Cell Proliferation in Breast Cancer is a Major Determinant of Clinical Outcome in Node-Positive but Not in Node-Negative Patients

Prognostic value of different cut-off levels of Ki-67 in breast cancer: a systematic review and meta-analysis of 64,196 patients

A proliferative marker, expressed as the percentage of cells in a cell cycle, has been developed and used as a discriminant of more aggressive malignant phenotypes in early breast cancer (BC). The marker is usually expressed by the immunohistochemical staining of the cell cycle antigen Ki-67. It has not, however, yet been definitely evaluated, due to methodological concerns, which specific Ki-67 cut-off provide the strongest prognostic information in resected BC. We conducted a meta-analysis to explore the prognostic value of different cut-off levels of Ki-67 in terms of overall survival (OS) and disease-free survival (DFS) in early BC. The databases of PubMed, the ISI Web of Science, EMBASE, SCOPUS, the Cochrane Central Register of Controlled Trials, and CINHAL were used to identify the relevant literature. Data from studies reporting a hazard ratio (HR) and a 95 % confidence interval (CI) calculated as a multivariate analysis were pooled in a meta-analysis, with metaregression used to test for trends in predefined subgroups. All the statistical tests were 2-sided. Forty-one studies encompassing 64,196 BC patients were included in the analysis. Overall, n = 25 studies were available for the OS analysis. The pooled HR for high versus low Ki-67 was 1.57 (95 % CI 1.33-1.87, P < 0.00001). Twenty-nine studies were available for the DFS analysis. The pooled HR for high versus low Ki-67 was 1.50 (95 % CI 1.34-1.69, P < 0.00001). When a cut-off of Ki-67 staining ≥ 25 % was used, the pooled HR for OS was 2.05 (95 % CI 1.66-2.53, P < 0.00001), which was significantly different to studies where the cut-offs chosen were <25 %. In ER+ tumors, the HR for high versus low Ki-67 was similar and significant (HR = 1.51, 95 % CI 1.25-1.81, P < 0.0001). We conclude that Ki-67 has an independent prognostic value in terms of OS in BC patients. The Ki-67 threshold with the greatest prognostic significance is as yet unknown, but a cut-off >25 % is associated with a greater risk of death compared with lower expression rates.

Argyrophilic nucleolar organizer region in MIB-1 positive cells in non-small cell lung cancer: clinicopathological significance and survival

Objective

To evaluate the relation between argyrophilic nucleolar organizer region (AgNOR)-associated proteins and clinicopathological parameters and survival in non-small-cell lung cancer (NSCLC).

Methods

A total of 207 surgical specimens diagnosed as NSCLC were included in this study. Double-staining procedures were performed using antigen Ki-67 (clone MIB-1) and silver nitrate by immunohistochemical and AgNOR-staining methods.

Results

The AgNOR area in MIB-1-positive cells of NSCLC is related to clinicopathological parameters under the TNM (tumor, node, and metastasis) system. The survival of patients with small AgNOR area in MIB-1-positive cells is better than that of patients with large AgNOR area. Molecular, biological (AgNOR area in MIB-1-positive cells), and clinicopathological (greatest tumor dimension, metastases to regional lymph nodes, histology, and differentiation) parameters are independent prognostic factors of NSCLC.

Conclusion

The AgNOR area in MIB-1-positive cells is related to clinicopathological parameters and survival in NSCLC.

Regulation of Rad51 promoter

The DNA double-strand break repair and homologous recombination protein Rad51 is overexpressed in the majority of human cancers. This correlates with therapy resistance and decreased patient survival. We previously showed that constructs containing Rad51 promoter fused to a reporter gene are, on average, 850-fold more active in cancer cells than in normal cells. It is not well understood what factors and sequences regulate the Rad51 promoter and cause its high activity in cancerous cells. Here we characterized regulatory regions and examined genetic requirements for oncogenic stimulation of the Rad51 promoter. We identified specific regions responsible for up- and downregulation of the Rad51 promoter in cancerous cells. Furthermore, we show that Rad51 expression is positively regulated by EGR1 transcription factor. We then modeled the malignant transformation process by expressing a set of oncoproteins in normal human fibroblasts. Expression of different combinations of SV40 large T antigen, oncogenic Ras and SV40 small T antigen resulted in step-wise increase in Rad51 promoter activity, with all the 3 oncoproteins together leading to a 47-fold increase in expression. Cumulatively, these results suggest that Rad51 promoter is regulated by multiple factors, and that its expression is gradually activated as cells progress toward malignancy.

Long-term analysis to objectify the tumour grading by means of automated microscopic image analysis of the nucleolar organizer regions (AgNORs) in the case of breast carcinoma

Background

Apart from a number of cases of inaccurate prognosis in regard to individual patients, the inter- and intra-observer variability of the classical, histological prognosis parameters have been under repeated discussion. For this reason, a long-term analysis was carried out in regard to overall survival by means of automated microscopic image analysis of the nucleolar organizer regions (AgNORs) to objectify tumour grading in the case of breast carcinoma.

This consists of a selective representation of argyrophilic proteins that are associated with the nucleolus organising regions.

Methods

The evaluation included 244 female patients with an average age of 59.3 years. The characterisation of the histological sections was carried out on the basis of the AMBA/R system. With this software the histometric characterisation level was evaluated in terms of the nucleolus organizer regions. The post-observation data were obtained from the clinical register and were complemented by mortality data from the cancer registers and by data supplied by the residents’ registration office of Berlin.

Results

The average post-observation period was 106.6 months. With the Cox-Regression the influence of the co-variables (conventional prognosis parameters and AgNOR parameters) were examined. In the model, only the parameters pN, G and various AgNOR parameters remain present.

Conclusion

There is a strong correlation between survival and selected AgNOR parameters. These could replace the conventional grading as the standard measure for the mitosis rate together with the pleomorphism level. Instead of the-time consuming AMBA/R system originally used, a new implementation of AgNOR quantification with modern VM systems could be applied.

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1449591192859058.

Nucleolar organizer regions in oral squamous cell carcinoma

BACKGROUND AND AIMS

Several diagnostic methods are being employed to detect benign and malignant lesions, one of which is silver nitrate staining for organizer regions. The number of nucleolar organizing regions (NORs) can be used to show the degree of cell activity or metabolism in pathologic lesions. This study was designed to evaluate NORs as determi-nants of precancerous and squamous cell carcinoma.

MATERIALS AND METHODS

A silver colloid technique was applied on paraffin sections of 40 cases of oral squamous cell carcinoma and 25 cases of precancerous lesions; 15 specimens of normal epithelium were selected for the control group. After staining with silver nitrate, argyrophilic nucleolar organizer regions (AgNORs) were counted in 100 epithelial cells in three groups with the use of an oil immersion and ×1000 objective lens. One-way ANOVA and a post hoc Tukey test were used for statistical analysis.

RESULTS

The mean numbers and standard deviations of AgNORs were 1.58 ± 0.76 in normal epithelium, 2.1 ± 1.05 in pre-cancerous lesions and 2.43 ±1.33 in squamous cell carcinoma (SCC). There were statistically significant differences in Ag-NORs numbers between the groups (P<0.001) and significant differences in precancerous lesions between dysplastic and non-dysplastic epithelia (P<0.001). The mean AgNORs count per nucleus increased from healthy epithelium to precancer-ous lesion to SCC.

CONCLUSION

This study suggests that the silver staining technique for the detection of NORs (AgNOR) can be used to distinguish precancerous lesions and benign and malignant lesions.

Genomic instability and proliferative activity as risk factors for distant metastases in breast cancer

The role of genomic instability and proliferative activity for development of distant metastases in breast cancer was analysed, and the relative contribution of these two risk factors was quantified. A detailed quantitative comparison was performed between Ki67 and cyclin A as proliferative markers. The frequency of Ki67 and cyclin A-positive cells was scored in the same microscopic areas in 428 breast tumours. The frequency of Ki67-positive cells was found to be highly correlated with the frequency of cyclin A-positive cells, and both proliferation markers were equally good to predict risk of distant metastases. The relative contribution of degree of aneuploidy and proliferative activity as risk markers for developing distant metastases was studied independently. Although increased proliferative activity in general was associated with an increased risk of developing distant metastases, ploidy level was found to be an independent and even stronger marker when considering the group of small (T1) node negative tumours. By combining proliferative activity and ploidy level, a large group of low risk breast tumours (39%) could be identified in which only a few percentage of the tumours (5%) developed distant metastases during the 9-year follow-up time period.

Prognostic value of a proliferation index including MIB1 and argyrophilic nucleolar organizer regions proteins in node-negative breast cancer

OBJECTIVE

This study was designed to evaluate a cell proliferation marker, including the percentage of cycling cells (MIB1), and the duration of the cell cycle (assessed by argyrophilic nucleolar organizer regions proteins [AgNORs] measurement).

STUDY DESIGN

We included 90 patients with invasive node-negative breast cancer. None received chemotherapy. With the help of a double-staining technique, a proliferation index (PI) was determined by multiplying the percentage of MIB1-positive cells by the mean area of the AgNORs present in those MIB1-positive cells. PI was evaluated for its impact on overall survival (OS) and disease-free survival (DFS).

RESULTS

We demonstrated that PI was correlated to OS. For DFS, it conserved its high prognostic value only in univariate analysis. The global amount of AgNORs was more discriminative for DFS.

CONCLUSION

PI and AgNOR quantification supplied additional prognosis information in node-negative patients, and we propose to integrate them in further studies.

Prognostic relevance of a novel semiquantitative classification of Bcl2 immunohistochemical expression in human infiltrating ductal carcinomas of the breast

BACKGROUND

Bcl2 is an important prognostic parameter in human breast cancer. However, the evaluation of Bcl2 expression by immunohistochemistry is carried out using arbitrary scoring criteria. In the present study, we evaluated the clinical relevance of a novel, semiquantitative classification of the Bcl2 immunostaining based on both the distribution and the intensity of the staining reaction.

PATIENTS AND METHODS

The proposed classification was first validated in 69 breast cancer specimens by comparing the Bcl2 immunostaining with the Bcl2 messenger RNA (mRNA) levels evaluated by real-time RT-PCR. Since a highly significant association was found between protein and mRNA for Bcl2, the immunohistochemical scoring system was applied to 442 patients with infiltrating ductal carcinomas of the breast with long-term follow-up (median observation time 106 months).

RESULTS

In the entire series, the Bcl2 variable was an independent predictor of clinical outcome, and its prognostic independence was maintained when lymph node-negative and -positive patients were considered separately. In this regard, of particular interest was the observation of a subgroup of node-negative breast cancer patients with a negative Bcl2 immunostaining, who had a very high probability of relapse or death (respectively about five and seven times greater than patients with a positive Bcl2 immunostaining). Moreover, the Bcl2 variable retained prognostic significance also in subgroups of patients treated with either adjuvant endocrine therapy or chemotherapy.

CONCLUSIONS

Our results demonstrated that in breast cancer, Bcl2 protein expression parallels its mRNA level, and it has a highly significant and independent prognostic relevance.