Comparison of clinical characteristics between ACOSOG Z0011-eligible cohort and sentinel lymph node-positive breast cancer patients in Hong Kong

INTRODUCTION

The American College of Surgeons Oncology Group (ACOSOG) Z0011 trial resulted in de-escalation of axillary surgery among early-stage breast cancer patients with low-volume sentinel lymph node (SLN) disease undergoing breast-conserving surgery and radiation therapy. Nevertheless, the mastectomy rate in the Chinese population remains high. This study compared the clinical characteristics of the ACOSOG Z0011-eligible cohort with SLN-positive breast cancer patients in Hong Kong.

METHODS

This retrospective analysis of a prospectively maintained database at a university-affiliated breast cancer centre in Hong Kong was performed from June 2014 to May 2019. The database included all patients with clinical tumour (T) stage T1 or T2 invasive breast carcinoma, no palpable adenopathy, one or two positive SLNs on histological examination, and no prior neoadjuvant systemic treatment. Comparisons were made between the mastectomy and breast-conserving treatment groups in our cohort, along with the sentinel-alone arm in the ACOSOG Z0011 trial.

RESULTS

One hundred and seventy-one patients met the inclusion criteria: 112 underwent mastectomy and 59 underwent breast-conserving treatment. Our mastectomy group had higher prevalences of T2 tumours (P<0.001), lymphovascular invasion (P<0.001), and SLN macrometastases (P=0.004) compared with the ACOSOG Z0011 cohort. However, in our patient population, mean pathological size slightly differed between the mastectomy and breast-conserving treatment groups (2.2 cm vs 1.8 cm; P=0.005). Other histopathological features were similar.

CONCLUSION

This study demonstrated that clinicopathological features were comparable between SLN-positive breast cancer patients undergoing mastectomy and those undergoing breast-conserving treatment. Low-risk SLN-positive mastectomy patients may safely avoid completion axillary lymph node dissection.

Resveratrol enhanced chemosensitivity by reversing macrophage polarization in breast cancer

BACKGROUND

Resveratrol, a naturally occurring polyphenolic compound, has been shown to inhibit cancer growth by targeting several cancer-related signalling pathways. In the tumor microenvironment (TME), tumor-associated macrophages (TAMs) are the most abundant leukocyte population that are associated with poor prognosis in over 80% of breast cancer cases. However, little is known about the effect of resveratrol in the TME.

METHODS

In this study, MDA-MB-231(MB231), cisplatin resistance MDA-MB-231 (cisR), and T47D were used to examine the antitumor effect of resveratrol. The effectiveness of resveratrol, together with cisplatin as breast cancer treatment was investigated in vivo. Gene expressions of M1 (iNOS and CXCL10) and M2 (ARG1, CD163 and MRC1) markers in differentiated macrophages derived from THP-1 cells were examined to investigate the effect of resveratrol on TAM polarization in breast cancer progression.

RESULTS

Our results demonstrated that resveratrol significantly reduced cell proliferation and enhanced chemosensitivity in breast cancer cells by inhibiting production of IL-6 and STAT3 activation. Treatment of resveratrol increased CXCL10 (M1 marker) expression. Further, resveratrol decreased IL-6 levels in LPS-treated differentiated macrophages. The use of resveratrol with cisplatin inhibited suppressed tumor growth when compared with cisplatin alone.

CONCLUSION

This study revealed that resveratrol inhibited breast cancer cell proliferation by promoting M1/M2 macrophage polarization ratio and suppressing IL-6/pSTAT3 pathway.

Clinical outcomes of patients with ductal carcinoma in situ in Hong Kong: 10-year territory-wide cancer registry study

BACKGROUND

Incidence of ductal carcinoma in situ (DCIS) has increased in recent decades because of breast cancer screening. This study comprised a long-term survival analysis of DCIS using 10-year territory-wide data from the Hong Kong Cancer Registry.

METHODS

This study included all patients diagnosed with DCIS in Hong Kong from 1997 to 2006. Exclusion criteria were age <30 years or ≥70 years, lobular carcinoma in situ, Paget's disease, and co-existing invasive carcinoma. Patients were stratified into those diagnosed from 1997 to 2001 and those diagnosed from 2002 to 2006. The 5- and 10-year breast cancer-specific survival rates were evaluated; standardised mortality ratios were calculated.

RESULTS

Among the 1391 patients in this study, 449 were diagnosed from 1997 to 2001, and 942 were diagnosed from 2002 to 2006. The mean age at diagnosis was 49.2±9.2 years. Overall, 51.2% of patients underwent mastectomy and 29.5% received adjuvant radiotherapy. The median follow-up interval was 11.6 years; overall breast cancer-specific mortality rates were 0.3% and 0.9% after 5 and 10 years of follow-up, respectively. In total, 109 patients (7.8%) developed invasive breast cancer after a considerable delay. Invasive breast cancer rates were comparable between patients diagnosed from 1997 to 2001 (n=37, 8.2%) and those diagnosed from 2002 to 2006 (n=72, 7.6%).

CONCLUSION

Despite excellent long-term survival among patients with DCIS, these patients were more likely to die of breast cancer, compared with the general population of women in Hong Kong.

OPTN/SRTR 2018 Annual Data Report: Liver

Data on adult liver transplants performed in the US in 2018 are notable for (1) continued growth in numbers of new waitlist registrants (11,844) and transplants performed (8250); (2) continued increase in the transplant rate (54.5 per 100 waitlist-years); (3) a precipitous decline in waitlist registrations and transplants for hepatitis-C-related indications; (4) increases in waitlist registrants and recipients with alcoholic liver disease and with clinical profiles consistent with non-alcoholic fatty liver disease; (5) increased use of hepatitis C virus antibody-positive donor livers; and (6) continued improvement in graft survival despite changing recipient characteristics such as older age and higher rates of obesity and diabetes. Variability in transplant rates remained by candidate race, hepatocellular carcinoma status, urgency status, and geography. The volume of pediatric liver transplants was relatively unchanged. The highest rate of pre-transplant mortality persisted for children aged younger than 1 year. Children underwent transplant at higher acuity than in the past, as evidenced by higher model for end-stage liver disease/pediatric end-stage liver disease scores and listings at status 1A and 1B at transplant. Despite higher illness severity scores at transplant, pediatric graft and patient survival posttransplant have improved over time.

Effect of preoperative injection of superparamagnetic iron oxide particles on rates of sentinel lymph node dissection in women undergoing surgery for ductal carcinoma in situ (SentiNot study)

Background

One-fifth of patients with a preoperative diagnosis of ductal carcinoma in situ (DCIS) have invasive breast cancer (IBC) on definitive histology. Sentinel lymph node dissection (SLND) is performed in almost half of women having surgery for DCIS in Sweden. The aim of the present study was to try to minimize unnecessary SLND by injecting superparamagnetic iron oxide (SPIO) nanoparticles at the time of primary breast surgery, enabling SLND to be performed later, if IBC is found in the primary specimen.

Methods

Women with DCIS at high risk for the presence of invasion undergoing breast conservation, and patients with DCIS undergoing mastectomy were included. The primary outcome was whether this technique could reduce SLND. Secondary outcomes were number of SLNDs avoided, detection rate and procedure-related costs.

Results

This was a preplanned interim analysis of 189 procedures. IBC was found in 47 and a secondary SLND was performed in 41 women. Thus, 78·3 per cent of patients avoided SLND (P &lt; 0·001). At reoperation, SPIO plus blue dye outperformed isotope and blue dye in detection of the sentinel node (40 of 40 versus 26 of 40 women; P &lt; 0·001). Costs were reduced by a mean of 24·5 per cent in women without IBC (€3990 versus 5286; P &lt; 0·001).

Conclusion

Marking the sentinel node with SPIO in women having surgery for DCIS was effective at avoiding unnecessary SLND in this study. Registration number: ISRCTN18430240 (http://www.isrctn.com).

Abstract P6-05-04: NEAT1 enhances drug sensitivity by inhibiting cancer stem-like cells in triple-negative breast cancer

Background: Accumulating evidence showed that long non-coding RNAs (lncRNAs) dysregulation is the hallmark of cancer. Nuclear paraspeckle assembly transcript 1 (NEAT1) has been reported to overexpress in many cancers, and promote cell growth and disease progression. However, the role of NEAT1 on drug sensitivity and stem-cell like property in triple-negative breast cancer is largely unknown.

Methods: LncRNA expression profile were compared between breast cancer patients and healthy individuals using lncRNA array. Large scale validation of NEAT1 expression in blood samples were performed by real-time PCR. Triple-negative breast cancer (TNBC) cells, MDA-MB-231 and its cisplatin resistance subline (MDA-MB-231/cis) were used. Stable transfection of cells with NEAT1 knockdown by shRNA, and evaluated single cell clonogenic assay, aldehyde dehydrogenase (ALDH) activity, CD44+/CD24- and other cancer stem cell (CSC) markers. Drug sensitivity assay, flow cytometry analysis, immunofluorescence staining and xenograft model were used to assess the functional role of NEAT1.

Results: Array data showed that NEAT1 was the top upregulated lncRNAs in the plasma of breast cancer patients. Consistent with the array data, validation of larger cohort of patients and healthy individuals (n=369) also demonstrated a higher expression of NEAT1 in breast cancer patients, in particular TNBC subtype. Knockdown of NEAT1 by shRNA sensitized breast cancer cells to cisplatin and taxol treatment. Cell proliferation and colony formation abilities were reduced with S-phase cell cycle arrest in shNEAT1 cells. Flow cytometry analysis revealed an induction of apoptosis with increased cleaved caspase-3. Cells expressing shNEAT1 abrogated ALDH activity, CD44+/CD24- subpopulation and expression of CSC markers (SOX2, NANOG and OCT4). More importantly, shNEAT1 cells retarded tumor growth in xenograft mice model and reduced CSC markers.

Conclusion: Taken together, NEAT1 expression is differentially expressed in breast cancer patients, and particularly higher in patients with TNBC. These findings suggest a potent therapeutic target to improve drug sensitivity in patients with TNBC.

Citation Format: Kwong A, Chen J, Siu J, Chuek I, Shin V. NEAT1 enhances drug sensitivity by inhibiting cancer stem-like cells in triple-negative breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-05-04.

Abstract P5-09-12: Germline mutation in TP53 gene in a cohort of 2,561 Chinese high-risk breast cancer patients using multigene panel testing

Background: Li-Fraumeni syndrome (LFS) is a rare autosomal genetic disorder with germline TP53 mutations. Patients with TP53 mutations have a higher risk of developing breast cancer than those harboring BRCA mutations. Although limited studies have shown that TP53 mutation carriers are less responsive to low dose radiation and more susceptible to induce new malignancies from radiotherapy. Moreover screening strategies allows early detection of a spectrum of cancers related to TP53 mutations. From work of BRCA mutations where over 40% novel mutations were detected in Chinese cohort, it is important to evaluate the frequency of TP53 mutation in Chinese to better understand the spectrum to guide appropriate clinical management of these high risk individuals.

Methods: TP53 gene mutation screening was performed on 2,561 high-risk breast cancer patients using multigene panel testing. The patients were accrued by Hong Kong Hereditary and High Risk Breast Cancer Program from March 2007 to May 2018. All detected pathogenic mutations were further validated by bi-directional DNA sequencing and analyzed by our in-house developed bioinformatics pipeline.

Results: Sixteen distinct pathogenic or likely pathogenic variants were identified, and 3 of them were de novo TP53 mutations (18.75%). The mean age of patients who harbored TP53 mutation was 30.44 years (range 18-44), and 50% of the tumors were bilateral breast cancer. Of sixteen different pathogenic mutations, majority of them were missense mutation (87.5%), and 2 were nonsense mutation (12.5%). Four of the sixteen TP53 mutation carriers had family history of breast cancer, while others had a family history of lung cancer (43.75%).

Conclusion: This study revealed that seven patients were found to habor TP53 mutation even when they did not meet the criteria of LFS of LFS-like phenotype, implicated the importance of using multigene panel test for probands and their relatives to offer a comprehensive surveillance programe for TP53 carriers.

Citation Format: Kwong A, Shin V, Au CH, Ho C, Slavin T, Weitzel J, Chan TL, Ma E. Germline mutation in TP53 gene in a cohort of 2,561 Chinese high-risk breast cancer patients using multigene panel testing [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-09-12.

Abstract P4-01-24: S100A11 is a diagnostic marker and promotes cancer progression for luminal breast cancer

Background: S100A11, also known as calgizzarin, is a member of S100 calcium-binding protein family and is upregulated in various cancers including lung cancer, renal cell cancer, ovarian cancer and pancreatic cancer. Many studies have shown that S100A11 is related to cancer progression. However, the function of S100A11 in breast cancer remains largely unknown. In the present study, we aim to investigate the underlying mechanism(s) of S100A11 in cancer cell proliferation, invasion, migration, and evaluate the clinical association with breast cancer.

Methods: The mRNA expression level of S100A11 in plasma samples from breast cancer patients and normal control individuals was detected with quantitative real-time PCR. Knockdown of S100A11 using small interfering RNA (siRNA) in luminal breast cancer cells (MCF-7 and T-47D) were used to study the biological function of S100A11 for the progression of breast cancer. Cell proliferation ability was analysed with MTT assay and colony formation assay. Cell invasion ability was analysed with transwell invasion assay. Cell migration ability was detected by wound healing assay. Cell cycle distribution and apoptosis were determined by flow cytometry.

Results: The mRNA expression level of S100A11 was significantly increased in the plasma samples obtained from 182 breast cancer patients compared with 115 normal control individuals, and the area under curve was 0.83. In particular, higher expression was associated with luminal breast cancer subtype as well as respective cell lines. S100A11 siRNA effectively inhibited the proliferation, invasion, and migration abilities of MCF-7 and T-47D cells. Knockdown of S100A11 caused cell cycle G1 arrest and induced apoptosis. Silencing of S100A11 decreased the mRNA and protein expression levels of cyclin D1 and NF-κB p50 whereas increased the expression level of E-cadherin in MCF-7 and T-47D cells.

Conclusion: These results suggest that S100A11 is upregulated in breast cancer and promoted cell proliferation, invasion and migration in MCF-7 and T-47D cells through the upregulation of NF-κB p50 and cyclin D1. Thus, S100A11 may be a potential diagnostic marker for luminal breast cancer subtype and also a therapeutic target for breast cancer.

Citation Format: Kwong A, Wang J, Chen J, Siu MT, Chuek I, Shin V. S100A11 is a diagnostic marker and promotes cancer progression for luminal breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-01-24.

Breast-conserving surgery versus mastectomy in young women with breast cancer in Asian settings

Background

Mastectomy rates among women with early breast cancer in Asia have traditionally been high. This study assessed trends in the surgical management of young women with early‐stage breast cancer in Asian settings. Survival in women treated with breast‐conserving surgery (BCS; lumpectomy with adjuvant radiotherapy) and those undergoing mastectomy was compared.

Methods

Young women (aged less than 50 years) newly diagnosed with stage I or II (T1–2 N0–1 M0) breast cancer in four hospitals in Malaysia, Singapore and Hong Kong in 1990–2012 were included. Overall survival (OS) was compared for patients treated by BCS and those who had a mastectomy. Propensity score analysis was used to account for differences in demographic, tumour and treatment characteristics between the groups.

Results

Some 63·5 per cent of 3536 women underwent mastectomy. Over a 15‐year period, only a modest increase in rates of BCS was observed. Although BCS was significantly associated with favourable prognostic features, OS was not significantly different for BCS and mastectomy; the 5‐year OS rate was 94·9 (95 per cent c.i. 93·5 to 96·3) and 92·9 (91·7 to 94·1) per cent respectively. Inferences remained unchanged following propensity score analysis (hazard ratio for BCS versus mastectomy: 0·81, 95 per cent c.i. 0·64 to 1·03).

Conclusion

The prevalence of young women with breast cancer treated by mastectomy remains high in Asian countries. Patients treated with BCS appear to survive as well as those undergoing mastectomy.

Implications of nipple discharge in Hong Kong Chinese women

INTRODUCTION

There are no recent data on nipple discharge and its association with malignancy in Hong Kong Chinese women. This study reported our 5-year experience in the management of patients with nipple discharge, and our experience of mammography, ultrasonography, ductography, and nipple discharge cytology in an attempt to determine their role in the management of nipple discharge.

METHODS

Women who attended our Breast Clinic in a university-affiliated hospital in Hong Kong were identified by retrospective review of clinical data from January 2007 to December 2011. They were divided into benign and malignant subgroups. Background clinical variables and investigative results were compared between the two subgroups. We also reported the sensitivity, specificity, and positive and negative predictive values of the investigations that included mammography, ultrasonography, ductography, and cytology.

RESULTS

We identified 71 and 31 patients in the benign and malignant subgroups, respectively. The median age at presentation for the benign subgroup was younger than that of the malignant subgroup (48 vs 59 years; P=0.003). A higher proportion of patients in the malignant subgroup than the benign subgroup presented with blood-stained nipple discharge (87.1% vs 47.9%; P=0.002). Mammography had a specificity of 98.4% and positive predictive value of 66.7%; ultrasonography had a specificity of 87.0% and negative predictive value of 75.0%. Cytology and ductography were sensitive but lacked specificity. Ductography had a negative predictive value of 100% but a low positive predictive value (14.0%). Clinical variables including age at presentation, duration of discharge, colour of discharge, presence of an associated breast mass, and abnormal sonographic findings were important in suggesting the underlying pathology of nipple discharge. Multiple logistic regression showed that blood-stained discharge and an associated breast mass were statistically significantly more common in the malignant subgroup.

CONCLUSIONS

In patients with non-blood-stained nipple discharge, a negative clinical breast examination combined with negative imaging could reasonably infer a benign underlying pathology.

The Baby Moves prospective cohort study protocol: using a smartphone application with the General Movements Assessment to predict neurodevelopmental outcomes at age 2 years for extremely preterm or extremely low birthweight infants

INTRODUCTION

Infants born extremely preterm (EP; <28 weeks' gestation) and/or with extremely low birth weight (ELBW; <1000 g birth weight) are at increased risk for adverse neurodevelopmental outcomes. However, it is challenging to predict those EP/ELBW infants destined to have long-term neurodevelopmental impairments in order to target early intervention to those in most need. The General Movements Assessment (GMA) in early infancy has high predictive validity for neurodevelopmental outcomes in preterm infants. However, access to a GMA may be limited by geographical constraints and a lack of GMA-trained health professionals. Baby Moves is a smartphone application (app) developed for caregivers to video and upload their infant's general movements to be scored remotely by a certified GMA assessor. The aim of this study is to determine the predictive ability of using the GMA via the Baby Moves app for neurodevelopmental impairment in infants born EP/ELBW.

METHODS AND ANALYSIS

This prospective cohort study will recruit infants born EP/ELBW across the state of Victoria, Australia in 2016 and 2017. A control group of normal birth weight (>2500 g birth weight), term-born (≥37 weeks' gestation) infants will also be recruited as a local reference group. Parents will video their infant's general movements at two time points between 3 and 4 months' corrected age using the Baby Moves app. Videos will be scored by certified GMA assessors and classified as normal or abnormal. Parental satisfaction using the Baby Moves app will be assessed via survey. Neurodevelopmental outcome at 2 years' corrected age includes developmental delay according to the Bayley Scales of Infant and Toddler Development-III and cerebral palsy diagnosis.

ETHICS AND DISSEMINATION

This study was approved by the Human Research and Ethics Committees at the Royal Children's Hospital, The Royal Women's Hospital, Monash Health and Mercy Health in Melbourne, Australia. Study findings will be disseminated via peer-reviewed publications and conference presentations.

A prospective randomised controlled trial of octylcyanoacrylate tissue adhesive and standard suture for wound closure following breast surgery

INTRODUCTION

Several studies have demonstrated that octylcyanoacrylate tissue adhesive provides an equivalent cosmetic outcome as standard suture for wound closure. This study aimed to compare octylcyanoacrylate tissue adhesive with standard suture for wound closure following breast surgery.

METHODS

A prospective randomised controlled trial was conducted in a public hospital in Hong Kong. A total of 70 female patients, who underwent elective excision of clinically benign breast lump between February 2009 and November 2011, were randomised to have wound closure using either octylcyanoacrylate tissue adhesive or standard wound suture following breast surgery. Wound complications and cosmetic outcome were measured.

RESULTS

Octylcyanoacrylate tissue adhesive achieved wound closure in significantly less time than standard suturing (mean, 80.6 seconds vs 344.6 seconds; P<0.001). There was no statistical difference in wound condition or cosmetic outcome although number of clinic visits, ease of self-showering, and comfort of dressing significantly favoured octylcyanoacrylate tissue adhesive.

CONCLUSIONS

Octylcyanoacrylate tissue adhesive may be offered as an option for wound closure following breast surgery.

Comparing the meanings of living with advanced breast cancer between women resilient to distress and women with persistent distress: a qualitative study

BACKGROUND

Most women with advanced breast cancer (ABC) show little distress, but about one in ten show persistent distress over time. It remains unclear if meanings ascribed by patients to ABC differentiate these distress trajectories.

STUDY AIMS

This qualitative study (a) compared illness meanings of ABC between women with persistent psychological distress and those with low/transient distress, and (b) examined how illness meanings might influence coping strategies.

METHODS

The sample was drawn from a prior quantitative study exploring psychological distress trajectories following ABC diagnosis. Overall, 42 Cantonese- or Mandarin-speaking Chinese women diagnosed with locally advanced or metastatic ABC were recruited based on their distress trajectory status (low-stable, transient, or persistent distress). Interviews were recorded, transcribed, and analyzed following grounded theory approach using simultaneous analysis.

RESULTS

Women with persistent distress viewed their diagnosis as another blow in life, the illness was global, permeating every aspect of their life. Maladaptive rumination and thought suppression were common responses to illness demands. These women had poor social support. A sense of demoralization stood out in their narratives. In contrast, women with transient/low-stable distress encapsulated the illness, with minimum impacts of their life. They did not evidence dysfunctional repetitive thoughts. Living in a supportive environment, they were able to accept and/or live in the present-moment.

CONCLUSIONS

Rumination, thought suppression, social constraints, and pre-existing exposure to life stress may be potential risks for chronic distress in response to advanced breast cancer. Persistent and transient distress responses to cancer may have different underpinnings. Copyright © 2016 John Wiley & Sons, Ltd.

Abstract P1-05-04: A novel mechanism of epithelial-mesenchymal transition in breast cancer metastasis: Involvement of prostanoid receptor

Background: Triple-negative breast cancer is associated with higher metastatic rate and poor prognosis than other subtypes of breast cancer due to lack of targeted therapy. Epithelial-mesenchymal transition (EMT) is linked with metastasis with phenotypic conversion of epithelial cells. However, the regulation of EMT in breast cancer metastasis remains largely unstudied. Recent attention has focused on targeting the downstream of COX-2 pathway, understanding the role of prostanoid receptors in breast cancer metastasis may help the development of effective therapeutic interventions for patients with metastasis.

Methods: A stable EP2-expression cell line (MB-231-EP2) was used to study tumorigenesis and distant metastasis in human breast cancer metastatic model. Localization of EP2 and EMT markers were examined by immunostaining and immunofluorescence. Profiles of drug transporters genes were compared between siEP2 and siControl cells. Functional role of EP2 on cell proliferation, invasion and apoptosis were assessed. Alteration of EMT markers were examined by real-time PCR and Western blot analysis.

Results: Expression of EP2 receptor were higher in human primary tumors than non-tumor tissues. EP2 receptor was predominantly expressed in metastatic tumors than primary tumors in human breast cancer metastatic mice model. The metastatic tumors showed a higher Ki67 (cell proliferation) and CD31 (angiogenesis) than primary tumors in the xenograft tissues. Larger tumors and poor survival were seen in MD-231-EP2 bearing mice when compared with control. Silencing of EP2 by siRNA markedly reduced cell proliferation and invasion, but increased apoptosis and expression of solute carrier family 19 member A3 (SLC19A3) gene. Interestingly, SLC19A3 had a lower expression in primary tumors and was inversely correlated with EP2 expression. Ectopic expression of SLC19A3 suppressed cell proliferation and invasion through the restoration of E-cadherin and other EMT markers (Twist, Zeb1 and Snai2). Immunofluorescence staining showed that the localization of Twist and E-cadherin were altered in siEP2 cells.

Conclusion: Our results showed that EP2 promoted EMT and breast cancer metastasis through the downregulation of SLC19A3 expression. Taken together, targeting EP2/SLC19A3 signaling pathway maybe a potential treatment for metastasis and adjuvant chemotherapy to reduce the metastatic risk.

Citation Format: Kwong A, Siu MT, Cheuk I, Ho JC, Chen J, Shin VY. A novel mechanism of epithelial-mesenchymal transition in breast cancer metastasis: Involvement of prostanoid receptor. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-05-04.

Abstract P2-12-22: Atypical ductal hyperplasia and breast cancers - A ten year clinical and pathological review on core biopsy, lumpectomy and mastectomy specimens

Introduction

Atypical ductal hyperplasia (ADH) is known to be associated with underlying pre-malignant or malignant breast conditions. Here we report our 10-year data on ADH found in core biopsy, lumpectomy and mastectomy specimens

Methods

From 1st January 2005 to 31st December 2014, a total of 104 core needle biopsy specimens and 218 lumpectomy / mastectomy specimens were found to contain ADH. Clinical, radiological and pathology data were retrieved and analysed from a prospectively-maintained database.

Results

Out of the 104 patients with core biopsy showing ADH, 101 patients received excision and 3 refused operation. 34 patients turned out to have ductal carcinoma in-situ (DCIS) on excision, while 6 had invasive ductal carcinoma (IDC), 1 had lobular carcinoma in-situ (LCIS) and 1 had angiosarcoma resulting in an upstaging rate of 40.4% (42/104). The remaining patients had benign lesions including papillary lesions, fibrocystic disease, or ADH alone. Multivariate analysis found that the only correlating factor for the presence of DCIS or IDC was suspicious mammographic features (BIRADS 4 or above) (P = 0.008 and 0.02 respectively) but not other parameters such as extent of micro-calcifications (P = 0.12) or age (P = 0.11).

Histopathological diagnosis after excision of lesions containing ADH on core biopsyExcisional Biopsy ResultNumber (%)DCIS34 (32.7%)ADH32 (30.8%)Benign27 (26%)IDC6 (5.8%)LCIS1 (0.9%)Angiosarcoma1 (0.9%)Refuse operation3 (2.9%)

218 lumpectomy or mastectomy specimens were found to harbor ADH. 62 (28.4%) had co-existing pre-malignant or malignant breast diseases. The only determining factor for the presence of malignant or pre-malignant condition was suspicious breast imaging features (BIRADS 4 or above) after multivariate analysis (P = 0.0003).

Co-existing conditions in the lumpectomy / mastectomy specimens with ADHCo-existing Patholog(ies)Number (%)Atypical Ductal Hyperplasia alone97 (44.4%)Fibroadenoma / Fibrocystic disease31 (14.2%)Intraductal papilloma22 (10%)Phyllodes tumor6 (2.8%)Ductal carcinoma in-situ36 (16.5%)Invasive ductal carcinoma23 (10.6%)Lobular carcinoma in-situ1 (0.5%)Invasive lobular carcinoma1 (0.5%)Malignant phyllodes tumor1 (0.5%)

Conclusion

ADH is closely related to the presence of invasive cancer or DCIS especially when suspicious breast imaging features are present. The upstaging rate is still high in patients where initial biopsy was ADH.

Citation Format: Co M, Kwong A. Atypical ductal hyperplasia and breast cancers - A ten year clinical and pathological review on core biopsy, lumpectomy and mastectomy specimens. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-12-22.

Abstract P2-09-20: Evaluation on the mutation screening by next-generation sequencing in hereditary breast and ovarian cancer: Implementation of recurrent mutation panel

Background: Hereditary disposition accounts for 10-15% in breast cancers and 20-25% in ovarian cancers, in which 5-10% of women have genomic alteration in breast cancer predisposition genes, BRCA1 and BRCA2, while the rest are likely due to less penetrant genes. In specific ethnicities such as Ashkenazi Jewish, three founder mutations have been identified which covers 95 % of all the BRCA mutations identified in this race. These genes are screened prior to the gold standard Sanger Sequencing in order to reduce cost. Sanger Sequencing, however, still has the limitation on the necessity of laborious processing and results interpretation. Moreover, it limits the number of genes that can be analyzed in one setting. With the use of next-generation sequencing (NGS), identification of hereditary breast and ovarian cancer (HBOC) syndrome associated genes, other than BRCA, can be sequenced at the same time but yet a faster turnover time. This allows more timely targeted risk-reducing strategies and interventions to be implemented for mutation positive carriers and their family members.

Methods: In this study cohort, 948 high-risk breast/ovarian patients who met the HBOC selection criteria were recruited for mutation screening by our NGS pipeline. With the inclusion of 90 Sanger-validated known mutation cases, the performance of the NGS pipeline were proven to be comparable to Sanger sequencing. PTEN and TP53, other than BRCA1 and BRCA2, a 4 gene sequencing panel were included in the mutation screening for high-risk patients.

Results: The prevalence of BRCA1/BRCA2 germline mutations was 7.28% in our Chinese cohort and 47.8% of the mutation were recurrent mutations. Based on this finding, we further adopted a new workflow by screening the recurrent mutations including founder mutations from Chinese cohort prior to NGS for those who tested negative. In a testing cohort of 343 cases, the recurrent mutation pick-up rate was 3.5%, this implicated a more cost-effective method for mutation screening in the clinical setting. Moreover, the frequencies of PTEN and TP53 were 0.21% and 0.53% respectively in our population with breast and ovarian cases.

Conclusion: Taken together, our data demonstrated a strategic upfront screening for recurrent mutations in Chinese population which is highly applicable in most of the diagnostic laboratories. Multi-gene sequencing using the NGS technology will be the upcoming strategies for mutation screening for HBOC patients.

Citation Format: Kwong A, Shin VY, Au CH, Law FB, Ho DN, Ip BK, Wong AT, Lau SS, To RM, Choy G, Ford JM, Ma ES, Chan TL. Evaluation on the mutation screening by next-generation sequencing in hereditary breast and ovarian cancer: Implementation of recurrent mutation panel. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-09-20.

Circulating cell-free miRNAs as biomarker for triple-negative breast cancer

Background:

Triple-negative breast cancer (TNBC) accounts for 15–20% of all breast cancer in women globally. This subtype often has early and high recurrence rates resulting in poor survival, partially due to lack of targeted therapies. Therefore, there is an urgent need to identify TNBC-specific biomarkers for early diagnosis and treatment monitoring, and to develop more effective targeted therapy.

Methods:

By using miRCURY LNA array platform, we compared the differential miRNA expressions in plasma of patient with TNBC (n=5) and non-TNBC (n=5), as well as healthy controls (n=5). Potential miRNAs were then validated in a large cohort of patients by real-time PCR.

Results:

Ten putative miRNAs from the microarray data that differentially expressed between non-TNBC and healthy controls were identified. In the screening phase (n=90), we selected five miRNAs (miR-92a-3p, miR-342-3p, miR-16, miR-21 and miR-199a-5p) that could discriminate TNBC from non-TNBC for further validation. Results showed that miR-16, miR-21 and miR-199a-5p were underexpressed in TNBC when compared with non-TNBC, and were further validated in a large cohort (n=252). In addition, post-operative plasma levels of miR-16, miR-21 and miR-199a-5p were significantly restored when compared with pre-operative plasma of TNBC. Plasma miR-199a-5p expression in TNBC had significant difference when compared with non-TNBC and healthy controls, the receiver-operator characteristics curve analysis revealed the highest area under curve (AUC=0.8838) among all. The expression levels were associated with TNM stage and tumour subtypes.

Conclusions:

Our data suggest that miR-199a-5p could be a TNBC-specific marker with diagnostic value and provide insights into targeted therapy in the treatment of TNBC.

Treatment outcomes for male breast cancer: a single-centre retrospective case-control study

BACKGROUND

Male breast cancer (bc) is a rare disease, and the availability of information on treatment outcomes is limited compared with that for female bc. The objective of the present study was to compare disease-free (dfs) and overall survival (os) for men compared with women having early-stage bc.

METHODS

This retrospective case-control study compared men and women treated for stage 0-iiib bc at a single institution between 1981 and 2009. Matching was based on age at diagnosis, year of diagnosis, and stage. Treatment, recurrence, and survival data were collected. Kaplan-Meier analysis was used to calculate os and dfs.

RESULTS

For the 144 eligible patients (72 men, 72 women), median age at diagnosis was 66.5 years. Treatments included mastectomy (72 men, 38 women), radiation (29 men, 44 women), chemotherapy (23 men, 20 women), and endocrine therapy (57 men, 57 women). Mean dfs was 127 months for women compared with 93 months for men (p = 0.62). Mean os was 117 months for women compared with 124 months for men (p = 0.35). In multivariate analysis, the only parameter that affected both dfs and os was stage at diagnosis.

CONCLUSIONS

This case-control study is one of the largest to report treatment outcomes in early-stage male bc patients treated in a non-trial setting. Male patients received systemic therapy that was comparable to that received by their female counterparts, and they had similar os and dfs. These results add to current evidence from population studies that male sex is not a poor prognostic factor in early-stage breast cancer.

Abstract P2-07-03: High-throughput germline mutation screening for hereditary breast cancer in southern Chinese patients by massively parallel DNA sequencing

Introduction: Breast cancer is the most common malignancy and 3rd leading cause of deaths among the female population in Hong Kong. Since the establishment of The Hong Kong Hereditary Breast Cancer Family Registry in 2007, 1344 patients with breast and/or ovarian cancer who met the selection criteria were recruited for genetic testing in Hong Kong. Since 2011 we started to employ next-generation DNA sequencing (NGS) to expedite the analysis workflow and expand the panel of genes for sequencing.

Aim: To evaluate the workflow of NGS in mutation screening of BRCA1, BRCA2, TP53 and PTEN genes, and compared with the sequence data obtained by Sanger sequencing.

Methods: We sequenced BRCA1, BRCA2, TP53 and PTEN genes in peripheral blood samples of 410 patients, 53 positive controls and 107 healthy local individuals using 454 GS Junior System. Generation of barcoded amplicon libraries was streamlined by microfluidic PCR using Fluidigm Access Array System. Sequencing data were analyzed by an in-house developed fully automatic bioinformatics pipeline, which mainly consists of GS Amplicon Variant Analyzer, SAMtools and Ensembl Variant Effect Predictor. All putative mutations identified were validated by Sanger sequencing. Furthermore, the frequency of BRCA1, BRCA2 and PTEN missense variants of unknown significance (VUS) identified in the cohort were compared among 107 healthy local individuals and 1000 Genomes project samples. The VUS were also subjected to a panel of in silico prediction methods including PolyPhen and SIFT.

Results: Among 410 patients, there were 7 in BRCA1, 6 in BRCA2 and 1 in TP53 mutations found, including 1 novel recurrent BRCA2 (c.7007G&gt;T) and 1 novel founder BRCA2 (c.5164_5165delAG) mutations. Based on multiple criteria, 12 in BRCA1, 12 in BRCA2 and 1 in PTEN VUS could be prioritized for further investigation. The bioinformatics pipeline was extensively evaluated with Sanger-validated controls. The evaluation determined minimum sequencing coverage needed in this sequencing platform for accurate analysis. The pipeline accuracy was demonstrated by successful detecting mutations from 53 positive controls, including single nucleotide variants, insertions and deletions in different sequence context.

Conclusion: BRCA1, BRCA2, TP53 and PTEN mutation screening of 410 patients were expedited by high-throughput DNA sequencing. This method could detect 14 positive cases, including recurrent mutations, in a shorter period of time when compared with Sanger full gene sequencing. High-risk patients who are negative for the gene panel may need further investigation other than screening for BRCA1/2. The in-house developed bioinformatics pipeline was validated to detect various types of mutations and potentially become a conventional platform for genetic screening.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-07-03.

Abstract P4-11-02: Novel BRCA1 and BRCA2 genomic rearrangements in Southern Chinese breast/ovarian cancer patients

Background and Aims: Germline mutations in the two breast cancer susceptibility genes, BRCA1 and BRCA2 account for a significant portion of hereditary breast/ovarian cancer. Most of the BRCA mutations reported in Southern Chinese patients were point mutations, small deletions, and insertions. The spectrum of large genomic rearrangement (LGR) is largely unknown. Here we perform the first study on the LGR of BRCA genes in a Hong Kong Chinese population. We aimed to determine the spectrum of BRCA LGRs in Southern Chinese patients with breast cancer.

Methods: A total of 555 clinically high-risk breast and/or ovarian cancer patients were recruited from the Hong Kong Hereditary Breast Cancer Family Registry, diagnosed from March 2007 to November 2011. Multiplex ligation-dependent probe amplification (MLPA) for detecting BRCA LGRs together with comprehensive BRCA1 and BRCA2 gene sequencing of all coding exons were performed. cDNA sequencing of the LGRs was performed to locate the breakpoint of the deletions.

Results: Overall BRCA1/2 mutation prevalence among this cohort was 12.4% (69/555). Among the 69 mutations identified, 4 novel LGRs (2 in BRCA1 and 2 in BRCA2) were detected only by MLPA but not full gene sequencing. Overall the LGR genes accounted for 5.8% (4/69) of all BRCA mutations in our cohort, 6.9% (2/29) of all BRCA1 mutations and 5% (2/40) of all BRCA2 mutations.

Conclusions: These findings highlight the LGR spectrum of BRCA1 and BRCA2 genes in Southern Chinese breast cancer patients. LGR testing together with BRCA1/2 full gene sequencing is superior to other methods for comprehensive BRCA1/2 analysis in clinical settings.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P4-11-02.

Abstract P3-11-03: Treatment outcomes for early stage male breast cancer: a single centre retrospective case-control study

Background: Male breast cancer (BC) is a rare disease with a reported incidence of 1%, and treatment strategies are therefore driven by studies conducted in the female BC population. There is also limited information with regards to treatment outcomes for men with early stage BC, particularly when compared with their female counterparts. The objective of this study is to compare the disease free survival (DFS) and overall survival (OS) of males with early stage BC compared to age and stage matched females in a single institution.

Methods: A retrospective matched case-control study was conducted to compare male and female pts treated for stage 0 to IIIB BC, at the Ottawa Hospital Cancer Centre, between 1981 and 2009. Matching of male and female pts was done based on age at diagnosis (+/− 2 years), year of diagnosis (+/− 1 year), and disease stage. Data regarding surgery, adjuvant radiation, chemotherapy, and endocrine therapy was collected. Overall survival and disease-free survival were calculated using Kaplan-Meir analysis.

Results: A total of 144 pts (72 female; 72 male) were eligible for this study; median age at diagnosis for both groups was 74 years (r: 30–85). Median follow-up was 54 months (r: 2–204) for males and 54 months (r: 4–241) for females. All 72 men underwent mastectomy compared to 38 females (53%). Forty-four (61%) females received adjuvant radiation therapy compared to 29 (40%) males. Twenty (28%) females received adjuvant chemotherapy, compared to 23 (31%) males. All female pts had estrogen receptor positive (ER+) disease, while 59 males (13 unknown) had ER+ disease. An equal number of males and females (79%) received endocrine treatment. The mean DFS for females was 127 months (25th percentile 33 months; median 104 months; 75th percentile 174 months), compared to 93 months (25th percentile 46 months; median 88 months; 75th percentile 112 months) for males (p = 0.62). Mean OS for females was 117 months (25th percentile 40 months; median 107 months; 75th percentile 136 months), and 124 months (25th percentile 48 months; median 90 months; 75th percentile 128 months) for males (p = 0.35). In multivariate analysis, the only parameter that affected both DFS and OS was stage at diagnosis (hazard ratio 0.42, 95% CI 0.18–1.00; hazard ratio 0.25, 96% CI 0.09–0.68).

Conclusions: This is one of the largest case-cohort studies to report on treatment outcomes of early stage male BC pts treated in a non-trial setting. Male pts received comparable systemic therapy (chemotherapy/endocrine) as their female counterparts and DFS and OS were similar. These results add to current evidence from population studies that male sex is not a poor prognostic factor for treatment outcomes in early stage BC. The development of a national male breast cancer registry would facilitate the evaluation of modern treatment strategies and patient outcomes in this population.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-11-03.

Abstract P3-11-02: Male breast cancer: A comparison between BRCA mutation carriers and non-carriers in Hong Kong, Southern China

Background: Male breast cancer is suggested to be biologically different from female breast cancer. The differences in clinicopathology between male and female breast cancer raise the issues of establishing specific strategies and treatment regime for male breast cancer patients. The single most significant risk factor for male breast cancer is a mutation in the BRCA2 gene. The lack of information on hereditary breast cancer in male, particularly in Asians, leaves great but forgiven research area on epidemiological studies for this group of patients.

Methods: All male breast cancer patients and their family members, from a Hong Kong Hereditary and High Risk Breast Cancer Program since year 2007, were recruited in this study. All received genetic counseling and BRCA mutation testing using DNA extracted from blood samples. A questionnaire was administered at their first visit which included questions on their demographics and socioeconomic status. Other information including family history of breast cancer or other kinds of cancer, method of diagnosis, surgical strategies, pathological results, treatment regime, relapse, metastasis, and outcomes were obtained from their medical records. Descriptive analysis was performed describing the background characteristics. Chi-square test and Student's t-test were applied to calculate the associations between BRCA mutation and risk factors. Survival analysis was performed to look for their survival patterns.

Results: Thirty-six male breast cancer patients were recruited between year 2007 and 2012, while 21 were diagnosed before year 2007 (range: 1996 to 2012). Mean, standard deviation, and median follow-up time were 5.75±4.31 and 5.25 years. Seven were found to carry the BRCA mutation. All were BRCA2 mutation and the mutation rate was 19.4% (N = 7). Family history of cancer was found in 52.8% (N = 19). Male BRCA mutation carriers were found to have higher risk of secondary cancer, and their first and second degree family members had higher risk of either breast cancer or other kinds of cancers. T stage in BRCA patients was significantly higher than non-BRCA patients (p = 0.028). All BRCA mutation carriers had ER positive cancers compared with 96.2% who were non-carriers. Half of the male BRCA patients were PR positive compared with higher percentage in non-BRCA patients (50% vs. 80.8%, p = 0.117). Both groups had similar overall (p = 0.962) and disease-free survivals (p = 0.919). The means and standard deviations of 5-year overall survival between BRCA and non-BRCA patients were 2.08±0.25 and 4.24±0.12 years respectively, and 2.08±3.03 and 4.41±1.46 years for disease-free survival.

Conclusions: The prevalence of male breast cancer patients with BRCA2 mutation in Hong Kong is comparable with other similar studies. Male breast cancer patients with BRCA2 mutation are suspected to have higher chance of secondary cancer and familial cancer. Although percentage of ER positive cancers are similar to the two groups, BRCA2 mutation carriers tend to have less PR positive cancers which may suggest a poorer prognosis although due to a small sample size this cannot be shown in this cohort. Further collaborative studies to better understand male breast cancer patients carrying the BRCA mutation is warranted.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-11-02.

P2-13-08: A Retrospective Study on Surveillance Behaviour and Prophylaxis after Genetic Testing for Hereditary Breast and Ovarian Cancer among High-Risk Chinese Females

Background

Research in the West has shown that the uptake rates of surveillance and prophylaxis may be different in BRCA mutation carriers and non carriers and this may vary between different ethnicities. To date there is limited comprehensive data available for the behavioural pattern of Asian cohorts. The present on-going study is the first to investigate the behavioural impact and medical compliance of Chinese high risk females who had undergone BRCA1/2 genetic testing up to 1.5 years after genetic testing.

Methods: 88 females with personal or family breast and/or ovarian cancer history who had BRCA1/2 genetic testing performed by the Hong Kong Hereditary Breast Cancer Family Registry were surveyed by a face-to-face or telephone interview. Sociodemographic information, genetic test results, pre-and post-testing surveillance practice, chemoprevention methods used and attitudes towards clinical management were obtained. Retrieval of medical records was performed using a prospective database.

Results: 39 carriers and 49 noncarriers of a BRCA 1/2 mutations were interviewed. 82.1% of carriers and 79.6% noncarriers had breast and/or ovarian cancer prior to testing. The uptake rate of breast surveillance by eligible carriers (85.2%) and noncarriers (71.1%) remained high after knowing the test results. 12.8% and 15.4% of the eligible carriers had prophylactic contralateral mastectomy and salpingo-oophorectomy respectively, while 5.1% chose to have both procedures within 1.5 years of knowing the genetic test result. Significantly more carriers (85.7%) than noncarriers (49%) underwent ovarian surveillance (p= 0.004). 25.6% of carriers and 26.5% of noncarriers with breast cancer history chose Western chemoprevention methods, while no carriers without breast cancer history chose such methods. 34.7% of carriers (30.8% of noncarriers) used Chinese herbal medicine as complementary prevention treatment after knowing the genetic test result. Clinicians’ advice was perceived as the major reason of choosing a particular surveillance or preventative strategy.

Conclusions: As population-based breast screening is unavailable in Hong Kong, the relatively high uptake rate of breast screening among noncarriers may be the result of enhancement in health-consciousness due to prior personal or family cancer experience. Proper education by clinicians is crucial to increase uptake of high risk screening. Traditional Chinese herbal medicine methods are commonly used as a form of prevention. A longitudinal prospective study will contribute to the understanding of attitude-change towards clinical management of this Chinese population who may have different cultural beliefs.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-13-08.

Abstract P3-01-02: Quantitative Analysis and Diagnostic Significance of Methylated SLC19A3 DNA in the Plasma of Breast Cancer Patients

Background: Previously, we have examined the methylation status of SLC19A3 (solute carrier family 19, member 3) promoter and found that SLC19A3 was epigenetically down-regulated in gastric cancer. Here, we aim to develop a new biomarker for cancer diagnosis using methylated SLC19A3 DNA in plasma.

Methods: SLC19A3 gene expression was examined by RT-qPCR. Methylation status of SLC19A3 promoter was evaluated by methylation-specific qPCR. A robust and simple methylation-sensitive restriction enzyme digestion and real-time quantitative PCR assay was developed to quantify SLC19A3 DNA methylation in plasma. Results: Expression of SLC19A3 was significantly down-regulated in 80% (12/15) of breast tumors (P &lt; 0.005). Breast tumors had significant increase in methylation percentage when compared to adjacent non-tumor tissues (P &lt; 0.05). A total of 155 independent plasma samples from participants including 60 breast cancer, 45 gastric cancer patients and 60 healthy subjects were analyzed. Plasma methylated SLC19A3 DNA yielded a ROC curve area of 77%, sensitivity of 82% and specificity of 60% in discriminating breast cancer from control subjects. This marker yielded a ROC curve area of 87%, sensitivity of 90.0% and specificity of 62% in discriminating gastric cancer from control subjects. Elevated level in plasma has been detected not only in advanced stages but also early stages of tumors. Intriguingly, of all DCIS cases from breast cancer patients this plasma marker generated a ROC value of 92%, sensitivity of 100% and specificity of 78% in discriminating DCIS cases from controls. Conclusions: These results suggested that aberrant SLC19A3 promoter hypermethylation in plasma may be a novel biomarker for early breast cancer diagnosis.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P3-01-02.

Abstract P2-10-01: The Accuracy of BRCA1/2 Mutation Prediction Models in Different Ethnicity and Gender: Experience in a Chinese Cohort

Background: Risk models (BRCAPRO, Myriad, Couch and Shattuck-Eidens, BOADICEA) are well established in Caucasian and African American cohorts to estimate the probability of BRCA1/2 mutation. Few studies have suggested its performance limitation in Asian cohorts. Most studies did not account for gender specific prediction. The aim of the study is to evaluate the performance of these models in a Chinese cohort who have breast/ovarian cancer at a pre-genetic test setting. Methods: Four risk assessment models, Boadicea, BRCAPRO, Myriad, Couch and Shattuck-Eidens, were used to perform risk calculations to 217 non-BRCA carriers (198 females and 19 males) and 32 BRCA carriers (28 females and 4 males. Sensitivity, specificity and area under the receiver operator characteristic (ROC) curve were calculated for each model to evaluate for calibration, discrimination and accuracy in BRCA mutation prediction stratified by gender.

Results: The mean in prediction score in all models were statistically significantly higher in female BRCA mutation carriers. However, there were no statistically difference in mean prediction score between BRCA carriers and non-carriers in all models for male patients. BRCAPRO slightly over-estimated the total numbers of BRCA1 and BRCA2 female carriers (13 vs. 11 and 20 vs.17), but underestimated the number of BRCA2 male carriers (2.8 vs. 4). While Myriad underestimated both the total numbers of BRCA1/2 male (3.1 vs. 4) and female (25.6 vs. 28) carriers. Boadicea did the closest estimation for both male (3.2 vs. 4) and female (1.5 vs. 11 for BRCA1 and 16.3 vs. 17 in BRCA2). BRCAPRO showed the greatest ROC area for BRCA1 (93%), BRCA2 (73%) and BRCA1/2 (79%) combination mutation prediction and highest sensitivity at conventional thresholds of 10% and 20% in female patients (71.4% vs.60.7%). Boadicea had the greatest ROC area for BRCA2 and BRCA1/2 combination mutation prediction and the same sensitivity at conventional thresholds of 10% and 20% in male patients (92% vs. 93%).

Conclusion: All 4 models could perform reasonably well in female patients, but not in male patients. Boadicea has the best performance in male and female Chinese cohort overall. Whereas when comparing females alone, BRCAPRO is most accurate.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P2-10-01.

Role of miR-143 Regulating DNA Methyltransferases 3A in Breast Cancer

Background and Aims: MicroRNAs (miRNAs) are 19-25-nucleotides regulatory non-protein-coding RNA molecules that regulate the expressions of a wide variety of genes including some involved in cancer development. In particular, decreased expression of miR-143 has been reported in various human cancers including colorectal cancer and B-cell lymphomas. The aim of this study was to elucidate the role of miR-143 dysregulation in breast cancer.Methods: Expression levels of human mature microRNAs (miRNAs) were compared with paired breast carcinomas and adjacent normal tissues by TaqMan real-time PCR based expression arrays. Decreased expression of miR-143 was further confirmed in breast cancer cell lines and paired breast tumors and normal adjacent tissues by qRT-PCR. Potential targets of miR-143 were defined. The functional effect of miR-143 and its targets was performed in human breast cancer cell lines to confirm target association.Results: Down-regulation of miR-143 was verified in both human breast cancer cell lines and 80% (12/15) of breast tumors (P &lt; 0.001). DNA methyltranferase 3A (DNMT3A), one of a key enzyme involved in DNA methylation, was defined as a potential target of miR-143 by in-silico analysis. Overexpression of miR-143 in breast cancer cell lines down-regulated expression of DNMT3A, decreased tumor cell growth by MTT assay and soft agar colony formation assay. DNMT3A was demonstrated to be a direct target of miR-143 by luciferase reporter assay. Inverse correlation between DNMT3A protein and miR-143 was found in tumor and normal breast tissues.Conclusions: In this study, we show for the first time in breast cancer that miR-143 specifically targeted DNMT3A and the expression of miR-143 was inversely correlated with DNMT3A expression. Our findings demonstrated that down-regulation of miR-143 and up-regulation of DNMT3A are significant changes in breast tumors. These findings indicate a tumor suppressive role of miR-143 in epigenetic aberration of breast cancer.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3148.