Population differences in breast cancer: survey in indigenous African women reveals over-representation of triple-negative breast cancer

Biologic, demographic, and social factors affecting triple negative breast cancer outcomes

BACKGROUND

Triple negative breast cancer (TNBC) is an aggressive breast cancer subtype that disproportionately affects women who are African American, younger, or carriers of the BRCA1 gene. No targeted treatments exist for the disease, which has distinct features and presents unique challenges to patients who have been diagnosed with it.

OBJECTIVES

TNBC is reviewed in this article according to incidence, tumor grade, stage of diagnosis, biologic and social risk factors, mortality, and treatment.

METHODS

Published articles pertaining to TNBC and located through online database searches were reviewed. Articles were selected either because they offered the most current information about TNBC or contributed to the understanding of TNBC.

FINDINGS

Biologic, demographic, and social factors present unique challenges in the treatment of women with TNBC. Knowing about the characteristics of TNBC and the populations who are most at risk for the disease might help healthcare providers better respond to their patients. It may also facilitate responsiveness to patients' needs and enhance their quality of life.

Greater absolute risk for all subtypes of breast cancer in the US than Malaysia

Hormone receptor (HR) negative breast cancers are relatively more common in low-risk than high-risk countries and/or populations. However, the absolute variations between these different populations are not well established given the limited number of cancer registries with incidence rate data by breast cancer subtype. We, therefore, used two unique population-based resources with molecular data to compare incidence rates for the 'intrinsic' breast cancer subtypes between a low-risk Asian population in Malaysia and high-risk non-Hispanic white population in the National Cancer Institute's surveillance, epidemiology, and end results 18 registries database (SEER 18). The intrinsic breast cancer subtypes were recapitulated with the joint expression of the HRs (estrogen receptor and progesterone receptor) and human epidermal growth factor receptor-2 (HER2). Invasive breast cancer incidence rates overall were fivefold greater in SEER 18 than in Malaysia. The majority of breast cancers were HR-positive in SEER 18 and HR-negative in Malaysia. Notwithstanding the greater relative distribution for HR-negative cancers in Malaysia, there was a greater absolute risk for all subtypes in SEER 18; incidence rates were nearly 7-fold higher for HR-positive and 2-fold higher for HR-negative cancers in SEER 18. Despite the well-established relative breast cancer differences between low-risk and high-risk countries and/or populations, there was a greater absolute risk for HR-positive and HR-negative subtypes in the US than Malaysia. Additional analytical studies are sorely needed to determine the factors responsible for the elevated risk of all subtypes of breast cancer in high-risk countries like the United States.

Differences in biological features of breast cancer between Caucasian (Italian) and African (Tanzanian) populations

Information on hormone receptor and human epidermal growth factor receptor-2 (HER2) expression in breast cancer is acknowledged as mandatory for prognostic stratification and treatment planning. Data on the biological features of African breast cancers are poor. We decided to compare histopathological and biomolecular characteristics (estrogen and progesterone receptor—ER, PgR, and HER2) of Tanzanian and Italian breast cancers. Differences in proliferating index and androgen receptor (AR) expression in triple-negative patients from the two case series were also assessed. Of the 103 consecutive patients seen at the Bugando Medical Center (Mwanza, Tanzania) from 2003 to 2010, who underwent biopsy or surgical resection of primary breast cancer, 69 patients had tissue samples that were evaluable for estrogen receptor (ER), progesterone receptor (PgR), and HER2. Histopathological assessment and biomolecular determinations were performed at the Cancer Institute of Romagna (IRST IRCCS, Meldola, Italy). Caucasian breast cancers were randomly extracted from an electronic database and matched (1:2 ratio) for year of diagnosis and age at diagnosis. Median age of both populations was 51 years (range 27–84). With respect to Caucasian tumors, Tanzanian breast cancers at diagnosis more frequently showed high histological grade (mainly grade 3) (P = 0.03), advanced clinical stage (III or IV) (P\0.001), ER negativity (52.2 %, P\0.001) and high proliferation (P = 0.0002). Triple-negative tumors were over-represented in Tanzanian women. AR was positive in 38.5 and 38 %of triple-negative Tanzanian and Italian breast cancers, respectively. Our results show that histopathological and biomolecular characteristics in Tanzanian and Italian breast cancers differ substantially. The high frequency of poorly differentiated, ER-negative, highly proliferating tumors, together with advanced stage at presentation, could be considered as the main prognostic factors linked to the high mortality rates for breast cancer in the African population.

US breast cancer mortality trends in young women according to race

BACKGROUND

Young age at diagnosis has a negative prognostic impact on outcome in patients with breast cancer (BC). In the current study, the authors sought to determine whether there is a differential effect of race and examined mortality trends according to race and age.

METHODS

The Surveillance, Epidemiology, and End Results program was used to identify women aged <50 years with invasive BC diagnosed between 1990 and 2009. Multivariate regression analyses were performed to determine the risk-adjusted likelihood of survival for white and black patients. Annual hazards of BC death according to race and calendar period and adjusted relative hazards of death for white and black women stratified by age were computed.

RESULTS

A total of 162,976 women were identified, 126,573 of whom were white, 20,405 of whom were black, and 15,998 of whom were of other races. At a median follow-up of 85 months, the 5-year disease specific survival rates were 90.1% for white patients and 79.3% for black patients. Annual hazards of death in white patients decreased by 26% at 5 years after diagnosis in contrast to the hazards in black patients, which decreased by only 19%. With 1990 as the referent year, the adjusted relative hazards of death in women aged <40 years in 2005 were 0.55 (95% confidence interval [95% CI], 0.46-0.66) and 0.68 (95% CI, 0.49-0.93), respectively, for white and black women. In women aged 40 to 49 years, adjusted hazards of death were 0.53 (95% CI, 0.47-0.60) and 0.78 (95% CI, 0.61-0.99), respectively, for white and black women.

CONCLUSIONS

Among young women diagnosed with BC, black patients have a worse outcome compared with white patients. Mortality declines have been observed over time in both groups, although more rapid gains have been reported to occur in white women. Emphasis should be placed on improving outcomes for young patients with BC.

Prevalence of papillomaviruses, polyomaviruses, and herpesviruses in triple-negative and inflammatory breast tumors from algeria compared with other types of breast cancer tumors

BACKGROUND

The possible role of viruses in breast cancer etiology remains an unresolved question. We hypothesized that if some viruses are involved, it may be in a subgroup of breast cancers only. Epidemiological arguments drove our interest in breast cancer subgroups that are more frequent in Africa, namely inflammatory breast cancer (IBC) and triple-negative breast cancer. We tested whether viral prevalence was significantly higher in these subgroups.

MATERIALS AND METHODS

One hundred fifty-five paraffin-embedded malignant breast tumors were randomly selected at the pathology laboratory of the University Hospital of Annaba (Algeria) to include one third of IBC and two thirds of non-IBC. They were tested for the presence of DNA from 61 viral agents (46 human papillomaviruses, 10 polyomaviruses, and 5 herpesviruses) using type-specific multiplex genotyping assays, which combine multiplex PCR and bead-based Luminex technology.

RESULTS

Viral DNA was found in 22 (17.9%) of 123 tumors. The most prevalent viruses were EBV1 and HPV16. IBC tumors carried significantly more viruses (any type) than non-IBC tumors (30% vs. 13%, p<0.04). Similarly, triple-negative tumors displayed higher virus-positivity than non-triple-negative tumors (44% vs. 14%, p<0.009).

CONCLUSIONS

Our results suggest an association between the presence of viral DNA and aggressive breast cancer phenotypes (IBC, triple-negative). While preliminary, they underline the importance of focusing on subgroups when studying viral etiology in breast cancer. Further studies on viruses in breast cancer should be conducted in much larger samples to confirm these initial findings.

The prevalence of estrogen receptor-negative breast cancer in Ethiopia

Background

In contrast with breast cancers (BCs) in other parts of the world, most previous studies reported that the majority of BCs in sub-Saharan Africa are estrogen-receptor (ER) negative. However, a recent study using the US SEER database showed that the proportion of ER-negative BC is comparable between US-born blacks and West-African born blacks but substantially lower in East African-born blacks, with over 74% of patients Ethiopians or Eritreans. In this paper, we provide the first report on the proportion of ER-negative BC in Ethiopia, and the relation to progesterone-receptor (PgR) status.

Methods

We analysed 352 female patients with ER results available out of 1208 consecutive female BC patients treated at Addis Ababa-University Hospital, Ethiopia, from June 2005 through December 2010. The influences of age, stage, and histology on the probability of ER-negative tumours were assessed by a log-linear regression model.

Results

Of the 352 patients, only 35% were ER-negative. The proportion of ER-negative tumours decreased with advancing age at diagnosis and was not affected by histology or stage. For age, the proportion decreased by 6% for each additional 5 years (stage-adjusted prevalence ratio PR = 0.94, 95% CI: 0.89–1.00). About 31% were ER- and PgR-negative, and 69% were ER- and/or PgR-positive.

Conclusions

Contrary to most previous reports in other parts of sub-Saharan Africa, the majority of patients in Ethiopia are ER-positive rather than ER-negative. These findings are in line with low proportions of ER-negative BCs from East African immigrants within the SEER database, and they have clinical implications for management of BC patients in Ethiopia and other parts of sub-Saharan Africa where ER-status is not ascertained as part of routine management of the disease. Since the majority of patients showed ER-positive BC, Tamoxifen-therapy should be given to all patients even with unknown ER status.

Epidemiology, biology, and treatment of triple-negative breast cancer in women of African ancestry

Breast cancer incidence is increasing worldwide, and breast cancer-related mortality is highest in women of African ancestry, who are more likely to have basal-like or triple-negative breast cancer (TNBC) than are women of European ancestry. Identification of cultural, epidemiological, and genetic risk factors that predispose women of African ancestry to TNBC is an active area of research. Despite the aggressive behaviour of TNBC, achievement of a pathological complete response with chemotherapy is associated with good long-term survival outcomes, and sensitivity to chemotherapy does not seem to differ according to ethnic origin. Discovery of the molecular signalling molecules that define TNBC heterogeneity has led to the development of targeted agents such as inhibitors of poly (ADP-ribose) polymerase-1 and mTOR and immunomodulatory drugs that are in the early stages of clinical testing. First, we summarise the existing published work on the differences reported on the epidemiology, biology, and response to systemic treatment of TNBC between women of African ancestry and white women, and identify some gaps in knowledge. Second, we review the opportunities for development of new therapeutic agents in view of the potential high clinical relevance for patients with TNBC irrespective of race or ethnic origin.

Racial comparison of receptor-defined breast cancer in Southern African women: subtype prevalence and age-incidence analysis of nationwide cancer registry data

BACKGROUND

Receptor-defined breast cancer proportions vary across Africa. They have important implications for survival prospects and research priorities.

METHODS

We studied estrogen receptor (ER), progesterone receptor (PR), and HER2 receptor statuses in two multiracial Southern African countries with routine diagnostic immunohistochemistry. A total of 12,361 women with histologically confirmed breast cancer diagnosed at age ≥20 years during (i) 2009-2011 from South Africa's national cancer registry (public sector) and (ii) 2011-2013 from Namibia's only cancer hospital were included. Crude, age, and age + laboratory-adjusted ORs of receptor status were analyzed using logistic regression, and age-incidence curves were analyzed using Poisson regression.

RESULTS

A total of 10,047 (81%) women had known ER status. Ranking of subtypes was consistent across races: ER(+)/PR(+)HER2(-) was most common (race-specific percentage range, 54.6%-64.8%), followed by triple-negative (17.4%-21.9%), ER(+)/PR(+)HER2(+) (9.6%-13.9%), and ER(-)PR(-)HER2(+) (7.8%-10.9%). Percentages in black versus white women were 33.8% [95% confidence (CI), 32.5-35.0] versus 26.0% (24.0-27.9) ER(-); 20.9% (19.7-22.1) versus 17.5% (15.4-19.6) triple-negative; and 10.7% (9.8-11.6) versus 7.8% (6.3-9.3) ER(-)PR(-)HER2(+). Indian/Asian and mixed-ancestry women had intermediate values. Age-incidence curves had similar shapes across races: rates increased by 12.7% per year (12.2-13.1) across ER subtypes under the age of 50 years, and thereafter slowed for ER(+) (1.95%) and plateaued for ER(-) disease (-0.1%).

CONCLUSIONS

ER(+) breast cancer dominates in all Southern African races, but black women have a modest excess of aggressive subtypes.

IMPACT

On the basis of the predominant receptor-defined breast tumors in Southern Africa, improving survival for the growing breast cancer burden should be achievable through earlier diagnosis and appropriate treatment.

A targetable androgen receptor-positive breast cancer subtype hidden among the triple-negative cancers

CONTEXT

Triple-negative breast cancer (TNBC) is a subgroup of breast cancers that by definition lack expression of estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 (HER2). A diverse group of tumors, TNBC shares some morphologic and molecular features with basal-like breast cancer, a category of breast cancer defined by gene expression profiling. More likely to occur in young women and African Americans, TNBCs may exhibit aggressive behavior and are associated with poor prognosis despite their initial response to conventional chemotherapy. Because hormonal or HER2-targeted therapies are ineffective for these tumors, the main therapeutic option is systemic chemotherapy. Therefore, identification of new targets for therapy is urgently needed for this group.

OBJECTIVE

To review and present recent literature along with our own experience regarding the clinical and morphologic characteristics and the prevalence of androgen receptor (AR) expression in TNBC, and to discuss the potential use of AR as a therapeutic target for AR(+) TNBC.

DATA SOURCES

Data sources are published articles from peer-reviewed journals in PubMed (US National Library of Medicine).

CONCLUSIONS

AR is the most commonly expressed hormone receptor among all breast carcinomas, with a prevalence of 25% to 75% among TNBCs. Therefore, we strongly support the routine assessment of AR in TNBC, and preferably in all breast carcinomas.

Breast cancer receptor status and stage at diagnosis in over 1,200 consecutive public hospital patients in Soweto, South Africa: a case series

Introduction

Estimates of the proportion of estrogen receptor negative (ERN) and triple-negative (TRN) breast cancer from sub-Saharan Africa are variable and include high values. Large studies of receptor status conducted on non-archival tissue are lacking from this region.

Methods

We identified 1218 consecutive women (91% black) diagnosed with invasive breast cancer from 2006–2012 at a public hospital in Soweto, South Africa. Immunohistochemistry based ER, progesterone receptor (PR) and human epidermal factor 2 (HER2) receptors were assessed at diagnosis on pre-treatment biopsy specimens. Mutually adjusted associations of receptor status with stage, age, and race were examined using risk ratios (RRs). ER status was compared with age-stratified US Surveillance Epidemiology and End Results program (SEER) data.

Results

35% (95% confidence interval (CI): 32–38) of tumors were ERN, 47% (45–52) PRN, 26% (23–29) HER2P and 21% (18–23) TRN. Later stage tumors were more likely to be ERN and PRN (RRs 1.9 (1.1-2.9) and 2.0 (1.3-3.1) for stage III vs. I) but were not strongly associated with HER2 status. Age was not strongly associated with ER or PR status, but older women were less likely to have HER2P tumors (RR, 0.95 (0.92-0.99) per 5 years). During the study, stage III + IV tumors decreased from 66% to 46%. In black women the percentage of ERN (37% (34–40)) and PRN tumors (48% (45–52)) was higher than in non-black patients (22% (14–31) and 34% (25–44), respectively, P = 0.004 and P = 0.02), which remained after age and stage adjustment. Age-specific ERN proportions in black South African women were similar to those of US black women, especially for women diagnosed over age 50.

Conclusion

Although a greater proportion of black than non-black South African women had ER-negative or TRN breast cancer, in all racial groups in this study breast cancer was predominantly ER-positive and was being diagnosed at earlier stages over time. These observations provide initial indications that late-stage aggressive breast cancers may not be an inherent feature of the breast cancer burden across Africa.

Receptor-defined subtypes of breast cancer in indigenous populations in Africa: a systematic review and meta-analysis

BACKGROUND

Breast cancer is the most common female cancer in Africa. Receptor-defined subtypes are a major determinant of treatment options and disease outcomes but there is considerable uncertainty regarding the frequency of poor prognosis estrogen receptor (ER) negative subtypes in Africa. We systematically reviewed publications reporting on the frequency of breast cancer receptor-defined subtypes in indigenous populations in Africa.

METHODS AND FINDINGS

Medline, Embase, and Global Health were searched for studies published between 1st January 1980 and 15th April 2014. Reported proportions of ER positive (ER+), progesterone receptor positive (PR+), and human epidermal growth factor receptor-2 positive (HER2+) disease were extracted and 95% CI calculated. Random effects meta-analyses were used to pool estimates. Fifty-four studies from North Africa (n=12,284 women with breast cancer) and 26 from sub-Saharan Africa (n=4,737) were eligible. There was marked between-study heterogeneity in the ER+ estimates in both regions (I2>90%), with the majority reporting proportions between 0.40 and 0.80 in North Africa and between 0.20 and 0.70 in sub-Saharan Africa. Similarly, large between-study heterogeneity was observed for PR+ and HER2+ estimates (I2>80%, in all instances). Meta-regression analyses showed that the proportion of ER+ disease was 10% (4%-17%) lower for studies based on archived tumor blocks rather than prospectively collected specimens, and 9% (2%-17%) lower for those with ≥ 40% versus those with <40% grade 3 tumors. For prospectively collected samples, the pooled proportions for ER+ and triple negative tumors were 0.59 (0.56-0.62) and 0.21 (0.17-0.25), respectively, regardless of region. Limitations of the study include the lack of standardized procedures across the various studies; the low methodological quality of many studies in terms of the representativeness of their case series and the quality of the procedures for collection, fixation, and receptor testing; and the possibility that women with breast cancer may have contributed to more than one study.

CONCLUSIONS

The published data from the more appropriate prospectively measured specimens are consistent with the majority of breast cancers in Africa being ER+. As no single subtype dominates in the continent availability of receptor testing should be a priority, especially for young women with early stage disease where appropriate receptor-specific treatment modalities offer the greatest potential for reducing years of life lost. Please see later in the article for the Editors' Summary.

Aromatase inhibitors for metastatic male breast cancer: molecular, endocrine, and clinical considerations

Male breast cancer is a rare condition. Aromatase inhibitors are widely used for treating metastatic male breast cancer patients. In this setting, their use is not substantiated by prospective clinical trials, but is rather driven by similarities supposedly existing with breast cancer in postmenopausal women. This oversimplified approach was questioned by studies addressing the molecular and endocrine roots of the disease. In this manuscript, we discuss relevant aspects of the current use of aromatase inhibitors in metastatic male breast cancer in light of the most updated evidence on the molecular landscape of the disease and the specific changes in the hormonal background occurring with aging. We further point to strategies for blocking multiple hormonal pathway nodes with the goal of improving their therapeutic potential. We searched PubMed from its inception until March 2014 for relevant literature on the use of aromatase inhibitors in metastatic male breast cancer. Selected terms were combined and used both as medical headings and text words. The reference list of the suitable manuscripts was inspected for further publications. Aromatase inhibitors represent the mainstay of treatment in the metastatic setting. Yet, efforts aimed at sharpening the therapeutic potential of aromatase inhibitors still pose a challenge due to the paucity of data. The choice of dual hormonal (or sequential) therapy combining aromatase inhibitors with a GnRH analogue may represent a valid alterative, particularly if informed by cancer- and patient-related features including molecular, endocrine, and clinic characteristics.

Preventing breast cancer in LMICs via screening and/or early detection: The real and the surreal

To review the present status of breast cancer (BC) screening/early detection in low- and middle-income countries (LMICs) and identify the way forward, an open focused search for articles was undertaken in PubMed, Google Scholar and Google, and using a snowball technique, further articles were obtained from the reference list of initial search results. In addition, a query was put up on ResearchGate to obtain more references and find out the general opinion of experts on the topic. Experts were also personally contacted for their opinion. Breast cancer (BC) is the most common cancer in women in the world. The rise in incidence is highest in LMICs where the incidence has often been much lower than high-income countries. In spite of more women dying of cancer than pregnancy or childbirth related causes in LMICs, most of the focus and resources are devoted to maternal health. Also, the majority of women in LMICs present at late stages to a hospital to initiate treatment. A number of trials have been conducted in various LMICs regarding the use of clinical breast examination and mammography in various combinations to understand the best ways of implementing a population level screening/early detection of BC; nevertheless, more research in this area is badly needed for different LMIC specific contexts. Notably, very few LMICs have national level programs for BC prevention via screening/early detection and even stage reduction is not on the public health agenda. This is in addition to other barriers such as lack of awareness among women regarding BC and the presence of stigma, inappropriate attitudes and lack of following proper screening behavior, such as conducting breast self-examinations. The above is mixed with the apathy and lack of awareness of policy makers regarding the fact that BC prevention is much more cost-effective and humane than BC treatment. Implementation of population level programs for screening/early detection of BC, along with use of ways to improve awareness of women regarding BC, can prove critical in stemming the increasing burden of BC in LMICs. Use of newer modalities such as ultrasonography which is more suited to LMIC populations and use of mHealth for awareness creation and increasing screening compliance are much needed extra additions to the overall agenda of LMICs in preventing BC.

Distinct breast cancer subtypes in women with early-onset disease across races

BACKGROUND

Racial disparities among breast cancer (BCa) patients are known but not well studied in early-onset BCa. We analyzed molecular subtypes in early-onset BCa across five major races.

METHODS

A total of 2120 cases were included from non-Hispanic White (NHW), African American (AA) and Hispanic, Chinese and Indian. Based on ER, PR and HER-2 status, BCa was classified into 4 intrinsic subtypes as Luminal A, Luminal B, HER2/neu overexpression and Triple negative BCa (TNBC) subtypes. Data was stratified according to race and age as younger/early-onset group (40-years and younger) and older group (50-years and older).

RESULTS

In early-onset BCa, incidence of TNBC was significantly higher (p = 0.0369) in Indian women followed by AA, Hispanic, NHW and Chinese women. Incidence of Her2 over-expression subtype also was highest in Indian women, followed by Hispanic, Chinese, AA and NHW women. In contrast, Luminal B subtype was most significantly higher in AA women (p = 0.0000) followed by NHW (p = 0.0002), Chinese (p = 0.0003), Hispanic (0.0128) and Indian (p = 0.0468) women. Luminal A subtype was most significantly reduced in Indian women (p = 0.0113) followed by Hispanic, AA, NHW and Chinese women. These results were based on statistical analysis with the mean of older group populations.

CONCLUSIONS

These results show significant disparities in receptor subtypes across races. This study will contribute in developing optimal clinical trial protocols and personalized management strategies for early-onset BCa patients.

A comparison of colorectal cancer in Nigerian and North American patients: is the cancer biology different?

BACKGROUND

Of the 24 million people predicted to have cancer by 2050, 70% will live in low- and middle-income countries (LMIC). As a result, cancer care is becoming a priority for health care systems in West Africa. This study compares the presentation and pattern of spread of colorectal cancer (CRC) observed in a hospital in West Africa with that of a North American referral center.

METHODS

Data on all adults presenting with CRC at a hospital in Nigerian patients (West Africa; 1990-2011) and all adults with stages III or IV CRC at a specialty hospital in (New York City, New York, North America; 2005-2011) were examined retrospectively. Demographic data, stage of disease, site of metastasis, and survival were compared.

RESULTS

There were 160 patients identified in West Africa and 1,947 patients identified in North America. Nigerian patients were younger (52 vs 59 years; P < .01) and presented with a later stage of disease (58% stage IV vs 47%; P < .01). Site of disease presentation was different between West African and North American patients (P < .01); 2.2% of West African patients presented with liver metastases only compared with 48.1% of North American patients. Conversely, 61.3% of patients in West Africa presented with peritoneal metastases only compared with 5.4% in North America. Overall survival stratified by stage at presentation (III/IV) showed worse prognosis for patients in either stage subgroup in Nigeria than North America.

CONCLUSION

We found differences in the presentation, metastatic pattern, and outcomes of CRC in Nigerian (West Africa) when compared with New York City (North America). Late detection and differential tumor biology may drive the differences observed between the sites. Future studies on early CRC detection and on tumor biology in LMIC will be critical for understanding and treating CRC in this region.

Building capacity for sustainable research programmes for cancer in Africa

Cancer research in Africa will have a pivotal role in cancer control planning in this continent. However, environments (such as those in academic or clinical settings) with limited research infrastructure (laboratories, biorespositories, databases) coupled with inadequate funding and other resources have hampered African scientists from carrying out rigorous research. In September 2012, over 100 scientists with expertise in cancer research in Africa met in London to discuss the challenges in performing high-quality research, and to formulate the next steps for building sustainable, comprehensive and multi-disciplinary programmes relevant to Africa. This was the first meeting among five major organizations: the African Organisation for Research and Training in Africa (AORTIC), the Africa Oxford Cancer Foundation (AfrOx), and the National Cancer Institutes (NCI) of Brazil, France and the USA. This article summarizes the discussions and recommendations of this meeting, including the next steps required to create sustainable and impactful research programmes that will enable evidenced-based cancer control approaches and planning at the local, regional and national levels.

Discovery of structure-based small molecular inhibitor of αB-crystallin against basal-like/triple-negative breast cancer development in vitro and in vivo

αB-crystallin (CRYAB) is present at a high frequency in poor prognosis basal-like breast tumours, which are largely absent of oestrogen, progesterone receptors and HER2 known as triple-negative breast cancer (TNBC). CRYAB functions as a molecular chaperone to bind to and correct intracellular misfolded/unfolded proteins such as vascular endothelial growth factor (VEGF), preventing non-specific protein aggregations under the influence of the tumour microenvironment stress and/or anti-cancer treatments including bevacizumab therapy. Directly targeting CRYAB can sensitize tumour cells to chemotherapeutic agents and decrease tumour aggressiveness. However, growing evidence shows that CRYAB is a critical adaptive response element after ischemic heart disease and stroke, implying that directly targeting CRYAB might cause serious unwanted side effects. Here, we used structure-based molecular docking of CRYAB and identified a potent small molecular inhibitor, NCI-41356, which can strongly block the interaction between CRYAB and VEGF165 without affecting CRYAB levels. The disruption of the interaction between CRYAB and VEGF165 elicits in vitro anti-tumour cell proliferation and invasive effects through the down-regulation of VEGF signalling in the breast cancer cells. The observed in vitro anti-tumour angiogenesis of endothelial cells might be attributed to the down-regulation of paracrine VEGF signalling in the breast cancer cells after treatment with NCI-41356. Intraperitoneal injection of NCI-41356 greatly inhibits the tumour growth and vasculature development in in vivo human breast cancer xenograft models. Our findings provide 'proof-of-concept' for the development of highly specific structure-based alternative targeted therapy for the prevention and/or treatment of TNBC.

Features of breast cancer in developing countries, examples from North-Africa

Epidemiological features of breast cancer appear to be different in developing countries compared to Western countries, with notably large proportions of young patients, male patients and aggressive forms of the disease. Using North-Africa (Morocco, Algeria, Tunisia, Libya and Egypt) as an example, we document the magnitude and explore possible explanations for such patterns. Articles and reports published since the seventies were reviewed. Results show that breast cancer incidence in females is 2-4 times lower in North-Africa than in Western countries while incidence in males is similar. Consequently, the relative proportion of male breast cancer is high (≈2% of all breast cancers). Similarly, the incidence of aggressive forms of the disease, like inflammatory or triple negative breast cancer (in females), is not higher in North Africa than in Western countries, but their relative proportion in case series (up to 10% for inflammatory and 15-25% for triple negative) is significantly higher because of low incidence of other forms of the disease. In North Africa, the incidence among women aged 15-49 is lower than in Western countries, but the very low incidence among women aged more than 50, combined to the young age pyramid of North-Africa, makes the relative proportions of young patients substantially higher (50-60% versus 20% in France). Such epidemiological features result mainly from peculiar risk factor profiles, which are typical for many developing countries and include notably rapid changes in reproductive behaviours. These features have important implications for breast cancer control and treatment.

Hormone receptors and Her2 expression in breast cancer in sub-Saharan Africa. A comparative study of biopsies from Ghana and Norway

Hormonal treatment of breast cancer is effective only in patients whose tumors express estrogen and/or progesterone receptors (ER, PR). Receptor assessment is often not available in low-resource areas, and the choice may be to apply endocrine therapy to all or none of breast cancer patients, depending on the proportion of patients that can be expected to respond. Fifty-one invasive breast cancers from Ghana and 100 from Norway diagnosed in the same laboratory during the same time period were reexamined in a blinded slide review. Of Ghanaian tumors, 76% were ER+ (≥1% ER+ tumor cells). Of Norwegian tumors, 85% were ER+. Triple-negative tumors were seen in 22% of Ghanaian patients and in 7% of Norwegian patients. A review of previous similar studies in sub-Saharan patients shows very discrepant results. Standardization and quality control of receptor assessment and well-designed clinical trials in sub-Saharan African breast cancer patients are needed to give a sound basis for endocrine treatment in this area.

Molecular breast cancer subtypes prevalence in an indigenous Sub Saharan African population

Introduction

Sub-Saharan Africa is predicted to face an unprecedented growth of cancers including breast cancer. There are indications of a significant burden of aggressive and late stage breast disease among premenopausal women in sub-Saharan Africa; because hormonal status tests are not routinely done, many women are given anti-hormonal therapy empirically. There is paucity of data on breast cancer molecular subtypes and their characteristics among women in sub Saharan Africa. The objective is to determine the prevalence of breast cancer molecular phenotypes among Ugandan women.

Methods

This was a cross sectional descriptive study, conducted at a tertiary hospital in Africa. Eligible participants’ formalin fixed and paraffin embedded sections were evaluated. H & E stains and Immunochemistry (Estrogen Receptor (ER), Progesterone Receptor (PR), Human Epidermal growth factor Receptor (HER2)) were performed. Ethical approval was obtained.

Results

A total of 226 patient samples were evaluated. The mean age was 45 years (SD 14);the prevalence of Triple Negative Breast Cancer (TNBC) was 34% (77/226), Luminal A 38% (83/226), HER2 positive was 22% (49/226), and Luminal B was 5% (13/226). High-grade (III) tumors were 68%, stage III and IV constituted 75% of presentations. Histological type was mostly invasive ductal carcinoma. Most patients (55%) were from rural areas.

Conclusion

Ugandan women had an over representation of TNBC and high-grade breast tumors. Underlying reasons ought to be investigated. The empirical use of tamoxifen (anti-hormonal therapy) should be reexamined.

Increasing Black:White disparities in breast cancer mortality in the 50 largest cities in the United States

INTRODUCTION

This paper presents race-specific breast cancer mortality rates and the corresponding rate ratios for the 50 largest U.S. cities for each of the 5-year intervals between 1990 and 2009.

METHODS

The 50 largest cities in the U.S. were the units of analysis. Numerator data were abstracted from national death files where the cause was malignant neoplasm of the breast (ICD-9=174 and ICD-10=C50) for women. Population-based denominators were obtained from the U.S. Census Bureau for 1990, 2000, and 2010. To measure the racial disparity, we calculated non-Hispanic Black:non-Hispanic White rate ratios (RRs) and confidence intervals for each 5-year period.

RESULTS

At the final time point (2005-2009), two RRs were less than 1, but neither significantly so, while 39 RRs were >1, 23 of them significantly so. Of the 41 cities included in the analysis, 35 saw an increase in the Black:White RR between 1990-1994 and 2005-2009. In many of the cities, the increase in the disparity occurred because White rates improved substantially over the 20-year study period, while Black rates did not. There were 1710 excess Black deaths annually due to this disparity in breast cancer mortality, for an average of about 5 each day.

CONCLUSION

This analysis revealed large and growing disparities in Black:White breast cancer mortality in the U.S. and many of its largest cities during the period 1990-2009. Much work remains to achieve equality in breast cancer mortality outcomes.

Breast cancer in Sub-Saharan Africa: opportunities for prevention

Although breast cancer is a growing health problem in sub-Saharan Africa, reasons for its increased occurrence remain unclear. We reviewed the published literature to determine the magnitude of the increase in breast cancer, associated risk factors (including for breast cancer subtypes), and ways to reduce incidence and mortality. Some of the increased breast cancer occurrence likely reflects that women are living longer and adopting lifestyles that favor higher incidence rates. However, a greater proportion of breast cancers occur among premenopausal women as compared to elsewhere, which may reflect unique risk factors. Breast cancers diagnosed among African women reportedly include a disproportionate number of poor prognosis tumors, including hormone receptor negative, triple negative, and core basal phenotype tumors. However, it is unclear how lack of standardized methods for tissue collection, fixation, and classification contribute to these rates. Given appropriate classifications, it will be of interest to compare rates with other populations and to identify risk factors that relate to specific tumor subtypes. This includes not only risk factors that have been recognized in other populations but also some that may play unique roles among African women, such as genetic factors, microbiomata, xenoestrogens, hair relaxers, and skin lighteners. With limited opportunities for effective treatment, a focus is needed on identifying etiologic factors that may be amenable to intervention. It will also be essential to understand reasons why women delay seeking care after the onset of symptoms and for there to be educational campaigns about the importance of early detection.

Up-regulation and worse prognostic marker of cytoplasmic TARBP2 expression in obstinate breast cancer

Expression of trans-activation-responsive-RNA-binding protein 2 (TARBP2) varied from normal cell lines to various cancer cell lines. The discussion of TARBP2 serve as tumor suppressor or tumor promotor goes on. However, its expression in breast cancer remains unknown. The aim of present study was to assess the expression of cytoplasm TARBP2 as potential prognostic marker in breast cancer. We further investigated cytoplasm TARBP2 could be a novel target in treatment for late-stage breast cancer and triple-negative breast cancer (TNBC). A total of patients with breast cancer were involved in our cohort. Immunohistochemical staining for TARBP2 on tissue microarray and western blot were used. Immunohistochemistry showed that cytoplasm TARBP2 was frequently up-regulated in breast carcinoma. This finding was in line with the result of western blot analysis. Further investigation showed that cytoplasm TARBP2 expression in non-TNBC was higher than that of their adjacent normal breast tissues (NBT), and TNBC was the highest of the three groups. The positive expression of cytoplasm TARBP2 in stage III breast cancer, stage I-II breast cancer, and NBT decreased gradually. In addition, univariate and multivariate survival analysis revealed cytoplasm TARBP2 was an independent prognostic factor for breast cancer. Breast cancer patients with cytoplasm TARBP2 expression had poorer disease-free survival and overall survival, and similar results were obtained in TNBC group and stage III breast cancer group. Our results provide convincing evidence for the first time that the expression of cytoplasm TARBP2 is up-regulated in breast cancer. Breast cancer patients with TARBP2 cytoplasm expression have unfavorable prognosis. Patients of TNBC and late-stage breast cancer with higher cytoplasm TARBP2 expression have an unfavorable prognosis.

Replication of breast cancer susceptibility loci in whites and African Americans using a Bayesian approach

Genome-wide association studies (GWAS) and candidate gene analyses have led to the discovery of several dozen genetic polymorphisms associated with breast cancer susceptibility, many of which are considered well-established risk factors for the disease. Despite attempts to replicate these same variant-disease associations in African Americans, the evaluable populations are often too small to produce precise or consistent results. We estimated the associations between 83 previously identified single nucleotide polymorphisms (SNPs) and breast cancer among Carolina Breast Cancer Study (1993-2001) participants using maximum likelihood, Bayesian, and hierarchical methods. The selected SNPs were previous GWAS hits (n = 22), near-hits (n = 19), otherwise well-established risk loci (n = 5), or located in the same genes as selected variants (n = 37). We successfully replicated 18 GWAS-identified SNPs in whites (n = 2,352) and 10 in African Americans (n = 1,447). SNPs in the fibroblast growth factor receptor 2 gene (FGFR2) and the TOC high mobility group box family member 3 gene (TOX3) were strongly associated with breast cancer in both races. SNPs in the mitochondrial ribosomal protein S30 gene (MRPS30), mitogen-activated protein kinase kinase kinase 1 gene (MAP3K1), zinc finger, MIZ-type containing 1 gene (ZMIZ1), and H19, imprinted maternally expressed transcript gene (H19) were associated with breast cancer in whites, and SNPs in the estrogen receptor 1 gene (ESR1) and H19 gene were associated with breast cancer in African Americans. We provide precise and well-informed race-stratified odds ratios for key breast cancer-related SNPs. Our results demonstrate the utility of Bayesian methods in genetic epidemiology and provide support for their application in small, etiologically driven investigations.

Breast cancer survival in Ethiopia: a cohort study of 1,070 women

There is little information on breast cancer (BC) survival in Ethiopia and other parts of sub-Saharan Africa. Our study estimated cumulative probabilities of distant metastasis-free survival (MFS) in patients at Addis Ababa (AA) University Radiotherapy Center, the only public oncologic institution in Ethiopia. We analyzed 1,070 females with BC stage 1-3 seen in 2005-2010. Patients underwent regular follow-up; estrogen receptor-positive and -unknown patients received free endocrine treatment (an independent project funded by AstraZeneca Ltd. and facilitated by the Axios Foundation). The primary endpoint was distant metastasis. Sensitivity analysis (worst-case scenario) assumed that patients with incomplete follow-up had events 3 months after the last appointment. The median age was 43.0 (20-88) years. The median tumor size was 4.96 cm [standard deviation (SD) 2.81 cm; n = 709 information available]. Stages 1, 2 and 3 represented 4, 25 and 71%, respectively (n = 644). Ductal carcinoma predominated (79.2%, n = 1,070) as well as grade 2 tumors (57%, n = 509). Median follow-up was 23.1 (0-65.6) months, during which 285 women developed metastases. MFS after 2 years was 74% (69-79%), declining to 59% (53-64%) in the worst-case scenario. Patients with early stage (1-2) showed better MFS than patients with stage 3 (85 and 66%, respectively). The 5-year MFS was 72% for stages 1 and 2 and 33% for stage 3. We present a first overview on MFS in a large cohort of female BC patients (1,070 patients) from sub-Saharan Africa. Young age and advanced stage were associated with poor outcome.

Variants of estrogen-related genes and breast cancer risk in European and African American women

It has been observed previously that compared with women of European ancestry (EA), those of African ancestry (AA) are more likely to develop estrogen receptor (ER)-negative breast cancer, although the mechanisms have not been elucidated. We tested the associations between breast cancer risk and a targeted set of 20 genes known to be involved in estrogen synthesis, metabolism, and response and potential gene-environment interactions using data and samples from 1307 EA (658 cases) and 1365 AA (621 cases) participants from the Women's Circle of Health Study (WCHS). Multivariable logistic regression found evidence of associations with single-nucleotide polymorphisms (SNPs) in the ESR1 gene in EA women (rs1801132, odds ratio (OR)=1.47, 95% CI=1.20-1.80, P=0.0002; rs2046210, OR=1.24, 95% CI=1.04-1.47, P=0.02; and rs3020314, OR=1.43, 95% CI=1.19-1.70, P=0.00009), but not in AA women. The only other gene associated with breast cancer risk was CYP1A2 in AA women (rs2470893, OR=1.42, 95% CI=1.00-2.02, P=0.05), but not in EA women. When stratified by ER status, ESR1 rs1801132, rs2046210, and rs3020314 showed stronger associations in ER-positive than in ER-negative breast cancer in only EA women. Associations with the ESR1 SNPs in EA women also appeared to be stronger with longer endogenous estrogen exposure or hormonal replacement therapy use. Our results indicate that there may be differential genetic influences on breast cancer risk in EA compared with AA women and that these differences may be modified by tumor subtype and estrogen exposures. Future studies with a larger sample size may determine the full contribution of estrogen-related genes to racial/ethnic differences in breast cancer.

Breast cancer statistics, 2013

In this article, the American Cancer Society provides an overview of female breast cancer statistics in the United States, including data on incidence, mortality, survival, and screening. Approximately 232,340 new cases of invasive breast cancer and 39,620 breast cancer deaths are expected to occur among US women in 2013. One in 8 women in the United States will develop breast cancer in her lifetime. Breast cancer incidence rates increased slightly among African American women; decreased among Hispanic women; and were stable among whites, Asian Americans/Pacific Islanders, and American Indians/Alaska Natives from 2006 to 2010. Historically, white women have had the highest breast cancer incidence rates among women aged 40 years and older; however, incidence rates are converging among white and African American women, particularly among women aged 50 years to 59 years. Incidence rates increased for estrogen receptor-positive breast cancers in the youngest white women, Hispanic women aged 60 years to 69 years, and all but the oldest African American women. In contrast, estrogen receptor-negative breast cancers declined among most age and racial/ethnic groups. These divergent trends may reflect etiologic heterogeneity and the differing effects of some factors, such as obesity and parity, on risk by tumor subtype. Since 1990, breast cancer death rates have dropped by 34% and this decrease was evident in all racial/ethnic groups except American Indians/Alaska Natives. Nevertheless, survival disparities persist by race/ethnicity, with African American women having the poorest breast cancer survival of any racial/ethnic group. Continued progress in the control of breast cancer will require sustained and increased efforts to provide high-quality screening, diagnosis, and treatment to all segments of the population.

A prognostic gene signature for metastasis-free survival of triple negative breast cancer patients

Although triple negative breast cancers (TNBC) are the most aggressive subtype of breast cancer, they currently lack targeted therapies. Because this classification still includes a heterogeneous collection of tumors, new tools to classify TNBCs are urgently required in order to improve our prognostic capability for high risk patients and predict response to therapy. We previously defined a gene expression signature, RKIP Pathway Metastasis Signature (RPMS), based upon a metastasis-suppressive signaling pathway initiated by Raf Kinase Inhibitory Protein (RKIP). We have now generated a new BACH1 Pathway Metastasis gene signature (BPMS) that utilizes targets of the metastasis regulator BACH1. Specifically, we substituted experimentally validated target genes to generate a new BACH1 metagene, developed an approach to optimize patient tumor stratification, and reduced the number of signature genes to 30. The BPMS significantly and selectively stratified metastasis-free survival in basal-like and, in particular, TNBC patients. In addition, the BPMS further stratified patients identified as having a good or poor prognosis by other signatures including the Mammaprint® and Oncotype® clinical tests. The BPMS is thus complementary to existing signatures and is a prognostic tool for high risk ER-HER2- patients. We also demonstrate the potential clinical applicability of the BPMS as a single sample predictor. Together, these results reveal the potential of this pathway-based BPMS gene signature to identify high risk TNBC patients that can respond effectively to targeted therapy, and highlight BPMS genes as novel drug targets for therapeutic development.

Characterizing the heterogeneity of triple-negative breast cancers using microdissected normal ductal epithelium and RNA-sequencing

Triple-negative breast cancers (TNBCs) are a heterogeneous set of tumors defined by an absence of actionable therapeutic targets (ER, PR, and HER-2). Microdissected normal ductal epithelium from healthy volunteers represents a novel comparator to reveal insights into TNBC heterogeneity and to inform drug development. Using RNA-sequencing data from our institution and The Cancer Genome Atlas (TCGA) we compared the transcriptomes of 94 TNBCs, 20 microdissected normal breast tissues from healthy volunteers from the Susan G. Komen for the Cure Tissue Bank, and 10 histologically normal tissues adjacent to tumor. Pathway analysis comparing TNBCs to optimized normal controls of microdissected normal epithelium versus classic controls composed of adjacent normal tissue revealed distinct molecular signatures. Differential gene expression of TNBC compared with normal comparators demonstrated important findings for TNBC-specific clinical trials testing targeted agents; lack of over-expression for negative studies and over-expression in studies with drug activity. Next, by comparing each individual TNBC to the set of microdissected normals, we demonstrate that TNBC heterogeneity is attributable to transcriptional chaos, is associated with non-silent DNA mutational load, and explains transcriptional heterogeneity in addition to known molecular subtypes. Finally, chaos analysis identified 146 core genes dysregulated in >90 % of TNBCs revealing an over-expressed central network. In conclusion, use of microdissected normal ductal epithelium from healthy volunteers enables an optimized approach for studying TNBC and uncovers biological heterogeneity mediated by transcriptional chaos.

Global nutrition research: nutrition and breast cancer prevention as a model

The gene-environment interaction is paramount in light of the worldwide rise in incidence of chronic diseases, with cancers in the pole position. Diet is an environmental factor with potential to influence cancer onset by shaping the epigenome (i.e., the genome organization that controls the differential expression of genes). Yet, there is no consensus regarding how diet might help prevent breast cancer, the second most frequent malignancy globally. The complexity of breast cancers requires working on a global and multidisciplinary scale to further understand the relationship between breast cancer type, diet, and the epigenome. This article describes the International Breast Cancer & Nutrition collaboration as one such approach. A global endeavor brings the diversity necessary to pinpoint important diet-gene relationships. Being developed are models, detection and assessment tools, and funding and public policy frameworks necessary to advance primary prevention research for the benefit of all populations affected by breast cancer. This paradigm can be adapted to understanding diet-gene relationships for other chronic diseases.

Breast cancer subtypes and previously established genetic risk factors: a bayesian approach

BACKGROUND

Gene expression analyses indicate that breast cancer is a heterogeneous disease with at least five immunohistologic subtypes. Despite growing evidence that these subtypes are etiologically and prognostically distinct, few studies have investigated whether they have divergent genetic risk factors. To help fill in this gap in our understanding, we examined associations between breast cancer subtypes and previously established susceptibility loci among white and African-American women in the Carolina Breast Cancer Study.

METHODS

We used Bayesian polytomous logistic regression to estimate ORs and 95% posterior intervals for the association between each of 78 single nucleotide polymorphisms (SNP) and five breast cancer subtypes. Subtypes were defined using five immunohistochemical markers: estrogen receptors (ER), progesterone receptors (PR), human epidermal growth factor receptors 1 and 2 (HER1/2), and cytokeratin (CK) 5/6.

RESULTS

Several SNPs in TNRC9/TOX3 were associated with luminal A (ER/PR+, HER2-) or basal-like breast cancer (ER-, PR-, HER2-, HER1, or CK 5/6+), and one SNP (rs3104746) was associated with both. SNPs in FGFR2 were associated with luminal A, luminal B (ER/PR+, HER2+), or HER2+/ER- disease, but none were associated with basal-like disease. We also observed subtype differences in the effects of SNPs in 2q35, 4p, TLR1, MAP3K1, ESR1, CDKN2A/B, ANKRD16, and ZM1Z1.

CONCLUSION AND IMPACT

We found evidence that genetic risk factors for breast cancer vary by subtype and further clarified the role of several key susceptibility genes. .

Immunohistochemistry-based subtyping of breast carcinoma in Egyptian women: a clinicopathologic study on 125 patients

Breast carcinoma is a heterogeneous disease affected by patients' ethnicity. Gene expression analysis identified several molecular subtypes, and similar subtyping has now been found to be feasible using immunohistochemistry. This study estimated the distribution of intrinsic breast cancer subtypes using estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2 (Her2/neu), and cytokeratin 5/6 immunostaining in a cohort of 125 Egyptian women diagnosed as having invasive breast carcinoma. Associations with clinicopathologic variables and the prognostic markers Bcl-2 and Cyclin D1 were investigated and statistically analyzed. Population difference in breast cancer subtypes was detected, suggesting etiologic and genetic heterogeneity among demographic groups. As reported worldwide, most tumors were luminal A (39.2%), but basal-like and unclassified subtypes had higher proportions among our cohort (16.8% and 16%, respectively), particularly in premenopausal patients (P = .0001), in contrast to postmenopausal African Americans, premenopausal European Americans, and other populations. Her2-overexpressing subtype was the least common subtype (13.65%) among our patients, although it is more common in Asians. Basal-like and unclassified carcinomas were more frequently grade 3 neoplasms (P = .035). Lobular histology was distributed among luminal A, B and unclassified subtypes (P = .006). The highest frequency of nodal positivity was associated with Her2 overexpressing carcinomas (94.1%, P = .0001). Luminal and unclassified carcinomas more likely expressed Bcl-2 (P = .011) and Cyclin D1 (P = .0001), whereas basal and Her2 subtypes had the lowest expression levels. Immunohistochemistry-based subtyping can be helpful in separating breast carcinoma into subtypes that vary in distribution among different populations. These subtypes have distinct clinicopathologic features and diverse prognostication, which may imply different therapeutic options for each subtype.

Spectrum of EGFR gene copy number changes and KRAS gene mutation status in Korean triple negative breast cancer patients

Anti-epidermal growth factor receptor (EGFR) therapy has been tried in triple negative breast cancer (TNBC) patients without evaluation of molecular and clinical predictors in several randomized clinical studies. Only fewer than 20% of metastatic TNBCs showed response to anti-EGFR therapy. In order to increase the overall response rate, first step would be to classify TNBC into good or poor responders according to oncogenic mutation profiles. This study provides the molecular characteristics of TNBCs including EGFR gene copy number changes and mutation status of EGFR and KRAS gene in Korean TNBC patients. Mutation analysis for EGFR, KRAS, BRAF and TP53 from a total of 105 TNBC tissue samples was performed by direct sequencing, peptide nucleic acid-mediated PCR clamping method and real-time PCR. Copy number changes of EGFR gene were evaluated using multiplex ligation-dependent probe amplification. Out of all 105 TNBCs, 15.2% (16/105) showed EGFR copy number changes. Among them, increased or decreased EGFR copy number was detected in 13 (5 single copy gain, 2 amplification and 4 high-copy number amplification) and 3 cases (3 hemizygous deletion), respectively. The mutation frequencies of KRAS, EGFR and TP53 gene were 1.9% (G12V and G12D), 1.0% (exon 19 del) and 31.4%, respectively. There was no BRAF V600E mutation found. Future studies are needed to evaluate the clinical outcomes of TNBC patients who undergo anti-EGFR therapy according to the genetic status of EGFR.

Differential activation of Wnt-β-catenin pathway in triple negative breast cancer increases MMP7 in a PTEN dependent manner

Mutations of genes in tumor cells of Triple Negative subset of Breast Cancer (TNBC) deregulate pathways of signal transduction. The loss of tumor suppressor gene PTEN is the most common first event associated with basal-like subtype (Martins, De, Almendro, Gonen, and Park, 2012). Here we report for the first time that the functional upregulation of secreted-MMP7, a transcriptional target of Wnt-β-catenin signature pathway in TNBC is associated to the loss of PTEN. We identified differential expression of mRNAs in several key-components genes, and transcriptional target genes of the Wnt-β-catenin pathway (WP), including beta-catenin, FZD7, DVL1, MMP7, c-MYC, BIRC5, CD44, PPARD, c-MET, and NOTCH1 in FFPE tumors samples from TNBC patients of two independent cohorts. A similar differential upregulation of mRNA/protein for beta-catenin, the functional readout of WP, and for MMP7, a transcriptional target gene of beta-catenin was observed in TNBC cell line models. Genetic or pharmacological attenuation of beta-catenin by SiRNA or WP modulators (XAV939 and sulindac sulfide) and pharmacological mimicking of PTEN following LY294002 treatment downregulated MMP7 levels as well as enzymatic function of the secreted MMP7 in MMP7 positive PTEN-null TNBC cells. Patient data revealed that MMP7 mRNA was high in only a subpopulation of TNBC, and this subpopulation was characterized by a concurrent low expression of PTEN mRNA. In cell lines, a high expression of casein-zymograph-positive MMP7 was distinguished by an absence of functional PTEN. A similar inverse relationship between MMP7 and PTEN mRNA levels was observed in the PAM50 data set (a correlation coefficient of -0.54). The PAM50 subtype and outcome data revealed that the high MMP7 group had low pCR (25%) and High Rd (74%) in clinical stage T3 pathologic response in contrast to the high pCR (40%) and low residual disease (RD) (60%) of the low MMP7 group.

Cytokine and cytokine receptor genes of the adaptive immune response are differentially associated with breast cancer risk in American women of African and European ancestry

Disparities in breast cancer biology are evident between American women of African ancestry (AA) and European ancestry (EA) and may be due, in part, to differences in immune function. To assess the potential role of constitutional host immunity on breast carcinogenesis, we tested associations between breast cancer risk and 47 single nucleotide polymorphisms (SNPs) in 26 cytokine-related genes of the adaptive immune system using 650 EA (n = 335 cases) and 864 AA (n = 458 cases) women from the Women's Circle of Health Study (WCHS). With additional participant accrual to the WCHS, promising SNPs from the initial analysis were evaluated in a larger sample size (1,307 EAs and 1,365 AAs). Multivariate logistic regression found SNPs in genes important for T helper type 1 (Th1) immunity (IFNGR2 rs1059293, IL15RA rs2296135, LTA rs1041981), Th2 immunity (IL4R rs1801275), and T regulatory cell-mediated immunosuppression (TGFB1 rs1800469) associated with breast cancer risk, mainly among AAs. The combined effect of these five SNPs was highly significant among AAs (P-trend = 0.0005). When stratified by estrogen receptor (ER) status, LTA rs1041981 was associated with ER-positive breast cancers among EAs and marginally among AAs. Only among AA women, IL15 rs10833 and IL15RA rs2296135 were associated with ER-positive tumors, and IL12RB1 rs375947, IL15 rs10833 and TGFB1 rs1800469 were associated with ER-negative tumors. Our study systematically identified genetic variants in the adaptive immune response pathway associated with breast cancer risk, which appears to differ by ancestry groups, menopausal status and ER status.

Disparities in race/ethnicity and socioeconomic status: risk of mortality of breast cancer patients in the California Cancer Registry, 2000-2010

BACKGROUND

Racial disparities in breast cancer survival have been well documented. This study examines the association of race/ethnicity and socioeconomic status (SES) on breast cancer-specific mortality in a large population of women with invasive breast cancer.

METHODS

We identified 179,143 cases of stages 1-3 first primary female invasive breast cancer from the California Cancer Registry from January, 2000 through December, 2010. Cox regression, adjusted for age, year of diagnosis, grade, and ER/PR/HER2 subtype, was used to assess the association of race/ethnicity on breast cancer-specific mortality within strata of stage and SES. Hazard ratios (HR) and 95% confidence intervals were reported.

RESULTS

Stage 1: There was no increased risk of mortality for any race/ethnicity when compared with whites within all SES strata. Stage 2: Hispanics (HR = 0.85; 0.75, 0.97) in the lowest SES category had a reduced risk of mortality.. Blacks had the same risk of mortality as whites in the lowest SES category but an increased risk of mortality in the intermediate (HR = 1.66; 1.34, 2.06) and highest (HR = 1.41; 1.15, 1.73) SES categories. Stage 3: Hispanics (HR = 0.74; 0.64, 0.85) and APIs (HR = 0.64; 0.50, 0.82) in the lowest SES category had a reduced risk while blacks had similar mortality as whites. Blacks had an increased risk of mortality in the intermediate (HR = 1.52; 1.20, 1.92) and highest (HR = 1.53; 1.22, 1.92) SES categories.

CONCLUSIONS

When analysis of breast cancer-specific mortality is adjusted for age and year of diagnosis, ER/PR/HER2 subtype, and tumor grade and cases compared within stage and SES strata, much of the black/white disparity disappears. SES plays a prominent role in breast cancer-specific mortality but it does not fully explain the racial/ethnic disparities and continued research in genetic, societal, and lifestyle factors is warranted.

Use of Web-based training for quality improvement between a field immunohistochemistry laboratory in Nigeria and its United States-based partner institution

The importance of hormone receptor status in assigning treatment and the potential use of human epidermal growth factor receptor 2 (HER2)-targeted therapy have made it beneficial for laboratories to improve detection techniques. Because interlaboratory variability in immunohistochemistry (IHC) tests may also affect studies of breast cancer subtypes in different countries, we undertook a Web-based quality improvement training and a comparative study of accuracy of immunohistochemical tests of breast cancer biomarkers between a well-established laboratory in the United States (University of Chicago) and a field laboratory in Ibadan, Nigeria. Two hundred and thirty-two breast tumor blocks were evaluated for estrogen receptors (ERs), progesterone receptors (PRs), and HER2 status at both laboratories using tissue microarray technique. Initially, concordance analysis revealed κ scores of 0.42 (moderate agreement) for ER, 0.41 (moderate agreement) for PR, and 0.39 (fair agreement) for HER2 between the 2 laboratories. Antigen retrieval techniques and scoring methods were identified as important reasons for discrepancy. Web-based conferences using Web conferencing tools such as Skype and WebEx were then held periodically to discuss IHC staining protocols and standard scoring systems and to resolve discrepant cases. After quality assurance and training, the agreement improved to 0.64 (substantial agreement) for ER, 0.60 (moderate agreement) for PR, and 0.75 (substantial agreement) for HER2. We found Web-based conferences and digital microscopy useful and cost-effective tools for quality assurance of IHC, consultation, and collaboration between distant laboratories. Quality improvement exercises in testing of tumor biomarkers will reduce misclassification in epidemiologic studies of breast cancer subtypes and provide much needed capacity building in resource-poor countries.

Racial disparities in treatment patterns and clinical outcomes in patients with HER2-positive metastatic breast cancer

Data characterizing demographics, treatment patterns, and clinical outcomes in black patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (MBC) are limited. registHER is a large, observational cohort study of patients (n = 1,001) with HER2-positive MBC diagnosed ≤6 months of enrollment and followed until death, disenrollment, or June 2009 (median follow-up of 27 months). Demographics, treatment patterns, and clinical outcomes were described for black (n = 126) and white patients (n = 793). Progression-free survival (PFS) following first-line therapy and overall survival (OS) were examined. Multivariate analyses adjusted for baseline and treatment factors. Black patients were more likely than white patients to be obese (body mass index ≥30), to have diabetes, and to have a history of cardiovascular disease; they were also less likely to have estrogen receptor or progesterone receptor positive disease. In patients treated with trastuzumab, the incidence of cardiac safety events (grade ≥3) was higher in black patients (10.9 %) than in white patients (7.9 %). Unadjusted median OS and PFS (months) were significantly lower in black patients than in white patients (OS: black: 27.1, 95 % confidence interval [CI] 21.3–32.1; white: 37.3, 95 % CI 34.6–41.1; PFS: black: 7.0, 95 % CI 5.7–8.2; white: 10.2, 95 % CI 9.3–11.2). The adjusted OS hazard ratio (HR) for black patients compared with white patients was 1.29 (95 % CI 1.00–1.65); adjusted PFS HR was 1.29 (95 % CI 1.05–1.59). This real-world evaluation of a large cohort of patients with HER2-positive MBC shows poorer prognostic factors and independently worse clinical outcomes in black versus white patients. Further research is needed to identify potential biologic differences that could have predictive impact for black patients or that could explain these differences.

Integrating genetic and genomic information into effective cancer care in diverse populations

This paper provides an overview of issues in the integration of genetic (related to hereditary DNA) and genomic (related to genes and their functions) information in cancer care for individuals and families who are part of health care systems worldwide, from low to high resourced. National and regional cancer plans have the potential to integrate genetic and genomic information with a goal of identifying and helping individuals and families with and at risk of cancer. Healthcare professionals and the public have the opportunity to increase their genetic literacy and communication about cancer family history to enhance cancer control, prevention, and tailored therapies.

Innate immunity pathways and breast cancer Risk in African American and European-American women in the Women's Circle of Health Study (WCHS)

African American (AA) women are more likely than European American (EA) women to be diagnosed with early, aggressive breast cancer. Possible differences in innate immune pathways (e.g., inflammatory responses) have received little attention as potential mechanisms underlying this disparity. We evaluated distributions of selected genetic variants in innate immune pathways in AA and EA women, and examined their associations with breast cancer risk within the Women's Circle of Health Study (WCHS). In stage I of the study (864 AA and 650 EA women) we found that genotype frequencies for 35 of 42 tested SNPs (18 candidate genes) differed between AAs and EAs (corroborated by ancestry informative markers). Among premenopausal AA women, comparing variant allele carriers to non-carriers, reduced breast cancer risk was associated with CXCL5-rs425535 (OR=0.61, P=0.02), while among EA women, there were associations with TNFA-rs1799724 (OR =2.31, P =0.002) and CRP-rs1205 (OR=0.54, P=0.01). For postmenopausal women, IL1B-rs1143627 (OR=1.80, P=0.02) and IL1B-rs16944 (OR=1.85, P =0.02) were associated with risk among EA women, with significant associations for TNFA-rs1799724 limited to estrogen receptor (ER) positive cancers (OR=2.0, P =0.001). However, none of the SNPs retained significance after Bonferroni adjustment for multiple testing at the level of P0.0012 (0.05/42) except for TNFA-rs1799724 in ER positive cancers. In a stage II validation (1,365 AA and 1,307 EA women), we extended evaluations for four SNPs (CCL2-rs4586, CRP-rs1205, CXCL5-rs425535, and IL1RN-rs4251961), which yielded similar results. In summary, distributions of variants in genes involved in innate immune pathways were found to differ between AA and EA populations, and showed differential associations with breast cancer according to menopausal or ER status. These results suggest that immune adaptations suited to ancestral environments may differentially influence breast cancer risk among EA and AA women.

Disparities in breast cancer treatment and outcomes: biological, social, and health system determinants and opportunities for research

Racial disparities in breast cancer mortality have been widely documented for several decades and persist despite advances in receipt of mammography across racial groups. This persistence leads to questions about the roles of biological, social, and health system determinants of poor outcomes. Cancer outcomes are a function not only of innate biological factors but also of modifiable characteristics of individual behavior and decision making as well as characteristics of patient-health system interaction and the health system itself. Attempts to explain persistent racial disparities have mostly been limited to discussion of differences in insurance coverage, socioeconomic status, tumor stage at diagnosis, comorbidity, and molecular subtype of the tumor. This article summarizes existing literature exploring reasons for racial disparities in breast cancer mortality, with an emphasis on treatment disparities and opportunities for future research. Because breast cancer care requires a high degree of multidisciplinary team collaboration, ensuring that guideline recommended treatment (such as endocrine therapy for hormone receptor positive patients) is received by all racial/ethnic groups is critical and requires coordination across multiple providers and health care settings. Recognition that variation in cancer care quality may be correlated with race (and socioeconomic and health system factors) may assist policy makers in identifying strategies to more equally distribute clinical expertise and health infrastructure across multiple user populations.

Overweight, obesity and risk of premenopausal breast cancer according to ethnicity: a systematic review and dose-response meta-analysis

The association of overweight and obesity with premenopausal breast cancer remained unclear, ethnicity could play a role. A MEDLINE and PUBMED search of all studies on obesity and premenopausal breast cancer published from 2000 to 2010 was conducted. Dose-response meta-analysis was used to determine the risk of premenopausal breast cancer associated with different anthropometric measurements in different ethnic groups. For body mass index (BMI), each 5 kg m(-2) increase was inversely associated with the risk of premenopausal breast cancer (RR = 0.95, 95% confidence interval [CI]: 0.94, 0.97). After stratification by ethnicity, the inverse association remained significant only among Africans (RR = 0.95, 95% CI: 0.91, 0.98) and Caucasians (RR = 0.93, 95% CI: 0.91, 0.95). In contrast, among Asian women, a significant positive association was observed. For waist-to-hip ratio (WHR), each 0.1 unit increase was positively associated with premenopausal breast cancer (RR = 1.08, 95% CI: 1.01, 1.16); the largest effect was detected in Asian women (RR = 1.19, 95% CI: 1.15, 1.24), while small effects of 5% and 6% were observed in African and Caucasian women, respectively. Our results suggest the importance of considering both fat distribution and ethnicity when studying premenopausal breast cancer.

Silencing CDK4 radiosensitizes breast cancer cells by promoting apoptosis

Background

The discovery of molecular markers associated with various breast cancer subtypes has greatly improved the treatment and outcome of breast cancer patients. Unfortunately, breast cancer cells acquire resistance to various therapies. Mounting evidence suggests that resistance is rooted in the deregulation of the G1 phase regulatory machinery.

Methods

To address whether deregulation of the G1 phase regulatory machinery contributes to radiotherapy resistance, the MCF10A immortalized human mammary epithelial cell line, ER-PR-Her2+ and ER-PR-Her2- breast cancer cell lines were irradiated. Colony formation assays measured radioresistance, while immunocytochemistry, Western blots, and flow cytometry measured the cell cycle, DNA replication, mitosis, apoptosis, and DNA breaks.

Results

Molecular markers common to all cell lines were overexpressed, including cyclin A1 and cyclin D1, which impinge on CDK2 and CDK4 activities, respectively. We addressed their potential role in radioresistance by generating cell lines stably expressing small hairpin RNAs (shRNA) against CDK2 and CDK4. None of the cell lines knocked down for CDK2 displayed radiosensitization. In contrast, all cell lines knocked down for CDK4 were significantly radiosensitized, and a CDK4/CDK6 inhibitor sensitized MDA-MB-468 to radiation induced apoptosis. Our data showed that silencing CDK4 significantly increases radiation induced cell apoptosis in cell lines without significantly altering cell cycle progression, or DNA repair after irradiation. Our results indicate lower levels of phospho-Bad at ser136 upon CDK4 silencing and ionizing radiation, which has been shown to signal apoptosis.

Conclusion

Based on our data we conclude that knockdown of CDK4 activity sensitizes breast cancer cells to radiation by activating apoptosis pathways.

Risk factors for pregnancy-associated breast cancer: a report from the Nigerian Breast Cancer Study

PURPOSE

Little is known about risk factors for pregnancy-associated breast cancer (PABC), diagnosed during pregnancy or postpartum.

METHODS

We enrolled 1715 premenopausal women from the Nigerian Breast Cancer Study from 1998 to 2011. Based on recency of last pregnancy from diagnosis, breast cancer cases were categorized as (1) PABC diagnosed 2 years or longer postpartum, (2) PABC diagnosed 3 to 5 years postpartum, or (3) non-PABC diagnosed more than 5 years postpartum. Controls were matched to cases on recency of last pregnancy. Multiple logistic regressions were performed comparing cases and controls within each group.

RESULTS

Of the 718 cases, 152 (21.2%) had PABC 2 or more years postpartum, and 145 (20.2%) 3 to 5 years postpartum. Although not statistically significant, women with higher parity tend to have an elevated risk of PABC but reduced risk of non-PABC (p for heterogeneity = 0.097). Family history of breast cancer might be a strong predictor particularly for PABC 2 or more years postpartum (odds ratio, 3.28; 95% confidence interval, 1.05-10.3). Compared with non-PABC cases, PABC 2 or more years postpartum cases were more likely to carry BRCA1/2 mutations (P = .03).

CONCLUSIONS

Parity may have different roles in the development of PABC versus other premenopausal breast cancer in Nigerian women. Prospective mothers with multiple births and a family history of breast cancer may have an elevated risk of breast cancer during their immediate postpartum period.

Treatment of cancer in sub-Saharan Africa

Cancer is rapidly becoming a public health crisis in low-income and middle-income countries. In sub-Saharan Africa, patients often present with advanced disease. Little health-care infrastructure exists, and few personnel are available for the care of patients. Surgeons are often central to cancer care in the region, since they can be the only physician a patient sees for diagnosis, treatment (including chemotherapy), and palliative care. Poor access to surgical care is a major impediment to cancer care in sub-Saharan Africa. Additional obstacles include the cost of oncological care, poor infrastructure, and the scarcity of medical oncologists, pathologists, radiation oncologists, and other health-care workers who are needed for cancer care. We describe treatment options for patients with cancer in sub-Saharan Africa, with a focus on the role of surgery in relation to medical and radiation oncology, and argue that surgery must be included in public health efforts to improve cancer care in the region.

Biomarkers for the clinical management of breast cancer: international perspective

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

Difference in Risk Factors for Breast Cancer by ER Status in an Indigenous African Population

Introduction. Breast cancer is the commonest cancer among women globally. In Uganda, it is on the rise, projected at a 4.5% annual ASR increase (age standardized incidence rate). The reasons for this steep increase are not fully established. In the recent past, gene profiling in tumor tissues suggests that breast cancers are divided into subtypes dependent on the presence or absence of oestrogen receptor, progesterone, and human epidermal growth factor receptor 2 (HER 2). These subtypes do have distinctive clinical outcomes and perhaps risk factors from past studies. There is paucity of data on hormonal receptor status and the traditionally known risk factors in sub-Saharan Africa. The purpose of this study therefore was to establish the differences between ER status and the traditionally known risk factors for breast cancer in Uganda. Methods. An observational analytical hospital, based study, carried out at Makerere University, College of Health Sciences. Formalin fixed and paraffin imbedded sections were prepared for haemotoxylin and eosin (H&E) stains and immunohistochemistry (IHC). Ethical approval was obtained. Results. A total of 113 women were recruited. Mean age was 45 years (SD14). There were no significant differences in selected risk factors (setting, age, contraceptive use, parity, breast feeding, or menarche) by ER status although ER negative tumors had significantly higher grade tumors (by a factor of two) compared to ER positive tumors. Conclusion. There were no significant differences among risk factors by ER status contrary to what several other studies suggest. The manifestation of breast cancer in Africa warrants further extensive inquiry.