Ki67 and cyclin A as prognostic factors in early breast cancer. What are the optimal cut-off values?

High miR-30 Expression Associates with Improved Breast Cancer Patient Survival and Treatment Outcome

Simple Summary

Previous research on the miR-30 family and breast cancer patient survival and on miR-30-related chemosensitivity prompted us to design a comprehensive study on the role of the miR-30 family in general and on miR-30d in particular in breast cancer. We present a study consisting of a tumor microarray analysis of 1238 breast cancer patients, a survival analysis, a drug-sensitivity screen with six breast cancer cell lines, and an in-silico pathway analysis. In our analysis, high miR-30d expression was associated with improved survival in breast cancer patients with aggressive tumor phenotypes. In the drug-sensitivity analysis, ectopic expression of miR-30 family members sensitized the cell lines to the treatment. The pathway analysis based on miRNA and mRNA expression in the METABRIC data suggested that the miR-30 family may have an inhibitory role in pathways contributing to EMT and metastasis. Our results suggest prognostic and predictive potential for the miR-30 family for further investigation.

Abstract

Deregulated miRNA expression has been suggested in several stages of breast cancer pathogenesis. We have studied the miR-30 family, in particular miR-30d, in relation to breast cancer patient survival and treatment outcomes. With tumor specimens from 1238 breast cancer patients, we analyzed the association of miR-30d expression with tumor characteristics with the 5-year occurrence of breast cancer-specific death or distant metastasis (BDDM), and with 10-year breast cancer survival (BCS). We conducted a two-stage drug-screen to investigate the impact of miR-30 family members (miR-30a-30e) on sensitivity to doxorubicin and lapatinib in six breast cancer cell lines HCC1937, HCC1954, MDA-MB-361, MCF7, MDA-MB-436 and CAL-120, using drug sensitivity scores (DSS) to compare the miR-30 family mimics to their specific inhibitors. The study was complemented with Ingenuity Pathway Analysis (IPA) with the METABRIC data. We found that while high miR-30d expression is typical for aggressive tumors, it predicts better metastasis-free (p_BDDM = 0.035, HR = 0.63, 95% CI = 0.4–0.9) and breast cancer-specific survival (p_BCS = 0.018, HR = 0.61, 95% CI = 0.4–0.9), especially in HER2-positive (p_BDDM = 0.0009), ER-negative (p_BDDM = 0.003), p53-positive (p_BDDM = 0.011), and highly proliferating (p_BDDM = 0.0004) subgroups, and after adjuvant chemotherapy (p_BDDM = 0.035). MiR-30d predicted survival independently of standard prognostic markers (p_BDDM = 0.0004). In the drug-screening test, the miR-30 family sensitized the HER2-positive HCC1954 cell line to lapatinib (p < 10⁻²) and HCC1937, MDA-MB-361, MDA-MB-436 and CAL120 to doxorubicin (p < 10⁻⁴) with an opposite impact on MCF7. According to the pathway analysis, the miR-30 family has a suppressive effect on cell motility and metastasis in breast cancer. Our results suggest prognostic and predictive potential for the miR-30 family, which warrants further investigation.

Prognostic and Clinicopathological Correlations of Cell Cycle Marker Expressions before and after the Primary Systemic Therapy of Breast Cancer

We aimed to analyze the expression of cell-cycle regulation markers - minichromosome maintenance protein 2 (MCM2), Ki-67, Cyclin-A and phosphohistone-H3 (PHH3) - in pre-treatment core-biopsy samples of breast carcinomas in correlation with known predictive and prognostic factors. Totally 52 core biopsy samples obtained prior to neoadjuvant therapy were analyzed. Immunohistochemistry was performed to analyze the expression of MCM2, Ki-67, Cyclin A and PHH3, which were correlated with the following clinicopathological parameters: clinical TNM, tumor grade, biological subtype, the presence of tumor infiltrating lymphocytes (TIL), pathological tumor response rate to the neoadjuvant therapy and patient survival. All investigated markers showed higher expression in high grade and in triple negative tumors (p < 0.01 and p < 0.05, respectively). Hormone receptor negative tumors showed significantly higher expression of Ki-67 (p < 0.01), MCM2 (p < 0.01) and Cyclin A (p < 0.01) than hormone receptor positive ones. Tumors with increased TIL showed significantly higher Ki-67 expression (p = 0.04). Pattern analysis suggested that novel cell-cycle marker-based subgrouping reveals predictive and prognostic potential. Tumors with high MCM2, Cyclin A or PHH3 expression showed significantly higher rate of pathological complete remission. Tumors with early relapse (progression-free survival ≤2 years) and shortened overall survival also show a higher rate of proliferation. Our cell cycle marker (Ki-67, MCM2, Cyclin A, PHH3) based testing could identify tumors with worse prognosis, but with a favorable response to primary systemic therapy. The pattern of cell-cycle activity could also be useful for predicting early relapse, but our findings need to be further substantiated in larger patient cohorts.

Thymidine phosphorylase affects clinical outcome following surgery and mRNA expression levels of four key enzymes for 5-fluorouracil metabolism in patients with stage I and II non-small cell lung cancer

The expression levels of thymidine phosphorylase (TP), dihydropyrimidine dehydrogenase (DPD), thymidylate synthase (TS) and orotate phosphoribosyltransferase (OPRT) may predict the clinical efficacy of 5-fluorouracil-based chemotherapy in patients with cancer. We herein investigated the differences in the mRNA levels of these enzymes in non-small-cell lung cancer (NSCLC) and evaluated their prognostic value for NSCLC treated by surgical resection. The intratumoral mRNA levels of TP, DPD, TS, and OPRT were quantified in 66 patients with pathological stage I and II NSCLC (adenocarcinoma or squamous cell carcinoma) following complete resection according to the Danenberg Tumor Profile method. The TP level was the only significant prognostic factor for disease-specific survival (DSS) following complete resection; the mean TP mRNA level differed significantly between the high and low mRNA expression groups. The DSS at 5 years was significantly higher in the low TP mRNA compared with that in the high TP mRNA expression group (83.4 vs. 58.6%, respectively; P=0.005). A Cox proportional hazards model revealed that pathological stage, sex, and TP expression were independent prognostic factors for DSS in patients with stage I and II NSCLC following complete resection. Thus, TP level may be used to monitor treatment efficacy and predict the outcome of NSCLC patients.

Nuclear inverse polarity papillary lesions lacking myoepithelial cells: A report of two cases

Here, cases of a 68- (Case 1) and a 44-year-old (Case 2) female are presented. They had an abnormality in the breast, and came to our hospital for further examination and treatment. Radiologically, malignancy could not completely excluded so breast excision was performed. Histologically, both cases revealed papillary neoplastic lesions lined by fibrovascular core and nuclear inverse polarity without atypia. Loss of myoepithelial cells was observed by HE, p63, and calponin. Previous report indicate CK5/6, ER, p63 and MUC3 are important for distinguishing between papillary lesions according to the differential index (based on Allred score) of ([ER total score] + [MUC3 total score])/([CK5/6 total score] + [p63 total score] + 1). Based on this analysis, our two cases had benign lesions. However, based on immunopositivity for cell-cycle marker Cyclin-D1, Case 1 was negative, and Case 2 was about 70% positive. Additionally, the Ki-67 index was <1% in both cases, and no evidence of disease was observed after a maximum 62 months of follow-up in both cases, despite lack of additional treatment. Thus, we propose that lack of myoepithelial cells in papillary lesions do not necessarily indicate malignancy and are thought to be, at the most, uncertain malignant potential.

Breast cancer in young women and prognosis: How important are proliferation markers?

AIM

Compared to middle-aged women, young women with breast cancer have a higher risk of systemic disease. We studied expression of proliferation markers in relation to age and subtype and their association with long-term prognosis.

METHODS

Distant disease-free survival (DDFS) was studied in 504 women aged <40 years and 383 women aged ≥40 years from a population-based cohort. Information on patient characteristics, treatment and follow-up was collected from medical records. Tissue microarrays were produced for analysis of oestrogen receptor, progesterone receptor (PR), Her2, Ki-67 and cyclins.

RESULTS

Young women with luminal tumours had significantly higher expression of Ki-67 and cyclins. Proliferation markers were prognostic only within this subtype. Ki-67 was a prognostic indicator only in young women with luminal PR+ tumours. The optimal cut-off for Ki-67 varied by age. High expression of cyclin E1 conferred a better DDFS in women aged <40 years with luminal PR- tumours (hazard ratio [HR] 0.47 [0.24-0.92]). Age <40 years was an independent risk factor of DDFS exclusively in women with luminal B PR+ tumours (HR 2.35 [1.22-4.50]). Young women with luminal B PR- tumours expressing low cyclin E1 had a six-fold risk of distant disease compared with luminal A (HR 6.21 [2.17-17.6]).

CONCLUSIONS

The higher expression of proliferation markers in young women does not have a strong impact on prognosis. Ki-67 is only prognostic in the subgroup of young women with luminal PR+ tumours. The only cyclin adding prognostic value beyond subtype is cyclin E1. Age is an independent prognostic factor only in women with luminal B PR+ tumours.

Ki67 expression in invasive breast cancer: the use of tissue microarrays compared with whole tissue sections

BACKGROUND

Although the prognostic value of Ki67 in breast cancer is well documented, using optimal cut-points for patient stratification, reproducibility of the scoring and interpretation of the results remains a matter of debate particularly when using tissue microarrays (TMAs). This study aims to assess Ki67 expression assessed on TMAs and their matched whole tissue sections (WTS). Moreover, whether the cut-off used for WTS is reproducible on TMA in BC molecular classes and the association between Ki67 expression cut-off, assessed on TMAs and WTS, and clinicopathological parameters and patient outcome were tested.

METHOD

A large series (n = 707) of primary invasive breast tumours were immunostained for Ki67 using both TMA and WTS and assessed as percentage staining and correlated with each other, clinicopathological parameters and patient outcome. In addition, MKI67 mRNA expression was correlated with Ki67 protein levels on WTS and TMAs in a subset of cases included in the METABRIC study.

RESULTS

There was moderate concordance in Ki67 expression between WTS and TMA when analysed as a continuous variable (Intraclass correlation coefficient = 0.61) and low concordance when dichotomised (kappa value = 0.3). TMA showed low levels of Ki67 with mean percentage of expression of 35 and 22% on WTS and TMA, respectively. MKI67 mRNA expression was significantly correlated with protein expression determined on WTS (Spearman Correlation, r = 0.52) and to a lesser extent on TMA (r = 0.34) (p < 0.001). Regarding prediction of patient outcome, statistically significant differences were detected upon stratification of patients with tumours expressing Ki67 at 10, 15, 20, 25 or 30% in TMA. Using TMA, ≥20% Ki67 provided the best prognostic cut-off particularly in triple-negative and HER2-positive classes.

CONCLUSION

Ki67 expression in breast cancer can be evaluated using TMA although different cut-points are required to emulate results from WTS. A cut-off of ≥20% for Ki67 expression in BC provides the best prognostic correlations when TMAs are used.

Ghrelin is a prognostic marker and a potential therapeutic target in breast cancer

Ghrelin and obestatin are gastrointestinal peptides, encoded by the same preproghrelin gene. Both are expressed in breast cancer tissue and ghrelin has been implicated in breast cancer tumorigenesis. Despite recent advances in breast cancer management the need for new prognostic markers and potential therapeutic targets in breast cancer remains high. We studied the prognostic impact of ghrelin and obestatin in women with node negative breast cancer.

Within a cohort of women with breast cancer with tumor size ≤ 50 mm, no lymph node metastases and no initiation of adjuvant chemotherapy, 190 women were identified who died from breast cancer and randomly selected 190 women alive at the corresponding time as controls. Tumor tissues were immunostained with antibodies versus the peptides.

Ghrelin expression was associated with better breast cancer specific survival in univariate analyses (OR 0.55, 95% CI 0.36–0.84) and in multivariate models, adjusted for endocrine treatment and age (OR 0.57, 95% CI 0.36–0.89). Obestatin expression was non-informative (OR 1.2, 95% CI 0.60–2.46). Ghrelin expression is independent prognostic factor for breast cancer death in node negative patients—halving the risk for dying of breast cancer. Our data implies that ghrelin could be a potential therapeutic target in breast cancer treatment.

Expression of cell cycle markers is predictive of the response to primary systemic therapy of locally advanced breast cancer

We aimed to analyze to what extent expression of four cell cycle regulation markers-minichromosome maintenance protein (MCM2), Ki-67, cyclin A, and phosphohistone-H3 (PHH3)-predict response to primary systemic therapy in terms of pathological complete remission (pCR). In search of an accurate and reproducible scoring method, we compared computer-assisted (CA) and routine visual assessment (VA) of immunoreactivity. We included 57 patients with breast cancer in the study. The cell cycle markers were detected using immunohistochemistry on pre-therapy core biopsy samples. Parallel CA (validated by manual labeling) and standard VA were performed and compared for diagnostic agreement and predictive value for pCR. CA and VA results were dichotomized based on receiver operating characteristic analysis defined optimal cut-off values. "High" was defined by staining scores above the optimal cut-off, while "low" had staining scores below the optimal cut-off. The CA method resulted in significantly lower values for Ki-67 and MCM2 compared to VA (mean difference, -3.939 and -4.323). Diagnostic agreement was highest for cyclin A and PHH3 (-0.586 and -0.666, respectively). Regardless of the method (CA/VA) used, all tested markers were predictive of pCR. Optimal cut-off-based dichotomization improved diagnostic agreement between the CA and VA methods for every marker, in particular for MCM2 (κ = 1, p < 0.000). Cyclin A displayed excellent agreement (κ = 0.925; p < 0.000), while Ki-67 and PHH3 showed good agreement (κ = 0.789, p < 0.000 and κ = 0.794, p < 0.000, respectively). We found all cell cycle markers (Ki-67, MCM2, cyclin A, and PHH3) predictive of pCR. Diagnostic agreement between CA and VA was better at lower staining scores but improved after optimal cut-off-based dichotomization.

Differences in Clinical Outcomes between Luminal A and B Type Breast Cancers according to the St. Gallen Consensus 2013

Purpose

Human epidermal growth factor receptor 2 (HER2)-positive luminal B type comprises estrogen receptor (ER)-positive and HER2-positive cancers, and HER2-negative luminal B type comprises ER-positive cancers showing a Ki-67 labeling index ≥14% or progesterone receptor (PR) expression of <20% according to the St. Gallen consensus 2013. The current study aimed to classify intrinsic subtypes according to the St. Gallen consensus 2013 and determine the differences in clinicopathological parameters and survival outcomes among the molecular types, especially among the luminal types.

Methods

Assessment of molecular types was performed for 267 invasive ductal carcinomas. The differences in clinicopathological parameters, disease-free survival (DFS), and overall survival (OS) among the molecular types were analyzed.

Results

The luminal B type was the most prevalent, at 44.9%, followed by the luminal A, triple-negative (including basal-like type), and HER2 type, at 21.7%, 18.7%, and 14.6%, respectively. There were statistically significant differences in size (p=0.003), nodal status (p=0.046), histologic grade (p<0.001), p53 (p<0.001) and cyclooxygenase 2 (COX-2) positivity (p=0.002), recurrence (p=0.001) and death rates (p=0.036), DFS (p=0.002), and OS (p=0.039) among the molecular types. Significant differences in size (p=0.009), nodal metastasis (p=0.019), histologic grade (p<0.001), p53 positivity (p=0.001), and PR expression (p<0.001) were noted between the luminal A and B types. Among the luminal B type cancers, the distributions of ER and PR scores showed significant differences (p=0.003, p=0.003). p53 positivity in the luminal B type cancers was related to shortened DFS (p=0.034). In luminal type cancers, COX-2 positivity was related to longer DFS (p=0.026).

Conclusion

Different management guidelines should be considered for the luminal A and luminal B breast cancer types. Positive p53 expression in luminal B type cancers and negative COX-2 expression in luminal type cancers seem to be related to poor clinical outcome.

A standardized method for quantifying proliferation by Ki-67 and cyclin A immunohistochemistry in breast cancer

Immunohistochemical analysis of proliferation markers such as Ki-67 and cyclin A is widely used in clinical evaluation as a prognostic factor in breast cancer. The proliferation status of tumors is guiding the decision of whether or not a patient should be treated with chemotherapy because low-proliferative tumors are less sensitive by such treatment. However, the lack of optimal cutoff points and selection of tumor areas hamper its use in clinical practice. This study was performed to compare the Ki-67 and cyclin A expression counted in hot-spot vs average counting based on 5 to 14 random tumor areas in 613 breast carcinomas. We correlated the findings with 10-year follow-up in order to standardize the evaluation of proliferation markers in clinical practice. A significant correlation was found between the percentage of positive cells estimated by Ki-67 and cyclin A both by hot-spot and by average counting. Both methods showed that high expression of Ki-67 and cyclin A is associated with more adverse tumor stage. The cutoff value for Ki-67 for distant metastases was set to 22% and to 15%, using hot-spot and average counting, respectively. For cyclin A, the values were set to 14% and 8% using the respective methods. Survival curves revealed that patients with a high hot-spot proliferation index had a significantly greater risk of shorter tumor-free survival. Our findings suggest that the determination of proliferation markers in breast cancer should be standardized to hot-spot counting and that specific cutoff values for proliferation could be useful as prognostic markers in clinical practice. Moreover, we suggest that expression levels of cyclin A could be used as a complementary marker to estimate the proliferation status in tumors, especially those with "borderline" expression levels of Ki-67, in order to more accurately estimate the proliferations status of the tumors.

Amplification of Mdmx and overexpression of MDM2 contribute to mammary carcinogenesis by substituting for p53 mutations

Background

The p53 tumor suppressor gene is mutated or deleted in nearly half of human cancers. The murine double minute 2 (Mdm2) and Mdmx represent two important cellular regulators of p53. The aim of this study was to evaluate the abnormalities of p53, Mdmx and Mdm2 genes in archived breast cancers.

Methods

We assessed the genetic instability at p53, Mdmx and Mdm2 using high resolution multi-color fluorescent in situ hybridization (FISH) protocol and detected the expression status of the tumor protein p53 (TP53), MDMx and MDM2 by immunohistochemistry in 115 archived samples of infiltrating ductal breast carcinomas with foci of ductal carcinoma in situ (DCIS) components.

Results

The presence of p53 allelic loss and/or TP53 overexpression was observed in 38% out of all patients, and was significantly more often in larger, high grade, ER negative and high ki67 tumors. Mdmx amplification with low-level increase of gene copy number is at high frequency while Mdm2 amplification is rare in primary breast cancer. Mdmx amplification was seen in more invasive carcinomas than preinvasive lesions. MDMx and MDM2 overexpression were detected in 65% and 38% of all cases respectively. Moreover it was showed that most tumors contained either p53 dysfunction or Mdm2 alteration, but not both. This distribution was significant (P < 0.05). Inverse correlation between Mdmx amplification/overexpression and p53 disfunction was also observed (P < 0.05).

Conclusions

Our results suggest the involvement of Mdm2 and Mdmx in p53-independent breast carcinogenesis and Mdmx may contribute to the regulation of p53 independently of Mdm2.

Virtual slides

The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1450529994118798.

The prognostic value of mitotic activity index (MAI), phosphohistone H3 (PPH3), cyclin B1, cyclin A, and Ki67, alone and in combinations, in node-negative premenopausal breast cancer

Proliferation, either as the main common denominator in genetic profiles, or in the form of single factors such as Ki67, is recommended for clinical use especially in estrogen receptor-positive (ER) patients. However, due to high costs of genetic profiles and lack of reproducibility for Ki67, studies on other proliferation factors are warranted. The aim of the present study was to evaluate the prognostic value of the proliferation factors mitotic activity index (MAI), phosphohistone H3 (PPH3), cyclin B1, cyclin A and Ki67, alone and in combinations. In 222 consecutive premenopausal node-negative breast cancer patients (87% without adjuvant medical treatment), MAI was assessed on whole tissue sections (predefined cut-off ≥10 mitoses), and PPH3, cyclin B1, cyclin A, and Ki67 on tissue microarray (predefined cut-offs 7th decile). In univariable analysis (high versus low) the strongest prognostic proliferation factor for 10-year distant disease-free survival was MAI (Hazard Ratio (HR)=3.3, 95% Confidence Interval (CI): 1.8-6.1), followed by PPH3, cyclin A, Ki67, and cyclin B1. A combination variable, with patients with MAI and/or cyclin A high defined as high-risk, had even stronger prognostic value (HR=4.2, 95%CI: 2.2-7). When stratifying for ER-status, MAI was a significant prognostic factor in ER-positive patients only (HR=7.0, 95%CI: 3.1-16). Stratified for histological grade, MAI added prognostic value in grade 2 (HR=7.2, 95%CI: 3.1-38) and grade 1 patients. In multivariable analysis including HER2, age, adjuvant medical treatment, ER, and one proliferation factor at a time, only MAI (HR=2.7, 95%CI: 1.1-6.7), and cyclin A (HR=2.7, 95%CI: 1.2-6.0) remained independently prognostic. In conclusion this study confirms the strong prognostic value of all proliferation factors, especially MAI and cyclin A, in all patients, and more specifically in ER-positive patients, and patients with histological grade 2 and 1. Additionally, by combining two proliferation factors, an even stronger prognostic value may be found.

St Gallen molecular subtypes in primary breast cancer and matched lymph node metastases--aspects on distribution and prognosis for patients with luminal A tumours: results from a prospective randomised trial

Background

The St Gallen surrogate molecular subtype definitions classify the oestrogen (ER) positive breast cancer into the luminal A and luminal B subtypes according to proliferation rate and/or expression of human epidermal growth factor receptor 2 (HER2) with differences in prognosis and chemo-responsiveness. Primary tumours and lymph node metastases might represent different malignant clones, but in the clinical setting only the biomarker profile of the primary tumour is used for selection of adjuvant systemic treatment. The present study aimed to classify primary breast tumours and matched lymph node metastases into luminal A, luminal B, HER2-positive and triple-negative subtypes and compare the distributions.

Methods

Eighty-five patients with available tumour tissue from both locations were classified. The distribution of molecular subtypes in primary tumours and corresponding lymph node metastases were compared, and related to 5-year distant disease-free survival (DDFS).

Results

The St Gallen molecular subtypes were discordant between primary tumours and matched lymph node metastases in 11% of the patients (p = 0.06). The luminal A subtype in the primary tumour shifted to a subtype with a worse prognostic profile in the lymph node metastases in 7 of 45 cases (16%) whereas no shift in the opposite direction was observed (0/38) (p = 0.02). All subtypes had an increased hazard for developing distant metastasis during the first 5 years after diagnosis in both primary breast tumours and matched lymph node metastases, compared with the luminal A subtype.

Conclusion

The classification according to the St Gallen molecular subtypes in primary tumours and matched lymph node metastases, implicates a shift to a more aggressive subtype in synchronous lymph node metastases compared to the primary breast tumour. The selection of systemic adjuvant therapy might benefit from taking the molecular subtypes in the metastatic node into account.

Eukaryotic translation initiation factor 4E (eIF4E) expression is associated with breast cancer tumor phenotype and predicts survival after anthracycline chemotherapy treatment

Abnormal translation of mRNAs frequently occurring during carcinogenesis is among the mechanisms that can affect the expression of proteins involved in tumor development and progression. Eukaryotic initiation factor eIF4E is a key regulator of translation of many cancer-related transcripts and its expression is altered in various cancers and has been associated with worse survival. We determined the eIF4E protein levels using immunohistochemistry (IHC) in 1,233 breast tumors on tissue microarrays. We analyzed the effects of the IHC expression level on tumor characteristics and patient survival, also with stratification by adjuvant chemotherapy treatment. In 1,085 successfully stained tumors, high level of eIF4E protein expression was associated with features of aggressive tumor phenotype, namely grade, estrogen and progesterone receptor negativity, HER2 receptor positivity, and high expression of p53 and Ki67, and with triple negative subtype (p < 0.001). High eIF4E expression was associated with worse breast cancer-specific survival with a hazard ratio (HR) of 1.99 (95 % CI 1.32-3.00, p = 0.0008) and was in a multivariate analysis an independent prognostic factor. High eIF4E expression was associated with worse outcome also after detection of distant metastasis (HR = 1.88, 95 % CI 1.20-2.94, p = 0.0060). In the subgroup analysis the survival effect was strongest among patients treated with anthracycline chemotherapy (HR = 3.34, 95 % CI 1.72-6.48, p = 0.0002), whereas no such effect was seen among patients who had not received anthracycline with significant difference in heterogeneity between the two groups (p = 0.0358). High expression of eIF4E is associated with adverse tumor characteristics and predicts poor breast cancer-specific survival. This effect is emphasized in patients treated with anthracycline chemotherapy. eIF4E as a treatment predictive factor warrants further studies.

Prognostic value of proliferation markers expression in breast cancer

In this study, immunohistochemical expression of five proliferation markers: Ki-67, aurora-A kinase, survivin, B-Myb and cyclin B1, was analyzed. Consecutive 215 tumor samples from breast cancer patients operated from 2002 to 2003 were analyzed using the TMA ("tissue microarray") method. The median follow-up was 95 months (from 7.8 to 107 months). Statistically significant correlations between expression levels in five proliferation markers, and correlations between some of the proliferation markers and traditional prognostic factors were found. Statistically significant prognostic influence of aurora-A kinase, survivin and B-Myb expression levels on overall and disease-free survival was found, and cyclin B1 expression level on disease-free survival. A multivariate analysis confirmed survivin and B-Myb expression as independent prognostic factors of overall (p = 0.0195; p = 0.0004) and disease-free survival (p = 0.0107 and p = 0.0205) in breast cancer patients.

High proliferation is associated with inferior outcome in male breast cancer patients

Assessment of proliferation is important in female breast cancer and individual treatment decisions are based upon its results, especially in the luminal subgroups. Gene expression analyses fail to group male breast cancer into the intrinsic subgroups previously established in female breast cancer. Even though proliferation has been shown to divide male breast cancer into molecular subgroups with different prognoses, the clinical importance of proliferation markers has not yet been elucidated. Previous studies in male breast cancer have demonstrated contradictory results regarding the prognostic impact of histological grade and Ki-67, parameters strongly associated with proliferation. The aim of the present project was to study proliferation in male breast cancer by assessing other proliferation-related markers viz. cyclins A, B, D1 and mitotic count. A total of 197 male breast cancer cases with accessible paraffin-embedded material and outcome data were investigated. Immunohistochemical stainings were performed on tissue microarrays. Kaplan-Meier estimates and the Cox proportional regression models were used for survival analyses with breast cancer death as the event. The subset of patients with high expression of cyclin A (hazard ratio (HR) 3.7; P=0.001) and B (HR 2.7; P=0.02) demonstrated a poorer survival. Furthermore, high mitotic count was associated with an increased risk of breast cancer death (HR 2.5; P=0.01). In contrast, cyclin D1 overexpression was predictive of better breast cancer survival (HR 0.3; P=0.001). In conclusion, high levels of cyclin A and B expression and an elevated mitotic count result in a two to threefold higher risk for breast cancer death, whereas cyclin D1 overexpression halves the risk. The clinical utility of these proliferation markers needs further elucidation.

Analysis of the potent prognostic factors in luminal-type breast cancer

Purpose

Luminal-type breast cancer has a good prognosis compared to other types, such as human epidermal growth factor receptor 2 and triple negative types. Luminal-type breast cancer is classified into luminal A and B, according to the proliferation index. We investigated the clinicopathological factors that affect the prognosis of the luminal-type subgroups.

Methods

We reviewed the medical records and the pathologic reports of 159 luminal-type breast cancer patients who were treated between February 2005 and November 2007. We divided luminal-type breast cancer into luminal A and B, according to Ki-67 (cutoff value, 14%) and analyzed the clinicopathologic factors, such as age at diagnosis, intensity score of estrogen receptor and progesterone receptor, histologic grade, and Bcl-2. Moreover, we compared the disease-free survival (DFS) of each group.

Results

In the univariate analysis, age (p=0.004), tumor size (p=0.010), lymph node metastasis (p=0.001), and Bcl-2 (p=0.002) were statistically significant factors in luminal-type breast cancer. In the multivariate analysis, lymph node (p=0.049) and Bcl-2 (p=0.034) were significant relevant factors in luminal-type breast cancer. In the subgroup analysis, the increased Bcl-2 (cutoff value, 33%) was related with a longer DFS in the luminal B group (p=0.004).

Conclusion

In our study, luminal A breast cancer showed a longer DFS than luminal B breast cancer, further, Bcl-2 may be a potent prognostic factor in luminal-type breast cancer.

Retrospective analysis of risk factors for central nervous system metastases in operable breast cancer: effects of biologic subtype and Ki67 overexpression on survival

OBJECTIVE

Identifying factors that predispose patients to central nervous system (CNS) metastases may hasten disease detection and improve treatment outcomes.

METHODS

We reviewed the records of patients who were diagnosed with clinical stage I-III primary breast cancer at the National Cancer Center Hospital East from 2003 to 2005. Cox proportional hazard models were fitted to reveal risk factors for CNS metastases.

RESULTS

The median follow-up period after the operation was 53.5 months. Among the 591 identified patients with breast cancer, 76 experienced a relapse. Seventeen patients developed CNS metastases. Multivariate analysis indicated that the triple negative (TN) subtype (hazard ratio = 5.5) and a high Ki67 labeling index (LI; hazard ratio = 3.9) were associated with a higher risk for CNS metastases. At 4 years, the TN subtype was associated with significantly worse overall and disease-free survival rates and a higher cumulative incidence of CNS metastases compared with hormone receptor-positive/ human epidermal growth factor receptor-2-negative tumors. Breast cancers with a Ki67 LI ≥30% were also associated with lower overall and disease-free survival rates and a higher cumulative incidence of CNS metastases compared with cancers with a Ki67 LI <30%.

CONCLUSION

TN or Ki67-overexpressing breast cancer produced earlier CNS metastases and lower disease-free and overall survival rates.

Predictive factors for local recurrence in breast cancer

Risk factors for local recurrence in breast cancer after breast conserving therapy (BCT) differ from those for local recurrence after mastectomy. To better guide optimal treatment of individual patients, it is desirable to identify patients at high risk for local recurrence. Several clinical and histopathologic factors, such as young age and presence of ductal carcinoma in situ, are known to be predictors for local recurrence after BCT. After mastectomy, lymph node status and tumor size are dominant risk factors for local recurrence. The results of recent expression profiling studies have explained differences in prognosis and risk for local recurrence and also explained response to different therapies (adjuvant systemic therapy and radiotherapy). Because of the variation in different subtypes of breast cancer and the difference in amount of tumor burden remaining after surgery, finding robust predictive profiles is complex. In this review, we describe the predictive and prognostic factors for local recurrence after mastectomy and BCT and also describe the role of radiosensitivity in local recurrence.

Clinical, genetic, and immunohistochemical characterization of 70 Ukrainian adult cases with post-Chornobyl papillary thyroid carcinoma

BACKGROUND

Increased incidence of papillary thyroid carcinoma (PTC) is observed as a consequence of radiation exposure in connection to the Chornobyl nuclear plant accident in 1986. In this study, we report a cohort of adult Ukrainian patients diagnosed with PTC from 2004 to 2008 following exposure at the age of 18 years or younger.

METHODS

In total, 70 patients were identified and clinically characterized. The common BRAF 1799T>A mutation was assessed by pyrosequencing, the RET/PTC1 and RET/PTC3 (NCOA4) rearrangements by RT-PCR, and the expression of Ki-67 (MIB-1 index), BCL2, cyclin A, and cyclin D1 by immunohistochemistry.

RESULTS

In total, 46/70 (66%) cases carried a BRAF mutation and/or a RET/PTC rearrangement. A BRAF mutation was detected in 26 tumors, RET/PTC1 in 20 cases, and RET/PTC3 in four cases. In four of these cases, BRAF mutation and RET/PTC rearrangement were coexisting. The BRAF mutation was underrepresented among PTCs with accompanying chronic lymphocytic thyroiditis (CLT) compared with PTCs without this feature (12 vs 44%). MIB-1 proliferation index determined by double staining with leukocyte common antigen was low (mean 0.8%; range 0.05-4.5%). Moreover, increased expression of cyclin A was observed in PTCs with a tumor size >2 cm compared with PTCs ≤2 cm (1.2 vs 0.6%). BCL2 and cyclin D1 showed frequent expression but without associations to clinical characteristics or amplification of the CCND1 locus.

CONCLUSIONS

Our results suggest that this cohort has frequent BRAF mutation, RET/PTC1 rearrangement, and low proliferation index. Furthermore, BRAF 1799T>A was underrepresented in PTCs with CLT, and cyclin A expression was associated with increased PTC tumor size.

Combined evaluation of CK5/6, ER, p63, and MUC3 for distinguishing breast intraductal papilloma from ductal carcinoma in situ

The differentiation of intraductal papilloma (IDP) in the breast from ductal carcinoma in situ (DCIS) is sometimes difficult. Fifty papillary lesions (25 DCIS and 25 IDP) were immunohistochemically examined using a panel of antibodies, including CK5/6, ER, p63, Ki-67, chromogranin A, synaptophysin, neuron specific enolase, CD56, MUC1, MUC3, CD44, p21, p27, and p53. The immunohistochemical staining pattern of each antibody was evaluated using the Allred scoring system. Then, the area under curve (AUC) for each antibody was computed by receiver operating characteristic (ROC) analysis. DCIS typically showed high scores for ER and MUC3 reactivity compared with IDP, and the AUC for ER and MUC3 were 0.941 and 0.908, respectively. In contrast, IDP showed high scores for CK5/6 and p63 reactivity compared with DCIS, and the AUC for CK5/6 and p63 were 1.00 and 0.954, respectively. We devised a 'Differential Index' (DI) using the following formula: [S(ER) + S(MUC3)]/[S(CK5/6) + S(p63) + 1]. The distributions of the DI for IDP and DCIS did not overlap when the cutoff value was placed arbitrarily at DI = 1.0. From these results, it is concluded that a panel of four CK5/6, ER, p63, and MUC3 antibodies provide valuable information for differentiating IDP from DCIS.

Effect of image compression and scaling on automated scoring of immunohistochemical stainings and segmentation of tumor epithelium

Background

Digital whole-slide scanning of tissue specimens produces large images demanding increasing storing capacity. To reduce the need of extensive data storage systems image files can be compressed and scaled down. The aim of this article is to study the effect of different levels of image compression and scaling on automated image analysis of immunohistochemical (IHC) stainings and automated tumor segmentation.

Methods

Two tissue microarray (TMA) slides containing 800 samples of breast cancer tissue immunostained against Ki-67 protein and two TMA slides containing 144 samples of colorectal cancer immunostained against EGFR were digitized with a whole-slide scanner. The TMA images were JPEG2000 wavelet compressed with four compression ratios: lossless, and 1:12, 1:25 and 1:50 lossy compression. Each of the compressed breast cancer images was furthermore scaled down either to 1:1, 1:2, 1:4, 1:8, 1:16, 1:32, 1:64 or 1:128. Breast cancer images were analyzed using an algorithm that quantitates the extent of staining in Ki-67 immunostained images, and EGFR immunostained colorectal cancer images were analyzed with an automated tumor segmentation algorithm. The automated tools were validated by comparing the results from losslessly compressed and non-scaled images with results from conventional visual assessments. Percentage agreement and kappa statistics were calculated between results from compressed and scaled images and results from lossless and non-scaled images.

Results

Both of the studied image analysis methods showed good agreement between visual and automated results. In the automated IHC quantification, an agreement of over 98% and a kappa value of over 0.96 was observed between losslessly compressed and non-scaled images and combined compression ratios up to 1:50 and scaling down to 1:8. In automated tumor segmentation, an agreement of over 97% and a kappa value of over 0.93 was observed between losslessly compressed images and compression ratios up to 1:25.

Conclusions

The results of this study suggest that images stored for assessment of the extent of immunohistochemical staining can be compressed and scaled significantly, and images of tumors to be segmented can be compressed without compromising computer-assisted analysis results using studied methods.

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2442925476534995

Variants on the promoter region of PTEN affect breast cancer progression and patient survival

Introduction

The PTEN gene, a regulator of the phosphatidylinositol-3-kinase (PI3K)/Akt oncogenic pathway, is mutated in various cancers and its expression has been associated with tumor progression in a dose-dependent fashion. We investigated the effect of germline variation in the promoter region of the PTEN gene on clinical characteristics and survival in breast cancer.

Methods

We screened the promoter region of the PTEN gene for germline variation in 330 familial breast cancer cases and further determined the genotypes of three detected PTEN promoter polymorphisms -903GA, -975GC, and -1026CA in a total of 2,412 breast cancer patients to evaluate the effects of the variants on tumor characteristics and disease outcome. We compared the gene expression profiles in breast cancers of 10 variant carriers and 10 matched non-carriers and performed further survival analyses based on the differentially expressed genes.

Results

All three promoter variants associated with worse prognosis. The Cox's regression hazard ratio for 10-year breast cancer specific survival in multivariate analysis was 2.01 (95% CI 1.17 to 3.46) P = 0.0119, and for 5-year breast cancer death or distant metastasis free survival 1.79 (95% CI 1.03 to 3.11) P = 0.0381 for the variant carriers, indicating PTEN promoter variants as an independent prognostic factor. The breast tumors from the promoter variant carriers exhibited a similar gene expression signature of 160 differentially expressed genes compared to matched non-carrier tumors. The signature further stratified patients into two groups with different recurrence free survival in independent breast cancer gene expression data sets.

Conclusions

Inherited variation in the PTEN promoter region affects the tumor progression and gene expression profile in breast cancer. Further studies are warranted to establish PTEN promoter variants as clinical markers for prognosis in breast cancer.

Ki67 proliferation in core biopsies versus surgical samples - a model for neo-adjuvant breast cancer studies

BACKGROUND

An increasing number of neo-adjuvant breast cancer studies are being conducted and a novel model for tumor biological studies, the "window-of-opportunity" model, has revealed several advantages. Change in tumor cell proliferation, estimated by Ki67-expression in pre-therapeutic core biopsies versus post-therapeutic surgical samples is often the primary end-point. The aim of the present study was to investigate potential differences in proliferation scores between core biopsies and surgical samples when patients have not received any intervening anti-cancer treatment. Also, a lack of consensus concerning Ki67 assessment may raise problems in the comparison of neo-adjuvant studies. Thus, the secondary aim was to present a novel model for Ki67 assessment.

METHODS

Fifty consecutive breast cancer cases with both a core biopsy and a surgical sample available, without intervening neo-adjuvant therapy, were collected and tumor proliferation (Ki67, MIB1 antibody) was assessed immunohistochemically. A theoretical model for the assessment of Ki67 was constructed based on sequential testing of the null hypothesis 20% Ki67-positive cells versus the two-sided alternative more or less than 20% positive cells..

RESULTS

Assessment of Ki67 in 200 tumor cells showed an absolute average proliferation difference of 3.9% between core biopsies and surgical samples (p = 0.046, paired t-test) with the core biopsies being the more proliferative sample type. A corresponding analysis on the log-scale showed the average relative decrease from the biopsy to the surgical specimen to be 19% (p = 0.063, paired t-test on the log-scale). The difference was significant when using the more robust Wilcoxon matched-pairs signed-ranks test (p = 0.029). After dichotomization at 20%, 12 of the 50 sample pairs had discrepant proliferation status, 10 showed high Ki67 in the core biopsy compared to two in the surgical specimen (p = 0.039, McNemar's test). None of the corresponding results for 1000 tumor cells were significant - average absolute difference 2.2% and geometric mean of the ratios 0.85 (p = 0.19 and p = 0.18, respectively, paired t-tests, p = 0.057, Wilcoxon's test) and an equal number of discordant cases after dichotomization. Comparing proliferation values for the initial 200 versus the final 800 cancer cells showed significant absolute differences for both core biopsies and surgical samples 5.3% and 3.2%, respectively (p < 0.0001, paired t-test).

CONCLUSIONS

A significant difference between core biopsy and surgical sample proliferation values was observed despite no intervening therapy. Future neo-adjuvant breast cancer studies may have to take this into consideration.

Does analysis of biomarkers in tumor cells in lymph node metastases give additional prognostic information in primary breast cancer?

BACKGROUND

Prognostic and treatment-predictive biomarkers in primary breast cancer are routinely analyzed in the primary tumor, whereas metastatic tumor cells in lymph node metastases are not characterized. The present study aimed to define the concordance between biomarkers in matched pairs of breast cancers and lymph node metastases and to relate their expression to clinical outcome.

METHODS

Patients with primary breast cancer treated with adjuvant tamoxifen for 2 years were included. A tissue microarray of primary tumors and lymph node metastases was constructed, and estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), and Ki67 were analyzed immunohistochemically in 262, 257, 104, and 101 patients, respectively. Five years' distant disease-free survival (DDFS) was used as the primary end point.

RESULTS

The concordance for biomarker expression in primary tumors and corresponding lymph node metastases was 93% for ER, 84% for PR, 97% for HER2, and 85% for Ki67. The discordant cases for HER2 status were all negative in the tumor but positive in the node. ER positivity was a significant independent predictor of improved 5-year DDFS when analyzed in the primary tumor as well as in the lymph node metastases. Ki67 positivity analyzed in both locations correlated with shortened DDFS. HER2 positivity at both locations was an indicator of early relapse.

CONCLUSIONS

The concordance for the biomarkers analyzed in matched pairs of primary tumors and lymph node metastases was high. Moreover, survival analyses showed that the expression of biomarkers in lymph node metastases can provide prognostic information when no analyses of the primary tumor can be done. Treatment selection based on biomarkers in the lymph node is a topic for further studies.

Detection of CHK1 and CCND1 gene copy number changes in breast cancer with dual-colour fluorescence in-situ hybridization

AIMS

To investigate the correlation between CCND1 amplification and CHK1 deletion in breast cancer, and to explore their role in tumorigenesis and progression, a comparative study of the gene copy number changes of CCND1 and CHK1 was performed with dual-colour fluorescence in-situ hybridization (FISH).

METHODS AND RESULTS

Sixty-one infiltrating ductal breast carcinomas with foci of ductal carcinoma in situ (DCIS) components were selected for dual-colour FISH. A strong correlation was found between CCND1 amplification and CHK1 deletion (P<0.0001). Fourteen cases were detected that demonstrated both CCND1 amplification and CHK1 deletion. Interestingly, when comparing the infiltrating and non-invasive areas for the same tumour, we found three cases with CCND1 amplification in the infiltrating areas but not in the DCIS areas. We did not find a CHK1 gene profile difference between infiltrating and DCIS areas in the same lesions.

CONCLUSIONS

Our findings suggest that CCND1 amplification and CHK1 deletion are common events in breast cancer, and that the two genetic alterations often coexist. Our data also suggest that CHK1 deletion is an early genetic event in the development of breast cancer and can be detected at the DCIS stage, whereas CCND1 amplification is more likely to be associated with tumour progression.

Development and evaluation of a virtual microscopy application for automated assessment of Ki-67 expression in breast cancer

Background

The aim of the study was to develop a virtual microscopy enabled method for assessment of Ki-67 expression and to study the prognostic value of the automated analysis in a comprehensive series of patients with breast cancer.

Methods

Using a previously reported virtual microscopy platform and an open source image processing tool, ImageJ, a method for assessment of immunohistochemically (IHC) stained area and intensity was created. A tissue microarray (TMA) series of breast cancer specimens from 1931 patients was immunostained for Ki-67, digitized with a whole slide scanner and uploaded to an image web server. The extent of Ki-67 staining in the tumour specimens was assessed both visually and with the image analysis algorithm. The prognostic value of the computer vision assessment of Ki-67 was evaluated by comparison of distant disease-free survival in patients with low, moderate or high expression of the protein.

Results

1648 evaluable image files from 1334 patients were analysed in less than two hours. Visual and automated Ki-67 extent of staining assessments showed a percentage agreement of 87% and weighted kappa value of 0.57. The hazard ratio for distant recurrence for patients with a computer determined moderate Ki-67 extent of staining was 1.77 (95% CI 1.31-2.37) and for high extent 2.34 (95% CI 1.76-3.10), compared to patients with a low extent. In multivariate survival analyses, automated assessment of Ki-67 extent of staining was retained as a significant prognostic factor.

Conclusions

Running high-throughput automated IHC algorithms on a virtual microscopy platform is feasible. Comparison of visual and automated assessments of Ki-67 expression shows moderate agreement. In multivariate survival analysis, the automated assessment of Ki-67 extent of staining is a significant and independent predictor of outcome in breast cancer.

PIK3CA mutations may be discordant between primary and corresponding metastatic disease in breast cancer

PURPOSE

PIK3CA mutations are frequent in breast cancer and activate the PI3K/Akt pathway. Unexpectedly, PIK3CA mutation appears in general to be associated with better outcome. In a cohort of patients where both primary and metastatic lesions were available, the objective was to assess changes in PIK3CA mutations. We wished to discern whether selective pressures occur and the influence of PIK3CA mutation on time to recurrence.

EXPERIMENTAL DESIGN

Formalin-fixed paraffin-embedded tumor blocks were obtained from 104 patients with paired samples from primary tumors and corresponding asynchronous metastatic breast tumors. Samples were analyzed for PIK3CA mutations (exons 9 and 20) as well as immunohistochemical evaluation for PTEN, pAKT, Ki67, ER, and HER2.

RESULTS

PIK3CA mutation was detected in 45% of the primary tumors. Overall, there was a net gain in mutation in metastatic disease, to 53%; nonetheless, there were instances where metastases were wild type in patients with PIK3CA mutant primary tumors. Laser capture microdissection on a subset of cases revealed microheterogeneity for PIK3CA mutational status in the primary tumor. PIK3CA mutants overall showed a significantly longer time to first recurrence than wild type cases (P = 0.03).

CONCLUSION

PIK3CA mutations occur at high frequency in primary and metastatic breast cancer; these may not necessarily confer increased aggressiveness as mutants had a longer time to recurrence. Because PIK3CA status quite frequently changes between primary and metastatic disease, it emphasizes the necessity of assessing the PIK3CA status in the metastatic lesion for selection of PIK3CA inhibitor therapy.

Circulating Ki-67 index in plasma as a biomarker and prognostic indicator in chronic lymphocytic leukemia

Ki-67 is a nuclear antigen that is expressed in all stages of the cell cycle, except G(0), and is widely used as a marker of cellular proliferation in human tumors. We recently showed that elevated levels of Ki-67 circulating in plasma (cKi-67) are associated with shorter survival in patients with acute lymphoblastic leukemia. The current study included 194 patients with CLL and 96 healthy control subjects. cKi-67 levels in plasma were determined using an electrochemiluminescent immunoassay. We normalized the cKi-67 level to the absolute number of lymphocytes in the patient's peripheral blood to establish the plasma cKi-67 index. The cKi-67 index showed significant correlation with lymph node involvement and Rai stage (P=0.05). Higher cKi-67 index values were significantly associated with shorter survival. Multivariate Cox proportional hazards regression analysis demonstrated that the association of the cKi-67 index with shorter survival was independent of IgV(H) mutation status. In a multivariate model incorporating the cKi-67 index with B2M and IgV(H), only cKi-67 index and B2M levels remained as independent predictors of survival. The results of this study suggest that the plasma cKi-67 index, along with B2M level, is a strong predictor of clinical behavior in CLL.

Glycodelin expression associates with differential tumour phenotype and outcome in sporadic and familial non-BRCA1/2 breast cancer patients

Glycodelin (encoded by PAEP gene) is a secreted lipocalin protein mainly expressed in reproductive tissues, but also in several tumour types. In the breast, glycodelin is expressed both in normal epithelial and cancerous tissue. To investigate the association of glycodelin with clinicopathological features of breast cancer and outcome of patients we evaluated the protein expression of glycodelin in a large series of breast tumours. Immunohistochemical analysis of tissue microarrays was used to study glycodelin expression on 399 sporadic and 436 familial non-BRCA1/2 tumours with strong family history. Gene expression analysis was used to define genes co-expressed with PAEP in sporadic and familial non-BRCA1/2 breast tumours. In the sporadic series, the glycodelin expression associated with low proliferation rate (P < 0.001), with a tendency towards well-differentiated tumours (grades 1 and 2, P = 0.012) and high cyclin D1 (P = 0.034) expression. However, in familial non-BRCA1/2 cases with strong family history glycodelin expression associated with a less favourable phenotype, i.e. positive lymph node status (P = 0.003) and HER2-positive tumours (P = 0.009). Moreover, the patients with glycodelin-positive tumours had an increased risk for distant metastases (P = 0.001) and in multivariate analysis glycodelin expression was an independent predictor of metastasis (hazard ratio (HR) = 2.22, 95% confidence interval (95% CI) = 1.22-4.03, P = 0.009) in familial non-BRCA1/2 breast cancer. Gene expression analysis further revealed different gene expression profiles correlating with the PAEP expression in the sporadic and familial non-BRCA1/2 breast cancers. Our findings suggest differential progression pathways in the sporadic and familial non-BRCA1/2 breast tumours expressing glycodelin.

The Expression Patterns of ER, PR, HER2, CK5/6, EGFR, Ki-67 and AR by Immunohistochemical Analysis in Breast Cancer Cell Lines

The molecular classification for breast carcinomas has been used in clinical studies with a simple surrogate panel of immunohistochemistry (IHC) markers. The objective of this current project was to study the molecular classification of commonly used breast cancer cell lines by IHC analysis. Seventeen breast cancer cell lines were harvested, fixed in formalin and made into cell blocks. IHC analyses were performed on each cell block with antibodies to estrogen receptor (ER), progesterone receptor (PR), HER2, EGFR, CK5/6, Ki-67 and androgen receptor (AR). Among the 17 cell lines, MCF-7 and ZR-75-1 fell to Luminal A subtype; BT-474 to Luminal B subtype; SKBR-3, MDA-MD-435 and AU 565 to HER2 over-expression subtype; MDA-MB-231, MCF-12A, HBL 101, HS 598 T, MCF-10A, MCF-10F, BT-20, 468 and BT-483 to basal subtype. MDA-MB-453 belonged to Unclassified subtype. Since each subtype defined by this IHC-based molecular classification does show a distinct clinical outcome, attention should be paid when choosing a cell line for any study.

Histopathological prognostic factors in early breast carcinoma: an evaluation of cell proliferation in carcinoma cells

Early breast carcinoma is defined as pathological stage 1 (pT1N0M0) tumour and its incidence has recently increased possibly due to the advent of mammography based mass screening. Overall survival of these patients is in general excellent, but more than 20% of them will eventually develop distant metastasis and die. Therefore, an establishment of prognostic factors could contribute greatly to determining the algorithm for treating these patients after surgery. Histopathological prognostic factors still play pivotal roles in the management of these patients. Among these, Nottingham histological grade is considered the gold standard for determining the clinical outcome of early breast cancer patients if done in optimally processed tissue specimens by well-trained pathologists. Among these histological factors of Nottingham histological grade, mitotic index has been demonstrated to provide the most significant information as to prognosis of these patients. Attempts have been made to assess the status of tumour cell proliferation in practical, reproducible and accurate manners in the past. Among these attempts, immunohistochemical analysis of cell cycle associated nuclear antigens, especially Ki67/MIB1 labelling index in archival materials, has been reported to provide clinically inert and significant information. However, its methodologies, including processing of the specimens, and modes of interpretation should be standardised before this Ki67/MIB1 labelling index can become incorporated into routine clinical practice in the management of early breast carcinoma patients.

The prognostic value of Ki67 is dependent on estrogen receptor status and histological grade in premenopausal patients with node-negative breast cancer

The aim of this study was to evaluate the prognostic value of Ki67 in relation to established prognostic factors in lymph node-negative breast cancer, and furthermore, whether the prognostic impact was dependent on estrogen receptor (ER) status and histological grade. In 200 premenopausal patients, with 5 years of follow-up, Ki67 was determined on tissue microarrays. In univariate analysis, Ki67 (< or = 20 vs >20%) was a prognostic factor for distant disease-free survival (hazard ratio: 2.7, 95% confidence interval: 1.3-5.4, P=0.005) and overall survival (hazard ratio: 4.9, 95% confidence interval: 1.7-14, P=0.003). When stratifying for ER status and histological grade, Ki67 was a significant prognostic factor for distant disease-free survival and overall survival only in the ER-positive group, and only in patients with histological grade 2, respectively. In multivariate analysis, human epidermal growth factor receptor 2 and age were independent prognostic factors for distant disease-free survival, whereas Ki67, histological grade, and tumor size were not. Ki67 was, however, an independent prognostic factor in the 87% of the patients who had not received adjuvant medical treatment. Agreement between the three readers was very good (kappa-values: 0.83-0.88). Furthermore, Ki67 was a significant prognostic factor for all three investigators (hazard ratio: 2.7-3.2). This study shows that Ki67 is a prognostic factor in node-negative breast cancer. It is noteworthy that the prognostic information of Ki67 is restricted to ER-positive patients, and to patients with histological grade 2. Taken together, Ki67, as an easily assessed and reproducible proliferation factor, may be an alternative or complement to histological grade as a prognostic tool and for selection of adjuvant treatment.

Circulating Ki-67 protein in plasma as a biomarker and prognostic indicator of acute lymphoblastic leukemia

Tissue-based determination of Ki-67, a marker of cellular proliferation, has shown prognostic value in solid tumors and hematological malignancies. We developed and validated an electrochemiluminescence-based method for sensitive measurement of circulating Ki-67 in plasma (cKi-67). This assay demonstrated significantly higher levels of cKi-67 in patients with newly diagnosed acute lymphoblastic leukemia (ALL) (n=27; median, 762; range, 0-4574U/100 microL) than in healthy control subjects (n=114; median, 399; range, 36-2830U/100 microL). Moreover, elevated plasma cKi-67 was associated with significantly shorter survival in ALL patients (P=0.05). These findings suggest that Ki-67 can be detected in circulation and has potential for use as a biomarker for predicting clinical behavior in ALL.

Analysis of cyclins A, B1, D1 and E in breast cancer in relation to tumour grade and other prognostic factors

Background

The cell cycle is promoted by activation of cyclin dependent kinases (Cdks), which are regulated positively by cyclins and negatively by Cdk inhibitors. Proliferation of carcinoma is associated with altered regulation of the cell cycle. Little is known on the combined alterations of cyclins A, B1, D1 and E in breast cancer in relation to the tumour grade and other prognostic factors.

Findings

Immunohistochemical analysis of cyclins A, B1, D1 and E, estrogen receptor, progesterone receptor, Ki-67, Her-2/neu and CK5/6 was performed on 53 breast carcinomas. mRNA levels of the cyclins were analysed of 12 samples by RT-PCR. The expression of cyclins A, B1 and E correlated with each other, while cyclin D1 correlated with none of these cyclins. Cyclins A, B1 and E showed association with tumour grade, Her-2/neu and Ki-67. Cyclin E had a negative correlation with hormone receptors and a positive correlation with triple negative carcinomas. Cyclin D1 had a positive correlation with ER, PR and non-basal breast carcinomas.

Conclusion

Cyclin A, B1 and E overexpression correlates to grade, Ki-67 and Her2/neu expression. Overexpression of cyclin D1 has a positive correlation with receptor status and non-basal carcinomas suggesting that cyclin D1 expression might be a marker of good prognosis. Combined analysis of cyclins indicates that cyclin A, B and E expression is similarly regulated, while other factors regulate cyclin D1 expression. The results suggest that the combined immunoreactivity of cyclins A, B1, D and E might be a useful prognostic factor in breast cancer.

The breast cancer susceptibility mutation PALB2 1592delT is associated with an aggressive tumor phenotype

PURPOSE

To determine the effect of the breast cancer susceptibility mutation PALB2 1592delT on tumor phenotype and patient survival.

EXPERIMENTAL DESIGN

We defined the PALB2 mutation status in 947 familial and 1,274 sporadic breast cancer patients and 1,079 population controls, and compared tumor characteristics and survival in mutation carriers relative to other familial and sporadic cases and to 79 BRCA1 and 104 BRCA2 mutation carrier cases.

RESULTS

The PALB2 1592delT mutation was found in 19 familial [2.0%; odds ratio, 11.03; 95% confidence interval (95% CI), 2.65-97.78; P < 0.0001] and eight sporadic patients (0.6%; odds ratio, 3.40; 95% CI, 0.68-32.95; P = 0.1207) compared with two (0.2%) control individuals. Tumors of the PALB2 mutation carriers presented triple negative (estrogen receptor negative/progesterone receptor negative/HER negative) phenotype more often (54.5%; P < 0.0001) than those of other familial (12.2%) or sporadic (9.4%) breast cancer patients. They were also more often of higher grade (P = 0.0027 and P = 0.0017, respectively) and had higher expression of Ki67 (P = 0.0004 and P = 0.0490, respectively). Carrying a PALB2 mutation was also associated with reduced survival, especially in familial cases (hazard ratio, 2.30; 95% CI, 1.01-5.24; P = 0.0466) and among familial patients with HER2-negative tumors (hazard ratio, 4.57; 95% CI, 1.96-10.64; P = 0.0004). Carrying a BRCA2 mutation was also found to be an independent predictor of poor survival at 10-year follow-up (P = 0.04).

CONCLUSIONS

The PALB2 1592delT mutation has a strong effect on familial breast cancer risk. The tumors rising in patients carrying this mutation manifest a phenotype associated with aggressive disease. Our results also suggest a significant impact of carrying a BRCA2 mutation on long-term breast cancer survival.

High cyclin B1 expression is associated with poor survival in breast cancer

Cyclin B1 regulates the G₂-M transition of the cell cycle. Cyclin B1 expression is higher in premalignant and malignant than normal breast lesions. Correlation of cyclin B1 expression with other histopathological variables and prognostic role in breast cancer are not fully understood. Traditionally used prognostic criteria identify large subset of patients to receive adjuvant chemotherapy and to be exposed to adverse effects. A reliable and simple method helping prognostic evaluation in breast cancer is needed. We analysed cyclin B1 expression on 1348 invasive breast cancers and studied correlations with other histopathological variables and survival. High cyclin B1 correlated with high tumour grade, large tumour size and positive nodal status, oestrogen and progesterone receptor negativity, positive HER2 and p53 status, young age at diagnosis, and high cyclin E, cyclin A and Ki67 expression. Among patients not given adjuvant chemotherapy high cyclin B1 was a strong predictor of shorter overall and metastasis-free survival (RR 3.74, P<0.0005 and RR 3.51, P<0.0005, respectively), and remained as an independent prognostic factor also in multivariate analysis (RR 1.80, P=0.04 and RR 2.31, P=0.02, respectively). This study suggests high cyclin B1 associates with aggressive phenotype and is an independent prognostic factor in breast cancer.

Cell-cycle-phase progression analysis identifies unique phenotypes of major prognostic and predictive significance in breast cancer

Multiparameter analysis of core regulatory proteins involved in G1–S and G2–M cell-cycle transitions provides a powerful biomarker readout for assessment of the cell-cycle state. We have applied this algorithm to breast cancer to investigate how the cell cycle impacts on disease progression. Protein expression profiles of key constituents of the DNA replication licensing pathway (Mcm2, geminin) and mitotic machinery (Plk1, Aurora A and the Aurora substrate histone H3S10ph) were generated for a cohort of 182 patients and linked to clinicopathological parameters. Arrested differentiation and genomic instability were associated with an increased engagement of cells into the cell division cycle (P<0.0001). Three unique cell-cycle phenotypes were identified: (1) well-differentiated tumours composed predominantly of Mcm2-negative cells, indicative of an out-of-cycle state (18% of cases); (2) high Mcm2-expressing tumours but with low geminin, Aurora A, Plk1 and H3S10ph levels (S–G2–M progression markers), indicative of a G1-delayed/arrested state (24% cases); and (3) high Mcm2-expressing tumours and also expressing high levels of the S–G2–M progression markers, indicative of accelerated cell-cycle progression (58% of cases). The active cell-cycle progression phenotype had a higher risk of relapse when compared with out-of-cycle and G1-delayed/arrested phenotypes (HR=3.90 (1.81–8.40, P<0.001)), and was associated with Her-2 and triple negative subtypes (P<0.001). It is of note that high-grade tumours with the G1-delayed/arrested phenotype showed an identical low risk of relapse compared with well-differentiated out-of-cycle tumours (HR=1.00 (0.22–4.46), P=0.99). Our biomarker algorithm provides novel insights into the cell-cycle state of dynamic tumour cell populations in vivo. This information is of major prognostic significance and may impact on individualised therapeutic decisions. Patients with an accelerated phenotype are more likely to derive benefit from S- and M-phase-directed chemotherapeutic agents.

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.