(q24;q32), t(11;14)(q13;q32), t(14;18)((q32;q21) and c-Myc amplification, respectively. Morphological examination and/or histology showed BLCs in all patients. Burkitt-like lymphoma (BLL) is a highly proliferative lymphoma that morphologically resembles Burkitt's lymphoma (BL) but has more polymorph and pleiomorph cells or large lymphoid cells than BL. The mean percentage of Ki-67 positive cells was 80% (range, 70–100%). A normal karyotype was present in 3 cases and a complex karyotype was observed in 12 cases (80%). When combining conventional cytogenetic studies and FISH studies, t(8;14) or the variants t(2;8) or t(8;22) were never detected. In contrast t(11;14)(q13;q32) was found in 4 cases and t(14;18) in 6 cases. Interestingly, c-Myc amplification was observed in all cases with 3 to more than 9 copies in 10–77% metaphase or interphase cells. The diagnosis of follicular lymphoma (FL) was confirmed by a CD5− and CD10− immunologic profile, typical t(14;18) in 4/6 cases and IgH/Bcl-2 fusion gene in all cases. Four cases were classified as mantle cell lymphoma (MCL) with a blastoid variant: MCL diagnosis was established by lymph-node biopsy in 1 case, CD5+ and CD23+ expression in 3/4 cases and 2/4 cases respectively, typical t(11;14)(q13;q32) in 3 cases, complex caryotype including 11 and 14 chromosomal abnormalities in 1 case and IgH/Bcl-1 fusion gene in all cases. Two patients had marginal MZL with a CD5− and CD10− profile and a complex caryotype including +3 and +18. Two patients presented a DLBCL (CD19+, CD20+) with BLCs and one case was classified as T-NHL (CD2+, CD4+, T-cell receptor gene rearrangements) in leukemic phase with BLCs. All these 15 patients have a poor prognosis with a death occurring in 6 patients during the first month after diagnosis. The presence of BLCs was observed independently of the type of lymphomas, FL, MCL or MZL. c-MYC amplification was associated with BLCs and progressive disease. In conclusion, we identified a new subgroup of patients with NHL (14 B-NHL, 1 T-NHL) and a profile including a poor prognosis, Burkitt-like features at presentation without t(8;14)(q24;q32) or its variants and Myc amplification in all cases.

Is adjuvant therapy necessary for breast cancer lesions of less than 1 cm?

9575 Background: The use of adjuvant therapy should be based on appropriate prognostic factors. The aim of this study was to correlate the clinical, biological and pathological characteristics of women with breast cancer lesions of ≤1 cm. Methods: The 3033 patients with invasive operable breast cancer attending the Universitary and Civic Hospitals of Verona between January 1992 and June 2001 were divided into two groups: 664 women (21.9%) with lesions of ≤1cm (group A) and 2369 (78.1%) with lesions >1cm (group B). The patients with a diagnosis of ductal carcinoma in situ, lobular carcinoma in situ or breast sarcoma were excluded. The Chi-squared test and linear correlation were used to study the associations between lesion diameter and other variables. Results: Chi-squared test. Group A had fewer involved nodes (85.1% had no node involvement vs 55%, p<0.001), more ER+ and PgR+ tumours (86.1% vs 76.8%, p<0.001 and 65.8% vs 61.1%, p=0.04), a lower grading (30.7% vs 8.4% G1, 54.7% vs 56.8% G2, and 14.6% vs 34.8% G3, p<0.001) and a lower proliferative index (Ki-67 0–15%: 78.8% vs 53.9%; Ki-67 16–25%: 13.6% vs 24.7%; Ki-67 26–100%: 7.6% vs 21.5%, p<0.001); vascular invasion was present in 14% of the tumours in group A and 44.1% in group B (p<0.001). Group A was less likely to have a symptomatic diagnosis (36% vs 72.3%, p<0.001), and more likely to have a family history of breast cancer (none 62.9% vs 71.6%, I degree 19.2% vs 14.4%, II degree 17.9% vs 14%, p<0.001), an age of >49 years (77.3% vs 74%, p=0.03) and to be postmenopausal (74.6% vs 69.2%, p=0.01); these last two associations may be due to screening in women older than 49 years. Linear correlation. Our results suggest that a larger lesion diameter is related to more positive nodes (mean: 1.8, p<0.001), a lower percentage of ER and PgR positivity (mean 58.47and 35.41, both p<0.001), a higher percentage of Ki-67 positive cells (mean 15.89, p<0.001) and an older age (mean 59.98, p=0.002). Conclusions: Our results show that women with breast cancer ≤1cm have prognostic factors that indicate less aggressive disease, which may be useful when choosing adjuvant therapy. No significant financial relationships to disclose.

Correlation of different markers (p53, EGF-R, c-erbB-2, Ki-67) expression in the diagnostic biopsies and the corresponding resected tumors in non-small cell lung cancer

Substaging using molecular markers has been proposed to try to identify prognostic factors allowing to define groups of patients with lung cancer for whom specific therapy might be of benefit. The pre-operative assessment of these markers seems to be important specially in case of neoadjuvant chemotherapy. The aim of our study was to compare the expression of two potential prognostic factors (p53 and Ki-67) and two potential therapeutic targets (EGF-R and c-erbB-2) assessed on biopsy samples (B) of non-small cell lung cancer (NSCLC) with that of the corresponding resected tumor (RT). The expression of these biological markers was evaluated by immunohistochemistry on B and on the paired RT in 28 patients. The mean percentage of p53 positive cells was 28% in RT and 38% in B with 81% CR between B and RT and 19% FP on B. Considering RT results as standard, the positive (PPV) and negative predictive value (NPV) of the B were, respectively, 74 and 100%. The mean percentage of EGF-R positive cells was 11% in RT and 28% in B. With a cut-off of 1%, we found 85% concordant results (CR) between B and RT, 4% false negative (FN) and 11% false positive (FP) on B. The PPV and NPV values of the B were, respectively, 80 and 92%. The 8% B and 19% RT were considered as positive for c-erbB-2. We found 15% FN and 4% FP on B with 81% CR between B and RT for c-erbB-2. The NPV of the B was 83%. The mean percentage of Ki-67 positive cells was 32% in RT and 14% in B. We found 82% CR between B and RT, 14% FN and 4% FP on B. The PPV of the B was 96%. In conclusion, biopsies may provide reliable information about p53, EGF-R, c-erbB-2 and Ki-67 in lung carcinoma and could help to elaborate a therapeutic strategy.

Proliferation patterns in the canine endometrium during the estrous cycle

The proliferative activity in the endometrium of 58 bitches in different stages of the estrous cycle was assessed by immunohistochemical detection of the Ki-67 proliferation associated nuclear antigen and by counting mitotic figures. The Ki-67 labelling index and the mitotic index were determined in the surface epithelium, the stroma, the crypts and the basal glands by calculating the percentage of Ki-67 positive cells and mitotic figures, respectively, on a total of 500 cells of each category. Endometrial vascular proliferation was also verified by counting the number of Ki-67 positive cells on a total of 100 endothelial cells. The present study showed two proliferation peaks involving different cell groups. In the surface epithelium, the stroma, the blood vessels and the crypts, the highest labelling and mitotic indexes were noticed during proestrus, whereas for the basal glands these indexes significantly increased (P<0.05) during estrus compared to late metestrus and anestrus. Furthermore, a slightly positive correlation (P<0.05) was found between the labelling index in the basal glands and the serum progesterone levels, whereas the labelling indexes in the other cell groups were positively correlated with the estradiol-17β levels, although not always significantly. These findings suggest that regulation of the proliferation in the surface epithelium, the stroma, the blood vessels and the crypts is different from the proliferation in the basal glands.