Prognostic value of proliferation in invasive breast cancer: a review

Biomarkers for the clinical management of breast cancer: international perspective

The higher incidence of breast cancer in developed countries has been tempered by reductions in mortality, largely attributable to mammographic screening programmes and advances in adjuvant therapy. Optimal systemic management requires consideration of clinical, pathological and biological parameters. Oestrogen receptor alpha (ERα), progesterone receptor (PgR) and human epidermal growth factor receptor 2 (HER2) are established biomarkers evaluated at diagnosis, which identify cardinal subtypes of breast cancer. Their prognostic and predictive utility effectively guides systemic treatment with endocrine, anti-HER2 and chemotherapy. Hence, accurate and reliable determination remains of paramount importance. However, the goals of personalized medicine and targeted therapies demand further information regarding residual risk and potential benefit of additional treatments in specific circumstances. The need for biomarkers which are fit for purpose, and the demands placed upon them, is therefore expected to increase. Technological advances, in particular high-throughput global gene expression profiling, have generated multi-gene signatures providing further prognostic and predictive information. The rational integration of routinely evaluated clinico-pathological parameters with key indicators of biological activity, such as proliferation markers, also provides a ready opportunity to improve the information available to guide systemic therapy decisions. The additional value of such information and its proper place in patient management is currently under evaluation in prospective clinical trials. Expanding the utility of biomarkers to lower resource settings requires an emphasis on cost effectiveness, quality assurance and possible international variations in tumor biology; the potential for improved clinical outcomes should be justified against logistical and economic considerations.

Biomarker expression and St Gallen molecular subtype classification in primary tumours, synchronous lymph node metastases and asynchronous relapses in primary breast cancer patients with 10 years' follow-up

Molecular profiles of asynchronous breast cancer metastases are of clinical relevance to individual patients' treatment, whereas the role of profiles in synchronous lymph node metastases is not defined. The present study aimed to assess individual biomarkers and molecular subtypes according to the St Gallen classification in primary breast tumours, synchronous lymph node metastases and asynchronous relapses and relate the results to 10-year breast cancer mortality (BCM). Tissue microarrays were constructed from archived tissue blocks of primary tumours (N = 524), synchronous lymph node metastases (N = 147) and asynchronous relapses (N = 36). The samples were evaluated by two independent pathologists according to oestrogen receptor (ER), progesterone receptor (PR), Ki67 and human epidermal growth factor receptor 2 (HER2) by immunohistochemistry and in situ hybridisation. The expression of biomarkers and molecular subtypes in the primary tumour was compared with that in the synchronous lymph node metastases and relapses, and related to 10-year BCM. Discordances were found between primary tumours and relapses (ER: p = 0.006, PR: p = 0.04, Ki67: p = 0.02, HER2: p = 0.02, St Gallen subtypes: p = 0.07) but not between primary tumours and metastatic lymph node. Prognostic information was gained by the molecular subtype classification in primary tumours and nodal metastases; triple negative subtype had the highest BCM compared with the luminal A subtype (primary tumours: HR 4.0; 95 % CI 2.0-8.2, p < 0.001, lymph node metastases: HR 3.5; 95 % CI 1.3-9.7, p = 0.02). When a shift in subtype inherence between primary tumour and metastatic lymph node was identified, the prognosis seemed to follow the subtype of the lymph node. Molecular profiles are not stable throughout tumour progression in breast cancer. Prognostic information for individual patients appears to be available from the analysis of biomarker expression in synchronous metastatic lymph nodes. The study supports biomarker analysis also in asynchronous relapses.

Intratumoral concentration of estrogens and clinicopathological changes in ductal carcinoma in situ following aromatase inhibitor letrozole treatment

Background:

Estrogens have important roles in ductal carcinoma in situ (DCIS) of the breast. However, the significance of presurgical aromatase inhibitor treatment remains unclear. Therefore, we examined intratumoral concentration of estrogens and changes of clinicopathological factors in DCIS after letrozole treatment.

Methods:

Ten cases of postmenopausal oestrogen receptor (ER)-positive DCIS were examined. They received oral letrozole before the surgery, and the tumour size was evaluated by ultrasonography. Surgical specimens and corresponding biopsy samples were used for immunohistochemistry. Snap-frozen specimens were also available in a subset of cases, and used for hormone assays and microarray analysis.

Results:

Intratumoral oestrogen levels were significantly lower in DCIS treated with letrozole compared with that in those without the therapy. A great majority of oestrogen-induced genes showed low expression levels in DCIS treated with letrozole by microarray analysis. Moreover, letrozole treatment reduced the greatest dimension of DCIS, and significantly decreased Ki-67 and progesterone receptor immunoreactivity in DCIS tissues.

Conclusion:

These results suggest that estrogens are mainly produced by aromatase in DCIS tissues, and aromatase inhibitors potently inhibit oestrogen actions in postmenopausal ER-positive DCIS through rapid deprivation of intratumoral estrogens.

ROS1 expression in invasive ductal carcinoma of the breast related to proliferation activity

PURPOSE

ROS1 is an oncogene, expressed primarily in glioblastomas of the brain that has been hypothesized to mediate the effects of early stage tumor progression. In addition, it was reported that ROS1 expression was observed in diverse cancer tissue or cell lines and ROS1 is associated with the development of several tumors. However, ROS1 expression has not been studied in breast cancer to date. Therefore, we investigated ROS1 expression at the protein and gene level to compare expression patterns and to verify the association with prognostic factors in invasive ductal carcinoma (IDC) of the breast.

MATERIALS AND METHODS

Tissue samples from 203 patients were used. Forty-six cases were available for fresh tissue. We performed immunohistochemical staining and real-time polymerase chain reaction (PCR).

RESULTS

ROS1 expression was significantly lower in proportion to higher histologic grade, higher mitotic counts, lower estrogen receptor expression, and a higher Ki-67 proliferation index, although ROS1 expression was not significantly associated with the survival rate. The result of real-time PCR revealed similar trends, however not statistically significant.

CONCLUSION

Higher ROS1 expression may be associated with favorable prognostic factors of IDC and its expression in IDC is related to the proliferation of tumor cells.

Cell proliferation of the primary tumor predicts ipsilateral axillary node disease in elderly breast cancer patients

The present study investigated whether tumor markers such as cell proliferation and steroid receptor status, which have been shown to have relevance for important endpoints (relapse-free and overall survival), can also predict axillary disease in elderly patients with breast cancer. We evaluated 351 consecutive elderly women with breast cancer ≥70 years of age with estrogen receptor (ER)‑positive tumors with no palpable axillary nodes, for whom information on cell proliferation determined by the 3H-thymidine labeling index (TLI) and progesterone receptor (PgR) was available. Patients underwent quadrantectomy (70.1%) or quadrantectomy plus radiotherapy (29.9%) without axillary node dissection, followed by adjuvant tamoxifen for at least 2 years. Univariable (cumulative incidence curves) and multivariable analyses (Fine and Gray models) were carried out. After a median follow-up of 16 years, ipsilateral axillary relapse was not related to PgR status but was strongly associated with tumor cell proliferation in both small (pT1) and large (pT2-4b) tumors. Axillary relapse cumulative incidence increased from 1% in patients with low-TLI (≤3%), PgR-positive and pT1 tumors to a maximum of 20% in patients with high-TLI, PgR-negative and pT2-4b tumors. Tumor cell proliferation, determined by TLI at primary surgery, is an important predictor of axillary relapse in elderly ER-positive breast cancer patients and could help to identify patients who should undergo axillary surgery.

Prognostic value of mitotic index and Bcl2 expression in male breast cancer

The incidence of male breast cancer (MBC) is rising. Current treatment regimens for MBC are extrapolated from female breast cancer (FBC), based on the assumption that FBC prognostic features and therapeutic targets can be extrapolated to MBC. However, there is yet little evidence that prognostic features that have been developed and established in FBC are applicable to MBC as well. In a recent study on FBC, a combination of mitotic index and Bcl2 expression proved to be of strong prognostic value. Previous papers on Bcl2 expression in MBC were equivocal, and the prognostic value of Bcl2 combined with mitotic index has not been studied in MBC. The aim of the present study was therefore to investigate the prognostic value of Bcl2 in combination with mitotic index in MBC. Immunohistochemical staining for Bcl2 was performed on tissue microarrays of a total of 151 male breast cancer cases. Mitotic index was scored. The prognostic value of Bcl2 expression and Bcl2/mitotic index combinations was evaluated studying their correlations with clinicopathologic features and their prediction of survival. The vast majority of MBC (94%) showed Bcl2 expression, more frequently than previously described for FBC. Bcl2 expression had no significant associations with clinicopathologic features such as tumor size, mitotic count and grade. In univariate survival analysis, Bcl2 had no prognostic value, and showed no additional prognostic value to tumor size and histological grade in Cox regression. In addition, the Bcl2/mitotic index combination as opposed to FBC did not predict survival in MBC. In conclusion, Bcl2 expression is common in MBC, but is not associated with major clinicopathologic features and, in contrast to FBC, does not seem to have prognostic value, also when combined with mitotic index.

Proliferation indices of phosphohistone H3 and Ki67: strong prognostic markers in a consecutive cohort with stage I/II melanoma

Cellular proliferation is correlated with the progression of melanoma. Accordingly, the proliferation index of H&E-stained thin melanomas was recently included in the staging system of the American Joint Committee on Cancer. Yet, the immunohistochemical markers of proliferation phosphohistone H3 and Ki67 may improve such indices. To accurately quantify these markers, they should be combined with a melanocytic marker, for example, MART1 in an immunohistochemical double stain; also enabling automated quantification by image analysis. The aim of the study was to compare the prognostic impact of phosphohistone H3/MART1, Ki67/MART1, and H&E stains in primary cutaneous melanoma, and to determine the difference between indices established in hot spots and the global tumor areas. The study included 153 consecutive stage I/II melanoma-patients. The follow-up time was 8-14 years for event-free melanoma. Recurrent disease occurred in 43 patients; 37 died of melanoma. Both events occurred in only three thin melanomas. Their paraffin-embedded tissue was stained for phosphohistone H3/MART1, Ki67/MART1, and with H&E. And proliferation indices were established in 1-mm(2) hot spots and in the global tumor areas. In multivariate Cox analyses, only hot spot indices of phosphohistone H3/MART1 and Ki67/MART1 were independent prognostic markers. Phosphohistone H3/MART1 tended to be better than Ki67/MART1 with adjusted hazard ratios of 3.66 (95% CI, 1.40-9.55; P=0.008) for progression-free survival and 3.42 (95% CI, 1.29-9.04; P=0.013) for melanoma-specific death. In all stains, prognostic performance was substantially improved by using hot spots instead of the global tumor areas. In conclusion, phosphohistone H3/MART1 and Ki67/MART1 were superior to H&E stains, and hot spots superior to the global tumor areas. Given the potential for automated analysis, these double stains seem to be robust alternatives to conventional mitotic detection by H&E in stage I/II melanomas in general. This was particularly true for thick melanomas whereas no specific analyses for thin melanomas only could be performed.

Combined analysis of vascular invasion, grade, HER2 and Ki67 expression identifies early breast cancer patients with questionable benefit of systemic adjuvant therapy

INTRODUCTION

Over-treatment of low-risk early breast cancer patients with adjuvant systemic therapies is an important clinical challenge. Better techniques are required which can be used to distinguish between the large group of patients with no residual disease after surgery and consequently no benefit of adjuvant treatment, from the smaller group with high relapse risk. A better integration of available prognostic factors might contribute to improved prediction of clinical outcome.

MATERIAL AND METHODS

The current study included 346 unselected pT1pN0 patients who did not receive adjuvant systemic treatment. In Norway, no patients with this stage were recommended systemic treatment at the time of the study (1995-1998). Histological type, tumour size, grade, vascular invasion (VI), hormone receptor (HR) status, HER2 and Ki67 (cut-off 10%) were analysed. Median follow-up was 86 months for relapse and 101 months for death.

RESULTS

Thirty-eight patients experienced relapse, 31 with distant metastasis. Twenty-one patients died of breast cancer. In univariate analysis grade, HER2, HR, VI and Ki67 had impact on clinical outcome (p < 0.005, log rank). In multivariate analysis, only grade 1-2 vs. grade 3, HER2, VI, and Ki67 status were significant for disease free survival, distant disease free survival, and/or breast cancer specific survival. These factors were used in combination, to separate patients into groups based on the number of unfavourable factors present [combined prognostic score (CPS) 0-4]. Close to 2/3 of the patients (61.4%) had no unfavourable factor (CPS0), whilst 18.4% had CPS ≥ 2. Only 3.6% of those with CPS0 developed metastasis (p < 0.001). The outcome was clearly worse for patients with CPS ≥ 2 (p < 0.001), systemic relapse was detected in approximately 40%.

CONCLUSIONS

This study indicates that the combined use of grade, VI, HER2 and Ki67 identifies a subgroup of breast cancer patients with a relapse risk that may question the benefit of adjuvant systemic therapy.

A network module-based method for identifying cancer prognostic signatures

Discovering robust prognostic gene signatures as biomarkers using genomics data can be challenging. We have developed a simple but efficient method for discovering prognostic biomarkers in cancer gene expression data sets using modules derived from a highly reliable gene functional interaction network. When applied to breast cancer, we discover a novel 31-gene signature associated with patient survival. The signature replicates across 5 independent gene expression studies, and outperforms 48 published gene signatures. When applied to ovarian cancer, the algorithm identifies a 75-gene signature associated with patient survival. A Cytoscape plugin implementation of the signature discovery method is available at http://wiki.reactome.org/index.php/Reactome_FI_Cytoscape_Plugin.

High SUVmax on FDG-PET indicates pleomorphic subtype in epithelioid malignant pleural mesothelioma: supportive evidence to reclassify pleomorphic as nonepithelioid histology

BACKGROUND

We have recently proposed to reclassify the pleomorphic subtype of epithelioid malignant pleural mesothelioma (MPM) as nonepithelioid (biphasic/sarcomatoid) histology because of its similarly poor prognosis. We sought to investigate whether preoperative maximum standardized uptake value (SUVmax) on F-fluorodeoxyglucose (FDG) positron emission tomography (PET) correlates with histologic subtype in MPM.

METHODS

Clinical data were collected for 78 patients with MPM who underwent preoperative FDG-PET. We retrospectively classified the epithelioid tumors into five subtypes: trabecular, tubulopapillary, micropapillary, solid, and pleomorphic. Tumors were categorized by SUVmax into two groups: low (<10.0) and high (≥10.0).

RESULTS

The median overall survival of epithelioid tumors with high SUVmax (n = 12) was significantly shorter (7.1 months) than that of epithelioid tumors with low SUVmax (n = 54, 18.9 months, p < 0.001) and comparable to nonepithelioid tumors (n = 12, 7.2 months). Epithelioid tumors with pleomorphic subtype (n = 9) had marginally higher SUVmax (mean ± SD: 10.6 ± 5.9) than epithelioid nonpleomorphic subtype (n = 57, 6.5 ± 3.2, p = 0.050), and were comparable to that of nonepithelioid tumors (n = 12, 9.1 ± 4.8). Among the epithelioid tumors with high SUVmax (n = 12), 50% (n = 6) showed pleomorphic subtype. In contrast, among epithelioid tumors with low SUVmax (n = 54), 6% (n = 3) showed epithelioid pleomorphic subtypes (p = 0.001). A positive correlation between mitotic count and SUVmax was observed (r = 0.30, p = 0.010).

CONCLUSIONS

Pleomorphic subtype of epithelioid MPM showed higher SUVmax than the epithelioid nonpleomorphic subtype and was similar to nonepithelioid histology. Preoperative SUVmax on FDG-PET in epithelioid MPM can indicate patients with pleomorphic subtype with poor prognosis, supporting their reclassification as nonepithelioid.

Quantitative assessment and classification of tissue-based biomarker expression with color content analysis

CONTEXT

The use of computer aids has been suggested as a way to reduce interobserver variability that is known to exist in the interpretation of immunohistochemical staining in pathology. Such computer aids should be automated in their usage but also they should be trained in an automated and reproducible fashion.

OBJECTIVE

To present a computer aid for the quantitative analysis of tissue-based biomarkers, based on color content analysis.

DESIGN

The developed system incorporates an automated algorithm to allow retraining based on the color properties of different training sets. The algorithm first generates a color palette containing the colors present in a training subset. Based on the palette, color histograms are derived and are used as feature vectors to a pattern recognition system, which returns an output proportional to biomarker continuous expression or a categorical classification. The method was evaluated on a database of HER2/neu digital breast cancer slides, for which expression scores from a pathologist panel were available. The system was retrained and evaluated on different transformations of the database, including compression, blurring, and changes in illumination, to examine its robustness to different imaging conditions frequently met in digital pathology.

RESULTS

Results showed high agreement between the results of the algorithm and the truth from the pathologist panel as well as robustness to image transformations.

CONCLUSIONS

The results of the study are encouraging for the potential of this method as a computer aid to assess biomarker expression in a consistent and reproducible manner.

HDAC1 Expression in Invasive Ductal Carcinoma of the Breast and Its Value as a Good Prognostic Factor

Background

Histone deacetylase 1 (HDAC1) is associated with the expression and function of estrogen receptors and the proliferation of tumor cells, and has been considered a very important factor in breast tumor progression and prognosis. Several studies have reported an association between HDAC1 expression and poorer prognosis in cancers including breast cancer, with a few exceptions. However, because of the dearth of studies on HDAC1 expression in breast cancer, its significance for breast cancer prognosis has not been well defined. Therefore, we examined HDAC1 expression in invasive ductal carcinoma (IDC), the most common breast cancer, and investigated its potential prognostic significance.

Methods

We used 203 IDC tissue samples. Immunohistochemical stains for HDAC1 and real-time polymerase chain reaction for HDAC1 mRNA were performed and the results were compared to generally well-established prognostic factors in breast cancer and patient survival rates.

Results

HDAC1 expression was significantly reduced in proportion to higher histologic grade, higher nuclear pleomorphism score, and higher mitotic counts, and with lower estrogen receptor expression. Furthermore, it was significantly associated with the survival rate.

Conclusions

HDAC1 expression is a good prognostic indicator in IDC.

Digital slide images for primary diagnostics in breast pathology: a feasibility study

Digital slide images have been used in many areas of pathology such as teaching, research, digital archiving, teleconsultation, and quality assurance testing. However, they have not much been used as yet for upfront diagnostics. The aim of this study was therefore to test the feasibility of digital slide image-based diagnosis of breast specimens. Sections of 100 breast specimens previously diagnosed conventionally were scanned and rediagnosed on digital slide images by the same pathologists who performed the initial light microscopy-based diagnosis. The digital slide image diagnoses were compared with the light microscopy diagnoses and classified as concordant, slightly discrepant (without clinical or prognostic consequences), or discrepant. The original light microscopy- and digital slide image-based diagnoses were concordant in 93% and slightly discrepant in 6% of cases. There was only 1 discrepant case with clinical or prognostic implication to the patient. However, for this case, no final agreement could be achieved. For 4 of the 6 slightly discrepant cases, digital slide image diagnosis was considered the better one, whereas the original diagnosis was preferred in only 1 case. In addition, for 1 case categorized as slightly discrepant, both the digital slide image and conventional diagnosis were imperfect according to 2 reviewing breast pathologists. This study demonstrates that upfront histopathologic diagnosis of breast biopsies and resections can reliably be done on digital slide image.

A grading system combining architectural features and mitotic count predicts recurrence in stage I lung adenocarcinoma

The International Association for the Study of Lung Cancer (IASLC)/American Thoracic Society (ATS)/European Respiratory Society (ERS) has recently proposed a new lung adenocarcinoma classification. We investigated whether nuclear features can stratify prognostic subsets. Slides of 485 stage I lung adenocarcinoma patients were reviewed. We evaluated nuclear diameter, nuclear atypia, nuclear/cytoplasmic ratio, chromatin pattern, prominence of nucleoli, intranuclear inclusions, mitotic count/10 high-power fields (HPFs) or 2.4 mm(2), and atypical mitoses. Tumors were classified into histologic subtypes according to the IASLC/ATS/ERS classification and grouped by architectural grade into low (adenocarcinoma in situ, minimally invasive adenocarcinoma, or lepidic predominant), intermediate (papillary or acinar), and high (micropapillary or solid). Log-rank tests and Cox regression models evaluated the ability of clinicopathologic factors to predict recurrence-free probability. In univariate analyses, nuclear diameter (P=0.007), nuclear atypia (P=0.006), mitotic count (P<0.001), and atypical mitoses (P<0.001) were significant predictors of recurrence. The recurrence-free probability of patients with high mitotic count (≥5/10 HPF: n=175) was the lowest (5-year recurrence-free probability=73%), followed by intermediate (2-4/10 HPF: n=106, 80%), and low (0-1/10 HPF: n=204, 91%, P<0.001). Combined architectural/mitotic grading system stratified patient outcomes (P<0.001): low grade (low architectural grade with any mitotic count and intermediate architectural grade with low mitotic count: n=201, 5-year recurrence-free probability=92%), intermediate grade (intermediate architectural grade with intermediate-high mitotic counts: n=206, 78%), and high grade (high architectural grade with any mitotic count: n=78, 68%). The advantage of adding mitotic count to architectural grade is in stratifying patients with intermediate architectural grade into two prognostically distinct categories (P=0.001). After adjusting for clinicopathologic factors including sex, stage, pleural/lymphovascular invasion, and necrosis, mitotic count was not an independent predictor of recurrence (P=0.178). However, patients with the high architectural/mitotic grade remained at significantly increased risk of recurrence (high vs low: P=0.005) after adjusting for clinical factors. We proposed this combined architectural/mitotic grade for lung adenocarcinoma as a practical method that can be applied in routine practice.

Oestrogen-induced genes in ductal carcinoma in situ: their comparison with invasive ductal carcinoma

It is well known that oestrogens play important roles in both the pathogenesis and development of invasive ductal carcinoma (IDC) of human breast. However, molecular features of oestrogen actions have remained largely unclear in pure ductal carcinoma in situ (pDCIS), regarded as a precursor lesion of many IDCs. This is partly due to the fact that gene expression profiles of oestrogen-responsive genes have not been examined in pDCIS. Therefore, we first examined the profiles of oestrogen-induced genes in oestrogen receptor (ER)-positive pDCIS and DCIS (DCIS component (DCIS-c)) and IDC (IDC component (IDC-c)) components of IDC cases (n=4 respectively) by microarray analysis. Oestrogen-induced genes identified in this study were tentatively classified into three different groups in the hierarchical clustering analysis, and 33% of the genes were predominantly expressed in pDCIS rather than DCIS-c or IDC-c cases. Among these genes, the status of MYB (C-MYB), RBBP7 (RBAP46) and BIRC5 (survivin) expressions in carcinoma cells was significantly higher in ER-positive pDCIS (n=53) than that in ER-positive DCIS-c (n=27) or IDC-c (n=27) by subsequent immunohistochemical analysis of the corresponding genes (P<0.0001, P=0.03 and P=0.0003 respectively). In particular, the status of C-MYB immunoreactivity was inversely (P=0.006) correlated with Ki67 in the pDCIS cases. These results suggest that expression profiles of oestrogen-induced genes in pDCIS may be different from those in IDC; and C-MYB, RBAP46 and survivin may play important roles particularly among oestrogen-induced genes in ER-positive pDCIS.

Automated Quantification of MART1-Verified Ki67 Indices by Digital Image Analysis in Melanocytic Lesions

Context.—The proliferation marker Ki67 is an important diagnostic and prognostic aid in surgical pathology. However, manual quantification in a counting frame to accurately establish the proliferation rate (Ki67 index) is cumbersome and time-consuming. Instead, digital image analysis of Ki67/MART1 double stains may provide fast and novel index computations for entire tumor sections.

Objectives.—To design and compare image analysis protocols that compute Ki67 indices of Ki67/MART1 double stains, to compare automated indices with previously published manual indices, and to compare the total number of proliferating cells (mimicking a Ki67 single stain) with the number of MART1-verified proliferating cells.

Design.—Whole slide images were captured from 48 melanomas and 77 nevi stained with an immunohistochemical cocktail against Ki67 and MART1. Ki67 indices were determined by digital image analysis and different equations based on number or area.

Results.—The differences between mean indices of melanomas and nevi were significant (P &lt; .001) in all index computations. Number-based image analysis of lesions with more than 250 melanocytic cells misclassified 1 of 42 melanomas and 4 of 53 nevi, numbers comparable with manual counting. Automated indices were significantly higher than manual indices, as were indices of mimicked Ki67 single stains compared with MART1-verified Ki67 indices (P &lt; .001).

Conclusions.—Ki67 indices established by digital image analysis of Ki67/MART1 double stains demonstrated excellent abilities to discriminate melanomas from nevi with diagnostic performances equal to manually performed indices. Testing different definitions of the automated MART1-verified Ki67 index, no single definition stood out; thus, a variety of definitions may be used.

The BRAF V600E mutation in papillary thyroid carcinoma is associated with glucose transporter 1 overexpression

BACKGROUND

The glucose transporter 1 (GLUT1) is a key protein that facilitates the extensive glucose uptake of cancer cells, and its overexpression is associated with more aggressive tumor phenotypes. In cases of BRAF mutations, GLUT1 seems to be a target of the constitutive activation of the RAF/MEK/ERK pathway. In this study, we hypothesized that the common BRAF V600E mutation was associated with GLUT1 overexpression and proliferation in papillary thyroid carcinomas (PTCs).

METHODS

A total of 57 cases of paraffin-embedded PTC (31 BRAF V600E, 26 wild-type BRAF) were investigated using immunohistochemistry with antibodies against GLUT1 and Ki-67 (MK167) protein. The BRAF V600E mutations were detected using direct sequencing of genomic DNA that was isolated from formalin-fixed paraffin-embedded tumor tissues. GLUT1 expression was assessed using the Remmele immunoreactive score and subdivided into three groups (I=negative, II=weakly positive, and III=positive). The Ki-67 labeling index (Ki-67 LI) was determined by counting Ki-67-positive nuclei.

RESULTS

GLUT1 expression was found in 39/57 (68.4%) samples of PTC. The occurrence of the BRAF V600E genetic variant was significantly correlated with GLUT1 overexpression (p=0.007) and showed a trend toward higher proliferation, which was indicated by Ki-67 LI (p=0.06). Moreover, GLUT1 overexpression was positively associated with Ki-67 labeling (p=0.023).

CONCLUSIONS

The V600E BRAF mutation in PTC may contribute to the initiation of the glycolytic phenotype and confers growth advantages in cancer cells. Better understanding of the molecular mechanisms of cancer cell energy metabolism may lead to the implementation of targeted treatment modalities, which regulate cancer glucose uptake.

A nuclear grading system is a strong predictor of survival in epitheloid diffuse malignant pleural mesothelioma

Epithelioid mesothelioma is the most prevalent subtype of diffuse malignant pleural mesothelioma in which only staging is prognostic for survival. In this study of epithelioid diffuse malignant pleural mesothelioma, we investigate the prognostic utility of nuclear features. The slides of 232 epithelioid diffuse malignant pleural mesothelioma patients (14 stage I, 54 stage II, 130 stage III, and 34 stage IV) from a single institution were reviewed for the following seven nuclear features: nuclear atypia, nuclear/cytoplasmic ratio, chromatin pattern, intranuclear inclusions, prominence of nucleoli, mitotic count, and atypical mitoses. MIB-1 immunohistochemistry was performed using tissue microarray, and MIB-1 labeling index was recorded as the percentage of positive tumor cells. Median overall survival of all patients was 16 months and correlated with nuclear atypia (P<0.001), chromatin pattern (P=0.031), prominence of nucleoli (P<0.001), mitotic count (P<0.001), and atypical mitoses (P<0.001) by univariate analysis. Multivariate analysis revealed nuclear atypia (P=0.012) and mitotic count (P<0.001) as independent prognostic factors, and these two factors were utilized to create a three-tier nuclear grade score. The resulting nuclear grade stratified patients into three distinct prognostic groups: grade I (n=107, median overall survival=28 months), grade II (n=91, 14 months), and grade III (n=34, 5 months). Not only was nuclear grade an independent predictor of overall survival (P<0.001), but it was also a stronger discriminator of survival than all currently available factors. Furthermore, nuclear grade was associated with time to recurrence (P=0.004) in patients who underwent complete surgical resection (n=159). MIB-1 labeling index correlated with mitotic count (P<0.001) and nuclear atypia (P=0.037) and stratified overall survival (P<0.001) and time to recurrence (P=0.048), confirming the prognostic value of the nuclear grade. Nuclear grading in epithelioid mesothelioma provides a simple, practical, and cost-effective prognostic tool that better stratifies clinical outcome and time to recurrence than currently available clinicopathologic factors.

Prognostic value of proliferation assay in the luminal, HER2-positive, and triple-negative biologic classes of breast cancer

Introduction

Although the prognostic significance of proliferation in early invasive breast cancer has been recognized for a long time, recent gene-expression profiling studies have reemphasized its biologic and prognostic value and the potential application of its assessment in routine practice, particularly to define prognostic subgroups of luminal/hormone receptor-positive (HR⁺) tumors. This study aimed to assess the prognostic value of a proliferation assay by using Ki-67 immunohistochemistry as compared with mitotic count scores.

Method

Proliferation was assessed by using Ki-67 labeling index (Ki-67LI) and mitotic scores in a large (n = 1,550) and well-characterized series of clinically annotated primary operable invasive breast cancer with long-term follow-up. Tumors were phenotyped based on their IHC profiles into luminal/HR⁺, HER2⁺, and triple-negative (TN) classes. We used a split-sample development and validation approach to determine the optimal Ki-67LI cut-offs.

Results

The optimal cut-points of Ki-67LI were 10% and 50% for the luminal class. Both Ki7LI and MS were able to split luminal tumors into subgroups with significantly variable outcomes, independent of other variables. Neither mitotic count scores nor Ki-67LI was associated with outcome in the HER2⁺ or the TN classes.

Conclusions

Assessment of proliferation by using Ki-67LI and MS can distinguish subgroups of patients within luminal/hormone receptor-positive breast cancer significantly different in clinical outcomes. Overall, both Ki-67 LI and mitotic-count scores showed comparable results. The method described could provide a cost-effective method for prognostic subclassification of luminal/hormone receptor-positive breast cancer in routine clinical practice.

gef gene expression in MCF-7 breast cancer cells is associated with a better prognosis and induction of apoptosis by p53-mediated signaling pathway

Breast cancer research has developed rapidly in the past few decades, leading to longer survival times for patients and opening up the possibility of developing curative treatments for advanced breast cancer. Our increasing knowledge of the biological pathways associated with the progression and development of breast cancer, alongside the failure of conventional treatments, has prompted us to explore gene therapy as an alternative therapeutic strategy. We previously reported that gef gene from E. coli has shown considerable cytotoxic effects in breast cancer cells. However, its action mechanism has not been elucidated. Indirect immunofluorescence technique using flow cytometry and immunocytochemical analysis were used to detect breast cancer markers: estrogen (ER) and progesterone (PR) hormonal receptors, human epidermal growth factor receptor-2 proto-oncogene (c-erbB-2), ki-67 antigen and p53 protein. gef gene induces an increase in ER and PR expressions and a decrease in ki-67 and c-erbB-2 gene expressions, indicating a better prognosis and response to treatment and a longer disease-free interval and survival. It also increased p53 expression, suggesting that gef-induced apoptosis is regulated by a p53-mediated signaling pathway. These findings support the hypothesis that the gef gene offers a new approach to gene therapy in breast cancer.

Adjuvant early breast cancer systemic therapies according to daily used technologies

Prognosis of early breast cancer patients is significantly improved with the use of adjuvant therapies. Various guidelines have been proposed to select patients who will derive the most benefit from such treatments. However, classifications have limited usefulness in subsets of patients such as those with node negative breast cancer. The 2007 St. Paul de Vence Clinical Practice Recommendations proposed to consider adjuvant therapy in accordance with the 10-year relapse-free survival reduction estimated by Adjuvant! Online. However, many limitations remain regarding the use of Adjuvant! Online. Among them, adverse prognostic and/or predictive factors such as vascular invasion, mitotic activity, progesterone receptor negativity, and HER-2 expression are not incorporated in the routine clinical decision process. Our group has therefore issued guidelines based on the consideration of both Adjuvant! Online calculations and the prognostic and/or predictive effects of these markers. In addition, web-accessible comprehensive tables summarizing these recommendations are provided.

Global mitotic phosphorylation of C2H2 zinc finger protein linker peptides

Cessation of transcriptional activity is a hallmark of cell division. Many biochemical pathways have been shown and proposed over the past few decades to explain the silence of this phase. In particular, many individual transcription factors have been shown to be inactivated by phosphorylation. In this report, we show the simultaneous phosphorylation and mitotic redistribution of a whole class of modified transcription factors. C(2)H(2) zinc finger proteins (ZFPs) represent the largest group of gene expression regulators in the human genome. Despite their diversity, C(2)H(2) ZFPs display striking conservation of small linker peptides joining their adjacent zinc finger modules. These linkers are critical for DNA binding activity. It has been proposed that conserved phosphorylation of these linker peptides could be a common mechanism for the inactivation of the DNA binding activity of C(2)H(2) ZFPs, during mitosis. Using a novel antibody, raised against the phosphorylated form of the most conserved linker peptide sequence, we are able to visualize the massive and simultaneous mitotic phosphorylation of hundreds of these proteins. We show that this wave of phosphorylation is tightly synchronized, starting in mid-prophase right after DNA condensation and before the breakdown of the nuclear envelope. This global phosphorylation is completely reversed in telophase. In addition, the exclusion of the phospho-linker signal from condensed DNA clearly demonstrates a common mechanism for the mitotic inactivation of C(2)H(2) ZFPs.

Vascular proliferation is a prognostic factor in breast cancer

Angiogenesis is important for the growth and spread of malignant tumors, and anti-angiogenesis treatment is currently being evaluated for breast cancer and other tumors. Although microvessel density is the most commonly used tissue-based marker of tumor associated angiogenesis, it has significant limitations and has not proven effective as a predictive factor in selecting patients for treatment. We here wanted to explore the significance of vascular endothelial cell proliferation in breast carcinoma. We examined microvessel proliferation in breast cancer by dual immunohistochemical staining, using the pan-endothelial marker Factor-VIII combined with proliferation of endothelial cells by Ki-67 expression, in three independent series of breast cancer, including a total of 499 patients and 141 events during follow-up. Common statistical tests of associations as well as univariate and multivariate regression analysis of patient survival were used. By counting vessels with actively proliferating endothelium, we show that microvascular proliferation is a significant predictor of disease progression in breast cancer, especially among high-grade and ER-negative tumors. Our findings indicate that this novel marker of active tumor angiogenesis might be of value in patient management and should be further studied in the context of patient selection for anti-angiogenesis treatment.

Immunohistochemical double stains against Ki67/MART1 and HMB45/MITF: promising diagnostic tools in melanocytic lesions

Distinction between benign and malignant melanocytic lesions may be difficult by today's methods, even for highly skilled dermatopathologists, emphasizing the need for improved diagnostic tools. We have studied the discriminative abilities of immunohistochemical (IHC) double stains using the IHC markers Ki67 combined with MART1, and HMB45 combined with MITF. Paraffin-embedded tissue sections from 50 melanomas and 78 benign nevi were stained using a simple simultaneous IHC double staining technique. Both simple semiquantitative estimates of the immunopositivity in the deepest third of the lesions and full-scale quantitative measurements of the Ki67 and HMB45 indices were performed, and scores for melanomas and nevi were compared. The differences between melanomas and nevi were significant (P < 0.0001) using either analysis or stain. The misclassification rates for melanomas and nevi were generally lower for Ki67/MART1 stains than for HMB45/MITF stains. In the simple semiquantitative Ki67/MART1 analysis, the misclassification rates were 6% (2%-17%) for melanomas and 12% (6%-21%) for nevi. In full-scale quantitative analysis the corresponding rates were 4% (1%-14%) and 8% (4%-16%), and by combining Ki67 and HMB45 indices, the misclassification rates were 0% (0%-7%) for melanomas and 13% (7%-22%) for nevi. We conclude that both semiscale and fullscale quantitative analyses of Ki67/MART1 stains are valuable diagnostic tools to distinguish melanomas and nevi with a large degree of certainty. The HMB45/MITF stains may serve as adjuncts to predict malignancy and the diagnostic potential of combining the HMB45 and Ki67 indices are promising. The IHC double stains may potentially reduce misinterpretations of melanomas in histopathology.

Predictors of disease progression in ductal carcinoma in situ of the breast and vascular patterns

Breast carcinoma-induced angiogenesis helps meet growing metabolic needs of tumors and progressively increases with malignant transformation of benign ducts to ductal carcinoma in situ (DCIS) and ductal carcinoma in situ to invasive carcinoma. There are conflicting data regarding the difference in angiogenesis in low-, intermediate-, and high-grade ductal carcinoma in situ. If angiogenesis is related to ductal carcinoma in situ progression, the types of ductal carcinoma in situ with more aggressive biologic potential would have different vascular patterns than the less aggressive ones. In this study, we classified 51 cases of ductal carcinoma in situ as low (10-20 years to progression to invasive carcinoma), moderate, or high aggressive (2-5 years to progression to invasive carcinoma), based on criteria outlined by Tsikitis and Chung (Am J Clin Oncol 2006; 29:305), which takes into account nuclear grade, mitotic rate, Ki-67, Her2Neu, P53, estrogen, and progesterone receptor expression. We correlated these 3 groups of ductal carcinoma in situ with the extent of periductal and stromal vascularity and the presence and type of vascular breaks. No association of aggressive biologic behavior of ductal carcinoma in situ with any vascular pattern was found. Moreover, no correlation was found between vascular patterns and classifiers of aggressiveness, microvascular density, or outcome (local recurrence, invasive carcinoma, or metastatic disease). To validate our cohort, we confirmed expected correlations of all measured parameters of aggressiveness by correlating them with each other. In summary, vascular patterns in ductal carcinoma in situ do not correlate with the predictors of aggressive behavior, suggesting that the biologic potential of ductal carcinoma in situ is independent of angiogenesis.

The prognostic importance of cathepsin D and E-cadherin in early breast cancer: A single-institution experience

Molecular tools have increasingly been used for decision-making in patients with early breast cancer (EBC). Nevertheless, simple tools such as immunohistochemistry may still be required in particular cases to complement traditional and molecular prognosticators. In this study, the prognostic significance of three well-known immunohistochemical biomarkers, cathepsin D, E-cadherin and Ki67, was studied in 270 patients with EBC, followed by a median time of 126 months in a single institution. Histological examination was performed to confirm the histopathological diagnosis and select specimens. The specimens were evaluated using immunohistochemistry and survival curves were plotted. Results revealed the following patient characteristics: node-negative/1-3 lymph nodes in 228 (86%) patients, hormone receptor-positive in 217 (80%); triple-negative in 31 (11%), and Her2-overexpression in 23 (9%) patients. Breast cancer-related events occurred in 37 patients (14%). A total of 217 patients (80%) survived. Receiver operating characteristic analysis for breast cancer-specific survival showed an area under curve for the clinicopathological model of 0.75 (95% CI, 0.64-0.86), 0.79 (95% CI, 0.68-0.90) for the three-biomarker model, and 0.82 (95% CI, 0.72-0.92) for the E-cadherin and cathepsin D only model. We propose that a simple prognostic model based on combined scores of E-cadherin and cathepsin D may aid treatment decisions in patients with EBC.

Recurrence risk score based on the specific activity of CDK1 and CDK2 predicts response to neoadjuvant paclitaxel followed by 5-fluorouracil, epirubicin and cyclophosphamide in breast cancers

BACKGROUND

We established the cell cycle profiling (C2P) assay for specific activity (SA; activity/expression) of cyclin-dependent kinases (CDKs). C2P risk score (C2P-RS) based on CDK1 and CDK2 SAs was significantly associated with relapse in breast cancer (BC). This study was conducted to investigate the predictive value of C2P-RS for neoadjuvant chemotherapy (NAC).

PATIENTS AND METHODS

Among 124 eligible patients, 122 were treated with weekly paclitaxel followed by 5-fluorouracil, epirubicin and cyclophosphamide (P-FEC) and 2 were treated with paclitaxel monotherapy. C2P-RS was determined via C2P using frozen biopsy samples before NAC.

RESULTS

Negative estrogen receptor (ER), negative progesterone receptor (PR), positive human epidermal growth factor receptor 2 (HER2), high Ki-67 expression and intermediate + high C2P-RS were significantly associated with high pathological complete response (pCR) rates compared with positive ER (30% versus 9%), positive PR (25% versus 6%), negative HER2 (34% versus 11%), low Ki-67 expression (24% versus 7%) or low C2P-RS (24% versus 9%), respectively. The combination of C2P-RS and Ki-67 had a stronger impact on pCR than each parameter alone, and a multivariate analysis showed that the combination was an independent predictor of pCR (odds ratio 3.3, 95% confidence interval 1.1-9.5).

CONCLUSIONS

C2P-RS was significantly associated with pCR after P-FEC and may be a useful predictor for chemotherapy in BCs.

The cell cycle profile test is a prognostic indicator for breast cancer patients treated with postoperative 5-fluorouracil-based chemotherapy

OBJECTIVE

The cell cycle profile test is suggested to be an independent prognostic indicator for breast cancer patients. To further clarify the prognostic value, we applied this to breast cancer patients treated with postoperative 5-fluorouracil-based chemotherapy.

METHODS

A total of 153 breast cancer patients, who were treated with postoperative 5-fluorouracil-based chemotherapies, were randomly selected. Specific activities of cyclin-dependent kinases 1 and 2 in the tumor samples were analyzed. Patients were divided into three categories (low, intermediate or high risk) based on cell cycle profile analysis.

RESULTS

The proportions of the cell cycle profile categories were 39% for low risk, 10% for intermediate risk and 45% for high risk, respectively. Although the cell cycle profile test did not show a significant predictive power for relapse-free survival (high vs. low risk; P = 0.052), the cell cycle profile categories were significant prognostic factors in a subgroup of 98 patients with fewer than three involved nodes (high vs. low risk, P = 0.004). Multivariate analyses also indicated that a cell cycle profile parameter (high vs. low risk) was an independent prognostic indicator from the number of involved nodes and clinical stage in this subgroup (hazard ratio = 2.46, P = 0.01). Interestingly, the prognostic power of the cell cycle profile test was significant in 75 patients treated with oral 5-fluorouracil derivatives alone (hazard ratio = 6.29 for high vs. low risk, P = 0.02).

CONCLUSIONS

These findings suggest that the cell cycle profile test is useful for predicting a higher risk of relapse in patients treated with postoperative 5-fluorouracil-based chemotherapy.

A signature inferred from Drosophila mitotic genes predicts survival of breast cancer patients

Introduction

The classification of breast cancer patients into risk groups provides a powerful tool for the identification of patients who will benefit from aggressive systemic therapy. The analysis of microarray data has generated several gene expression signatures that improve diagnosis and allow risk assessment. There is also evidence that cell proliferation-related genes have a high predictive power within these signatures.

Methods

We thus constructed a gene expression signature (the DM signature) using the human orthologues of 108 Drosophila melanogaster genes required for either the maintenance of chromosome integrity (36 genes) or mitotic division (72 genes).

Results

The DM signature has minimal overlap with the extant signatures and is highly predictive of survival in 5 large breast cancer datasets. In addition, we show that the DM signature outperforms many widely used breast cancer signatures in predictive power, and performs comparably to other proliferation-based signatures. For most genes of the DM signature, an increased expression is negatively correlated with patient survival. The genes that provide the highest contribution to the predictive power of the DM signature are those involved in cytokinesis.

Conclusion

This finding highlights cytokinesis as an important marker in breast cancer prognosis and as a possible target for antimitotic therapies.

PTOV1 is overexpressed in human high-grade malignant tumors

The prostate tumor overexpressed-1 (PTOV1) protein was first described overexpressed in prostate cancer but not detected in normal prostate. PTOV1 expression is associated to increased cancer proliferation in vivo and in vitro. In prostate biopsy, PTOV1 detection is helpful in the early diagnosis of cancer. The purpose of this study was to analyze the relevance of PTOV1 expression to identify aggressive tumors derived from 12 different histological tissues. Tissue microarrays (TMAs) containing 182 biopsy samples, including 168 human tumors, were analyzed for PTOV1 and Ki67 expression by immunohistochemistry. Tumors of low and high histological grade were selected from lung, breast, endometrium, pancreas liver, skin, ovary, colon, stomach, kidney, bladder, and cerebral gliomas. One TMA with representative tissues without cancer (14 samples) was used as control. PTOV1 expression was analyzed semiquantitatively for the intensity and percentage of positive cells. Ki67 was evaluated for tumors proliferative index. Results show that PTOV1 was expressed in over 95% of tumors examined. Its expression was significantly associated to high-grade tumors (p = 0.014). This association was most significant in urothelial bladder carcinomas (p = 0.026). Overall, the expression of Ki67 was associated to high-grade tumors, and it was significant in several tumor types. PTOV1 and Ki67 were significantly co-overexpressed in all tumors (p = 0.001), and this association was significant in clear cell renal carcinoma (p = 0.005). In conclusion, PTOV1 expression is associated to more aggressive human carcinomas and more significantly to bladder carcinomas suggesting that this protein is a potential new marker of aggressive disease in the latter tumors.

Phytohemagglutinin-induced mitotic index in blood lymphocytes: a potential biomarker for breast cancer risk

Background

Cell proliferation is associated with the pathogenesis of cancer because it provides opportunities for accumulating genetic mutations. However, biomarkers of cell proliferation in response to environmental stimuli have not been adequately explored for breast cancer risk.

Methods

In a case-control study of 200 breast cancer patients and 360 healthy controls, we investigated the association between phytohemagglutinin (PHA)-induced mitotic index in blood lymphocyte and breast cancer risk.

Results

Having high mitotic index (>3.19%) was associated with an increased risk of breast cancer, with adjusted odds ratios (95% confidence interval) of 1.54 (1.03–2.30) and 2.03 (1.18–3.57) for all women and post-menopausal women, respectively. Mitotic index was correlated with some reproductive factors and body mass index in controls.

Conclusions

Our data suggest increased PHA-induced mitotic index in blood lymphocytes is associated with an increased breast cancer risk and that this association may be modulated by reproductive and other hormones.

Histological grading of breast cancer on needle core biopsy: the role of immunohistochemical assessment of proliferation

Aims

Histological grade assessed on needle core biopsy (NCB) moderately concurs with the grade in the surgical excision specimen (SES) (κ-values between 0.35 and 0.65). A major cause of the discrepancy is underestimation of mitoses in the NCB specimen. The aim was to determine the best method of assessing proliferation on NCB.

Methods and results

Proliferative activity of 101 invasive carcinomas of the breast on NCB and SES was assessed using mitotic counts on routine haematoxylin and eosin (H&E) sections and immunohistochemical markers Mib-1 and phosphorylated histone H3 (PPH3). H&E mitotic count in SES was considered as the gold standard. H&E mitotic count was found to be underestimated on NCB when compared with that in SES (P < 0.001), but no significant difference was detected between NCB and SES regarding Mib-1 (P = 0.13) or PPH3 (P = 0.073). Using receiver–operating characteristic curve, Mib-1 on NCB was found to agree with the gold standard significantly better than routine H&E on NCB.

Conclusions

Immunohistochemical markers in NCB showed better concordance with H&E mitotic count in SES (gold standard) than routine H&E mitotic count in NCB. Further refinement of cut-offs and scoring methods is needed.

The XbaI G>T polymorphism of the glucose transporter 1 gene modulates 18F-FDG uptake and tumor aggressiveness in breast cancer

We investigated the relevance of single-nucleotide polymorphisms (SNPs) in the glucose transporter 1 (GLUT1) gene to the uptake of (18)F-FDG and tumor aggressiveness in breast cancer.

METHODS

In 52 individuals with breast cancer, a diagnostic PET/CT scan was obtained, and the standardized uptake value was determined as a measure of (18)F-FDG uptake using a region-of-interest technique. Three GLUT1 SNPs (XbaI G>T, HpyCH4V A>T, and HaeIII T>C) were investigated in genomic DNA that was isolated from the paraffin-embedded specimens of all patients. Tumors were typed and graded according to the World Health Organization classifications.

RESULTS

The GG genotype of the XbaI G>T SNP was associated with increased tumor uptake of (18)F-FDG, with a mean standardized uptake value of 11.7 (TT/GT genotypes, 5.9; P = 0.03). Furthermore, the GG genotype was positively related to enhanced tumor proliferation (mitotic count, P = 0.01). In line with this finding, the GG genotype was absent in grade 1 carcinomas and increasingly prevalent in tumors with higher malignancy (grade 2, 28.0%; grade 3, 50%; P = 0.04).

CONCLUSION

This study found that the XbaI G>T SNP of the GLUT1 gene is associated with an increased (18)F-FDG uptake and a more advanced tumor grade or growth in breast cancer. Thus, this genetic variant might favor aggressive phenotypes by modulating the efficiency of cancer cells to recruit glucose and escalate growth rate, suggesting the XbaI G>T SNP as a proliferation-related prognostic factor.

Progression of Ductal Carcinoma in Situ from the Pathological Perspective

Ductal carcinoma in situ (DCIS) now represents up to 20% of breast cancer cases, yet its behaviour is still poorly understood. Morphological classifications go some way to predicting prognosis, but more sophisticated approaches are required to better tailor therapy to the individual. A number of biological molecules have been identified that appear to relate to prognosis and, in model systems, promote progression to invasive disease. Some of these, such as COX-2, provide real therapeutic opportunities, whilst other marker combinations are showing promise in categorising women according to risk. Gene expression studies have led to an emerging molecular classification of invasive breast cancer, and it is now evident that at least some of these molecular subtypes can be identified at the pre-invasive stage. The difference in frequency of these subtypes between DCIS and invasive cancer may hold clues as to the biological mechanisms underpinning disease transition. It is increasingly clear that the host microenvironment can have a major impact on disease behaviour, and as well as acting as potential predictive factors, the altered microenvironment phenotype also offers novel therapeutic opportunities.

Molecular profiling of invasive breast cancer by multiplex ligation-dependent probe amplification-based copy number analysis of tumor suppressor and oncogenes

Several oncogenes and tumor-suppressor genes have been shown to be implicated in the development, progression and response to therapy of invasive breast cancer. The phenotypic uniqueness (and thus the heterogeneity of clinical behavior) among patients' tumors may be traceable to the underlying variation in gene copy number of these genes. To obtain a more complete view of gene copy number changes and their relation to phenotype, we analyzed 20 breast cancer-related genes in 104 invasive breast cancers with the use of multiplex ligation-dependent probe amplification (MLPA). We identified MYC gene amplification in 48% of patients, PRDM14 in 34%, topoisomerase IIalpha (TOP2A) in 32%, ADAM9 in 32%, HER2 in 28%, cyclin D1 (CCND1) in 26%, EMSY in 25%, IKBKB in 21%, AURKA in 17%, FGFR1 in 17%, estrogen receptor alpha (ESR1) in 16%, CCNE1 in 12% and EGFR in 9% of patients. There was a significant correlation between the number of amplified genes and the histological grade and mitotic index of the tumor. Gene amplifications of EGFR, CCNE1 and HER2 were negatively associated with estrogen receptor status whereas FGFR1, ADAM9, IKBKB and TOP2A revealed a positive association. Amplifications of ESR1, PRDM14, MYC and HER2 were associated with a high mitotic index, and PRDM14 and HER2 amplifications with high histological grade. MYC amplification was detected more frequently in ductal tumors and high-level MYC amplifications were significantly associated with large tumor size. HER2/MYC, HER2/CCNE1 and EGFR/MYC co-amplified tumors were significantly larger than tumors with either of these amplifications. Gene loss occurred most frequently in E-cadherin (CDH1) (20%) and FGFR1 (10%). In conclusion, MLPA analysis with this 'breast cancer kit' allowed to simultaneously assess copy numbers of 20 important breast cancer genes, providing an overview of the most frequent (co)amplifications as well as interesting phenotypic correlations, and thereby data on the potential importance of these genes in breast cancer.

Correlation Between Anthropometric Measures and Biomarker Changes After Neoadjuvant Therapy With Tamoxifen or Anastrozole in Postmenopausal Women With Breast Cancer

Background

Epidemiological studies have reported positive associations between anthropometric measures and risk for developing breast cancers that express hormone receptors and associated mortality. However, the impact of nutritional status on the molecular response to endocrine therapy has yet to be described.

Methods

Body mass index (BMI), waist circumference (WC), hip circumference (HP), and waist-to-hip ratio (WHR) were measured in patients with invasive ductal carcinoma (IDC) before and after neoadjuvant treatment with either tamoxifen or anastrozole, and a possible correlation with prognostic factors, as estrogen receptor (ER), progesterone receptor (PgR), and proliferative index (Ki-67), was analyzed. Fifty-seven patients with palpable ER-positive IDC were randomized into three neoadjuvant treatment groups and received anastrozole or placebo or tamoxifen for twenty-one days. Biomarker status was obtained by comparing the immunohistochemical evaluation of samples collected before and after treatment, using the Allred scoring system. Statistical analysis was performed using the Statistical Package for the Social Sciences (SPSS).

Results and Conclusions

After treatment, the anastrozole group showed reduced ER and PgR expression (p < 0.05), and both the anastrozole and tamoxifen groups showed lower Ki-67 status. A significant reduction in PgR positivity (p < 0.05) was found in women with large WC and HC who were treated with anastrozole. Reduction in PgR positivity also tended to be associated with BMI (p = 0.09) in the anastrozole group. BMI, WC, HC and WHR correlated neither with biomarker levels in the tamoxifen and placebo groups nor with ER and Ki-67 status in the anastrozole group after primary endocrine treatment.

Protein interacting with C alpha kinase 1 (PICK1) is involved in promoting tumor growth and correlates with poor prognosis of human breast cancer

Protein interacting with C alpha kinase 1 (PICK1), which interacts with multiple different proteins in a variety of cellular contexts, is believed to play important roles in diverse pathological conditions including cancer. In this study, we attempted to investigate the correlation of PICK1 with clinicopathological features as well as prognosis of human breast cancer. In addition, we aimed at a better understanding of the biological function of PICK1 in breast cancer cell biology. As judged by semi- quantitative RT-PCR and western blotting, PICK1 was overexpressed in tumor cells as compared to adjacent normal epithelia in breast, lung, gastric, colorectal, and ovarian cancer. As judged by immunostaining breast cancer tissue microarrays, high levels of PICK1 expression correlated with shortened span of overall survival (OS). Protein interacting with C alpha kinase 1 (PICK1) expression seemed to be specifically associated with reduced OS in lymph node-positive, Her/neu-2 positive, and the basal-like type subgroups, respectively. Consistently, the expression of PICK1 correlated with histological grade, lymph node metastasis, Her-2/neu-positivity, and triple-negative basal-like breast cancer. Protein interacting with C alpha kinase 1 (PICK1) was not correlated with menopausal status, tumor size, or hormone receptor status. In a complementary study, transfection of MDA-MB-231 cells with PICK1 siRNA decreased cell proliferation and colony formation in vitro and inhibited tumorigenicity in nude mice. Our clinical and experimental evidence supports an oncogenic role of PICK1 in human breast cancer. In particular, our data suggest that PICK1 promotes tumor cell proliferation. Taken together, PICK1 may serve not only as a marker for poor prognosis, but also as a therapeutic target in breast cancer.

Prediction of breast cancer prognosis using gene set statistics provides signature stability and biological context

Background

Different microarray studies have compiled gene lists for predicting outcomes of a range of treatments and diseases. These have produced gene lists that have little overlap, indicating that the results from any one study are unstable. It has been suggested that the underlying pathways are essentially identical, and that the expression of gene sets, rather than that of individual genes, may be more informative with respect to prognosis and understanding of the underlying biological process.

Results

We sought to examine the stability of prognostic signatures based on gene sets rather than individual genes. We classified breast cancer cases from five microarray studies according to the risk of metastasis, using features derived from predefined gene sets. The expression levels of genes in the sets are aggregated, using what we call a set statistic. The resulting prognostic gene sets were as predictive as the lists of individual genes, but displayed more consistent rankings via bootstrap replications within datasets, produced more stable classifiers across different datasets, and are potentially more interpretable in the biological context since they examine gene expression in the context of their neighbouring genes in the pathway. In addition, we performed this analysis in each breast cancer molecular subtype, based on ER/HER2 status. The prognostic gene sets found in each subtype were consistent with the biology based on previous analysis of individual genes.

Conclusions

To date, most analyses of gene expression data have focused at the level of the individual genes. We show that a complementary approach of examining the data using predefined gene sets can reduce the noise and could provide increased insight into the underlying biological pathways.

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.

Combinatorial biomarker expression in breast cancer

Current clinical management of breast cancer relies on the availability of robust clinicopathological variables and few well-defined biological markers. Recent microarray-based expression profiling studies have emphasised the importance of the molecular portraits of breast cancer and the possibility of classifying breast cancer into biologically and molecularly distinct groups. Subsequent large scale immunohistochemical studies have demonstrated that the added value of studying the molecular biomarker expression in combination rather than individually. Oestrogen (ER) and progesterone (PR) receptors and HER2 are currently used in routine pathological assessment of breast cancer. Additional biomarkers such as proliferation markers and 'basal' markers are likely to be included in the future. A better understanding of the prognostic and predictive value of combinatorial assessment of biomarker expression could lead to improved breast cancer management in routine clinical practice and would add to our knowledge concerning the variation in behaviour and response to therapy. Here, we review the evidence on the value of assessing biomarker expression in breast cancer individually and in combination and its relation to the recent molecular classification of breast cancer.

c-Abl regulates estrogen receptor alpha transcription activity through its stabilization by phosphorylation

Estrogen receptors are members of the steroid hormone superfamily of nuclear receptors that act as ligand-activated transcription factors. Similar to other steroid hormone receptors, estrogen receptor alpha (ERalpha) is a substrate for protein kinases, and phosphorylation has profound effects on the function of this receptor. In this study, we show that ERalpha associates with c-Abl nonreceptor tyrosine kinase. The direct interaction is mediated by two PXXP motifs of ERalpha and the c-Abl SH3 domain. Mutational analysis and in vitro kinase assays show that ERalpha can be phosphorylated on two sites, tyrosine 52 (Y-52) and tyrosine 219 (Y-219). ERalpha phosphorylation by c-Abl stabilizes ERalpha, resulting in enhanced ERalpha transcriptional activity and increased expression of endogenous ERalpha target genes. Furthermore, ERalpha phosphorylation at the Y-219 site affects DNA binding and dimerization by ERalpha. Both the c-Abl inhibitor and the c-Abl kinase dead mutation abolish the c-Abl-induced accumulation of ERalpha and enhancement of ERalpha transcriptional activity, indicating that c-Abl kinase activity is required for regulation of the ERalpha function. Moreover, the ERalpha (Y52,219F) mutant shows reduced breast cancer cell growth and invasion. Taken together, these results show that c-Abl is a novel kinase that upregulates ERalpha expression and promotes breast cancer cell proliferation, suggesting a great potential for this kinase to function as a therapeutic target for breast cancer.

Anti-Tumoral Activity of a Short Decapeptide Fragment of the Alzheimer's Abeta Peptide

The inhibition of angiogenesis is regarded as a promising avenue for cancer treatment. Although some antiangiogenic compounds are in the process of development and testing, these often prove ineffective in vivo, therefore the search for new inhibitors is critical. We have recently identified a ten amino acid fragment of the Alzheimer Abeta peptide that is anti-angiogenic both in vitro and in vivo. In the present study, we investigated the antitumoral potential of this decapeptide using human MCF-7 breast carcinoma xenografts nude mice. We observed that this decapeptide was able to suppress MCF-7 tumor growth more potently than the antiestrogen tamoxifen. Inhibition of tumor vascularization as determined by PECAM-1 immunostaining and decreased tumor cell proliferation as determined by Ki67 immunostaining were observed following treatment with the Abeta fragment. In vitro, this peptide had no direct impact on MCF-7 tumor cell proliferation and survival suggesting that the inhibition of tumor growth and tumor cell proliferation observed in vivo is related to the antiangiogenic activity of the peptide. Taken together these data suggest that this short Abeta derivative peptide may constitute a new antitumoral agent.

Effect of anaesthetic technique on oestrogen receptor-negative breast cancer cell function in vitro

BACKGROUND

Metastatic recurrence is the main cause of breast cancer-related deaths. Tumour cell proliferation and migration are crucial steps in the metastatic process. Several perioperative factors, including general anaesthesia and opioid analgesia, adversely affect immune function, potentially increasing metastatic recurrence. Regional anaesthesia-analgesia has been consistently shown to attenuate the stress response to surgery, and also reduce opioid and general anaesthesia requirements, thereby attenuating this perioperative immunosuppression. We investigated the effect of serum from breast cancer surgery patients who received different anaesthetic techniques on breast cancer cell function in vitro.

METHODS

Patients were randomized to receive propofol/paravertebral anaesthesia-analgesia (propofol/paravertebral, n=11) or sevoflurane general anaesthesia with opioid analgesia (sevoflurane/opioid, n=11). The ER-negative MDA-MB-231 cell line was treated with patient serum from both groups. The effects on proliferation and migration were measured.

RESULTS

Treatment groups were well balanced for age, weight, surgical procedure, and cancer pathology. Pain scores were lower at 1 and 2 h in the propofol/paravertebral analgesia group. Compared with preoperative values, proliferation of MDA-MB-231 cells treated with postoperative patient serum at 10% concentration from the propofol/paravertebral group was significantly reduced compared with the sevoflurane/opioid group (-24% vs 73%, P=0.01). There was no significant change in MDA-MB-231 cell migration after treatment with patient serum between the two groups.

CONCLUSIONS

Serum from patients receiving propofol/paravertebral anaesthesia for breast cancer surgery inhibited proliferation, but not migration, of ER-MDA-MB-231 cells in vitro, to a greater extent than that from patients receiving sevoflurane/opioid anaesthesia-analgesia. This implies that anaesthetic technique alters the serum molecular milieu in ways that may affect breast cancer cell function, possibly by altering anaesthetic and opioid drug administration and resultant pain scores.

Prognostic significance of tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) receptor expression in patients with breast cancer

TNF-related apoptosis-inducing ligand (TRAIL) induces apoptosis upon binding to TRAIL receptors 1 and 2 (TRAIL-R1/DR4 and TRAIL-R2/DR5). TRAIL-R3 (DcR1) and TRAIL-R4 (DcR2) have no or only a truncated cytoplasmic death domain. Consequently, they cannot induce apoptosis and instead have been proposed to inhibit apoptosis induction by TRAIL. Agonists for the apoptosis-inducing TRAIL-R1 and TRAIL-R2 are currently tested in clinical trials. To determine the expression pattern of all surface-bound TRAIL receptors and their prognostic clinical value, we investigated tumour samples of 311 patients with breast cancer by immunohistochemistry. TRAIL receptor expression profiles were correlated with clinico-pathological data, disease-free survival and overall survival. TRAIL-R1 was more strongly expressed in better differentiated tumours, and correlated positively with surrogate markers of a better prognosis (hormone receptor status, Bcl-2, negative nodal status), but negatively with the expression of Her2/neu and the proliferation marker Ki67. In contrast, TRAIL-R2 and TRAIL-R4 expression correlated with higher tumour grades, higher Ki67 index, higher Her2/neu expression and a positive nodal status at the time of diagnosis, but with lower expression of Bcl-2. Thus, the TRAIL receptor expression pattern was predictive of nodal status. Patients with grade 1 and 2 tumours, who had TRAIL-R2 but no TRAIL-R1, showed a positive lymph node status in 47% of the cases. Vice versa, only 19% had a positive nodal status with high TRAIL-R1 but low TRAIL-R2. Most strikingly, TRAIL-R4 and -R2 expression negatively correlated with overall survival of breast cancer patients. Although TRAIL-R2 correlated with more aggressive tumour behaviour, mammary carcinoma could be sensitised to TRAIL-R2-induced apoptosis, suggesting that TRAIL-R2 might therefore be used to therapeutically target such tumours. Hence, determination of the TRAIL receptor expression profile may aid in defining which breast cancer patients have a higher risk of lymph node metastasis and worse overall survival and on the other hand will help to guide TRAIL-based tumour therapy.