Long-term prognostic performance of Ki67 rate in early stage, pT1-pT2, pN0, invasive breast carcinoma

Interobserver concordance in visual assessment of Ki67 immunohistochemistry in surgical excision specimens from patients with lymph node-negative breast cancer

PURPOSE

This study aimed to determine the interobserver concordance of two methods for proliferation assessment in breast cancer using Ki67 immunohistochemistry.

METHODS

Ki67 was independently assessed in randomly selected tumour samples from patients with lymph node-negative breast cancer using two different methods: either cell counting or visual estimation of hot spot areas. For hot spot cell counting, positive and negative cell numbers were recorded for total cell counts of 300-500, 500-800 and 800-1000 cells. Visual estimation involved allocation of a score from 1 to 5 using a visual scale to estimate percentage positivity. Interobserver agreement for hot spot counting was calculated using a two-way fixed effects intraclass correlation model, and by using Cohen's kappa measure for visual assessment. Prognostic concordance between the two methods was also calculated using Cohen's kappa.

RESULTS

Samples from 96 patients were included in this analysis. Interobserver agreement for hot spot cell counting was excellent (> 0.75) across all three cell count ranges, with correlation coefficients of 0.88 (95% CI 0.84-0.92), 0.87 (95% CI 0.82-0.91) and 0.89 (95% CI 0.85-0.92), respectively. Interobserver agreement with visual estimation was greatest for hot spots compared with areas of intermediate or low proliferation, with kappa scores of 0.49, 0.42 and 0.40, respectively. Both assessment methods demonstrated excellent prognostic agreement.

CONCLUSIONS

Interobserver and prognostic concordance in Ki67 immunohistochemistry assessments was high using either hot spot cell counting or visual estimation, further supporting the utility and reproducibility of these cost-efficient methods to assess proliferation.

Validation of Clinical Treatment Score post-5 years (CTS5) risk stratification in premenopausal breast cancer patients and Ki-67 labelling index

This study aimed to validate the Clinical Treatment Score post-5 years (CTS5)-based risk stratification in a cohort comprising pre- and postmenopausal patients with estrogen receptor (ER)–positive breast cancer. We investigated the clinicopathologic parameters including Ki-67 labelling index (LI) to identify factors affecting late distant recurrence (DR). Women with ER-positive breast cancer who were free of DR for 5 years were identified between January 2004 and December 2009. We investigated the risk of late DR (5–10 years) according to the CTS5 risk group. Cox regression analysis was used to determine the prognostic performance of CTS5 and identify factors associated with late DR. In all, 680 women were included. Of these, 379 (55.7%) were premenopausal and 301 (44.3%) were postmenopausal. At a median follow-up of 118 months, 32 women had late DR. CTS5 was a significant prognostic factor for late DR in both pre- and postmenopausal women. In the low CTS5 group, high Ki-67 LI (> 20%) was a significant risk factor for late DR. CTS5 is a useful tool for assessing the risk of late DR in pre- and postmenopausal women with ER-positive breast cancer. Extended endocrine therapy can be considered in patients with high Ki-67 LI (> 20%) in the low CTS5 group.

Current and potential immunohistochemical biomarkers for prognosis and therapeutic stratification of breast carcinoma

The identification of biomarkers on cancer tissue samples could be obtained through several technologies. In this setting, the immunohistochemistry and in situ hybridization are accessible in most pathology laboratories. Particularly, immunohistochemistry can be used not only for diagnostic issues, but also to define prognostic classes and to define response to specific therapies. Particularly the last applications have been firstly developed in the breast cancer pathology. In addition, the development of molecular classification proposed some prognostic/predictive classes that could be easily defined by immunohistochemistry. Thus, the role of the pathologists has become increasingly important in the definition of prognosis and in the choice therapy, because the immunohistochemical biomarkers are used to guide treatment, to classify breast cancer into biologically and prognostically distinct subtypes. In this review, we will provide information on the current application of the immunohistochemical biomarkers useful in the management of breast cancer patients. Moreover, we consider the application of immunohistochemistry in the definition of the most promising biomarkers derived from molecular studies of the breast cancer, that in the future could integrate the characterization of breast cancer into clinical practice.

Association between Ki-67 expression and clinicopathological features in prognosis of breast cancer: A retrospective cohort study

Background:

Breast cancer is the most common diagnosed female cancer. Breast cancer is also the leading cause of cancer death in females accounting for 13.7% of female cancer-related mortality globally. Variable known prognostic factors such as histological tumor type, tumor size, nodal status, grade, age, and estrogen receptor (ER) status and the proliferation marker – Ki-67 influence the type of treatment decision. The purpose of this present study is to investigate the association between Ki-67 expression with several clinicopathological variables and patients’ outcome.

Materials and Methods:

This is a retrospective cohort study from September 2008 to March 2017; 165 newly diagnosed breast cancer patients were enrolled in the study. Ki67 levels were measured using immunohistochemistry and compared with clinicopathological variables. The relation of Ki67 expression with disease-free survival (DFS) and overall survival (OS) was also analyzed.

Results:

The result of this study revealed that age, tumor size, menopausal status, and human epidermal growth factor receptor 2 (HER2) status had no effect on the patients’ outcome. Patients with ER-positive, progesterone receptor (PR)-positive, and HER2-negative tumors expressed a higher rate of Ki-67 (>10%) than patients with ER-negative, PR-negative, and HER2-positive tumors, respectively. However, we found that Ki-67 levels were not significantly increased statistically with ER, PR, and HER2 statuses. There was a statistically significant correlation between Ki-67 expression and with higher stages of the disease. Multivariate analysis showed that Ki-67 expression could not to be an independent prognostic factor for 5-year OS and DFS. Furthermore, p53 status was only prognostic factor for 5-year OS whereas higher stages of disease and p53 status were prognostic factors for 5-year DFS.

Conclusion:

Ki67 could not be an independent variable for prediction of breast cancer outcome.

Immunohistochemical Evaluation of Ki-67 and Comparison with Clinicopathologic Factors in Breast Carcinomas

Background: Patients primarily received tamoxifen based on their menopausal status due to the lack of immunohistochemistry. A recent study has shown that hormonal receptors were not correlated with menopausal status, and thus, indicating that they present limited therapeutic and prognostic significance in breast cancer management. This study aimed to evaluate Ki-67 value and analyze its association with clinicopathologic parameters in breast cancer patients. Methods: The formalin-fixed paraffin-embedded breast tissue blocks of 125 patients with primary breast carcinomas were subjected to immunohistochemical analysis using Ventana Benchmark® GX automated immunostainer. Analysis of variance and Chi-2 test were used to examine the relationship between Ki-67 and clinicopathologic variables. Results: The mean age of 125 patients included in the study was 47.7 years. The average score of Ki-67 was 56.0%. 84.8% of patients showed Ki-67 ≥ 14%. Mean scores of Ki-67 were correlated with grade (p = 0.006), PR (p = 0.026), histological type, ER, combined ER/RP, and molecular subtype (p < 0.001). Ki-67 was independent of HER2 (p = 0.402) and menopausal status (p = 0.471). The frequency of Ki-67 according to St Gallen 2011 was associated with histological type (p = 0.005), grade (p = 0.005), ER (p < 0.001), combined ER/PR (p = 0.004), and molecular subtype (p = 0.004). There was no significant relationship between the distribution of Ki-67 and the age of the patients (p = 0.859), menopausal status (p = 0.979), PR (p = 0.149), and HER2 (p = 0.597). Conclusion: Ki-67 is useful for treatment decisions in primary breast cancer patients. The high value of Ki-67 was associated with adverse clinicopathologic factors. The increased Ki-67 value should be carefully investigated in triple negative patients.

Knockout validation of antibodies to Ki67: a marker for cellular proliferation

At Abcam, providing a high level of validation has always been a priority and our strategies are constantly evolving as new technologies are developed. The recent knockout (KO) validation initiative, made possible through a partnership with Horizon Discovery and the use of their CRISPR/Cas9 KO cell lines, addresses both antibody specificity and reproducibility on a large scale.

Ki67 is a proliferation marker and determining its expression levels has prognostic and predictive values in cancer (1–5). Hence, it is critical that antibodies used to target Ki67 are highly specific. This study demonstrates the evolving strategies used in our laboratory to validate antibodies to Ki67. The use of a human haploid cell lines where Ki67 expression has been knocked out has unequivocally identified antibodies that bind specifically to Ki67.

Utilising this technology has enabled KO validation of antibodies and, at the time of abstract submission, there are over 650 KO validated antibodies on our catalogue. It is our hope that by using this technique we can help to raise industry standards and contribute to the generation of reproducible research.

Digital image analysis outperforms manual biomarker assessment in breast cancer

In the spectrum of breast cancers, categorization according to the four gene expression-based subtypes 'Luminal A,' 'Luminal B,' 'HER2-enriched,' and 'Basal-like' is the method of choice for prognostic and predictive value. As gene expression assays are not yet universally available, routine immunohistochemical stains act as surrogate markers for these subtypes. Thus, congruence of surrogate markers and gene expression tests is of utmost importance. In this study, 3 cohorts of primary breast cancer specimens (total n=436) with up to 28 years of survival data were scored for Ki67, ER, PR, and HER2 status manually and by digital image analysis (DIA). The results were then compared for sensitivity and specificity for the Luminal B subtype, concordance to PAM50 assays in subtype classification and prognostic power. The DIA system used was the Visiopharm Integrator System. DIA outperformed manual scoring in terms of sensitivity and specificity for the Luminal B subtype, widely considered the most challenging distinction in surrogate subclassification, and produced slightly better concordance and Cohen's κ agreement with PAM50 gene expression assays. Manual biomarker scores and DIA essentially matched each other for Cox regression hazard ratios for all-cause mortality. When the Nottingham combined histologic grade (Elston-Ellis) was used as a prognostic surrogate, stronger Spearman's rank-order correlations were produced by DIA. Prognostic value of Ki67 scores in terms of likelihood ratio χ(2) (LR χ(2)) was higher for DIA that also added significantly more prognostic information to the manual scores (LR-Δχ(2)). In conclusion, the system for DIA evaluated here was in most aspects a superior alternative to manual biomarker scoring. It also has the potential to reduce time consumption for pathologists, as many of the steps in the workflow are either automatic or feasible to manage without pathological expertise.

Quantum dots-based double imaging combined with organic dye imaging to establish an automatic computerized method for cancer Ki67 measurement

As a widely used proliferative marker, Ki67 has important impacts on cancer prognosis, especially for breast cancer (BC). However, variations in analytical practice make it difficult for pathologists to manually measure Ki67 index. This study is to establish quantum dots (QDs)-based double imaging of nuclear Ki67 as red signal by QDs-655, cytoplasmic cytokeratin (CK) as yellow signal by QDs-585, and organic dye imaging of cell nucleus as blue signal by 4′,6-diamidino-2-phenylindole (DAPI), and to develop a computer-aided automatic method for Ki67 index measurement. The newly developed automatic computerized Ki67 measurement could efficiently recognize and count Ki67-positive cancer cell nuclei with red signals and cancer cell nuclei with blue signals within cancer cell cytoplasmic with yellow signals. Comparisons of computerized Ki67 index, visual Ki67 index, and marked Ki67 index for 30 patients of 90 images with Ki67 ≤ 10% (low grade), 10% < Ki67 < 50% (moderate grade), and Ki67 ≥ 50% (high grade) showed computerized Ki67 counting is better than visual Ki67 counting, especially for Ki67 low and moderate grades. Based on QDs-based double imaging and organic dye imaging on BC tissues, this study successfully developed an automatic computerized Ki67 counting method to measure Ki67 index.

Hormonal receptor status, Ki-67 and HER2 expression: Prognostic value in the recurrence of ductal carcinoma in situ of the breast?

PURPOSE

Local recurrence is considered a major concern in patients diagnosed with ductal carcinoma in situ (DCIS), as its invasive occurrence is associated with high rates of distant disease and mortality. This study aims to assess the possible correlation of hormonal receptor status, Ki-67 and HER2 expression with recurrence rates in women with DCIS, taking also into account the potential prognostic effects of grade and age at diagnosis.

METHODS

230 consecutive patients with DCIS were included in this study. Invasive and non-invasive recurrence events were recorded, as a total. Clinicopathological information, as well as PR positivity, ER positivity, HER2 positivity and ki-67 expression were analyzed. Multivariable Cox regression analysis was performed, examining the risk factors for recurrence.

RESULTS

Recurrence was noted in 17.8% of cases; the median follow-up was 44 months. Higher grade (adjusted HR = 1.72, 95%CI: 1.06-2.78), age at diagnosis (adjusted HR = 0.60, 95%CI: 0.43-0.83), Ki-67 expression (adjusted HR = 1.78, 95%CI: 1.11-2.88), and type of administered treatment were independently associated with increased recurrence rates. Recurrence rates were not significantly associated with ER, PR status or HER2 expression.

CONCLUSION

In addition to high grade, administered treatment and younger age at diagnosis, high Ki-67 expression seems to be independently associated with increased likelihood of recurrence in patients with DCIS. Future studies with additional molecular markers seem necessary to further improve the identification of high-risk patients for DCIS recurrence.

Prognostic impact of discrepant Ki67 and mitotic index on hormone receptor-positive, HER2-negative breast carcinoma

Background:

Inconsistencies between mitotic index (MI) and Ki67 measures have been identified in many breast tumour samples. The aim of this study was to describe the prognosis of hormone receptor-positive (HR+) HER2− tumours having discrepant MI and Ki67.

Methods:

We included a cohort of breast cancer patients initially treated by surgery between 2001 and 2005 in the Institut Curie. Breast cancer-specific survival (BCSS) and disease-free survival (DFS) were analysed according to three proliferation groups: high MI/high Ki67 (MI=3, Ki67>20%), low MI/low Ki67 (MI<3, Ki67⩽20%) and discrepant (high MI/low Ki67 or low MI/high Ki67).

Results:

Among the 1430 patients, 19.6% had discrepant Ki67 and MI, 11.6% had high markers and 68.8% had low markers. The 5-year BCSS was 95.8%, 95% CI (0.93–0.98) in the discrepant group, 99.3%, 95% CI (0.993–0.999) in the low-proliferation group and 91.8%, 95% CI (0.88–0.96) in the high-proliferation group. In multivariate analysis, the survival of the discrepant group was lower than that of the low-proliferation group: BCSS hazard ratio (HR)=3.01 (1.32–6.84; P=0.008) and DFS HR=2.07, 95% CI (1.31–3.26; P=0.002). Among grade 2 tumours in multivariate analysis, DFS of the discrepant group was lower than that of the low MI/low Ki67 group: HR=1.98, 95% CI (1.14–3.46), P=0.02. Regarding BCSS, the obtained results were similar.

Conclusion:

The prognosis of patients with discrepant MI and Ki67 appears intermediate between that of low MI/low Ki67 and high MI/high Ki67 groups. These markers should be jointly analysed to clarify prognosis.

Evaluation of an Optimal Cut-Off Point for the Ki-67 Index as a Prognostic Factor in Primary Breast Cancer: A Retrospective Study

The Ki-67 index is an important biomarker for indicating the proliferation of cancer cells and is considered to be an effective prognostic factor for breast cancer. However, a standard cut-off point for the Ki-67 index has not yet been established. Therefore, the aim of this retrospective study was to determine an optimal cut-off point in order to establish it as a more accurate prognostic factor. Immunohistochemical analysis of the Ki-67 index was performed on 4329 patients with primary breast cancer from August 1987 to March 2012. Out of this sample, there were 3186 consecutive cases from September 1997 with simultaneous evaluations of ER, PgR and HER2 status. Cox's proportional hazard model was used to perform univariate and multivariate analyses of the factors related to OS. The hazard ratios (HR) and the p values were then compared to determine the optimal cut-off point for the Ki-67 index. The median Ki-67 index value was 20.5% (mean value 26.2%). The univariate analysis revealed that there was a statistically significant negative correlation with DFS and OS and the multivariate analysis revealed that the Ki-67 index value was a significant factor for DFS and OS. The top seven cut-off points were then carefully chosen based on the results of the univariate analysis using the lowest p-values and the highest HR as the main selection criteria. The multivariate analysis of the factors for OS showed that the cut-off point of 20% had the highest HR in all of the cases. However, the cutoff point of 20% was only a significant factor for OS in the Luminal/HER2- subtype. There was no correlation between the Ki-67 index value and OS in any of the other subtypes. These data indicate that the optimal cut-off point of 20% is the most effective prognostic factor for Luminal/HER2- breast cancer.

Associations and indications of Ki67 expression with clinicopathological parameters and molecular subtypes in invasive breast cancer: A population-based study

Ki67 has potential prognostic and predictive values for breast cancer patients, and has become an important biomarker in routine clinical practice. The aims of the present study were to investigate the distribution of Ki67 expression and its correlation with other clinicopathological parameters in central China. In total, 1,259 patients with newly-diagnosed invasive breast cancer were included in the present study. The clinical information was obtained from the electronic medical records. The expression levels of Ki67, estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) were detected by immunohistochemical analysis. The associations between Ki67 scores and other prognostic factors were evaluated as continuous and categorical variables. The mean value of the Ki67 scores of all patients was 31%. In total, ~36% (456/1,259) of the patients demonstrated a low expression of Ki67. A statistically significant correlation was identified between the mean Ki67 scores and the lymph node status, tumor grade, ER, PR and HER2 status, and clinical stage or molecular subtypes (all P<0.001). When Ki67 was categorized into high (>14%) and low (≤14%) level groups, the χ² test was used to verify these results. The Ki67 scores demonstrated no statistically significant differences between the HER2-positive (non-luminal) and three negative subtypes, with the exception of patients with a tumor size of >2 cm (P=0.02). In conclusion, the results revealed the presence of significant correlations between Ki67 and other clinicopathological parameters.

Quantum dot-based multispectral fluorescent imaging to quantitatively study co-expressions of Ki67 and HER2 in breast cancer

Both Ki67 and HER2 are key prognostic molecules for invasive breast cancer (BC), but the individual relative impacts on prognosis of these molecules are not known. This study was aimed at establishing a quantum dot (QD)-based double-color in-situ quantitative imaging technique to study the co-expressions of Ki67 and HER2, and delineate the individual impacts of these molecules on prognosis. The QD-based fluorescent immunostaining technique could simultaneously image the co-expressions of Ki67 and HER2 in BC specimens, with the former stained as clear red fluorescence in cancer cell nucleus, and the latter as bright green fluorescence on cancer cell membrane. Both Ki67 and HER2 expressions were significantly correlated with 8-year disease free survival (8-DFS) (P<0.05). However, the two molecules had different weights in terms of negative impacts on clinical prognosis. The median 8-DFS was statistically significantly shorter in High-Ki67 High-HER2 subgroup than Low-Ki67 High-HER2 subgroup (11.7 vs. 60.1months, P<0.05), shorter in High-Ki67 Low-HER2 subgroup than Low-Ki67 Low-HER2 subgroup (16.4 vs. 96.0months, P<0.01), shorter in High-Ki67 High-HER2 subgroup than Low-Ki67 Low-HER2 subgroup (11.7 vs. 96.0months, P<0.01), but there were no statistically significant differences in median 8-DFS between High-Ki67 Low-HER2 subgroup and High-Ki67 High-HER2 subgroup (11.7 vs. 16.4months, P=0.586). The hazard ratio (HR) of Ki67 negative impact on 8-DFS was about 3 fold of that of HER2 (HR 4.493 vs. 1.481). This study demonstrated that QD-based fluorescent imaging technique could help the quantitative study on the co-expressions of Ki67 and HER2 in BC, and Ki67 has a greater negative impact on BC prognosis than HER2.

Quantum dots-based quantitative and in situ multiple imaging on ki67 and cytokeratin to improve ki67 assessment in breast cancer

Background

As a marker for tumor cell proliferation, Ki67 has important impacts on breast cancer (BC) prognosis. Although immunohistochemical staining is the current standard method, variations in analytical practice make it difficult for pathologists to manually measure Ki67 index. This study was to develop a fluorescent spectrum-based quantitative analysis of Ki67 expression by quantum-dots (QDs) multiple imaging technique.

Methods

A QDs-based in situ multiple fluorescent imaging method was developed, which stained nuclear Ki67 as red signal and cytoplasmic cytokeratin (CK) as green signal. Both Ki67 and CK signals were automatically separated and quantified by professional spectrum analysis software. This technique was applied to tissue microarrays from 240 BC patients. Both Ki67 and CK values, and Ki67/CK ratio were obtained for each patient, and their prognostic value on 5-year disease free survival was assessed.

Results

This method simultaneously stains nuclear Ki67 and cytoplasmic CK with clear signal contrast, making it easy for signal separation and quantification. The total fluorescent signal intensities of both Ki67 sum and CK sum were obtained, and Ki67/CK ratio calculated. Ki67 sum and Ki67/CK ratio were each attributed into two grades by X-tile software based on the best P value principle. Multivariate analysis showed Ki67 grade (P = 0.047) and Ki67/CK grade (P = 0.004) were independent prognostic factors. Furthermore, area under curve (AUC) of ROC analysis for Ki67/CK grade (AUC: 0.683, 95%CI: 0.613–0.752) was higher than Ki67 grade (AUC: 0.665, 95%CI: 0.596–0.734) and HER-2 gene (AUC: 0.586, 95%CI: 0.510–0.661), but lower than N stage (AUC: 0.760, 95%CI: 0.696–0.823) and histological grade (AUC: 0.756, 95%CI: 0.692–0.820) on predicting the risk for recurrence.

Conclusions

A QDs-based quantitative and in situ multiple imaging on Ki67 and CK was developed to improve Ki67 assessment in BC, and Ki67/CK grade had better performance than Ki67 grade in predicting prognosis.

Prognostic significance of Ki-67 index value at the primary breast tumor in recurrent breast cancer

The Ki-67 index value is a prognostic factor in primary breast cancer and is a proliferation marker that also distinguishes between luminal type A and type B breast cancer. Moreover, a change in Ki-67 index values due to treatment and recurrence is considered to be important in treating breast cancer. In this study, we investigated whether the baseline Ki-67 value in the primary tumor is useful as a prognostic factor following disease recurrence. Immunohistochemical analysis of the Ki-67 index was performed on 4,701 patients with primary breast cancer from 1987 until March, 2013. Among these patients, there were 666 consecutive cases exhibiting recurrence after primary surgery. The fraction of proliferating cells was based on a count of at least 500 tumor cells in the area including the hot spot. The Ki-67 values were divided into 3 groups, namely <20, ≥20 and ≥50%. The investigated items included estrogen receptor (ER), progesterone receptor (PgR), human epidermal growth factor receptor 2 (HER2), tumor size, nodal status for the primary tumor, recurrence site (soft tissue, bone and viscera) and disease-free interval (DFI). The Cox's proportional hazard model was used to perform univariate and multivariate analyses of the factors associated with overall survival (OS) following recurrence. The median follow-up period was 65.9 months in the surviving group. The median Ki-67 value at baseline was 20% in all the cases and 27% in the recurrent cases. The Ki-67 values were low (24%) in patients with bone metastasis and significantly higher in patients with liver or brain metastasis (38 and 55%, respectively). Moreover, DFI was found to be inversely correlated with the Ki-67 values. Univariate analysis was performed to identify the prognostic factors for OS after recurrence. The significant factors included tumor size, lymph node status, ER, PgR, DFI, recurrence site and Ki-67 index value. Among these factors, a multivariate analysis identified the Ki-67 index value in the primary tumor as an independent significant factor, particularly in luminal type tumors. The Ki-67 index value in the primary tumor was a significant prognostic factor for OS after disease recurrence. It is, therefore, important to take the Ki-67 index value into consideration for the treatment and follow-up of breast cancer patients.

Serum Dickkopf-1 expression level positively correlates with a poor prognosis in breast cancer

BACKGROUND

The different expression level of Dickkopf-1 (DKK-1) in different cancers shows that the function of DKK-1 depends on the histological type of the cancer cells and the tissue microenvironment. To our knowledge, the serum expression level of DKK-1 in breast cancer is little known.

METHODS

Blood samples from 125 consecutive patients diagnosed with breast cancer and 53 control subjects from March 2008 to August 2013 were investigated. Serum DKK-1 expression levels were measured by enzyme-linked immunosorbent assay (ELISA). The overall survival (OS) and relapse-free survival (RFS) analyzed by log-rank test, and survival curves were plotted according to Kaplan-Meier.

RESULTS

The mean serum level of DKK-1 in patients with breast cancer was 4.99 ± 1.50 ng/mL, and was significantly higher than that in healthy individuals (1.88 ± 0.81 ng/mL, P < 0.001). DKK-1 level correlated significantly with TNM stage (P = 0.009), tumor grade (P = 0.02), lymph node metastasis (P = 0.001), and expression of HER2 (P = 0.002). The DKK-1 expression level was classified as high or low in relation to the median value, and patients with breast cancer (n = 125) were divided into a high expression group (n = 63) and a low expression group (n = 62). The Kaplan-Meier method for survival analysis showed that the patients with a high serum DKK-1 level had a poorer OS (48.7% vs. 81.3%, p = 0.01) and RFS (24.3% vs. 71.6%, p = 0.003) than those with a low expression level. The multivariate Cox regression analysis indicated that serum DKK-1 level was independent prognostic factors for OS and RFS.

CONCLUSIONS

Serum DKK-1 level can be used as a noninvasive biomarker for the prognosis of breast cancer.

VIRTUAL SLIDES

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/13000_2014_161.

Determinants of outcome of solitary fibrous tumors of the pleura: an observational cohort study

Background

Solitary fibrous tumors of the pleura (SFTP) are rare and their long-term outcome is difficult to predict, as there are insufficient data which allow accurate characterization of the malignant variant. Thus the aim of this study was to describe the outcome and possible determinants of malignant behavior of SFTPs.

Methods

Data were collected retrospectively from medical records of patients treated at the University Hospital Zurich from 1992 to 2012. Kaplan-Meier and Cox regression analysis were performed to define disease-free survival time (defined as survival without tumor-recurrence or tumor-related death) using the classical histo-morphological criteria (tumor size, localization, pedunculation, tumor necrosis or hemorrhage, mitotic activity and nuclear pleomorphism) and immunohistochemical parameters.

Results

42 patients (20 males) with SFTP (median (IQR) age 62 (56–71) years) could be identified. SFTP were associated with symptoms in 50% of all cases. Complete resection was achieved by video-assisted thoracic surgery or thoracotomy in 20 and 22 patients, respectively. Three SFTP-related deaths (7.1%) and four tumor recurrences (9.5%) were observed. Mean disease-free survival time was 136.2 (±13.1) months, and 2-, 5- and 10-year disease-free survival was 91%, 84%, and 67%, respectively. Mean disease-free survival inversely correlated with the mean tumor diameter, number of mitotic figures and proliferation rate (Ki-67 expression). Other criteria (tumor necrosis, atypical localization, sessile tumor, and pleomorphism) were not statistically significant prognostic parameters.

Conclusions

Patients with large SFTP with a high mitotic index and high proliferation rate should be followed-up closely and over a prolonged time period in order to recognize recurrence of the SFTP early and at a treatable stage. Future research on this topic should focus on the prognostic role of immunohistochemistry including Ki-67 expression and molecular parameters.

Decreased expression of C10orf10 and its prognostic significance in human breast cancer

Breast cancer is a common malignant tumor, which severely threatens the health of women with an increasing incidence in many countries. Here, we identified C10orf10 as a novel differentially expression gene using expression microarray screening. The expression analysis indicated that C10orf10 was frequently decreased in human breast cancers compared to noncancerous breast tissues (81/95, P = 0.0063). Kaplan-Meier analysis indicated that patients with low C10orf10 expression showed a poorer prognosis both in mRNA (n = 1115, P = 0.0013) and protein (n = 100, P = 0.003) levels. Univariate and multivariate analysis showed that the C10orf10 expression was an independent prognostic factor for overall survival of breast cancer patients. Further analysis revealed that low expression of C10orf10 was an unfavorable factor for the prognosis of the patients who were luminal A, luminal B, Her2+ subtypes, at histological grade 2, lymph node negative and ER positive. Our data provided the first evidence that C10orf10 expression was frequently decreased in breast cancer tissues, and low expression of C10orf10 may be an important prognostic factor for poorer survival time of breast cancer patients.

Distribution pattern of the Ki67 labelling index in breast cancer and its implications for choosing cut-off values

The Ki67 labelling index (LI - proportion of staining cells) is widely used to reflect proliferation in breast carcinomas. Several cut-off values have been suggested to distinguish between tumours with low and high proliferative activity. The aim of the current study was to evaluate the distribution of Ki67 LIs in breast carcinomas diagnosed at different institutions by different pathologists using the method reflecting their daily practice. Pathologists using Ki67 were asked to provide data (including the LI, type of the specimen, receptor status, grade) on 100 consecutively stained cases, as well as details of their evaluation. A full dataset of 1709 carcinomas was collected from 19 departments. The median Ki67 LI was 17% for all tumours and 14% for oestrogen receptor-positive and HER2-negative carcinomas. Tumours with higher mitotic counts were associated with higher Ki67 LIs. Ki67 LIs tended to cluster around values ending with 5 or 0 both in cases where the values were obtained by counting the proportion of stained tumour cell nuclei and those where the values were obtained by estimation. On the basis of the distribution pattern described, some currently used Ki67 LI cut off values are not realistic, and it is proposed to select more realistic values ending with 0 or 5.

MYC and MXI1 protein expression: potential prognostic significance in women with breast cancer in China

OBJECTIVE

To investigate the expression levels and the clinical significance of MYC and MXI1 proteins in breast cancer.

METHODS

The expression levels of MYC and MXI1 were detected by immunohistochemical assay in 166 cases of breast cancer; the relationships among MYC, MXI1 and the clinicopathological parameters were analyzed by χ2 test. Univariate analysis and Cox's proportional hazards model were used to evaluate the prognostic significance of the 2 proteins.

RESULTS

27.71% of the tumor specimens showed high staining intensity for MYC (high-expression group, HEG-MYC) and 22.89% showed high staining intensity for MXI1 (HEG-MXI1); the expression of 2 proteins was negatively correlated (r = -0.177 p = 0.022). The Kaplan-Meier method for survival analysis showed that patients of the MYC-HEG demonstrated a significantly worse disease-specific survival than those of the MYC-low-expression group (LEG) (χ2 = 11.102, p = 0.001). However, patients of the MXI1-HEG had a significantly better disease-specific survival than those of the MXI1-LEG (χ2 = 7.858, p = 0.005). Both univariate analysis and Cox's proportional hazards model indicated that MYC and MXI1 could be independent prognostic molecular markers.

CONCLUSION

MYC-HEG and MXI1-LEG levels are associated with poor prognosis in patients with breast cancer, suggesting that they may be useful molecular markers in breast cancer prognosis prediction.

Immunohistochemical quantification of the vitamin B12 transport protein (TCII), cell surface receptor (TCII-R) and Ki-67 in human tumor xenografts

BACKGROUND/AIM

Cancer cells have an essential demand for vitamin B12 (cobalamin) to enable cellular replication. The present pilot study quantified the immunohistochemical expression of vitamin B12 transport protein (Transcobalamin II; TCII), cell surface receptor (Transcobalamin II-R; TCII-R) and proliferation protein (Ki-67) in human tumor xenografts.

MATERIALS AND METHODS

Tissue microarray slides containing 34 xenograft tumor tissues were immunohistochemically stained using TCN2 (anti-TCII), CD320 (anti-TCII-R) and MIB-1 (anti-Ki-67) antibodies. Representatively stained areas of all slides were digitally imaged and protein expression was quantified using ImageJ software plugins.

RESULTS

All xenograft tumor tissues stained positively for TCII, TCII-R and Ki-67 proteins; expression varied both within and between tumor types. Correlation between TCII/TCII-R and Ki-67 expression was not significant in xenograft tissues.

CONCLUSION

Proliferating cancer cells express measurable levels of TCII and TCII-R. Immunohistochemical quantification of these markers may be useful as a tool for detection of tumors, tailored selection of anti-tumor therapies and surveillance for evidence of recurrent disease.