Oxytocin versus a combination of tranexamic acid and ethamsylate in reducing intraoperative bleeding during abdominal myomectomy: a randomized clinical trial

OBJECTIVE

Myomectomy is the preferred surgical approach to manage uterine fibroids. However, uterine fibroids are highly vascular tumors and, consequently, extremely susceptible to problems from myomectomy-related hemorrhage. Hence, we aim to compare oxytocin efficacy and safety profile versus tranexamic acid (TA) with ethamsylate for reducing bleeding during myomectomy.

METHODS

This randomized, double-blinded multicenter study was performed between 20th August 2020 and 20th October 2020 at El-Galaa Teaching Hospital, El Hussein University Hospital, Al-Azhar University Hospitals of Assiut, and Al-Azhar University Hospitals of Damietta. One hundred and eighty patients were enrolled and divided into three groups: group (1) received an injection of 30 IU of oxytocin in 500 ml of normal saline; group (2) received injections of 1 g of TA, 250 mg of Ethamsylate, and 110 ml of normal saline IV; and group (3) received an injection of 110 ml of normal saline IV just before surgical incision.

RESULTS

In 180 premenopausal women, oxytocin and TA with ethamsylate had no significant value in lowering intraoperative blood loss compared with the placebo for abdominal myomectomy (666.25 ± 183.03, 630.72 ± 145.83, and 646.67 ± 168.92, respectively (P = 0.506)). Non-significant trends were observed for a reduction in operation time (P = 0.760), intra/postoperative blood transfusion (P = 0.624), hospital stay (P = 0.986), postoperative fever (P = 0.659), and wound infection (P = 1).

CONCLUSION

Oxytocin and TA with ethamsylate had no significant value in lowering intraoperative blood loss compared with the placebo for abdominal myomectomy which opens a new question about the role of the use of the hemostatic drug during myomectomy especially in centers with limited resources and had higher rates.

TRIAL REGISTRATION

The study was registered on Pan African Clinical Trials Registry with the following number: PACTR202008739887429 and was approved on 24/08/2020.

Prenatal Rejecter NK Cells Enhance Allo-specific Th17/Tc17 Cell Responses via TGF-beta1, IL-6 and GM-CSF

In utero hematopoietic cellular transplantation (IUHCT) has the potential to treat congenital benign cellular disease without chemotherapy or radiation. Prenatal tolerance is essential in this regard. Previous studies involving prenatally created chimeras have shown that immunologically tolerant NK cells (friendly, fNK) from engrafter mice suppress allo Tc1 responses, while intolerant NK cells (hostile, hNK) from rejecter mice enhance allo Tc1 responses. Given that Th17 cells are also involved in allograft rejection, we sought to determine if rejecter hNK cells induce/expand allo-specific Th17/Tc17 cells.

We examined the helper potential of prenatally educated hNK cells in non-tolerant prenatal Balb/c --- > B6.Thy1.2 rejecter chimeras. Naïve Thy1.1+ responder T cells and allogenic target cells were adoptively transferred into rejecter or naïve hosts that had been depleted of endogenous T cells and fNK cells. We found increased Th17/Tc17 alloimmunity in the responder Thy1.1+T cell population in rejecters when compared to naïve hosts. Additionally, through ELISPOT, we confirmed increased IL-17A production by responder T cells when co-cultured with allo-specific hNK cells from rejecter mice. Hostile NK cells from rejecter mice produce higher levels of Th17 driving cytokines, TGF-beta 1, IL-6 and GM-CSF when compared to naïve hNK.

From these results, we conclude that prenatal rejecter hNK cells have an enhanced helper effect on Th17/Tc17 alloimmunity in vivo and in vitro. These findings support an evolving paradigm that prenatally educated NK cell can regulate the balance between Th1/Th17 and Treg functions.

Supported by NIH R01HL103745   Lurie Children’s Hospital Research Foundation  (to A.F.S.)

Presentation and Outcomes of Hepatocellular Carcinoma in the Arabian Peninsula: A Review of a Single Institution Experience in the Sorafenib Era

PURPOSE

There is a growing evidence showing that there are geographic differences in hepatocellular carcinoma (HCC). Little is known about the characteristics of hepatocellular carcinoma in the Arabian Peninsula. The present study examines the presentation and outcomes of HCC in a single institution.

METHODS

A retrospective chart review of patients presented with advanced-stage HCC to Kuwait Cancer Control Center (KCCC) between 2008 and 2018 was conducted. Data collected included patients demographics, HCC risk factors, performance status, Child-Pugh score, pick up of sorafenib, and survival.

RESULTS

About 111 cases were analyzed. The mean age of the cohort was 61.8 ± 11.4 years and 94 patients (84.7%) were males. HCV and diabetes were the most common risk factors for HCC and presented in 60 patients (54.1%) and 45 patients (40.5%), respectively. About 78 (70.3%) patients had an Eastern Cooperative Oncology Group (ECOG) performance status of 0-1 at presentation. Only 29 (26.1%) patients presented with Child-Pugh class A, while 42 (40.4%) patients received sorafenib. The median overall survival was only 3 months.

CONCLUSIONS

In our cohort, HCV and diabetes were the main risk factors for HCC. The majority of patients was not amenable to sorafenib treatment and carries a very poor prognosis.

Does the Time of Starting Progesterone Luteal Support Affect Embryo Transfer in Long Agonist Protocol Downregulated ICSI Cycles? A Randomized Controlled Trial

The aim of this study was to compare the effects of starting progesterone (P4) luteal support (LS) on day of egg retrieval (ER) or day of embryo transfer (ET) on the ratio of difficult ET and cycle outcome. This was a RCT ( ClinicalTrials.gov Identifier: NCT03040830) carried out at Mansoura Integrated Fertility Center (MIFC), Mansoura, Egypt, from November 2015 to January 2017. A total of 171 eligible long agonist ICSI cases were randomly allocated on day of ER into group A (86) starting LS as daily IM 100 mg P4 on day of ER and group B (85) starting P4-LS on day of ET. Difficult ET was defined as blood on ET catheter and/or sounding or dilating the cervix. Primary outcome was the overall ratio of difficult ET and ratios on day 3 and 5 ET. Secondary outcome was the ongoing pregnancy rate (OPR) and implantation rate (IR). The results are presented as % for groups A and B respectively: overall difficult ET (44.1, 24.7) (p = 0.009); day 3 difficult ET (23.2, 24.4) (p = 0.45); day 5 difficult ET (62.7, 25.6) (p = 0.001); overall OPR (38.3, 44.7) (p = 0.43); day 3 ET OPR (41.8, 33.3) (p = 0.51); day 5 ET OPR (34.8, 57.5) (p = 0.048); overall IR (20.0, 22.5) (p = 0.62); day 3 ET IR (17.8, 13.4) (p = 0.44); day 5 ET IR (22, 34.1) (p = 0.09). In conclusion, starting P4 luteal support on egg retrieval day is associated with significantly higher ratio of difficult embryo transfer and lower ongoing pregnancy rate and tendency to lower IR in day 5 ET, so starting P4-LS on day of ET is recommended.

Development of a multi-institutional registry for children with operative congenital lung malformations

INTRODUCTION

The purpose of this study was to develop a multi-institutional registry to characterize the demographics, management, and outcomes of a contemporary cohort of children undergoing congenital lung malformation (CLM) resection.

METHODS

After central reliance IRB approval, a web-based, secure database was created to capture retrospective cohort data on pathologically-confirmed CLMs performed between 2009 and 2015 within a multi-institutional research collaborative.

RESULTS

Eleven children's hospitals contributed 506 patients. Among 344 prenatally diagnosed lesions, the congenital pulmonary airway malformation volume ratio was measured in 49.1%, and fetal MRI was performed in 34.3%. One hundred thirty-four (26.7%) children had respiratory symptoms at birth. Fifty-eight (11.6%) underwent neonatal resection, 322 (64.1%) had surgery at 1-12 months, and 122 (24.3%) had operations after 12 months. The median age at resection was 6.7 months (interquartile range, 3.6-11.4). Among 230 elective lobectomies performed in asymptomatic patients, thoracoscopy was successfully utilized in 102 (44.3%), but there was substantial variation across centers. The most common lesions were congenital pulmonary airway malformation (n = 234, 47.3%) and intralobar bronchopulmonary sequestration (n = 106, 21.4%).

CONCLUSION

This multicenter cohort study on operative CLMs highlights marked disease heterogeneity and substantial practice variation in preoperative evaluation and operative management. Future registry studies are planned to help establish evidence-based guidelines to optimize the care of these patients.

LEVEL OF EVIDENCE

Level II.

Phenotypically Friendly Allospecific NK Cells Differentially Suppress Allospecific T cell Responses in Prenatal Hematopoietic Chimeras

Prenatal allospecific tolerance hinges on the developmental selection of NK cells expressing a friendly phenotype that is not cytotoxic to allogeneic donor cells. We wondered if prenatally educated friendly NK cells influenced allospecific T cell responses as an additional mechanism supporting prenatal tolerance. Therefore, we hypothesized that prenatally educated friendly NK cells exert suppressive effects on the induction of allospecific T cell responses.

To challenge this hypothesis, we examined the suppression potential of prenatally educated friendly NK cells through gain and loss of function experiments in stable prenatal Balb/c into B6.Thy1.2 chimeras (engrafter mice). We first depleted allospecific NK cells in host engrafter mice and then adoptively transferred Thy1.1+ naïve responder T cells along with CFSE-labeled allogenic or syngeneic target cells into the engrafter hosts. We found that the depletion of allospecific Ly49D+ NK cells in engrafter mice increased Thy1.1+ T cell alloimmunity in vivo. Conversely, adoptive transfer of friendly NK cells suppressed the induction of allospecific T cell responses in host mice. Furthermore, cultured friendly NK cells from engrafter mice showed stronger suppression on the induction of T cell alloimmunity in vitro than that of naïve mice. Lasltly, NK cell-mediated suppression of allospecific T cells required cell contact.

From these results, we conclude that prenatally educated friendly NK cell exert enhanced suppressive effects on T cell alloimmunity in vivo and in vitro. Depending on the context of their prenatal education, NK cells can differentially influence T cell responses in prenatal chimeras.

Maternal and Fetal Immune Response to in Utero Stem Cell Transplantation

Purpose of Review

In Utero Hematopoietic Cellular Transplantation (IUHCT) is a promising intervention for the non-toxic treatment of congenital disease that hinges on the assumption of fetal immunologic immaturity and an inability to reject a hematopoietic allograft. However, clinical IUCHT has failed except in cases where the fetus is severely immunocompromised. The current review examines recent studies of engraftment barriers stemming from either the fetal or maternal immune system.

Recent Findings

New reports have illuminated roles for maternal humoral and cellular immunity and fetal innate cellular immunity in the resistance to allogeneic IUHCT. These experimental findings have inspired new approaches to overcome these barriers. Despite these advances, postulates regarding a maternal immune barrier to IUHCT provide an inadequate explanation for the well-documented clinical success only in the treatment of fetal immunodeficiency with normal maternal immunity.

Summary

Characterization of the maternal and fetal immune response to allogeneic IUHCT provides new insight into the complexity of prenatal tolerance. Future work in this area should aim to provide a unifying explanation for the observed patterns of success and failure with clinical IUHCT.

Abstract P4-09-05: Withdrawn

This abstract was withdrawn by the authors.

Evaluation of applying IHC4 as a prognostic model in the translational study of Intergroup Exemestane Study (IES): PathIES

BACKGROUND

Intergroup Exemestane Study (IES) was a randomised study that showed a survival benefit of switching adjuvant endocrine therapy after 2-3 years from tamoxifen to exemestane. This PathIES aimed to assess the role of immunohistochemical (IHC)4 score in determining the relative sensitivity to either tamoxifen or sequential treatment with tamoxifen and exemestane.

PATIENTS AND METHODS

Primary tumour samples were available for 1274 patients (27% of IES population). Only patients for whom the IHC4 score could be calculated (based on oestrogen receptor, progesterone receptor, HER2 and Ki67) were included in this analysis (N = 430 patients). The clinical score (C) was based on age, grade, tumour size and nodal status. The association of clinicopathological parameters, IHC4(+C) scores and treatment effect with time to distant recurrence-free survival (TTDR) was assessed in univariable and multivariable Cox regression analyses. A modified clinical score (PathIEscore) (N = 350) was also estimated.

RESULTS

Our results confirm the prognostic importance of the original IHC4, alone and in conjunction with clinical scores, but no significant difference with treatment effects was observed. The combined IHC4 + Clinical PathIES score was prognostic for TTDR (P < 0.001) with a hazard ratio (HR) of 5.54 (95% CI 1.29-23.70) for a change from 1st quartile (Q1) to Q1-Q3 and HR of 15.54 (95% CI 3.70-65.24) for a change from Q1 to Q4.

CONCLUSION

In the PathIES population, the IHC4 score is useful in predicting long-term relapse in patients who remain disease-free after 2-3 years. This is a first trial to suggest the extending use of IHC4+C score for prognostic indication for patients who have switched endocrine therapies at 2-3 years and who remain disease-free after 2-3 years.

Management of fetal teratomas

Fetal teratomas are the most common tumors diagnosed prenatally. The majority of these tumors are benign and cured by complete resection of the mass during the neonatal period. Prenatal diagnosis has improved the perinatal management of these lesions and especially for the teratomas that might benefit from fetal intervention. A comprehensive prenatal evaluation including conventional ultrasounds, Doppler, echocardiography and fetal MRI, is essential for an effective counseling and perinatal management. Antenatal counseling helps the parents to better understand the natural history, fetal intervention, and perinatal management of these tumors, which differ dramatically depending on their size and location. Fetal surgical debulking improves survival in cases of sacrococcygeal teratoma with cardiac decompensation. Additionally, the use of an EXIT procedure reduces the morbidity and mortality if a complicated delivery in cases of cervical and mediastinal teratomas. Here, we offer an overview of all fetal teratomas and their recommended management, with emphasis on in utero treatment options.

Imaging features of haematological malignancies of kidneys

Haematological malignancies are relatively uncommon neoplasms of kidneys. Nevertheless, the incidence of these neoplasms is increasing, partly due to more widespread use of computed tomography and magnetic resonance imaging. This article discusses the clinical and imaging features of renal lymphoma, leukaemia, extra-osseous multiple myeloma, and post-transplant lymphoproliferative disorder. Although there is overlap of imaging features with other more common malignancies, such as transitional and renal cell cancers, the combination of imaging findings and the appropriate clinical picture should allow the radiologist to raise a provisional diagnosis of a haematological neoplasm. This has management implications including the preference for image-guided core biopsies and a shift towards medical rather than surgical therapy.

Self-healing dynamic bond-based rubbers: understanding the mechanisms in ionomeric elastomer model systems

Systematic structure-property investigations on the time-dependent mechanical properties of an ionomer model system with variation of the ionic fraction and the counter ion as obtained from SAXS, dynamic oscillatory rheology and tensile tests, deliver the prerequisites and tools for property adjustment and optimization of their self-healing efficiency.

Sacrococcygeal teratoma growth rate predicts adverse outcomes

PURPOSE

The purpose of this study was to characterize the growth rate of sacrococcygeal teratomas (SCTs) and determine its relationship to adverse outcomes.

METHODS

A retrospective review of all pathology-confirmed isolated SCT patients evaluated with at least two documented ultrasounds and followed through hospital discharge between 2005 and 2012 was conducted. SCT growth rate was calculated as the difference between tumor volumes on a late- and early-gestation ultrasound divided by the difference in time. Outcomes were death, high-output cardiac failure (HOCF), hydrops, and preterm delivery. Student's t-test, receiver operator characteristics, Fisher's Exact test, and Pearson's correlation were performed.

RESULTS

Of the 28 study subjects, there were 3 in utero demises and 2 neonatal deaths. Significantly faster SCT growth rates were seen in all adverse outcomes, including death (p<0.0001), HOCF (p=0.005), and preterm delivery (p=0.009). There was a significant association with adverse outcomes at >61cm(3)/week (AUC=0.87, p=0.001, LR=4.52). Furthermore, there was an even greater association with death at >165cm(3)/week (AUC=0.93, p=0.003, LR=18.42). Growth rate was directly correlated with the percent of solid tumor (r=0.60, p=0.0008).

CONCLUSION

Faster SCT growth is associated with adverse outcomes. SCT growth rate determined by ultrasound is an effective prognostic indicator for adverse outcomes and easily applied to patient management.

Self-education via Ly49 receptor engagement of donor and host iNKT cells following in utero hematopoietic cellular transplantation (TRAN1P.874)

Invariant NKT (iNKT) cells recognize glycolipid-CD1d complexes via their TCR but also express inhibitory Ly49 receptors (iLy49s) specific for MHC I ligands. However, little is known regarding the importance of iLy49s in the self-recognition of MHC I by iNKT cells during development. We hypothesized that self-engagement of iLy49s during development alters the phenotype and function of self-responsive iNKT cells. We examined this hypothesis in prenatal Balb/c to B6 and B6 to Balb/c allogeneic chimeras that were established by in utero hematopoietic cellular transplantation (IUHCT) of E14 fetal liver light density cells into age-matched fetal recipients. After birth, we compared iLy49 expression and the functional response of iNKT cells in the allogeneic chimeras to age-matched controls. The levels of allospecific iLy49s on host iNKT and donor iNKT were significantly reduced in all organs tested suggesting developmental recognition of both donor and host MHC class I had occurred. In contrast, the expression of irrelevant receptors was not altered. Lastly, iNKT cells from chimeric mice that expressed allospecific iLy49s exhibited significantly increased production of IL-4 in response to TCR stimulation suggesting that a shift toward a regulatory phenotype had occurred. Future studies will directly evaluate the impact of self-recognition by iNKT cells in the developmental pathogenesis of autoimmunity, allergy and allospecific tolerance.

Adenoviral-mediated gene transfer of insulin-like growth factor 1 enhances wound healing and induces angiogenesis

BACKGROUND

Chronic wounds are characterized by a wound healing and neovascularization deficit. Strategies to increase neovascularization can significantly improve chronic wound healing. Insulin-like growth factor (IGF)-1 is reported to be a keratinocyte mitogen and is believed to induce angiogenesis via a vascular endothelial growth factor (VEGF)-dependent pathway. Using a novel ex vivo human dermal wound model and a diabetic-impaired wound healing murine model, we hypothesized that adenoviral overexpression of IGF-1 (Ad-IGF-1) will enhance wound healing and induce angiogenesis through a VEGF-dependent pathway.

METHODS

Ex vivo: 6-mm full-thickness punch biopsies were obtained from normal human skin, and 3-mm full-thickness wounds were created at the center. Skin explants were maintained at air liquid interface. Db/db murine model: 8-mm full-thickness dorsal wounds in diabetic (db/db) mice were created. Treatment groups in both human ex vivo and in vivo db/db wound models include 1×10(8) particle forming units of Ad-IGF-1 or Ad-LacZ, and phosphate buffered saline (n=4-5/group). Cytotoxicity (lactate dehydrogenase) was quantified at days 3, 5, and 7 for the human ex vivo wound model. Epithelial gap closure (hematoxylin and eosin; Trichrome), VEGF expression (enzyme-linked immunosorbent assay), and capillary density (CD 31+CAPS/HPF) were analyzed at day 7.

RESULTS

In the human ex vivo organ culture, the adenoviral vectors did not demonstrate any significant difference in cytotoxicity compared with phosphate buffered saline. Ad-IGF-1 overexpression significantly increases basal keratinocyte migration, with no significant effect on epithelial gap closure. There was a significant increase in capillary density in the Ad-IGF-1 wounds. However, there was no effect on VEGF levels in Ad-IGF-1 samples compared with controls. In db/db wounds, Ad-IGF-1 overexpression significantly improves epithelial gap closure and granulation tissue with a dense cellular infiltrate compared with controls. Ad-IGF-1 also increases capillary density, again with no significant difference in VEGF levels in the wounds compared with control treatments.

CONCLUSIONS

In two different models, our data demonstrate that adenoviral-mediated gene transfer of IGF-1 results in enhanced wound healing and induces angiogenesis via a VEGF-independent pathway. Understanding the underlying mechanisms of IGF-1 effects on angiogenesis may help produce novel therapeutics for chronic wounds or diseases characterized by a deficit in neovascularization.

Abstract P2-02-01: Did established clinical practice regarding MRI bias the COMICE trial?

Introduction: The negative COMICE study and reports of inappropriate mastectomies worldwide have served to discredit the use of preoperative MRI for the purpose of aiding conservative breast surgery. We postulate that established clinical practice regarding MRI at the time of the COMICE trial lead to bias in case selection, with more complicated cases being preselected out prior to randomisation. We reviewed the local practice at the time of COMICE.

Methods and materials: Retrospective analysis of all cases of Breast MRI performed to assess disease extent pre-operatively during recruitment to COMICE (December 2001 - January 2007) was undertaken. Size on mammogram/ultrasound, MRI and histology was documented. As pre-PAC's era, the information was obtained from imaging and pathology reports. Where reports did not include distance between lesions in multifocal/multicentric disease, the sum of the lesions was used (taken as immediately adjacent) so as not to overestimate the size. All cases were reviewed blinded to COMICE status. Cases with mammogram/ultrasound size &gt;/ = 40mm were excluded as these were deemed unsuitable for conservative surgery.

Results: A total of 318 breast MRI examinations were performed in this interval to assess disease extent pre-operatively of which, 81 were excluded appropriately, for inadequate information (n = 47), size on conventional imaging &gt;/ = 40mm (n = 18), receiving neo-adjuvant treatment (n = 6), non cancer diagnosis (n = 7) and non invasive disease (n = 3). 242 cancers from 237 patients were included comprising 77COMICE and 160NON-COMICE patients. Statistical difference was noted in the types of surgery between the groups, p&lt;0.001. Re-excision rates were similar: COMICE = 11.7% and NON-COMICE = 8%. Mastectomy rates were however different, 15.6% of the COMICE group and 42% of the NON-COMICE group.

There was a significant difference in histological size between the 2 groups, mean size in NON-COMICE cases 32mm versus 26mm in the COMICE group (p = 0.009). There was a significant difference in the tumour types between the 2 groups (p&lt;0.001). Notably 37% of cases in the NON-COMICE group were of lobular type compared to 13% of the COMICE group.

Conclusion: Data from this well established MRI unit has demonstrated clinical bias in the COMICE trial with more complicated cases, which benefited from MRI, being pre-selected out prior to randomisation which understated the value of MRI. MRI in appropriately selected patients in conjunction with modern oncoplastic surgical techniques will increase the opportunities for conservative surgery rather than increase mastectomy rates. An aggressive biopsy policy for MRI detected lesions is required to avoid inappropriate mastectomies.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-02-01.

P3-04-01: Molecular Characterization of African Breast Cancer; Results from a Large Tissue Microarray Study

Introduction: Breast cancer in African women has been understudied for decades. Evidence derived mainly from studies on African-American women, supports that tumours of black women are biologically different and more aggressive than those occurring in the white population. Of the 4 main taxonomic groups of breast cancer, basal tumours are more represented in those women. In the present state of knowledge, very little is known about the biology and molecular profile of breast cancer in Africa. The aim of this study was to test the hypothesis that the molecular profile of African breast cancer is distinct from its Western counterpart. This was achieved by collecting a large cohort of breast carcinomas from an indigenous African population for phenotypical characterization and testing for expression of potential predictive and prognostic markers.

Methods: Breast tumours were collected via collaboration with five centres in Nigeria (the most populous country in Africa) and assembled into tissue microarrays (TMAs). All tumours were reviewed by a specialist breast pathologist following the Royal College of Pathologists (RCPath) guidelines to confirm diagnosis, type, grade and nodal status. Patients age, tumour size and clinical data, where available, were collected from the original pathology reports and case notes. Representative tumour areas were selected and marked for TMA construction. TMA sections were stained for a range of markers including hormone receptors (ERα, ERβ, PR, AR), cyclin D, HER2, Ki67, bcl2, basal (CK5/6, CK14) and luminal cytokeratins (CK18, 19).

Results: A total of 830 tumours were assembled into TMAs. The mean age at diagnosis was 47.69yrs with 58% of patients presenting under the age of 50. Only 8.5% of tumours were of grade 1. Most tumours (87%) were of ductal no special type, followed by lobular and metaplastic carcinomas. The majority of the tumours were ERα, PR and HER2 negative (77%, 80% and 81% respectively). The triple negative tumours were the predominant phenotype (55.6%). Luminal A type tumours comprised 24.3% followed by the HER2 positive (13.9%) and luminal B tumours (6.2%). The differences of all those parameters were statistically highly significant (p&lt;0.001). Most tumours expressed ERß including 75% of those that were ERα/PR negative. A large proportion of the tumours (22%) were of the basal phenotype of which two thirds were also triple negative. Over half of the triple negative tumours were also node positive.

Hierarchal cluster analysis showed the basal tumours dendrogram to comprise two groups; one showing clustering of ***ERα/PR/HER2 and the second showing clustering of ERß with CK5 and CK14.

Conclusion: To our knowledge, this is largest and most comprehensive study of African breast cancer to date. Our data confirms the hypothesis that African breast cancer is biologically distinct and shows remarkable differences in histological type, grade, hormone receptors & HER2 status when compared with breast cancer in white women. The early age at presentation, predominance of high grade and triple negative, but not necessarily basal phenotype, may explain the poor prognosis and requires tailoring treatment strategies to target this unique profile.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-04-01.

NM23-H2, an ERβ Associated Protein, as a Prognostic Marker in Breast Cancer

Purpose: Endocrine therapy is a well established therapy for estrogen receptor (ER) positive breast cancer. Two ER have been identified but currently only ERα is used in clinical practice. The role of ERβ in breast cancer is less well understood. Two human NM23 genes exist, NM23-H1 and NM23-H2. Several studies have shown an inverse relationship between overexpression of NM23-H1 in breast cancer and disease aggressiveness. NM23-H2, a metastasis suppressor protein, was recently identified as ERβ associated protein in vascular wall of atherosclerotic lesions, but the prognostic significance of this protein and its association with ERβ has not being studied in breast carcinoma. The purpose of this study was to investigate whether NM23-H2 is expressed in breast cancer and its potential clinical implications.Material and Methods: A cohort of 427 patients with diagnosis of primary invasive breast carcinoma between the period of 1994 to 1997 was used for this study. They all were patients diagnosed and treated at the Leeds Teaching Hospitals, UK. Immunohistochemistry was used primarily to identify the expression of NM23-H2 in this study. Regulation of NM23-H2 in vitro in MCF-7 cells was assessed by Western blotting. p&lt;0.05 was considered statistically significant.Results: Patients ages were 27-92 years (median = 58 years, IQ range 47-69 years) with median follow up of 110 months. Tumour size varied from 1 and 130 mm (median=22.7mm, IQ range 14-26mm). Seventy eight percent were invasive ductal carcinoma NST and 11.5% were invasive lobular; 3.9% were special type (tubular, mucinous); and 6.6% were mixed type. Twenty-three percent of the tumours were grade 1, 43.3% were grade 2 and 33.7% were grade 3. Axillary metastases were present in 51% of the cases. NM23-H2 expression was variable between tumours and demonstrated only in the cytoplasm of breast carcinomas. The percentage of staining ranged from 0% to 100% (median 80%).NM23-H2 was strongly correlated with ERβ1 and ERα (p &lt;0.001; correlation coefficient 0.252 and 0.176 respectively). No correlation was found between NM23-H2 with age, size, grade or lymph node status. NM23-H2 when expressed at levels higher than 30% was associated with improved overall survival (p= 0.030). In a multivariate Cox hazard analysis, NM23-H2 overexpression was a significant predictor of better survival independent of tumor grade, lymph node status, size or ERα. MCF-7 cells treated with 17β-estradiol (E2) expressed higher levels of NM23-H2(17.5kDa) compared with serum treated cells.Conclusion: This is the first time to our knowledge that the expression of NM23- H2 in breast cancer and its association with ERβ has been investigated. Our data provide evidence that immunohistochemical overexpression of NM23 H2 is associated with ERβ and ERα in breast cancer and with improved survival. NM23-H2 might be a good prognostic marker in breast cancer.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4148.

Methylation Status of Promoters 0K, 0N and a Newly Identified Promoter Regulate ERβ1 Expression in Breast Cancer

Gene expression is regulated at multiple levels, including transcriptional silencing by methylation. ERβ1 is downregulated in breast cancer compared to normal breast and mechanisms surrounding this are unclear. Two novel ERβ mRNA isoforms with distinct 5'-UTRs have been identified, ERβ-0K-1 and ERβ-0N-1. The aim of study was to examine whether methylation at these promoter regions plus a novel promoter identified by our group were involved in ERβ1 regulation (figure 1).Bisulfite modification and direct sequencing analysis were performed for promoters 0K, 0N, and a novel mini CpG island upstream of ERβ exon1 in two ERβ1- and one ERβ1+ breast cancer cell lines. Distinct methylation patterns were observed. Promoter 0N was completely methylated in BT20, partially methylated in MDAMB453 and unmethylated in T47D, while the mini CpG island was methylated in all 3 cell lines. In contrast, promoter 0K was unmethylated. Furthermore, a negative correlation between ERβ1 mRNA expression and the methylation status of promoter 0N was observed in breast cells. To further investigate whether methylation of the ERβ1 promoter was responsible for the loss of ERβ1 expression, BT20 and MDAMB453 cells were treated with either 5-aza-dC, TSA or both, concentrations of which had been previously optimised for each cell line. In BT20 cells which had complete methylation of 0N, both agents were required for induction of ERβ1 and ERβ-0N-1 but not ERβ-0K-1 expression, both of which are part of the 5'UTR region. However in MDAMB453 treatment with 5-aza-dC was sufficient to induce ERβ1 and ERβ-0N-1 expression with no additional re-expression seen with TSA and no effects on ERβ-0K-1. This suggests that promoter 0N is responsible for driving the transcription of ERβ1. On going work is confirming these observations in clinical samples. Our results suggest that promoter 0N plays an important role in regulation of ERβ1 mRNA expression in breast cancer. Our results add to growing literatures which demonstrate ERβ1 is regulated at multiple levels in breast cancer and that DNA methylation is an important mechanism for silencing ERβ1 gene expression.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1148.

miR-92 Is a Novel Regulator of ERβ1 Expression in Breast Cancer

Down-regulation of ERβ1 expression is thought to contribute to carcinogenesis in the breast and consequently is seen in many breast cancers. The molecular mechanisms responsible for the down-regulation of ERβ1 remain unclear. microRNAs are a novel family of regulators of gene expression that have been shown to act on the expression of many critical cancer genes but their relationship with ERβ1 has not so far been demonstrated. The aims of this study were to establish whether miR-92 regulates ERβ1 expression, and whether this regulation plays a role in defining ERβ1 expression levels in breast cancers.Using a bioinformatics approach we initially identified potential binding sites for miR-92 within the 3' untranslated regions of ERβ transcripts using RNAhybrid software (http://bibiserv.techfak.uni-bielefeld.de/rnahybrid/). Two conserved target-sites for miR-92 were identified within the ERβ1 3'-UTR sequence contained within Genebank. We confirmed the expression of these UTRs in MCF7 cells. Next, we performed 3' RACE reactions to determine the 3'-UTR sequence of ERβ1 in MCF7 cellsWe used qPCR analyses of expression in paired normal breast and breast tumour samples (n=6) to examine the relative expression of miR-92 and ERβ1. Upregulation of miR-92 expression was observed in breast tumours compared with normal breast. An inverse relationship with ERβ1 expression was observed in these samples. In a separate cohort of breast tumours (n=36), a significant negative correlation between ERβ1 mRNA and miR-92 was observed (Spearman's correlation coefficient, r = -0.5, p=0.001). Elevated ratios of ERβ1 mRNA /miR92 were also observed in ERβ1 positive compared to ERβ1 negative cells lines.Inhibition of miR-92 in MCF-7 cells increased ERβ1 expression in a dose–dependent manner at RNA levels. Enhanced GFP reporter constructs containing miR-92 binding sites from the 3'-UTR of ERβ1 were used to determine whether miR-92 downregulates ERβ1 via the direct targeting of this 3'-UTR. Inhibition of miR-92 increased the translational efficiency (protein produced per unit of mRNA) of the GFP reporter, confirming that the miR-92 binding sites are a critical regulatory region. Finally, we showed that miR-92 expression was upregulated by 17β-estradiol and downregulated by tamoxifen in MCF7 cells (ERα+ ERβ+) but not in ERβ negative cells (BT20 and MDAMB453), suggesting ERs can mediate miR-92 regulation. Our results demonstrate that ERβ1 expression in breast cancer is regulated by miRNA-92.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4139.