Age-related phenotypes in breast cancer: A population-based study

Breast cancer in young (<40 years) is associated with a higher frequency of aggressive tumor types and poor prognosis. It remains unclear if there is an underlying age-related biology that contributes to the unfavorable outcome. We aim to investigate the relationship between age and breast cancer biology, with emphasis on proliferation. Clinico-pathologic information, immunohistochemical markers and follow-up data were obtained for all patients aged <50 (Bergen cohort-1; n = 355, not part of a breast screening program) and compared to previously obtained information on patients aged 50 to 69 years (Bergen cohort-2; n = 540), who participated in the Norwegian Breast Cancer Screening Program. Young breast cancer patients presented more aggressive tumor features such as hormone receptor negativity, HER2 positivity, lymph-node metastasis, the HER2-enriched and triple-negative subtypes and shorter survival. Age <40 was significantly associated with higher proliferation (by Ki67). Ki67 showed weaker prognostic value in young patients. We point to aggressive phenotypes and increased tumor cell proliferation in breast cancer of the young. Hence, tumors of young breast cancer patients may present unique biological features, also when accounting for screen/interval differences, that may open for new clinical opportunities, stratifying treatment by age.

Patient-derived organoids reflect the genetic profile of endometrial tumors and predict patient prognosis

Background

A major hurdle in translational endometrial cancer (EC) research is the lack of robust preclinical models that capture both inter- and intra-tumor heterogeneity. This has hampered the development of new treatment strategies for people with EC.

Methods

EC organoids were derived from resected patient tumor tissue and expanded in a chemically defined medium. Established EC organoids were orthotopically implanted into female NSG mice. Patient tissue and corresponding models were characterized by morphological evaluation, biomarker and gene expression and by whole exome sequencing. A gene signature was defined and its prognostic value was assessed in multiple EC cohorts using Mantel-Cox (log-rank) test. Response to carboplatin and/or paclitaxel was measured in vitro and evaluated in vivo. Statistical difference between groups was calculated using paired t-test.

Results

We report EC organoids established from EC patient tissue, and orthotopic organoid-based patient-derived xenograft models (O-PDXs). The EC organoids and O-PDX models mimic the tissue architecture, protein biomarker expression and genetic profile of the original tissue. Organoids show heterogenous sensitivity to conventional chemotherapy, and drug response is reproduced in vivo. The relevance of these models is further supported by the identification of an organoid-derived prognostic gene signature. This signature is validated as prognostic both in our local patient cohorts and in the TCGA endometrial cancer cohort.

Conclusions

We establish robust model systems that capture both the diversity of endometrial tumors and intra-tumor heterogeneity. These models are highly relevant preclinical tools for the elucidation of the molecular pathogenesis of EC and identification of potential treatment strategies.

To study the biology of cancer and test new potential treatments, it is important to use models that mimic patients’ tumors. Such models have largely been lacking in endometrial cancer. We therefore aimed to developing miniature tumors, called “organoids”, directly from patient tumor tissue. Our organoids maintained the characteristics and genetic features of the tumors from which they were derived, would grow into endometrial tumors in mice, and exhibited patient-specific responses to chemotherapy drugs. In summary, we have developed models that will help us better understand the biology of endometrial tumors and can be used to potentially identify new effective drugs for endometrial cancer patients.

Berg et al. establish a panel of patient-derived endometrial cancer organoids and xenograft models. They show that their models recapitulate the genetic profile of the donor tumor and can be used for drug testing and development of a prognostic gene signature.

Baseline microvessel density predicts response to neoadjuvant bevacizumab treatment of locally advanced breast cancer

A subset of breast cancer patients benefits from preoperative bevacizumab and chemotherapy, but validated predictive biomarkers are lacking. Here, we aimed to evaluate tissue-based angiogenesis markers for potential predictive value regarding response to neoadjuvant bevacizumab treatment in breast cancer. In this randomized 1:1 phase II clinical trial, 132 patients with large or locally advanced HER2-negative tumors received chemotherapy ± bevacizumab. Dual Factor VIII/Ki-67 immunohistochemical staining was performed on core needle biopsies at baseline and week 12. Microvessel density (MVD), proliferative microvessel density (pMVD; Factor VIII/Ki-67 co-expression), glomeruloid microvascular proliferation (GMP), and a gene expression angiogenesis signature score, were studied in relation to pathologic complete response (pCR), clinico-pathologic features and intrinsic molecular subtype. We found that high baseline MVD (by median) significantly predicted pCR in the bevacizumab-arm (odds ratio 4.9, P = 0.012). High pMVD, presence of GMP, and the angiogenesis signature score did not predict pCR, but were associated with basal-like (P ≤ 0.009) and triple negative phenotypes (P ≤ 0.041). pMVD and GMP did also associate with high-grade tumors (P ≤ 0.048). To conclude, high baseline MVD significantly predicted response to bevacizumab treatment. In contrast, pMVD, GMP, and the angiogenesis signature score, did not predict response, but associated with aggressive tumor features, including basal-like and triple-negative phenotypes.

Abstract A16: Patient-derived organoid-based models for endometrial cancer

Introduction: Comprehensive profiling of tumors using omics technologies has improved our understanding of the molecular landscape of endometrial cancer (EC), building the foundation for precision medicine. However, targeted therapies that show promise in preclinical research are failing clinical trials, which is partly explained by the lack of models that mimic the physiopathology of patients. We aimed at establishing organoids and organoid-based patient-derived xenograft (O-PDX) models as part of a new preclinical platform for endometrial cancer.

Methods: Aggregates of tumor cells were isolated from fresh tumor samples, followed by long-term culturing as organoids in a chemically defined medium. Established organoids were implanted into the left uterine horn of NSG mice, and tumor growth was monitored using near-infrared fluorescence imaging (NIRF). Patient tissue, organoids, and corresponding O-PDXs were characterized by histology and whole-exome sequencing and by immunohistochemical staining of important endometrial cancer biomarkers. For proof of concept, selected models were treated with conventional therapeutic agents, including in vivo treatment with carboplatin.

Results: Organoids and orthotopic O-PDXs representing different subtypes of endometrial cancer were successfully established. Histologic and molecular profiles of organoids are similar to patient tissue, also after long-term culturing, and characteristics of O-PDXs were sustained after rederivation in vivo. Proof-of-concept drug testing shows heterogenous sensitivity to clinically administered chemotherapeutics.

Conclusion: We have extended the collection of EC organoids and established O-PDX models for in vivo studies. This state-of-the-art preclinical platform enables more clinically relevant drug testing that will facilitate translation into relevant clinical trials.

Citation Format: Hege F. Berg, Tina Fonnes, Elin Strand, Heidi Espedal, Ingunn M. Stefansson, Emmet McCormack, Line Bjørge, Jone Trovik, Ingfrid S. Haldorsen, Erling A. Hoyvik, Camilla Krakstad. Patient-derived organoid-based models for endometrial cancer [abstract]. In: Proceedings of the AACR Special Conference on the Evolving Landscape of Cancer Modeling; 2020 Mar 2-5; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2020;80(11 Suppl):Abstract nr A16.

In vivo MR spectroscopy predicts high tumor grade in endometrial cancer

Background In vivo magnetic resonance spectroscopy (MRS) enables non-invasive measurements of tumor metabolites. Choline-containing metabolites play a key role in tumor metabolism. Purpose To explore whether preoperative MRS-derived tumor choline levels are associated with clinical and histological features in endometrial carcinomas. Material and Methods Preoperative pelvic magnetic resonance imaging (MRI) (1.5T), including structural and diffusion-weighted imaging and localized multivoxel proton MR (1H-MR) spectroscopy, was performed in 77 prospectively included patients with histologically confirmed endometrial carcinomas. Relative levels of total choline-containing metabolites (tCho) in tumor and myometrium were measured using the ratios: tCho/Creatine; tCho/Water; and tCho/Noise. MRS parameters were analyzed in relation to histological subtype and grade, surgicopathological staging parameters, MRI-measured tumor volume, and tumor apparent diffusion coefficient (ADC) value and clinical outcome. Results Tumor tissue had significantly higher ratios for tCho/Creatine, tCho/Water, and tCho/Noise than normal myometrial tissue ( P < 0.001 for all). High tumor tCho/Water ratio was significantly associated with high tumor grade in endometrioid tumors ( P = 0.02). Tumor tCho/Creatine ratio was positively correlated to MRI-measured tumor volume (r_s = 0.25; P = 0.03). Conclusion High choline levels in tumor are associated with high-risk features. In vivo MRS may potentially aid in the preoperative risk stratification in endometrial cancer.

Type of vascular invasion in association with progress of endometrial cancer

Vascular invasion (VI) is a well-established marker for lymph node metastasis and outcome in endometrial cancer. Our study explored whether specific types of VI, defined as lymphatic (LVI) or blood vessel invasion (BVI), predict pattern of metastasis. From a prospectively collected cohort, we conducted a case-control study by selecting three groups of endometrial cancer patients (n = 183): 52 with positive lymph nodes at primary surgery, 33 with negative nodes at primary surgery and later recurrence and death from disease, and 98 with negative nodes and no recurrence. All patients underwent hysterectomy with lymphadenectomy. Immunohistochemical staining with D2-40 and CD31 antibodies was used to differentiate between BVI and LVI. By immunohistochemical staining, detection of VI increased from 24.6 to 36.1% of the cases. LVSI was significantly more often seen in patients with positive lymph nodes compared with patients with negative nodes (p = 0.001). BVI was significantly more often seen in node-negative patients with recurrence compared with node-negative patients without recurrence (p = 0.011). In multivariable analysis, BVI, age, and tumor grade were predictors separating patients with and without recurrence. Lymph node-positive patients showed more often LVI compared with lymph node-negative patients, while BVI seems to be a predictor for recurrent disease.

Expression of Nestin associates with BRCA1 mutations, a basal-like phenotype and aggressive breast cancer

We here examined whether Nestin, by protein and mRNA levels, could be a predictor of BRCA1 related breast cancer, a basal-like phenotype, and aggressive tumours. Immunohistochemical staining of Nestin was done in independent breast cancer hospital cohorts (Series I-V, total 1257 cases). Also, TCGA proteomic data (n = 103), mRNA microarray data from TCGA (n = 520), METABRIC (n = 1992), and 6 open access breast cancer datasets (n = 1908) were analysed. Patients with Nestin protein expression in tumour cells more often had BRCA1 germline mutations (OR 8.7, p < 0.0005, Series III), especially among younger patients (<40 years at diagnosis) (OR 16.5, p = 0.003). Nestin protein positivity, observed in 9–28% of our hospital cases (Series I-IV), was independently associated with reduced breast cancer specific survival (HR = 2.0, p = 0.035) and was consistently related to basal-like differentiation (by Cytokeratin 5, OR 8.7–13.8, p < 0.0005; P-cadherin OR 7.0–8.9, p < 0.0005; EGFR staining, OR 3.7–8.2, p ≤ 0.05). Nestin mRNA correlated significantly with Nestin protein expression (ρ = 0.6, p < 0.0005), and high levels were seen in the basal-like intrinsic subtype. Gene expression signalling pathways linked to high Nestin were explored, and revealed associations with stem-like tumour features. In summary, Nestin was strongly associated with germline BRCA1 related breast cancer, a basal-like phenotype, reduced survival, and stemness characteristics.

Tumour cell invasion into blood vessels is significantly related to breast cancer subtypes and decreased survival

AIMS

Vascular invasion in breast cancer is associated with increased risk of recurrence, metastases and death from disease. However, there are few studies discriminating between blood vessel invasion (BVI) and lymphatic vessel involvement (LVI).

METHODS

A population-based series of 282 breast cancers was examined (200 screen-detected and 82 interval patients) with respect to BVI and LVI in addition to basic features and molecular subtypes, using CD31 and D2-40 antibodies. This series is part of the prospective Norwegian Breast Cancer Screening Program.

RESULTS

The frequency of LVI and BVI was 25% and 15%, respectively. BVI was associated with HER2-positive and basal-like tumours, and several features of aggressive breast cancer, whereas LVI showed weaker associations. BVI was the strongest factor to predict interval cancer presentation. BVI showed significant associations with recurrence-free survival and disease-specific survival in univariate and multivariate analyses, whereas LVI was not significant.

CONCLUSIONS

Our findings indicate that BVI by tumour cells is strongly associated with aggressive tumour features including a basal-like phenotype, and BVI was an independent prognostic factor in contrast to what was found for LVI.

The genomic landscape and evolution of endometrial carcinoma progression and abdominopelvic metastasis

Recent studies have detailed the genomic landscape of primary endometrial cancers, but the evolution of these cancers into metastases has not been characterized. We performed whole-exome sequencing of 98 tumor biopsies including complex atypical hyperplasias, primary tumors and paired abdominopelvic metastases to survey the evolutionary landscape of endometrial cancer. We expanded and reanalyzed The Cancer Genome Atlas (TCGA) data, identifying new recurrent alterations in primary tumors, including mutations in the estrogen receptor cofactor gene NRIP1 in 12% of patients. We found that likely driver events were present in both primary and metastatic tissue samples, with notable exceptions such as ARID1A mutations. Phylogenetic analyses indicated that the sampled metastases typically arose from a common ancestral subclone that was not detected in the primary tumor biopsy. These data demonstrate extensive genetic heterogeneity in endometrial cancers and relative homogeneity across metastatic sites.

Increased angiogenesis is associated with a 32-gene expression signature and 6p21 amplification in aggressive endometrial cancer

Background

Angiogenesis is a hallmark of cancer. The aim of this study was to explore whether microvessel proliferation is associated with gene expression profiles or copy number alterations in endometrial cancer.

Methods

A prospective series of endometrial carcinomas was studied for angiogenesis markers, gene expression profiles, and gene copy number data. For validation, an independent series of endometrial carcinomas as well as an external cohort of endometrial cancer patients were examined by gene expression microarrays.

Results

Increased microvessel proliferation (MVP) was associated with aggressive tumor features and reduced survival, and a 32-gene expression signature was found to separate tumors with high versus low MVP. An increased 32-gene signature score was confirmed to associate with high-grade tumor features and reduced survival by independent cohorts. Copy number studies revealed that amplification of the 6p21 region was significantly associated with MVP, a high 32-gene score, as well as reduced survival.

Conclusion

Increased MVP was significantly associated with aggressive endometrial cancer and reduced survival. Integrated analyses demonstrated significant associations between increased vascular proliferation, amplification of the 6p21 region, VEGF-A mRNA expression, and the 32-gene angiogenesis signature. Our findings indicate amplification of 6p21 as a possible driver of tumor vascular proliferation in endometrial cancer.

Abstract 2429: Nestin expression in tumor cells is associated with BRCA1 positive genotype and a basal-like phenotype in breast cancer

Background:

The basal-like subtype of breast cancer is one of at least five molecular categories. These poor prognosis tumors are most often triple negative, i.e. negative for hormone receptors and HER2, and therefore lack targeted treatment options. There is at present no consensus on how to best define this subtype, and different surrogate immunohistochemistry based markers have been suggested. We here present data supporting nestin as a marker of the basal-like subtype. Originally reported in neuronal progenitor cells, nestin was later observed in the stem cell/progenitor compartment in a variety of tissues as well as in different cancer types, and suggested to be a cancer stem cell marker. In breast cancer, nestin has been reported in the basal-like and triple negative phenotypes. Here, we examined nestin expression in different breast cancer cohorts, including BRCA familial cancer, and breast cancer metastasis.

Materials and methods:

Immunohistochemical staining of nestin was done in four series of breast cancer, and a semi-quantitative measure of nestin positivity (staining index) was used for evaluation of expression. Series I include 190 breast cancer patients diagnosed during 1996-2001 in Hordaland, Norway. Series II comprise 192 breast cancer cases identified in Kampala, Uganda in 1990-2002. Series III includes 151 patients with breast cancer, 53 BRCA1 and 45 BRCA2 mutation carriers, identified during 1980-1995 in Montreal, Canada, and 51 BRCA negative patients from Norway. Series IV consists of 35 patients with tissue from the primary breast cancer and matched metastasis collected in 1996-2007. Finally, level 3 mRNA microarray data from TCGA (n = 520) and four open access breast cancer gene expression data sets (n = 1148) with information on molecular subtype were included.

Results:

The proportion of nestin positive breast tumors was 11%, 24% and 28% in Series I-III. Nestin expression was significantly associated with basal cell markers Cytokeratin 5/6 and P-cadherin (p-values &lt;0.0005), five immunohistochemical profiles for the basal-like phenotype (Odds ratio, OR, range 10.9-27.5) and the triple negative phenotype (OR range 11.8-28.2). Further, patients with BRCA1 mutation more often had nestin positive tumors (OR 8.7, Series III). Higher nestin mRNA levels were seen in basal-like tumors, compared with the luminal-like and HER2-enriched subtypes.

In Series IV, nestin expression in the primary tumor correlated with expression in the corresponding metastasis, with no statistically significant difference between the two groups (McNemar test, p = 1.0).

Conclusion:

We found nestin positivity in breast cancer cells to be significantly and strongly associated with the BRCA1 genotype, individual basal cell markers, and the basal-like and triple negative phenotypes.

Citation Format: Kristi Krüger, Elisabeth Wik, Hawa Nalwoga, Monica Mannelqvist, Ingunn M. Stefansson, Jarle B. Arnes, Gøril Knutsvik, Turid Aas, William D. Foulkes, Lars A. Akslen. Nestin expression in tumor cells is associated with BRCA1 positive genotype and a basal-like phenotype in breast cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2429. doi:10.1158/1538-7445.AM2015-2429

Abstract 3828: An 18-gene signature for vascular invasion is associated with aggressive features and reduced survival in breast cancer

Introduction: Vascular invasion, i.e. tumor cells entering the vascular system, is considered to be an early step in the metastatic process and important for the progress of malignant tumors. By microarray and qPCR, we previously constructed an 18-gene signature in relation to vascular invasion among endometrial cancer patients. Here, we wanted to investigate the vascular invasion signature (VIS) among breast cancers patients.

Methods: The 18-gene signature was studied in 11 gene expression data sets of breast cancer including information on 2423 patients. The genes in the signature were investigated in the external data sets and related to clinical data and follow-up information. We also wanted to examine if our signature was associated with other published signatures related to tumor progression.

Results and Conclusions: High VIS showed associations with aggressive features of breast cancer such as high tumor grade, hormone receptor negativity, HER2 positive tumors, presence of a basal-like phenotype, reduced patient survival and response to cytostatic treatment. Correlations between VIS and other signatures for tumor progression indicate an involvement in similar biological processes. In conclusion, the vascular invasion signature showed strong and consistent associations with aggressive features of breast cancer.

Citation Format: Monica Mannelqvist, Elisabeth Wik, Ingunn M. Stefansson, Lars A. Akslen. An 18-gene signature for vascular invasion is associated with aggressive features and reduced survival in breast cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3828. doi:10.1158/1538-7445.AM2014-3828

Endometrial Carcinoma Recurrence Score (ECARS) validates to identify aggressive disease and associates with markers of epithelial-mesenchymal transition and PI3K alterations

PURPOSE

Our previously reported 29-gene expression signature identified an aggressive subgroup of endometrial cancer patients with PI3K activation. We here wanted to validate these findings by independent patient series.

PATIENTS AND METHODS

The 29-gene expression signature was assessed in fresh frozen tumor tissue from 280 primary endometrial carcinomas (three independent cohorts), 19 metastatic lesions and in 333 primary endometrial carcinomas using TCGA data, and expression was related to clinico-pathologic features and survival. The 29-gene signature was assessed by real-time quantitative PCR, DNA oligonucleotide microarrays, or RNA sequencing. PI3K alterations were assessed by immunohistochemistry, DNA microarrays, DNA sequencing, SNP arrays or fluorescence in situ hybridization. A panel of markers of epithelial-mesenchymal transition (EMT) was also correlated to the 29-gene signature score.

RESULTS

High 29-gene Endometrial Carcinoma Recurrence Score (ECARS) values consistently validated to identify patients with aggressive clinico-pathologic phenotype and reduced survival. Within the presumed favorable subgroups of low grade, endometrioid tumors confined to the uterus, high ECARS still predicted a poor prognosis. The score was higher in metastatic compared to primary lesions (P<0.001) and was significantly associated with potential measures of PI3K activation, markers of EMT and vascular invasion as an indicator of metastatic spread (all P<0.001).

CONCLUSIONS

ECARS validates to identify aggressive endometrial carcinomas in multiple, independent patients cohorts. The higher signature score in metastatic compared to primary lesions, and the potential link to PI3K activation and EMT, support further studies of ECARS in relation to response to PI3K and EMT inhibitors in clinical trials of metastatic endometrial carcinoma.

An 18-gene signature for vascular invasion is associated with aggressive features and reduced survival in breast cancer

Aims

Vascular invasion by tumor cells is known to be important for cancer progression. By microarray and qPCR analyses, we earlier identified an 18-gene signature associated with vascular involvement in endometrial cancer. Here, we explored the significance of this vascular invasion signature in multiple series of breast cancer patients.

Methods and Results

The study includes 11 open access gene expression data sets which collectively provide information on 2423 breast cancer patients. The 18-gene signature showed consistent associations with aggressive features of breast cancer, like high tumor grade, hormone receptor negativity, HER2 positivity, a basal-like phenotype, reduced patient survival, and response to neoadjuvant chemotherapy. Also, the vascular invasion signature was associated with several other gene expression profiles related to vascular biology and tumor progression, including the Oncotype DX breast cancer recurrence signature.

Conclusions

The 18-gene vascular invasion signature showed strong and consistent associations with aggressive features of breast cancer and reduced survival.

Expression of thyroid transcription factor-1 is associated with a basal-like phenotype in breast carcinomas

Background

The differential diagnosis between primary and secondary breast cancers might be difficult, especially in poorly differentiated tumors. Thyroid Transcription Factor-1 (TTF-1) has been regarded as a reliable marker for lung or thyroid origin, with only occasional positive staining in other tumors. However, positive cases have recently been reported among primary breast carcinomas.

Methods and results

Here, we analyzed expression of TTF-1 protein (clone SPT24) by immunohistochemical staining of sections from paraffin embedded tumor samples in 247 primary breast cancers from the population-based Norwegian Breast Cancer Screening Program. Positive staining (weak or strong) was observed in 7 cases (2,8%). As novel observations, positivity was demonstrated more frequently in estrogen receptor negative cases (14,0% vs. 1,4%; p = 0,004), highly proliferative tumors (8,8% vs. 1,1%; p = 0,008), tumors with a basal-like phenotype by showing expression of CK5/6 and/or P-cadherin (11,1% vs. 1,4%; p = 0,01), and tumors with blood vessel invasion (9,7% vs. 1,9%; p = 0,04). Also, TTF-1 was associated with histological grade 3 tumors compared with grade 1 or 2 tumors (7,7% vs. 1,5%; p = 0,04) as well as lymph node positive cases (5,2% vs. 1,8%; p = 0,03).

Conclusions

Our population-based findings indicate that TTF-1 may be positive in approximately 3% of primary breast cancers, and positivity indicates an association with adverse prognostic factors.

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/8313753509421182

Lack of estrogen receptor-α is associated with epithelial-mesenchymal transition and PI3K alterations in endometrial carcinoma

PURPOSE

We hypothesized that estrogen receptor-α (ER-α) status in endometrial carcinomas, associated with poor prognosis, is reflected in transcriptional signatures suggesting targets for new therapy.

EXPERIMENTAL DESIGN

Endometrial carcinoma samples in a primary investigation cohort (n = 76) and three independent validation cohorts (n = 155/286/111) were analyzed through integrated molecular profiling. Biomarkers were assessed by immunohistochemistry (IHC), DNA oligonucleotide microarray, quantitative PCR (qPCR), single-nucleotide polymorphism (SNP) array, and Sanger sequencing in the cohorts, annotated for comprehensive histopathologic and clinical data, including follow-up.

RESULTS

ER-α immunohistochemical staining was strongly associated with mRNA expression of the receptor gene (ESR1) and patient survival (both P < 0.001). ER-α negativity associated with activation of genes involved in Wnt-, Sonic Hedgehog-, and TGF-β signaling in the investigation cohort, indicating epithelial-mesenchymal transition (EMT). The association between low ER-α and EMT was validated in three independent datasets. Furthermore, phosphoinositide 3-kinase (PI3K) and mTOR inhibitors were among the top-ranked drug signatures negatively correlated with the ER-α-negative tumors. Low ER-α was significantly associated with PIK3CA amplifications but not mutations. Also, low ER-α was correlated to high expression of Stathmin, a marker associated with PTEN loss, and a high PI3K activation signature.

CONCLUSION

Lack of ER-α in endometrial cancer is associated with EMT and reduced survival. We present a rationale for investigating ER-α's potential to predict response to PI3K/mTOR inhibitors in clinical trials and also suggest EMT inhibitors to ER-α-negative endometrial carcinomas.

Microvessel proliferation by co-expression of endothelial nestin and Ki-67 is associated with a basal-like phenotype and aggressive features in breast cancer

BACKGROUND

To quantify tumour angiogenesis, microvessel density (MVD) has been widely used. We here present a novel angiogenesis marker, microvessel proliferation (MVP), based on dual immunohistochemical staining of nestin and Ki-67. Immature endothelial cells express nestin, and when co-expressed with the proliferation marker Ki-67, the number of proliferating immature blood vessels can be measured.

MATERIALS AND METHODS

Microvessel proliferation was evaluated in 178 breast cancer samples and estimated by vascular proliferation index (VPI), the ratio between the number of vessels containing proliferating endothelial cells and the total number of immature vessels.

RESULTS

High VPI was strongly associated with several markers of aggressive breast cancer, such as negative oestrogen receptor (ER) status (p = 0.003), high tumour cell proliferation by Ki-67 (p = 0.004), high p53 expression (p = 0.001), and five profiles for the basal-like phenotype (odds ratios (OR); range 3.4-6.3). Also, high VPI was significantly associated with interval detected breast cancer compared with screening detected lesions (p < 0.0005), and adverse outcome in univariate and multivariate survival analysis (p = 0.034 and p = 0.022, respectively).

CONCLUSION

Microvessel proliferation is a novel marker of ongoing angiogenesis and was associated with aggressive tumour features, basal-like phenotypes, interval presentation, and prognosis in this series of breast cancer.

Lipocalin 2 expression is associated with aggressive features of endometrial cancer

Background

Increased expression of lipocalin 2 (LCN2) has been observed in several cancers. The aim of the present study was to investigate LCN2 in endometrial cancer in relation to clinico-pathologic phenotype, angiogenesis, markers of epithelial-mesenchymal transition (EMT), and patient survival.

Methods

Immunohistochemical staining was performed using a human LCN2 antibody on a population-based series of endometrial cancer patients collected in Hordaland County (Norway) during 1981-1990 (n = 256). Patients were followed from the time of primary surgery until death or last follow-up in 2007. The median follow-up time for survivors was 17 years. Gene expression data from a prospectively collected endometrial cancer series (n = 76) and a publicly available endometrial cancer series (n = 111) was used for gene correlation studies.

Results

Expression of LCN2 protein, found in 49% of the cases, was associated with non-endometrioid histologic type (p = 0.001), nuclear grade 3 (p = 0.001), >50% solid tumor growth (p = 0.001), ER and PR negativity (p = 0.028 and 0.006), and positive EZH2 expression (p < 0.001). LCN2 expression was significantly associated with expression of VEGF-A (p = 0.021), although not with other angiogenesis markers examined (vascular proliferation index, glomeruloid microvascular proliferation, VEGF-C, VEGF-D or bFGF2 expression). Further, LCN2 was not associated with several EMT-related markers (E-cadherin, N-cadherin, P-cadherin, β-catenin), nor with vascular invasion (tumor cells invading lymphatic or blood vessels). Notably, LCN2 was significantly associated with distant tumor recurrences, as well as with the S100A family of metastasis related genes. Patients with tumors showing no LCN2 expression had the best outcome with 81% 5-year survival, compared to 73% for intermediate and 38% for the small subgroup with strong LCN2 staining (p = 0.007). In multivariate analysis, LCN2 expression was an independent prognostic factor in addition to histologic grade and FIGO stage.

Conclusion

Increased LCN2 expression is associated with aggressive features and poor prognosis in endometrial cancer.

Loss of GPER identifies new targets for therapy among a subgroup of ERα-positive endometrial cancer patients with poor outcome

BACKGROUND

The G protein-coupled oestrogen receptor, GPER, has been suggested as an alternative oestrogen receptor. Our purpose was to investigate the potential of GPER as a prognostic and predictive marker in endometrial carcinoma and to search for new drug candidates to improve treatment of aggressive disease.

MATERIALS AND METHOD

A total of 767 primary endometrial carcinomas derived from three patient series, including an external dataset, were studied for protein and mRNA expression levels to investigate and validate if GPER loss identifies poor prognosis and new targets for therapy in endometrial carcinoma. Gene expression levels, according to ERα/GPER status, were used to search the connectivity map database for small molecular inhibitors with potential for treatment of metastatic disease for receptor status subgroups.

RESULTS

Loss of GPER protein is significantly correlated with low GPER mRNA, high FIGO stage, non-endometrioid histology, high grade, aneuploidy and ERα loss (all P-values ≤0.05). Loss of GPER among ERα-positive patients identifies a subgroup with poor prognosis that until now has been unrecognised, with reduced 5-year survival from 93% to 76% (P=0.003). Additional loss of GPER from primary to metastatic lesion counterparts further supports that loss of GPER is associated with disease progression.

CONCLUSION

These results support that GPER status adds clinically relevant information to ERα status in endometrial carcinoma and suggest a potential for new inhibitors in the treatment of metastatic endometrial cancers with ERα expression and GPER loss.

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.

Gene expression patterns related to vascular invasion and aggressive features in endometrial cancer

The presence of tumor cells entering vascular channels is a prognostic marker for many cancers, including endometrial carcinoma. Vascular invasion is considered to be an early step in the metastatic process and important for the progress of malignant tumors. Here, we investigated the gene expression patterns related to vascular involvement in 57 primary endometrial cancers, using DNA microarray and quantitative PCR techniques. A vascular invasion signature of 18 genes was significantly associated with patient survival and clinicopathological phenotype. Vascular involvement was also related to gene sets for epithelial-mesenchymal transition, wound response, endothelial cells, and vascular endothelial growth factor (VEGF) activity. With immunohistochemical validation, both collagen 8 and matrix metalloproteinase 3 (MMP3) were associated with vascular invasion, whereas ANGPTL4 and IL-8 were associated with patient survival. Our findings indicate that vascular involvement within primary tumors is associated with gene expression profiles related to angiogenesis and epithelial-mesenchymal transition. These data could contribute to an improved understanding of potential targets for metastatic spread and may provide clinically important information for better management of endometrial cancer.

Abstract 4169: Loss of GPR30 expression identifies estrogen receptor positive endometrial carcinoma patients with poor outcome

In industrialized countries, endometrial cancer is the most common pelvic gynecologic malignancy, with a 2% to 3% lifetime risk. Expression of estrogen receptor (ER) and progesterone receptor (PR) is known to be associated with good prognosis and response to anti-hormonal therapy. Still, up to 20% of receptor positive cancers recur. The G-protein coupled receptor GPR30 has been suggested as an alternative estrogen receptor. We have studied a prospective series of 472 endometrial cancer patients by immunohistochemistry and 76 for mRNA expression levels by oligonucleotide array. We identify that loss of GPR30 is significantly correlated with non-endometrioid histology and high histologic grade both at the mRNA and protein levels (all p-values≤0.006). In ER positive patients (n=363), loss of GPR30 significantly correlates with high FIGO stage, non-endometrioid histology and high histologic grade (all p-values≤0.005). Loss of GPR30 reduces the 5-year survival of ER positive patients from 93% to 76% (p=0.003) and identifies a subgroup of patients with poor prognosis that until now has been evaluated as favorable survivors. Examination of the gene expression profile for ER positive tumors with and without loss of GPR30, indicates mechanisms involved related to GPR30 expression.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4169. doi:10.1158/1538-7445.AM2011-4169

High BMI is significantly associated with positive progesterone receptor status and clinico-pathological markers for non-aggressive disease in endometrial cancer

BACKGROUND

Endometrial cancer incidence is increasing in industrialised countries. High body mass index (BMI, kg  m(-2)) is associated with higher risk for disease. We wanted to investigate if BMI is related to clinico-pathological characteristics, hormone receptor status in primary tumour, and disease outcome in endometrial cancer.

PATIENTS AND METHODS

In total, 1129 women primarily treated for endometrial carcinoma at Haukeland University Hospital during 1981-2009 were studied. Body mass index was available for 949 patients and related to comprehensive clinical and histopathological data, hormone receptor status in tumour, treatment, and follow-up.

RESULTS

High BMI was significantly associated with low International Federation of Gynaecology and Obstetrics (FIGO) stage, endometrioid histology, low/intermediate grade, and high level of progesterone receptor (PR) mRNA by qPCR (n=150; P=0.02) and protein expression by immunohistochemistry (n=433; P=0.003). In contrast, oestrogen receptor (ERα) status was not associated with BMI. Overweight/obese women had significantly better disease-specific survival (DSS) than normal/underweight women in univariate analysis (P=0.035). In multivariate analysis of DSS adjusting for age, FIGO stage, histological subtype, and grade, BMI showed no independent prognostic impact.

CONCLUSION

High BMI was significantly associated with markers of non-aggressive disease and positive PR status in a large population-based study of endometrial carcinoma. Women with high BMI had significantly better prognosis in univariate analysis of DSS, an effect that disappeared in multivariate analysis adjusting for established prognostic markers. The role of PR in endometrial carcinogenesis needs to be further studied.

Stathmin overexpression identifies high-risk patients and lymph node metastasis in endometrial cancer

PURPOSE

Overexpression of the oncogen Stathmin has been linked to aggressive endometrial carcinoma and a potential for PI3Kinase inhibitors in this disease. We wanted to validate the prognostic value of Stathmin expression in a large prospective multicenter setting. As lymph node sampling is part of current surgical staging, we also aimed to test if Stathmin expression in endometrial curettage specimens could predict lymph node metastasis.

EXPERIMENTAL DESIGN

A total of 1,076 endometrial cancer patients have been recruited from 10 centers to investigate the biological tumor marker Stathmin in relation to clinicopathologic variables, including lymph node status and survival. Stathmin immunohistochemical staining was carried out in 477 hysterectomy and 818 curettage specimens.

RESULTS

Seventy-one percent of the patients (n = 763) were subjected to lymph node sampling, of which 12% had metastatic nodes (n = 94). Overexpression of Stathmin was detected in 37% (302 of 818) of the curettage and in 18% (84 of 477) of the hysterectomy specimens investigated. Stathmin overexpression in curettage and hysterectomy specimens were highly correlated and significantly associated with nonendometrioid histology, high grade, and aneuploidy. Stathmin analysis in preoperative curettage samples significantly correlated with, and was an independent predictor of, lymph node metastases. High Stathmin expression was associated with poor disease-specific survival (P ≤ 0.002) both in curettage and hysterectomy specimens.

CONCLUSIONS

Stathmin immunohistochemical staining identifies endometrial carcinomas with lymph node metastases and poor survival. The value, as a predictive marker for response to PI3Kinase inhibition and as a tool to stratify patients for lymph node sampling in endometrial carcinomas, remains to be determined.

Deoxyribonucleic acid ploidy in endometrial carcinoma: a reproducible and valid prognostic marker in a routine diagnostic setting

OBJECTIVE

The objective of the study was to investigate the prognostic impact of deoxyribonucleic acid (DNA) ploidy in endometrial carcinoma in a routine diagnostic series as compared with a research series.

STUDY DESIGN

We studied a population-based series of 363 endometrial carcinomas prospectively collected, with long and complete follow-up. The prognostic value of DNA ploidy was investigated in a routine diagnostic series (n=262) and compared with the results from a previous research series (n=101).

RESULTS

The proportion of DNA aneuploid tumors was 21% in the research series and 25% in the routine diagnostic series (P=NS). In both series, DNA aneuploidy was significantly correlated to higher age at diagnosis, nonendometrioid subtype, and high histologic grade. Patients with DNA aneuploid tumors had significantly poorer survival, adjusted for established clinicopathologic prognostic factors.

CONCLUSION

DNA ploidy estimation in endometrial carcinoma adds independent prognostic information in a routine diagnostic setting.

GATA3 expression in estrogen receptor alpha-negative endometrial carcinomas identifies aggressive tumors with high proliferation and poor patient survival

OBJECTIVE

The transcription factor GATA3 has recently been found to be involved in the carcinogenesis for numerous cancers. We investigated this marker in relation to clinicopathologic characteristics, hormone receptors, other biomarkers, and survival in endometrial carcinoma.

STUDY DESIGN

A population-based study of 316 endometrial carcinomas with complete follow-up was studied for GATA3, estrogen receptor (ER)-alpha, ERbeta2, and progesterone receptor (PR) expression.

RESULTS

Positive GATA3 expression in hysterectomy specimens significantly correlated to high International Federation of Gynecology and Obstetrics stage, serous papillary/clear cell subtypes, high histologic grade, loss of PR expression, aneuploidy, high proliferation, pathologic p53 and p16 expression, and poor prognosis (P = .003). Loss of hormone receptors significantly correlated with aggressive phenotype and poor prognosis. Pathologic expression of GATA3/ERalpha in combination added independent prognostic information.

CONCLUSION

GATA3 expression is associated with an aggressive phenotype and adds independent prognostic information in addition to receptor status. Further studies of its value in tailored treatment protocols seem justified.

Drug-sensitive FGFR2 mutations in endometrial carcinoma

Oncogenic activation of tyrosine kinases is a common mechanism of carcinogenesis and, given the druggable nature of these enzymes, an attractive target for anticancer therapy. Here, we show that somatic mutations of the fibroblast growth factor receptor 2 (FGFR2) tyrosine kinase gene, FGFR2, are present in 12% of endometrial carcinomas, with additional instances found in lung squamous cell carcinoma and cervical carcinoma. These FGFR2 mutations, many of which are identical to mutations associated with congenital craniofacial developmental disorders, are constitutively activated and oncogenic when ectopically expressed in NIH 3T3 cells. Inhibition of FGFR2 kinase activity in endometrial carcinoma cell lines bearing such FGFR2 mutations inhibits transformation and survival, implicating FGFR2 as a novel therapeutic target in endometrial carcinoma.

Low BMI-1 expression is associated with an activated BMI-1-driven signature, vascular invasion, and hormone receptor loss in endometrial carcinoma

We studied the expression of polycomb group (PcG) protein BMI-1 in a large population-based patient series of endometrial carcinomas in relation to clinical and molecular phenotype. Also, 57 fresh frozen endometrial carcinomas were studied for the relationship between BMI-1 protein expression, BMI-1 mRNA level, and activation of an 11-gene signature reported to represent a BMI-1-driven pathway. BMI-1 protein expression was significantly weaker in tumours with vascular invasion (P<0.0001), deep myometrial infiltration (P=0.004), and loss of oestrogen receptor (ER) (P<0.0001) and progesterone receptors (PR) (P=0.03). Low BMI-1 protein expression was highly associated with low BMI-1 mRNA expression (P=0.002), and similarly low BMI-1 mRNA expression correlated significantly with vascular invasion, ER and PR loss, and histologic grade 3. In contrast, activation of the reported 11-gene signature, supposed to represent a BMI-1-driven pathway, correlated with low mRNA expression of BMI-1 (P<0.001), hormone receptor loss, presence of vascular invasion, and poor prognosis. We conclude that BMI-1 protein and mRNA expression are significantly correlated and that BMI-1 expression is inversely associated with activation of the 11-gene signature. Loss of BMI-1 seems to be associated with an aggressive phenotype in endometrial carcinomas.

HER-2/neu expression is associated with high tumor cell proliferation and aggressive phenotype in a population based patient series of endometrial carcinomas

Gene alterations and overexpression of various oncogenes and cell-cycle regulators are important in tumor development. In a population based series of 316 endometrial carcinomas with long and complete follow-up we investigated the distribution of HER-2/neu and EGFR expression and copy number alteration in endometrial cancers. HER-2/ neu, EGFR and Ki-67 expression in curettage and hysterectomy specimens were studied immunohistochemically for expression in relation to molecular markers and clinical phenotype. Fresh tumor samples (n=76) were studied by global characterization of genetic alterations by single nucleotide polymorphism (SNP) array for detection of high level amplification for HER-2/neu and EGFR. Pathological expression of HER-2/neu in curettage was detected in 23% which significantly correlated to high FIGO stage, non-endometrioid subtype, high grade and aneuploidy. In hysterectomy specimens, pathological HER-2/neu staining was seen in 13% which correlated significantly with high FIGO stage, non-endometrioid subtype, high proliferation and poor survival (p=0.009). Expression of EGFR was examined with three different antibodies, but none showed significant correlation with molecular markers or clinical phenotype. High level amplification of HER-2/neu or EGFR was seen in only one out of 76 samples, respectively. High proliferation estimated in tumors from hysterectomy specimens showed independent prognostic impact and was superior to estimation in curettage specimens as a prognostic marker. In conclusion, high level amplification of HER-2/neu or EGFR is infrequent in endometrial cancer. Pathological HER-2/neu staining identifies endometrial carcinomas with an aggressive phenotype, high proliferation and patients with poor survival in a population based setting. These results motivate further clinical trials with trastuzumab based on HER-2/neu status in endometrial carcinomas.

Vascular proliferation is important for clinical progress of endometrial cancer

Angiogenesis is essential for tumor growth, invasion, and metastatic spread. Whereas microvessel density (MVD) has been widely used as a measure of tumor-associated angiogenesis, we now wanted to examine the significance of other angiogenic markers, especially vascular proliferation (by Ki-67/factor VIII staining) and the degree of pericyte coverage [by alpha-smooth muscle actin (alpha-SMA)/factor VIII staining], in a large and population-based series of endometrial carcinoma with complete follow-up. Due to limited information on the role of lymphangiogenesis in these tumors, lymphatic vessel density (LVD) by LYVE-1 staining was also determined, as well as selected angiogenic factors [vascular endothelial growth factor (VEGF)-A, VEGF-C, VEGF-D and basic fibroblast growth factor (bFGF)], which could possibly be related to vascular proliferation and lymphangiogenesis. The information on angiogenic phenotype was related to clinicopathologic features and disease progress. Median vascular proliferation, as estimated by vascular proliferation index (VPI), was 3.9% and high VPI was associated with features of aggressive tumors and decreased survival. The prognostic effect of VPI was superior to that of MVD. Presence of pericyte coverage, as estimated by the alpha-SMA index (SMAI), was 35% and low SMAI was significantly associated with vascular invasion by tumor cells and impaired prognosis. Peritumoral lymphatic vessels (LVD-pt) were found in 39.5% of the cases and high LVD-pt was significantly associated with aggressive tumor features and decreased survival. In multivariate survival analysis, only the extent of vascular proliferation had independent prognostic effect, in addition to well-known clinicopathologic factors, whereas MVD did not have significant prognostic value. In conclusion, our study indicates that vascular proliferation is a meaningful variable in assessing the angiogenic phenotype of endometrial carcinoma.

Expression of enhancer of zeste homologue 2 is significantly associated with increased tumor cell proliferation and is a marker of aggressive breast cancer

The polycomb group protein enhancer of zeste homologue 2 (EZH2) has been linked to invasive properties of aggressive breast cancer. In this report, tissue microarray analysis of 190 breast carcinomas from a nested case-control study shows that EZH2 is significantly associated with interval breast cancers. Further, a strong relationship was found with tumor cell proliferation (by Ki-67 expression), locally advanced disease, metastasis at presentation, markers of the basal epithelial phenotype (positivity for cytokeratin 5/6 or P-cadherin), and p53 status. EZH2 expression was also significantly associated with glomeruloid microvascular proliferation, an aggressive angiogenic phenotype. For prediction of aggressive disease (any event of locally advanced disease, lymph node spread, or distant spread), EZH2 was the only variable of significance in multivariate analysis, whereas no additional information was given by Ki-67. Although EZH2 expression was significant in univariate survival analysis, only tumor cell proliferation and lymph node status were significant in the final multivariate model. In conclusion, our findings indicate an important relationship not only between EZH2 and markers of tumor cell proliferation but also with aggressive disease. These findings might be practically important and relevant because the polycomb group proteins have recently been suggested as candidates for targeted therapy.

Loss of p63 and cytokeratin 5/6 expression is associated with more aggressive tumors in endometrial carcinoma patients

p63 and cytokeratin (CK) 5/6 are markers of basal and squamous differentiation in several normal epithelia and human tumors and are also suggested to be markers of progenitor or stem cells in certain stratified epithelia. In endometrial carcinoma, there is very limited information about the expression pattern of p63 or CK5/6 and no prognostic information. The aim of our study was to examine whether the expression of these markers was associated with a certain tumor phenotype in terms of other biomarkers, clinicopathologic characteristics and patient prognosis. Immunohistochemical expression of p63 and CK5/6 was examined using tissue microarrays (TMAs) in a large population-based series of 276 endometrial carcinomas with long and complete follow-up. Selected cases of normal and hyperplastic endometrium were examined for comparison (n = 15). Absence of p63 expression (70%) was significantly associated with nonendometrioid carcinomas, high histologic grade (FIGO), higher mitotic count and tumor cell proliferation by Ki-67, microsatellite instability (MSI) and loss of hMSH6 expression. A tendency toward reduced patient survival was also seen (p = 0.098). Presence of CK5/6 expression was more frequent in endometrioid tumors with squamous differentiation, while loss of CK5/6 expression (54%) was significantly associated with high FIGO stage, reduced beta-catenin expression, MSI and reduced patient survival (p = 0.0001); the latter was also found within the endometrioid subgroup (p = 0.0004). Multivariate survival analysis revealed that loss of CK5/6 expression had an independent prognostic impact in addition to well-known prognostic variables. Expression of both markers was increased in simple hyperplasia compared with normal endometrium. In complex hyperplasia, p63 expression was also increased, whereas CK5/6 was positive in areas with squamous differentiation only. Thus, loss of p63 or CK5/6 was associated with features of aggressive tumors, and lack of CK5/6 was significantly associated with reduced survival in multivariate analysis.

EZH2 expression is associated with high proliferation rate and aggressive tumor subgroups in cutaneous melanoma and cancers of the endometrium, prostate, and breast

PURPOSE

EZH2 is a member of the polycomb group of genes and important in cell cycle regulation. Increased expression of EZH2 has been associated previously with invasive growth and aggressive clinical behavior in prostate and breast cancer, but the relationship with tumor cell proliferation has not been examined in human tumors. The purpose of this study was to validate previous findings in a population-based setting, also including tumors that have not been studied previously.

PATIENTS AND METHODS

In our study of nearly 700 patients, we examined EZH2 expression and its association with tumor cell proliferation and other tumor markers, clinical features, and prognosis in cutaneous melanoma and cancers of the endometrium, prostate, and breast.

RESULTS

Strong EZH2 expression was associated with increased tumor cell proliferation in all four cancer types. Associations were also found between EZH2 and important clinicopathologic variables. EZH2 expression showed significant prognostic impact in melanoma, prostate, and endometrial carcinoma in univariate survival analyses, and revealed independent prognostic importance in carcinoma of the endometrium and prostate. CONCLUSION Our findings point at EZH2 as a novel and independent prognostic marker in endometrial cancer, and validate previous findings on prostate and breast cancer. Further, EZH2 expression was associated with features of aggressive cutaneous melanoma. The fact that EZH2 might identify increased tumor cell proliferation and aggressive subgroups in several cancers may be of practical interest because the polycomb group proteins have been suggested as candidates for targeted therapy. EZH2 expression should, therefore, be further examined as a possible predictive factor.

A Basal Epithelial Phenotype Is More Frequent in Interval Breast Cancers Compared with Screen Detected Tumors

Interval breast cancer reduce the effectiveness of mammography screening programs. We studied 95 interval cancers, diagnosed during 1996 to 2001 as part of the population-based Norwegian Breast Cancer Screening Program. These cases were matched on size (+/-2.0 mm) to 95 screen-detected breast cancers, and the tumors were compared by immunohistochemical methods using tissue microarrays. Patients with interval cancers were more likely to be younger [odds ratio (OR), 4.7; P = 0.0001], to have dense breasts (OR, 3.4; P = 0.004), and to have estrogen receptor-negative tumors (OR, 2.6, P = 0.01), and p53 expression was more frequent (OR, 4.0; P = 0.001). Notably, interval cancers were more likely to have a basal epithelial phenotype, in that expression of cytokeratin 5/6 (OR, 2.3; P = 0.04) and P-cadherin (OR, 2.5; P = 0.04) was more frequent in interval cases than in size-matched, screen-detected tumors. In a logistic regression model, p53 expression, age, and breast density were independent predictors of interval cancers. Our data suggest that breast cancers with a basal epithelial phenotype are more likely than nonbasal breast cancers to present between regular mammograms.

Prognostic impact of histological grade and vascular invasion compared with tumour cell proliferation in endometrial carcinoma of endometrioid type

AIMS

The relative impact of different prognostic factors is important for endometrial carcinoma patients. The aim of our study was to examine the combined value of histological grade [International Federation of Gynaecology and Obstetrics (FIGO)] and vascular invasion in comparison with tumour cell proliferation assessed by mitotic count and Ki67. The recently proposed binary architectural grade was also evaluated, in addition to age, depth of myometrial infiltration and FIGO stage in our population-based series of 237 endometrioid carcinomas.

METHODS AND RESULTS

The tumours were studied for several histological features, including FIGO grade, binary grade, vascular invasion, mitotic count, myometrial invasion and expression of Ki67. FIGO grade was significantly associated with all investigated histological features, including Ki67 expression. Vascular invasion was significantly more frequent in FIGO grade 3 tumours, and was associated with a diffusely infiltrative growth pattern, solid growth, necrosis and deep myometrial invasion. All variables showed a highly significant relationship with patient survival in univariate analysis. In multivariate models, FIGO grade, vascular invasion, and proliferation assessed by Ki67 expression all had independent prognostic influence in this population-based study. Comparing tumour cell proliferation (Ki67) with vascular invasion as a marker of metastatic spread, the latter had a stronger survival impact.

CONCLUSIONS

Vascular invasion and tumour cell proliferation measured by Ki67 both had independent prognostic influence, and should be considered to identify aggressive tumours of the endometrioid subtype.

The prognostic implication of the basal-like (cyclin E high/p27 low/p53+/glomeruloid-microvascular-proliferation+) phenotype of BRCA1-related breast cancer

Previous studies have shown that BRCA1-related breast cancers are often high-grade tumors that do not express estrogen receptors, HER2, p27(Kip1), or cyclin D1, but do express p53 and cyclin E. In addition, the expression of cytokeratin 5/6 (CK5/6), indicating a basal epithelial phenotype, is frequent in BRCA1-related breast cancer. Here, in a series of 247 breast cancers, we demonstrate that CK5/6 expression was associated with nearly all of the features of BRCA1-related breast cancer and was also associated with a poor prognosis. In a parsimonious multivariable proportional hazards model, protein levels of cyclin E, p27(Kip1), p53, and the presence of glomeruloid microvascular proliferation all independently predicted outcome after breast cancer. In this model, only cyclin E and p27(Kip1) levels were independent predictors in lymph node-negative cancers, whereas glomeruloid microvascular proliferation and tumor size independently predicted outcome in node-positive disease. The molecular determinants of the basal epithelial phenotype encapsulate many of the key features of breast cancers occurring in germ-line BRCA1 mutation carriers and have independent prognostic value. Basal breast cancer deserves recognition as an important subtype of breast cancer.

Prognostic Impact of Alterations in P-Cadherin Expression and Related Cell Adhesion Markers in Endometrial Cancer

Purpose

Reduced tumor cell adhesion is associated with invasive growth and unfavorable prognosis. In endometrial carcinoma, the prognostic impact of adhesion markers (E-cadherin, beta-catenin [β-catenin], P-cadherin, and p120ctn) is partly unknown. We wanted to examine the expression pattern and prognostic value of these molecules in a population-based series of endometrial carcinoma patients.

Patients and Methods

All patients diagnosed with endometrial carcinoma between 1981 and 1990 in Hordaland County, Norway, were included. Paraffin-embedded tumor tissue was available for 96% of the patients (n = 286), and was studied immunohistochemically for expression of E-cadherin, β-catenin, P-cadherin, and p120ctn. The tissue microarray technique was used for P-cadherin and p120ctn. Median follow-up time for survivors was 9 years (range, 4 to 16 years) and follow-up was complete.

Results

Pathologic expression of P-cadherin, E-cadherin, and β-catenin was associated with a majority of the clinicopathologic variables. In univariate survival analyses, all adhesion markers influenced survival significantly (P < .05). Tumors with pathologic expression of both E-cadherin (low expression) and P-cadherin (high expression; 19%), and β-catenin (low expression) and P-cadherin (high expression; 16%), had significantly reduced survival compared with the remaining samples (P < .001 for both). In multivariate models, all markers except E-cadherin showed independent prognostic significance in addition to the traditional tumor features.

Conclusion

Differential expression of P-cadherin and β-catenin seems to be important in endometrial carcinoma and is associated with aggressive subgroups. Our findings also indicate that a shift from E-cadherin to P-cadherin expression (cadherin switch) is an important prognostic feature in these tumors.

Germline BRCA1 mutations and a basal epithelial phenotype in breast cancer

A basal epithelial phenotype is found in not more than 15% of all invasive breast cancers. Microarray studies have shown that this phenotype is associated with breast cancers that express neither estrogen receptor (ER) nor erbB-2 (HER2/neu) (i.e., ER/erbB-2-negative tumors). The ER/erbB-2- negative phenotype is also found in breast cancers occurring in BRCA1 mutation carriers (i.e., BRCA1-related breast cancers). We tested the hypothesis that BRCA1-related breast cancers are more likely than non-BRCA1/ 2-related breast cancer to express a basal epithelial phenotype. Among 292 breast cancer specimens previously analyzed for ER, erbB-2, p53, and germline mutations in BRCA1 and BRCA2, we identified 76 that did not overexpress ER or erbB-2. Of the 72 specimens with sufficient material for testing, 40 expressed stratified epithelial cytokeratin 5 and/or 6 (5/6). In univariate analysis, the expression of cytokeratin 5/6 was statistically significantly associated with BRCA1-related breast cancers (odds ratio = 9.0, 95% confidence interval = 1.9 to 43; P =.002, two-sided Fisher's exact test). Thus, germline BRCA1 mutations appear to be associated with a distinctive breast cancer phenotype.