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

MicroRNA-30c inhibits human breast tumour chemotherapy resistance by regulating TWF1 and IL-11

Chemotherapy resistance frequently drives tumour progression. However, the underlying molecular mechanisms are poorly characterized. Epithelial-to-mesenchymal transition has been shown to correlate with therapy resistance, but the functional link and signalling pathways remain to be elucidated. Here we report that microRNA-30c, a human breast tumour prognostic marker, has a pivotal role in chemoresistance by a direct targeting of the actin-binding protein twinfilin 1, which promotes epithelial-to-mesenchymal transition. An interleukin-6 family member, interleukin-11 is identified as a secondary target of twinfilin 1 in the microRNA-30c signalling pathway. Expression of microRNA-30c inversely correlates with interleukin-11 expression in primary breast tumours and low interleukin-11 correlates with relapse-free survival in breast cancer patients. Our study demonstrates that microRNA-30c is transcriptionally regulated by GATA3 in breast tumours. Identification of a novel microRNA-mediated pathway that regulates chemoresistance in breast cancer will facilitate the development of novel therapeutic strategies.

Gene copy number variations in breast cancer of Sub-Saharan African women

The goal of this study was CGH array profiling of breast cancer from Malian women in order to define differences with those from USA. CGH array was performed in 28 samples, 17 with a triple negative phenotype. The profiles were compared to those of 106 tumors from USA. 6 chromosomal regions (6p21, 9q34, 11q13, 12q24, 17q25 and 22q12.1-22q13.1) were identified with a significant higher rate of copy number alterations. These regions contain several genes of interest including BCR. FISH and IHC confirmed that BCR was amplified and overexpressed particularly in triple negative tumors. Finally, 5 regions presented a high level of amplification in two or more samples, including 2 regions located between 9p22.3-9p23 and 9p23-9p24.1. This study confirms that breast cancers from African women present biological differences with those from USA. Larger studies are needed to go further in the identification of therapeutic targets that would be specific to African women.

p16 expression correlates with basal-like triple-negative breast carcinoma

Background:

Basal-like breast carcinoma (BLBC) has attracted considerable attention over the past few years. It has been suggested that tumours expressing basal markers have a more aggressive clinical behaviour. However, a molecular basis for this disease remains unclear, and it lacks currently used therapeutic targets. Therefore developing a novel treatment strategy is crucial for improving the prognosis. The aim of this study was to characterise the immunohistochemical (IHC) expression of p16 in patients with BLBC compared with non-BLBC.

Materials and methods:

Eighty-five cases of grade-3 invasive ductal carcinomas not otherwise specified (IDC-NOS) were analyzed. Immunohistochemical stains for oestrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor type 2 (HER2), cytokeratin (CK) 5/6, epidermal growth factor receptor (EGFR) and p16 were performed. BLBC was defined as ER-, PR-, Her2- and CK5/6+, and/or EGFR+.

Results:

Twenty cases were categorised as BLBC versus 65 as non-basal. High mitotic count and presence of necrosis were associated with basal-like phenotype. Distant metastasis developed in 40% of cases of BLBC with frequent spread to brain and lung. p16 had significantly higher expression in the basal subgroup (80% versus 50.8%, P = 0.04). Patients with BLBCs were found to have a lower disease-free survival (DFS) rate (60% versus 70.8%, P = 0.03).

Conclusion:

BLBC typically demonstrates a unique profile. p16 is frequently expressed in breast cancers with basal-like phenotype; this suggests that p16 may play a role in the poor prognosis of this tumour, and it may be used in the development of a targeted therapy that will result in improved patient prognostication and outcome.

Expression and sub-cellular localization of an epigenetic regulator, co-activator arginine methyltransferase 1 (CARM1), is associated with specific breast cancer subtypes and ethnicity

BACKGROUND

Co-Activator Arginine Methyltransferase 1(CARM1) is an Estrogen Receptor (ER) cofactor that remodels chromatin for gene regulation via methylation of Histone3. We investigated CARM1 levels and localization across breast cancer tumors in a cohort of patients of either European or African ancestry.

METHODS

We analyzed CARM1 levels using tissue microarrays with over 800 histological samples from 549 female cancer patients from the US and Nigeria, Africa. We assessed associations between CARM1 expression localized to the nucleus and cytoplasm for 11 distinct variables, including; ER status, Progesterone Receptor status, molecular subtypes, ethnicity, HER2+ status, other clinical variables and survival.

RESULTS

We found that levels of cytoplasmic CARM1 are distinct among tumor sub-types and increased levels are associated with ER-negative (ER-) status. Higher nuclear CARM1 levels are associated with HER2 receptor status. EGFR expression also correlates with localization of CARM1 into the cytoplasm. This suggests there are distinct functions of CARM1 among molecular tumor types. Our data reveals a basal-like subtype association with CARM1, possibly due to expression of Epidermal Growth Factor Receptor (EGFR). Lastly, increased cytoplasmic CARM1, relative to nuclear levels, appear to be associated with self-identified African ethnicity and this result is being further investigated using quantified genetic ancestry measures.

CONCLUSIONS

Although it is known to be an ER cofactor in breast cancer, CARM1 expression levels are independent of ER. CARM1 has distinct functions among molecular subtypes, as is indicative of its sub-cellular localization and it may function in subtype etiology. These sub-cellular localization patterns, indicate a novel role beyond its ER cofactor function in breast cancer. Differential localization among ethnic groups may be due to ancestry-specific polymorphisms which alter the gene product.

Cell Proliferation (KI-67) Expression Is Associated with Poorer Prognosis in Nigerian Compared to British Breast Cancer Women

Background. Black women with breast cancer (BC) in Nigeria have higher mortality rate compared with British women. This study investigated prognostic features of cell proliferation biomarker (Ki-67) in Nigerian breast cancer women. Materials and Methods. The protein expression of Ki-67 was investigated in series of 308 Nigerian women, prepared as a tissue microarray (TMA), using immunohistochemistry. Clinic-pathological parameters, biomarkers, and patient outcome of tumours expressing Ki-67 in Nigerian women were correlated with UK grade-matched series. Results. A significantly larger proportion of breast tumours from Nigerian women showed high Ki-67 expression. Those tumours were significantly correlated with negative expression of the steroid hormone receptors (ER and PgR), p21, p27, E-cadherin, BRCA-1, and Bcl-2 (all P < 0.001), but positively associated with EGFR (P = 0.003), p53, basal cytokeratins: CK56, CK14, triple negative, and basal phenotype using Nielsen's classification (all P < 0.001) compared to UK women. Multivariate analyses showed that race was also associated with BCSS independent of tumour size, lymph node status, and ER status. Conclusion. Ki-67 expression was observed to have contributed to the difference in the BCSS in Nigerian compared with British BC women. Therefore, targeting Ki-67 in the indigenous black women with BC might improve the patient outcome in the black women with BC.

Triple-negative breast cancer: epidemiological considerations and recommendations

Breast cancer is a major problem for global public health. Breast Cancer is the most common incident form of cancer in women around the world. The incidence is increasing while mortality is declining in many high-income countries. The last decade has seen a revolution in the understanding of breast cancer, with new classifications proposed that have significant prognostic value and provide guides to treatment options. Breast cancers that demonstrate the absence of oestrogen receptor and progesterone receptor and no overexpression of human epidermal growth factor receptor 2 (HER2) are referred to as triple-negative breast cancer (TNBC). There is now evidence emerging from epidemiological studies regarding important characteristics of this group of tumours that carry a relatively poorer prognosis than the major breast cancer sub-types. From this review of available data and information, there are some consistent findings that emerge. Women with TNBC experience the peak risk of recurrence within 3 years of diagnosis, and the mortality rates appear to be increased for 5 years after diagnosis. TNBC represents 10%-20% of invasive breast cancers and has been associated with African-American race, deprivation status, younger age at diagnosis, more advanced disease stage, higher grade, high mitotic indices, family history of breast cancer and BRCA1 mutations. TNBC is regularly reported to be three times more common in women of African descent and in pre-menopausal women, and carries a poorer prognosis than other forms of breast cancer. Although prospects for prevention of non-hormone-dependent breast cancer are currently poor, it is still important to understand the aetiology of such tumours. There remains a great deal of work to be done to arrive at a comprehensive picture of the aetiology of breast cancer. Key recommendations are that there is a clear and urgent need to have more epidemiological studies of the breast cancer sub-types to integrate aetiological and lifestyle factors for prevention of incidence and death, and to have more population-based information of the clinical and biological relevance from cancer registries.

Are survivorship care plans responsive to African-American breast cancer survivors?: voices of survivors and advocates

PURPOSE

African-American breast cancer survivors (AABCS) suffer the greatest from cancer recurrence, morbidity, and mortality in part due to the lack of cancer follow-up care and surveillance. To improve survival and survivorship, the Institute of Medicine advises that cancer survivors be provided a survivorship care plan (SCP). The current study investigated AABCS' understanding of SCP and gathered preliminary feedback on infusing cultural and socioecological responsiveness.

METHODS

The study embraced a community-based participatory research framework. Three facilitated, structured, consensus meetings were conducted with AABCS (N = 25) and advocates (N = 3) to provide information towards identifying the content domains of an SCP that are culturally responsive to AABCS.

RESULTS

AABCS recommended inclusion of patient-centered information on the purpose and use of the SCP. They raised concerns that higher mortality in AABCS may be due to greater comorbidities and inadequate surveillance and follow-up care. Participants recommended that the SCP document all comorbidities and medications, regardless of relationship to cancer; referrals for cancer-related providers; and culturally informed health advisories.

CONCLUSION

Study findings indicate that the available SCP template lacked adequate content on health history, comorbidity, health promotion, and functioning. These factors constitute the underlying clinical, psychosocial, and behavioral risks for poor disease outcomes that may be exacerbated in AABCS.

IMPLICATIONS FOR CANCER SURVIVORS

SCPs are intended to educate and activate patients to join their oncology care team as informed partners. However, the emerging science and implementation of SCPs seem void of patient input. Our investigation suggests a practical approach for survivor engagement in the SCP discourse to increase their cultural responsiveness and patient-centeredness.

Variation in tumor natural history contributes to racial disparities in breast cancer stage at diagnosis

Black women tend to be diagnosed with breast cancer at a more advanced stage than whites and subsequently experience elevated breast cancer mortality. We sought to determine whether there are racial differences in tumor natural history that contribute to these disparities. We used the University of Wisconsin Breast Cancer Simulation Model, a validated member of the National Cancer Institute's Cancer Intervention and Surveillance Modeling Network, to evaluate the contribution of racial differences in tumor natural history to observed disparities in breast cancer incidence. We fit eight natural history parameters in race-specific models by calibrating to the observed race- and stage-specific 1975-2000 U.S. incidence rates, while accounting for known racial variation in population structure, underlying risk of breast cancer, screening mammography utilization, and mortality from other causes. The best fit models indicated that a number of natural history parameters must vary between blacks and whites to reproduce the observed stage-specific incidence patterns. The mean of the tumor growth rate parameter was 63.6 % higher for blacks than whites (0.18, SE 0.04 vs. 0.11, SE 0.02). The fraction of tumors considered highly aggressive based on their tendency to metastasize at a small size was 2.2 times greater among blacks than whites (0.41, SE 0.009 vs. 0.019, SE 0.008). Based on our simulation model, breast tumors in blacks grow faster and are more likely to metastasize earlier than tumors in whites. These differences suggest that targeted prevention and detection strategies that go beyond equalizing access to mammography may be needed to eliminate breast cancer disparities.

Clinicopathologic features and prognosis of triple-negative breast cancer in patients 40 years of age and younger in Saudi Arabia

BACKGROUND AND OBJECTIVES

Triple-negative breast cancer (TNBC) has a poor prognosis and overall survival (OS) compared to other types of breast cancer tumors. However, there is to date no evidence that this is also the case in Saudi Arabia.

DESIGN AND SETTING

Retrospective review of breast cancer patients who were treated from January 2001 to December 2008 (517 patients) at the King AbdulAziz Medical City, Riyadh, Saudi Arabia.

PATIENTS AND METHODS

Patients were selected as TNBC if all three markers of estrogen receptor (ER), progesterone receptor (PR) and the human epidermal growth factor (HER2) tested by immunohistochemistry as negative. They were then age- and stage-matched, and compared with non-TNBC patients to examine differences, if any, in their clinicopathologic features, prognosis and OS.

RESULTS

Twenty-six patients with a follow up time of at least three years were identified as TNBC. Thirty-three patients who were age- and stage-matched were selected as the non-TNBC controls. Clinicopathologic results illustrated significantly more grade 3 tumors (P=.02) and CK 5/6 expression (P<.001) in the TNBC group compared to the non-TNBC group. TNBC patients aged ≤40 years showed a significantly worse prognosis and OS compared to TNBC patients aged >40 years (P=.01), and when compared to the non-TNBC group (P=.04).

CONCLUSION

The incidence of TNBC in our cohort is similar to what has been illustrated in previous studies in Western population. There was no significant difference in 3-year survival between TNBC and non-TNBC groups. However, the aggressiveness of this type of tumor and OS is significantly higher in younger patients aged ≤40 years, compared to those over 40 years of age.

An Integrative Genomics Approach for Associating GWAS Information with Triple-Negative Breast Cancer

Genome-wide association studies (GWAS) have identified genetic variants associated with an increased risk of developing breast cancer. However, the association of genetic variants and their associated genes with the most aggressive subset of breast cancer, the triple-negative breast cancer (TNBC), remains a central puzzle in molecular epidemiology. The objective of this study was to determine whether genes containing single nucleotide polymorphisms (SNPs) associated with an increased risk of developing breast cancer are connected to and could stratify different subtypes of TNBC. Additionally, we sought to identify molecular pathways and networks involved in TNBC. We performed integrative genomics analysis, combining information from GWAS studies involving over 400,000 cases and over 400,000 controls, with gene expression data derived from 124 breast cancer patients classified as TNBC (at the time of diagnosis) and 142 cancer-free controls. Analysis of GWAS reports produced 500 SNPs mapped to 188 genes. We identified a signature of 159 functionally related SNP-containing genes which were significantly (P <10⁻⁵) associated with and stratified TNBC. Additionally, we identified 97 genes which were functionally related to, and had similar patterns of expression profiles, SNP-containing genes. Network modeling and pathway prediction revealed multi-gene pathways including p53, NFkB, BRCA, apoptosis, DNA repair, DNA mismatch, and excision repair pathways enriched for SNPs mapped to genes significantly associated with TNBC. The results provide convincing evidence that integrating GWAS information with gene expression data provides a unified and powerful approach for biomarker discovery in TNBC.

Breast cancer molecular subtypes and associations with clinicopathological characteristics in Iranian women, 2002- 2011

Breast cancer is a heterogeneous disease that is affected by ethnicity of patients. According to hormone receptor status and gene expression profiling, breast cancers are classified into four molecular subtypes, each showing distinct clinical behavior. Lack of sufficient data on molecular subtypes of breast cancer in Iran, prompted us to investigate the prevalence and the clinicopathological features of each subtype among Iranian women. A total of 428 women diagnosed with breast cancer from 2002 to 2011 were included and categorized into four molecular subtypes using immunohistochemistry. Prevalence of each subtype and its association with patients' demographics and tumor characteristics, such as size, grade, lymph-node involvement and vascular invasion, were investigated using Chi-square, analysis of variance and multivariate logistic regression. Luminal A was the most common molecular subtype (63.8%) followed by Luminal B (8.4%), basal-like (15.9%) and HER-2 (11.9%). Basal-like and HER-2 subtypes were mostly of higher grades while luminal A tumors were more of grade 1 (P<0.001). Vascular invasion was more prevalent in HER-2 subtype, and HER-2 positive tumors were significantly associated with vascular invasion (P=0.013). Using muti-variate analysis, tumor size greater than 5 cm and vascular invasion were significant predictors of 3 or more nodal metastases. Breast cancer was most commonly diagnosed in women around 50 years of age and the majority of patients had lymph node metastasis at the time of diagnosis. This points to the necessity for devising an efficient screening program for breast cancer in Iran. Further, prospective surveys are suggested to evaluate prognosis of different subtypes in Iranian patients.

Androgen receptor in triple negative breast cancer

The clinical management of triple negative breast cancer (TNBC) is challenging due to the relatively aggressive biological behaviour and paucity of specific targeted therapy. A subset of TNBC patients has been reported to express androgen receptor (AR) in carcinoma cells and the manipulation of androgen signalling or AR targeted therapies have been proposed. However, the biological significance of AR in TNBC has remained relatively unknown. Therefore, this review aims to summarise the reported studies assessing the rates of AR positivity in TNBC patients and androgenic effects in TNBC cell lines. The rates of AR positivity among TNBC cases varied depending on the study population (0-53% of all TNBC patients). This difference among the reported studies may be largely due to the methodological differences of analysing AR. While the majority of cell line studies suggest that androgen increase proliferation and preliminary clinical studies suggest that AR antagonists improve the prognosis of AR positive TNBC patients, cell line transfection experiments and survival analyses of histological samples suggest that the presence of AR in tumour is either benign or predicts better survival. Therefore further translational investigations regarding the mechanisms of androgen action in TNBC are required to explain this discrepancy between clinical and basic studies.

Descriptive analysis of molecular subtypes in Tunisian breast cancer

AIM

The objective is to report the correlation between pathology and molecular subtype classifications of breast cancer in Tunisian women.

METHODS

This retrospective study concerned data of 966 breast cancer cases collected from 2007 to 2009 at Salah Azaiz Institute of Tunis. These cases were classified by an immunohistochemistry test for estrogen and progesterone receptors and human epidermal growth factor receptor 2 (HER2) status in the four molecular subtypes, namely luminal A, luminal B, HER2+ and triple negative. The molecular classifications were correlated with the clinicopathological characteristics of the tumors.

RESULTS

Luminal A (50.7% of cases) was the most common subtype, with triple negative subtype 22.5%, luminal B 13.4% and HER2+ 13.4%. Triple negative and HER2+ subtypes were significantly associated with large tumor size (>5 cm, P < 0.001), younger age (<40 years, P < 0.03) and high grade (P < 0.001). Conversely, there was no correlation with the lymph node status.

CONCLUSION

Our data demonstrated that the luminal A subtype, associated with a favorable prognosis, was the most frequent subtype in the Tunisian population; however the triple negative subtype occurred at a high incidence in Tunisia compared to Western countries. The molecular subtypes are correlated to the tumor size, histological grade and patient's age.

Genome and transcriptome sequencing in prospective metastatic triple-negative breast cancer uncovers therapeutic vulnerabilities

Triple-negative breast cancer (TNBC) is characterized by the absence of expression of estrogen receptor, progesterone receptor, and HER-2. Thirty percent of patients recur after first-line treatment, and metastatic TNBC (mTNBC) has a poor prognosis with median survival of one year. Here, we present initial analyses of whole genome and transcriptome sequencing data from 14 prospective mTNBC. We have cataloged the collection of somatic genomic alterations in these advanced tumors, particularly those that may inform targeted therapies. Genes mutated in multiple tumors included TP53, LRP1B, HERC1, CDH5, RB1, and NF1. Notable genes involved in focal structural events were CTNNA1, PTEN, FBXW7, BRCA2, WT1, FGFR1, KRAS, HRAS, ARAF, BRAF, and PGCP. Homozygous deletion of CTNNA1 was detected in 2 of 6 African Americans. RNA sequencing revealed consistent overexpression of the FOXM1 gene when tumor gene expression was compared with nonmalignant breast samples. Using an outlier analysis of gene expression comparing one cancer with all the others, we detected expression patterns unique to each patient's tumor. Integrative DNA/RNA analysis provided evidence for deregulation of mutated genes, including the monoallelic expression of TP53 mutations. Finally, molecular alterations in several cancers supported targeted therapeutic intervention on clinical trials with known inhibitors, particularly for alterations in the RAS/RAF/MEK/ERK and PI3K/AKT/mTOR pathways. In conclusion, whole genome and transcriptome profiling of mTNBC have provided insights into somatic events occurring in this difficult to treat cancer. These genomic data have guided patients to investigational treatment trials and provide hypotheses for future trials in this irremediable cancer.

Genetic susceptibility loci for subtypes of breast cancer in an African American population

BACKGROUND

Most genome-wide association studies (GWAS) have been carried out in European ancestry populations; no risk variants for breast cancer have been identified solely from African ancestry GWAS data. Few GWAS hits have replicated in African ancestry populations.

METHODS

In a nested case-control study of breast cancer in the Black Women's Health Study (1,199 cases/1,948 controls), we evaluated index single-nucleotide polymorphisms (SNP) in 21 loci from GWAS of European or Asian ancestry populations, overall, in subtypes defined by estrogen receptor (ER) and progesterone receptor (PR) status (ER+/PR+, n = 336; ER-/PR-, n = 229), and in triple-negative breast cancer (TNBC, N = 81). To evaluate the contribution of genetic factors to population differences in breast cancer subtype, we also examined global percent African ancestry.

RESULTS

Index SNPs in five loci were replicated, including three associated with ER-/PR- breast cancer (TERT rs10069690 in 5p15.33, rs704010 in 10q22.3, and rs8170 in 19p13.11): per allele ORs were 1.29 [95% confidence interval (CI) 1.04-1.59], P = 0.02, 1.52 (95% CI 1.12-2.08), P = 0.01, and 1.30 (95% CI 1.01-1.68), P = 0.04, respectively. Stronger associations were observed for TNBC. Furthermore, cases in the highest quintile of percent African ancestry were three times more likely to have TNBC than ER+/PR+ cancer.

CONCLUSIONS

These findings provide the first confirmation of the TNBC SNP rs8170 in an African ancestry population, and independent confirmation of the TERT ER- SNP. Furthermore, the risk of developing ER- breast cancer, particularly TNBC, increased with increasing proportion of global African ancestry.

IMPACT

The findings illustrate the importance of genetic factors in the disproportionately high occurrence of TNBC in African American women.

High incidence of triple-negative tumors in sub-saharan Africa: a prospective study of breast cancer characteristics and risk factors in Malian women seen in a Bamako university hospital

OBJECTIVE

Few studies have been conducted on breast cancer in Sub-Saharan Africa and their results have been suspected to be impaired by artefacts. This prospective study was designed to determine tumor and patient characteristics in Mali with control of each methodological step. These data are necessary to define breast cancer treatment guidelines in this country.

METHODS

Clinical and tumor characteristics and known risk factors were obtained in a consecutive series of 114 patients. Each technical step for the determination of tumor characteristics [histology, TNM, grade, estrogen (ER) and progesterone receptors (PR), HER2, and Ki67] was controlled.

RESULTS

Patients had a mean age of 46 years. Most tumors were invasive ductal carcinomas (94%), T3-T4 (90%) with positive nodes (91%), grade III (78%), and ER (61%) and PR (72%) negative. HER2 was overexpressed in 18% of cases. The triple-negative subgroup represented 46%, displaying a particularly aggressive pattern (90% grade III; 88% Ki67 >20%).

CONCLUSION

This study demonstrates the high incidence of aggressive triple-negative tumors in Mali. Apart from a higher prevalence of premenopausal women, no significant difference in risk factors was observed between triple-negative tumors and other tumors. The hormonal therapy systematically prescribed therefore needs to be revised in light of this study.

Molecular characteristics and prognostic features of breast cancer in Nigerian compared with UK women

Although breast cancer (BC) incidence is lower in African-American women compared with White-American, in African countries such as Nigeria, BC is a common disease. Nigerian women have a higher risk for early-onset, with a high mortality rate from BC, prompting speculation that risk factors could be genetic and the molecular portrait of these tumours are different to those of western women. In this study, 308 BC samples from Nigerian women with complete clinical history and tumour characteristics were included and compared with a large series of BC from the UK as a control group. Immunoprofile of these tumours was characterised using a panel of 11 biomarkers of known relevance to BC. The immunoprofile and patients' outcome were compared with tumour grade-matched UK control group. Nigerian women presenting with BC were more frequently premenopausal, and their tumours were characterised by large primary tumour size, high tumour grade, advanced lymph node stage, and a higher rate of vascular invasion compared with UK women. In the grade-matched groups, Nigerian BC showed over representation of triple-negative and basal phenotypes and BRCA1 deficiency BC compared with UK women, but no difference was found regarding HER2 expression between the two series. Nigerian women showed significantly poorer outcome after development of BC compared with UK women. This study demonstrates that there are possible genetic and molecular differences between an indigenous Black population and a UK-based series. The basal-like, triple negative and BRCA1 dysfunction groups of tumours identified in this study may have implications in the development of screening programs and therapies for African patients and families that are likely to have a BRCA1 dysfunction, basal like and triple negative.

Expression of aldehyde dehydrogenase 1 as a marker of mammary stem cells in benign and malignant breast lesions of Ghanaian women

BACKGROUND

Breast cancers that are negative for the estrogen receptor (ER), the progesterone receptor (PR), and the HER2 (human epidermal growth factor receptor 2) marker are more prevalent among African women, and the biologically aggressive nature of these triple-negative breast cancers (TNBCs) may be attributed to their mammary stem cell features. Little is known about expression of the mammary stem cell marker aldehyde dehydrogenase 1 (ALDH1) in African women. Novel data are reported regarding ALDH1 expression in benign and cancerous breast tissue of Ghanaian women.

METHODS

Formalin-fixed, paraffin-embedded specimens were transported from the Komfo Anoyke Teaching Hospital in Kumasi, Ghana to the University of Michigan for centralized histopathology study. Expression of ER, PR, HER2, and ALDH1 was assessed by immunohistochemistry. ALDH1 staining was further characterized by its presence in stromal versus epithelial and/or tumor components of tissue.

RESULTS

A total of 173 women contributed to this study: 69 with benign breast conditions, mean age 24 years, and 104 with breast cancer, mean age 49 years. The proportion of benign breast conditions expressing stromal ALDH1 (n = 40, 58%) was significantly higher than those with cancer (n = 44, 42.3%) (P = .043). Among the cancers, TNBC had the highest prevalence of ALDH1 expression, either in stroma or in epithelial cells. More than 2-fold higher likelihood of ALDH1 expression was observed in TNBC cases compared with other breast cancer subtypes (odds ratio = 2.38, 95% confidence interval 1.03-5.52, P = .042).

CONCLUSIONS

ALDH1 expression was higher in stromal components of benign compared with cancerous lesions. Of the ER-, PR-, and HER2-defined subtypes of breast cancer, expression of ALDH1 was highest in TNBC.

Molecular subtypes of breast carcinoma in Egyptian women: clinicopathological features

Breast carcinoma may be classified into distinct molecular subtypes based on immunohistochemical markers for estrogen, progesterone and Her-2/neu receptors. The aim of the study was to identify the clinicopathological features of the molecular subtypes of breast carcinoma in our locality. A total of 274 surgically resected breast carcinomas were selected from the files of the Dr. KRZ referral pathology laboratory, Mansoura, Egypt, and the Pathology Department of Mansoura University. Molecular subtypes were classified into luminal A, luminal B, Her-2/neu-expressing and triple-negative. Clinicopathological and histological features of molecular subtypes were analyzed. Luminal A subtype was the most prevalent (41.2%), followed by triple-negative subtype (28.5%), then Her2-expressing subtype (19.4%) and luminal B subtype (13.9%). The commonest histological type was infiltrating duct carcinoma (83.2%), followed by infiltrating lobular carcinoma (9.1%) and medullary carcinoma (3.2%). The luminal A subtype was significantly correlated to low tumor grade, lower number of positive lymph nodes metastasis, absence of both necrosis and syncytial growth pattern. We concluded that the commonest molecular subtype of invasive breast carcinoma among Egyptian women is luminal subtype A, which displayed favorable features. Triple-negative subtype and medullary carcinomas are present in a ratio higher than in western countries.

Age-specific incidence of breast cancer subtypes: understanding the black-white crossover

BACKGROUND

Breast cancer incidence is higher among black women than white women before age 40 years, but higher among white women than black women after age 40 years (black-white crossover). We used newly available population-based data to examine whether the age-specific incidences of breast cancer subtypes vary by race and ethnicity.

METHODS

We classified 91908 invasive breast cancers diagnosed in California between January 1, 2006, and December 31, 2009, by subtype based on tumor expression of estrogen receptor (ER) and progesterone receptor (PR)-together referred to as hormone receptor (HR)-and human epidermal growth factor receptor 2 (HER2). Breast cancer subtypes were classified as ER or PR positive and HER2 negative (HR(+)/HER2(-)), ER or PR positive and HER2 positive (HR(+)/HER2(+)), ER and PR negative and HER2 positive (HR(-)/HER2(+)), and ER, PR, and HER2 negative (triple-negative). We calculated and compared age-specific incidence rates, incidence rate ratios, and 95% confidence intervals by subtype and race (black, white, Hispanic, and Asian). All P values are two-sided.

RESULTS

We did not observe an age-related black-white crossover in incidence for any molecular subtype of breast cancer. Compared with white women, black women had statistically significantly higher rates of triple-negative breast cancer at all ages but statistically significantly lower rates of HR(+)/HER2(-) breast cancers after age 35 years (all P < .05). The age-specific incidence of HR(+)/HER2(+) and HR(-)/HER2(+) subtypes did not vary markedly between white and black women.

CONCLUSIONS

The black-white crossover in breast cancer incidence occurs only when all breast cancer subtypes are combined and relates largely to higher rates of triple-negative breast cancers and lower rates of HR(+)/HER2(-) breast cancers in black vs white women.

Examination of ancestral informative markers and self-reported race with tumor characteristics of breast cancer among Black and White women

African American (AA) women have a higher mortality from breast cancer (BC) compared to European American (EA) women. This may be due to the higher proportion of AA women with tumors that are diagnosed at more advanced stages and are characterized as being estrogen receptor negative (ER-)/progesterone receptor negative (PR-). Our study sought to determine whether self-reported race and percent African ancestry were associated with BC tumor characteristics. In a multi-center, population-based case-control study of BC, we determined percent African ancestry using ancestry informative markers (AIM) among women self-reporting race as AA or Black. BC tumor characteristics were associated with self-reported race (including a 30 % reduction in ER+/PR+ tumors [95 % confidence interval [CI]: 0.6-0.9] and a 1.5-fold increased risk of high grade [95 % CI: 1.2-1.9] for AA women compared to EA women). AIMs among AA women were not associated with BC tumor characteristics (AA women with ≥95 % versus <80 % African ancestry, odds ratio [OR] = 1.0 for ER+/PR+ [95 % CI: 0.6-1.8] and OR = 0.9 for high-grade tumors [95 % CI: 0.6-1.4]). Similar findings were observed for BC stage. While BC subtypes were associated with self-reported race, BC subtypes were not associated with percent African ancestry. These study results suggest that subtle differences in percent African ancestry are less important than the overall presence of African ancestry in relation to BC tumor characteristics.

Elevated levels of proliferating and recently migrated tumor-associated macrophages confer increased aggressiveness and worse outcomes in breast cancer

PURPOSE

Macrophages play a major role in inflammatory processes and have been associated with poor prognosis in a variety of cancers, including breast cancer. Previously, we investigated the relationship of a subset of tumor-associated macrophages (PCNA(+) TAMs) with clinicopathologic characteristics of breast cancer. We reported that high PCNA(+) TAM counts were associated with hormone receptor (HR)-negative, high-grade tumors and early recurrence. To further understand the significance of elevated PCNA(+) TAMs and the functionality of TAMs, we examined the expression of S100A8/S100A9 with the antibody Mac387. The heterodimeric S100A8/S100A9 complex plays a role in inflammation and is increased in several cancer types.

METHODS

We performed immunohistochemistry using the Mac387 antibody on 367 invasive human breast cancer cases. Results were compared to previous PCNA(+) TAM counts and were correlated with patient outcomes adjusting for HR status and histologic grade.

RESULTS

Like PCNA(+) TAMs, high Mac387 counts were associated with HR negativity, high tumor grade, younger age, and decreased recurrence-free survival. Mac387, however, appears to identify both a subset of macrophages and a subset of tumor cells. The concordance between Mac387 and PCNA(+) TAM counts was low and cases that had both high Mac387 and high PCNA(+) TAMs counts had a stronger association with early recurrence.

CONCLUSIONS

The presence of high numbers of PCNA(+) TAMs and Mac387-positive cells in breast cancers with poor outcomes may implicate a subset of TAMs in breast cancer pathogenesis, and may ultimately serve to develop potential cellular targets for therapeutic interventions.

Outcome for patients with triple-negative breast cancer is not dependent on race/ethnicity

Introduction. Triple negative breast cancer (TNBC) is biologically aggressive and is associated with a worse prognosis. To understand the impact of race/ethnicity on outcome for patients with TNBC, confounding factors such as socioeconomic status (SES) need to be controlled. We examined the impact of race/ethnicity on a cohort of patients of low SES who have TNBC. Methods. 786 patients with Stage 0-III breast cancer were evaluated. Of these, 202 patients had TNBC (26%). Primary endpoints were cancer recurrence and death. ZIP code-based income tract and institutional financial data were used to assess SES. Data were analyzed using Kaplan-Meier survival analysis, log-rank tests, Cox Proportional hazard regression, chi square test, and t-tests. A P value ≤0.05 was considered statistically significant. Results. Of the 468 African-Americans (60%) in the database, 138 had TNBC; 64 of 318 Caucasians had TNBC. 80% of patients had an annual income of ≤$20,000. The 5-year overall survival was 77% for African-American women versus 72% for Caucasian women (P = 0.95). On multivariate analysis, race/ethnicity had an impact on disease-free survival (P = 0.027) but not on overall survival (P = 0.98). Conclusion. In a predominantly indigent population, race/ethnicity had no impact on overall survival for patients with triple negative breast cancer.

Invasive breast carcinomas in Ghana: high frequency of high grade, basal-like histology and high EZH2 expression

Breast cancer in African-American women has a worse outcome than in Caucasian women. The ancestors of most African-American women come from West Africa, including Ghana. The Polycomb group protein EZH2 is a marker of poor outcome in breast cancers from Caucasian women. The histopathological features and biomarker expression of African breast cancers remain obscure. Here, we investigated a cohort of Ghanaian breast cancers to better define the prevalent tumor types and to test if EZH2 protein may identify aggressive tumors. A group of 169 breast tissues (100 invasive carcinomas and 69 benign) from women treated at Komfo Anoyke Teaching Hospital between 2006 and 2011 were histologically classified and investigated for EZH2 expression. EZH2 nuclear expression we defined as high or low following previously published criteria. Of the 100 invasive carcinomas, 89 % were ductal, 2 % were lobular, and 9 % were metaplastic. Basal-like pathological features were present in 30 % of the tumors. Of the invasive carcinomas, 7 % were grade 1, 41 % grade 2, and 52 % grade 3. EZH2 protein was overexpressed in invasive carcinomas compared to benign breast (p < 0.0001). In invasive carcinomas nuclear EZH2 overexpression was significantly associated with basal-like subtype (p = 0.03) and high histologic grade (p < 0.05). Cytoplasmic EZH2, which has not been previously reported, was present in 16 % of invasive carcinomas and it was associated with triple negative status (p = 0.02). Our results provide the first comprehensive histopathological study of this patient population and uncover the association of EZH2 with high grade and basal-like tumors. We provide the basis for further detailed investigations on this cohort to advance diagnosis and treatment of African and African-American women.

High motility of triple-negative breast cancer cells is due to repression of plakoglobin gene by metastasis modulator protein SLUG

One of highly pathogenic breast cancer cell types are the triple negative (negative in the expression of estrogen, progesterone, and ERBB2 receptors) breast cancer cells. These cells are highly motile and metastatic and are characterized by high levels of the metastasis regulator protein SLUG. Using isogenic breast cancer cell systems we have shown here that high motility of these cells is directly correlated with the levels of the SLUG in these cells. Because epithelial/mesenchymal cell motility is known to be negatively regulated by the catenin protein plakoglobin, we postulated that the transcriptional repressor protein SLUG increases the motility of the aggressive breast cancer cells through the knockdown of the transcription of the plakoglobin gene. We found that SLUG inhibits the expression of plakoglobin gene directly in these cells. Overexpression of SLUG in the SLUG-deficient cancer cells significantly decreased the levels of mRNA and protein of plakoglobin. On the contrary, knockdown of SLUG in SLUG-high cancer cells elevated the levels of plakoglobin. Blocking of SLUG function with a double-stranded DNA decoy that competes with the E2-box binding of SLUG also increased the levels of plakoglobin mRNA, protein, and promoter activity in the SLUG-high triple negative breast cancer cells. Overexpression of SLUG in the SLUG-deficient cells elevated the motility of these cells. Knockdown of plakoglobin in these low motility non-invasive breast cancer cells rearranged the actin filaments and increased the motility of these cells. Forced expression of plakoglobin in SLUG-high cells had the reverse effects on cellular motility. This study thus implicates SLUG-induced repression of plakoglobin as a motility determinant in highly disseminating breast cancer.

Evaluation of 19 susceptibility loci of breast cancer in women of African ancestry

Multiple breast cancer susceptibility loci have been identified in genome-wide association studies (GWAS) in populations of European and Asian ancestry using array chips optimized for populations of European ancestry. It is important to examine whether these loci are associated with breast cancer risk in women of African ancestry. We evaluated 25 single nucleotide polymorphisms (SNPs) at 19 loci in a pooled case-control study of breast cancer, which included 1509 cases and 1383 controls. Cases and controls were enrolled in Nigeria, Barbados and the USA; all women were of African ancestry. We found significant associations for three SNPs, which were in the same direction and of similar magnitude as those reported in previous fine-mapping studies in women of African ancestry. The allelic odds ratios were 1.24 [95% confidence interval (CI): 1.04-1.47; P = 0.018] for the rs2981578-G allele (10q26/FGFR2), 1.34 (95% CI: 1.10-1.63; P = 0.0035) for the rs9397435-G allele (6q25) and 1.12 (95% CI: 1.00-1.25; P = 0.04) for the rs3104793-C allele (16q12). Although a significant association was observed for an additional index SNP (rs3817198), it was in the opposite direction to prior GWAS studies. In conclusion, this study highlights the complexity of applying current GWAS findings across racial/ethnic groups, as none of GWAS-identified index SNPs could be replicated in women of African ancestry. Further fine-mapping studies in women of African ancestry will be needed to reveal additional and causal variants for breast cancer.

Incidence and risk factors for breast cancer subtypes in three distinct South-East Asian ethnic groups: Chinese, Malay and natives of Sarawak, Malaysia

We determined the incidences of the estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) subtypes among breast cancer cases in Sarawak, Malaysia and their correlation with various risk factors in the three ethnic groups: Chinese, Malay and native. Subtype status was ascertained for 1,034 cases of female breast cancer (93% of all cases diagnosed since 2003), and the age-standardized incidence rates (ASRs) of each subtype were inferred. Case-case comparisons across subtypes were performed for reproductive risk factors. We found 48% luminal A (ER+/PR+/HER2-), 29% triple-negative (ER-/PR-/HER2-), 12% triple-positive (ER+/PR+/HER2+) and 11% HER2-overexpressing (ER-/PR-/HER2+) subtypes, with ASRs of 10.6, 6.0, 2.8 and 2.8 per 100,000, respectively. The proportions of subtypes and ASRs differed significantly by ethnic groups: HER2-positive cases were more frequent in Malays (29%; 95% CI [23;35]) than Chinese (22%; [19;26] and natives (21%; [16;26]); triple-negative cases were less frequent among Chinese (23%; [20;27]) than Malays (33%; [27;39]) and natives (37%; [31;43]). The results of the case-case comparison were in accordance with those observed in western case series. Some uncommon associations, such as between triple-negative subtype and older age at menopause (OR, 1.59; p < 0.05), were found. The triple-negative and HER2+ subtypes predominate in our region, with significant differences among ethnic groups. Our results support the idea that the risk factors for different subtypes vary markedly. Westernized populations are more likely to have factors that increase the risk for the luminal A type, while risk factors for the triple-negative type are more frequent in local populations.

Prevalence of BRCA1 mutations among 403 women with triple-negative breast cancer: implications for genetic screening selection criteria: a Hellenic Cooperative Oncology Group Study

In spite the close association of the triple-negative breast cancer immunophenotype with hereditary breast cancers and the BRCA1 pathway, there is a lack of population studies that determine the frequency of BRCA1 mutations among triple-negative breast cancer patients. To address this, we have screened a large sample of 403 women diagnosed with triple-negative invasive breast cancer, independently of their age or family history, for germline BRCA1 mutations. Median age at diagnosis was 50 years (range 20-83). The overall prevalence of triple-negative cases among the initial patient group with invasive breast cancer was 8%. BRCA1 was screened by direct DNA sequencing in all patients, including all exons where a mutation was previously found in the Greek population (exons 5, 11, 12, 16, 20, 21, 22, 23, 24-77% of the BRCA1 coding region), including diagnostic PCRs to detect the three Greek founder large genomic rearrangements. Sixty-five deleterious BRCA1 mutations were identified among the 403 triple-negative breast cancer patients (16%). Median age of onset for mutation carriers was 39 years. Among a total of 106 women with early-onset triple-negative breast cancer (<40 years), 38 (36%) had a BRCA1 mutation, while 27% of women with triple-negative breast cancer diagnosed before 50 years (56/208) had a BRCA1 mutation. A mutation was found in 48% (50/105) of the triple-negative breast cancer patients with family history of breast or ovarian cancer. It is noteworthy, however, that of the 65 carriers, 15 (23%) had no reported family history of related cancers. All but one of the carriers had grade III tumors (98%). These results indicate that women with early-onset triple-negative breast cancer, and ideally all triple-negative breast cancer patients, are candidates for BRCA1 genetic testing even in the absence of a family history of breast or ovarian cancer.

Estrogen-related genes and their contribution to racial differences in breast cancer risk

Racial differences in breast cancer risk, including the risks of hormone receptor subtypes of breast cancer, have been previously reported. We evaluated whether variation in genes related to estrogen metabolism (COMT, CYP1A1, CYP1B1, CYP17A1, CYP19A1, ESR1, GSTM1, GSTP1, GSTT1, HSD17B1, SULT1A1, and UGT1A1) contributes to breast cancer risk and/or racial differences in risk within the CARE study, a multi-centered, population-based case-control study of breast cancer. Genetic variation was assessed as single nucleotide polymorphisms (SNPs), haplotypes, and SNP-hormone therapy (HT) interactions within a subset of 1,644 cases and 1,451 controls, including 949 Black women (493 cases and 456 controls), sampled from the CARE study population. No appreciable associations with breast cancer risk were detected for single SNPs or haplotypes in women overall. We detected SNP-HT interactions in women overall within CYP1B1 (rs1800440; p (het) = 0.003) and within CYP17A1 (rs743572; p (het) = 0.009) in which never users of HT were at a decreased risk of breast cancer, while ever users were at a non-significant increased risk. When investigated among racial groups, we detected evidence of an SNP-HT interaction with CYP1B1 in White women (p value = 0.02) and with CYP17A1 in Black women (p value = 0.04). This analysis suggests that HT use may modify the effect of variation in estrogen-related genes on breast cancer risk, which may affect Black and White women to a different extent.

Epidemiology of triple negative breast cancers

Triple negative (TN) breast cancers fail to express the three most common breast cancer receptors; i.e., estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor-2 (HER2). Accumulating data demonstrate that epidemiological risk factor profiles also vary between TN (ER-PR-HER2-) and other breast cancers, especially the so-called Luminal A breast cancers (ER+PR ± HER2-) [1]. A more comprehensive understanding of the epidemiology of TN breast cancers has important public health implications for risk assessment [2], prevention and treatment. The epidemiology of TN breast cancers can be first understood in the age-related reproductive risk factor patterns for ER, PR, and HER2. For example, there is a clear and strong association between older age at diagnosis (and therefore postmenopausal status) and the development of ER positive, PR positive, and HER2 negative breast cancers. On the other hand, younger age at diagnosis (and premenopausal status) is related to the development of ER negative, PR negative, and HER2 positive breast cancers. This gives rise to the somewhat counterintuitive suggestion that menopause has a greater relative impact upon hormone receptor negative than positive breast cancers [3,4]. Throughout this review, we will primarily contrast ER-PR-HER2- (TN) with ER+PR ± HER2- (Luminal A) breast cancers. We will first summarize the population-based age-specific incidence rate patterns and clinical outcomes, and then will review the available analytical studies. Information sources for this review included the National Cancer Institute's Surveillance, Epidemiology, and End Results 13 Registries Public-Use Database [5], CANCERLIT, Index Medicus, and PubMed.

A meta-analysis of male breast cancer in Africa

To characterize male breast cancer in Africa in recent decades, we systematically reviewed literature and conducted a meta-analysis of available data on male breast cancer in Africa. A paper was included if both male and female breast cancer were available. If two publications covered the same geographic area, only the publication with a longer study period was included. Random effects models and mixed effect meta-regressions were used to analyze data of 1201 male and 36,172 female breast cancer patients from 27 African countries. We showed that the male-to-female breast cancer ratio was 0.042 overall and it has decreased in recent years. Additionally, male breast cancer patients in Africa had the disease at age 54.6 on average, 7 years older than female patients. In conclusion, male breast cancers in Africa are characterized as late onset and male-to-female breast cancer ratio in Africa is higher than populations in developed countries.

Experience of initial symptoms of breast cancer and triggers for action in ethiopia

Objective. This study assessed the initial experiences, symptoms, and actions of patients in Ethiopia ultimately determined to have breast cancer. Methods. 69 participants in a comprehensive breast cancer treatment program at the main national cancer hospital in Ethiopia were interviewed using mixed qualitative and quantitative approaches. Participants' narratives of their initial cancer experience were coded and analyzed for themes around their symptoms, time to seeking advice, triggers for action, and contextual factors. The assessment was approved by the Addis Ababa University Faculty of Medicine Institutional Review Board. Results. Nearly all women first noticed lumps, though few sought medical advice within the first year (average time to action: 1.5 years). Eventually, changes in their symptoms motivated most participants to seek advice. Most participants did not think the initial lump would be cancer, nor was a lump of any particular concern until symptoms changed. Conclusion. Given the frequency with which lumps are the first symptom noticed, raising awareness among participants that lumps should trigger medical consultation could contribute significantly to more rapid medical advice-seeking among women in Ethiopia. Primary care sites should be trained and equipped to offer evaluation of lumps so that women can be referred appropriately for assessment if needed.

Experience of initial symptoms of breast cancer and triggers for action in ethiopia

Background. In Haiti, breast cancer patients present at such advanced stages that even modern therapies offer modest survival benefit. Identifying the personal, sociocultural, and economic barriers-to-care delaying patient presentation is crucial to controlling disease. Methods. Patients presenting to the Hôpital Bon Sauveur in Cange were prospectively accrued. Delay was defined as 12 weeks or longer from initial sign/symptom discovery to presentation, as durations greater than this cutoff correlate with reduced survival. A matched case-control analysis with multivariate logistic regression was used to identify factors predicting delay. Results. Of N = 123 patients accrued, 90 (73%) reported symptom-presentation duration and formed the basis of this study: 52 patients presented within 12 weeks of symptoms, while 38 patients waited longer than 12 weeks. On logistic regression, lower education status (OR = 5.6, P = 0.03), failure to initially recognize mass as important (OR = 13.0, P < 0.01), and fear of treatment cost (OR = 8.3, P = 0.03) were shown to independently predict delayed patient presentation. Conclusion. To reduce stage at presentation, future interventions must educate patients on the recognition of initial breast cancer signs and symptoms and address cost concerns by providing care free of charge and/or advertising that existing care is already free.

Cancer burden in Africa and opportunities for prevention

Cancer is an emerging public health problem in Africa. About 715,000 new cancer cases and 542,000 cancer deaths occurred in 2008 on the continent, with these numbers expected to double in the next 20 years simply because of the aging and growth of the population. Furthermore, cancers such as lung, female breast, and prostate cancers are diagnosed at much higher frequencies than in the past because of changes in lifestyle factors and detection practices associated with urbanization and economic development. Breast cancer in women and prostate cancer in men have now become the most commonly diagnosed cancers in many Sub-Saharan African countries, replacing cervical and liver cancers. In most African countries, cancer control programs and the provision of early detection and treatment services are limited despite this increasing burden. This paper reviews the current patterns of cancer in Africa and the opportunities for reducing the burden through the application of resource level interventions, including implementation of vaccinations for liver and cervical cancers, tobacco control policies for smoking-related cancers, and low-tech early detection methods for cervical cancer, as well as pain relief at the palliative stage of cancer.

Basal breast cancer: a complex and deadly molecular subtype

During the last decade, gene expression profiling of breast cancer has revealed the existence of five molecular subtypes and allowed the establishment of a new classification. The basal subtype, which represents 15-25% of cases, is characterized by an expression profile similar to that of myoepithelial normal mammary cells. Basal tumors are frequently assimilated to triple-negative (TN) breast cancers. They display epidemiological and clinico-pathological features distinct from other subtypes. Their pattern of relapse is characterized by frequent and early relapses and visceral locations. Despite a relative sensitivity to chemotherapy, the prognosis is poor. Recent characterization of their molecular features, such as the dysfunction of the BRCA1 pathway or the frequent expression of EGFR, provides opportunities for optimizing the systemic treatment. Several clinical trials dedicated to basal or TN tumors are testing cytotoxic agents and/or molecularly targeted therapies. This review summarizes the current state of knowledge of this aggressive and hard-to-treat subtype of breast cancer.

Patterns of seeking medical care among Egyptian breast cancer patients: relationship to late-stage presentation

Breast cancer is the most common cancer among Egyptian women, accounting for 37.6% of female tumors, and is often diagnosed at later stages. The objective of this study was to investigate breast cancer patient navigation through the health care system in the Nile Delta. Interviews were conducted with 163 newly diagnosed breast cancer patients at the Tanta Cancer Center (TCC), the major cancer center of the region. Patients described their medical care pathway from the initial symptom experienced until their arrival at TCC. Patients whose initial contact was with a general surgeon (OR: 7.6, 95% CI: 2.1, 27.6), primary care provider (OR: 12.2, 95% CI: 2.9, 51.0), or gynecologist (OR: 8.6, 95% CI: 1.4, 53.4) were significantly more likely to experience a delay in reaching the TCC as compared to those visiting a surgical oncologist. Overcoming health care system and patient navigation barriers in developing countries may reduce the time for breast cancer patients to reach a cancer center for early management.

Early developments in gene-expression profiling of breast tumors: potential for increasing black-white patient disparities in breast cancer outcomes?

New prognostic tests, such as gene-expression profiling (GEP) of breast tumors, are expected to prolong survival and improve the quality of life for many breast cancer patients. In this article, we argue that GEP has not been adequately validated in minority populations, and that both biological and social factors might affect the broad utility of these tests in diverse populations. We suggest that the widespread use of this technology could potentially lead to suboptimal treatment for black women, resulting in a further increase in black-white patient disparities in treatment response, morbidity and mortality rates. We argue for the need to build a large and diverse evidence base for GEP and other emerging technologies in personalized medicine.

A common variant at the TERT-CLPTM1L locus is associated with estrogen receptor-negative breast cancer

Estrogen receptor (ER)-negative breast cancer shows a higher incidence in women of African ancestry compared to women of European ancestry. In search of common risk alleles for ER-negative breast cancer, we combined genome-wide association study (GWAS) data from women of African ancestry (1,004 ER-negative cases and 2,745 controls) and European ancestry (1,718 ER-negative cases and 3,670 controls), with replication testing conducted in an additional 2,292 ER-negative cases and 16,901 controls of European ancestry. We identified a common risk variant for ER-negative breast cancer at the TERT-CLPTM1L locus on chromosome 5p15 (rs10069690: per-allele odds ratio (OR) = 1.18 per allele, P = 1.0 × 10(-10)). The variant was also significantly associated with triple-negative (ER-negative, progesterone receptor (PR)-negative and human epidermal growth factor-2 (HER2)-negative) breast cancer (OR = 1.25, P = 1.1 × 10(-9)), particularly in younger women (<50 years of age) (OR = 1.48, P = 1.9 × 10(-9)). Our results identify a genetic locus associated with estrogen receptor negative breast cancer subtypes in multiple populations.

Prevalence and prognostic role of triple-negative breast cancer by race: a surveillance study

INTRODUCTION

Emerging research suggests a substantially greater prevalence of the adverse triple-negative (TN) subtype (human epidermal growth factor receptor [HER]2(-), estrogen receptor [ER](-), and progesterone receptor [PR])(-)) among black patients with breast cancer. No reports however have been generated from a statewide cancer registry.

PATIENTS AND METHODS

The study consisted of all black patients (N = 643) and a random sample of white patients (n = 719) diagnosed with primary invasive breast cancer (2000-2003) listed in the National Cancer Institute-Surveillance Epidemiology and End Results (NCI-SEER) Connecticut Tumor Registry (CTR). HER2 status was obtained from pathology reports submitted to the registry. Remaining data were obtained from the registry database.

RESULTS

TN tumors were more prevalent in black compared with white patients (30.8% vs. 11.2%, respectively; P < .001.) There was a 2-fold greater frequency of ER(-) and PR(-) phenotypes among black patients, but HER2 status did not differ by race. Patients with lobular cancer were less likely to have TN breast cancer compared with patients with ductal tumors (odds ratio [OR] = 0.23; 95% confidence interval [CI], 0.10-0.58). Among patients with regional disease, black patients exhibited increased risk of death (relative risk [RR] = 2.71; 95% CI, 1.48-4.97) independent of TN status. No survival disparity was found among patients with local disease.

DISCUSSION

These registry-based data corroborate reports that TN breast cancer varies substantially by race and histologic subtype. A survival disparity among patients with advanced disease, but not local disease, casts some doubt on TN status as an explanation for differences.

CONCLUSION

More research is warranted to understand why black patients with advanced breast cancer may be at increased risk for death whether or not their tumors express the TN phenotype.

Molecular subtype analysis determines the association of advanced breast cancer in Egypt with favorable biology

BACKGROUND

Prognostic markers and molecular breast cancer subtypes reflect underlying biological tumor behavior and are important for patient management. Compared to Western countries, women in North Africa are less likely to be prognosticated and treated based on well-characterized markers such as the estrogen receptor (ER), progesterone receptor (PR) and Her2. We conducted this study to determine the prevalence of breast cancer molecular subtypes in the North African country of Egypt as a measure of underlying biological characteristics driving tumor manifestations.

METHODS

To determine molecular subtypes we characterized over 200 tumor specimens obtained from Egypt by performing ER, PR, Her2, CK5/6, EGFR and Ki67 immunohistochemistry.

RESULTS

Our study demonstrated that the Luminal A subtype, associated with favorable prognosis, was found in nearly 45% of cases examined. However, the basal-like subtype, associated with poor prognosis, was found in 11% of cases. These findings are in sharp contrast to other parts of Africa in which the basal-like subtype is over-represented.

CONCLUSIONS

Egyptians appear to have favorable underlying biology, albeit having advanced disease at diagnosis. These data suggest that Egyptians would largely profit from early detection of their disease. Intervention at the public health level, including education on the benefits of early detection is necessary and would likely have tremendous impact on breast cancer outcome in Egypt.

Molecular stratification of triple-negative breast cancers

Research focused on the analysis and classification of breast tumors, primarily using DNA microarrays and patterns of gene expression, has resulted in distinct tumor subtypes. Although no knowledge of patient survival or outcomes was used to derive these gene descriptions, these different classes based upon patterns of gene expression have important prognostic implications. Predictive markers in estrogen receptor-negative and triple-negative disease will be particularly important because in the absence of therapy, these tumor subtypes tend to have a poor prognosis. In addition, the claudin-low subgroup has been found to be common within the triple-negative cancers and may have further prognostic and therapeutic implications. Patients with triple-negative breast cancer do benefit from chemotherapy, but better treatment options are needed that are less toxic, reduce the risk of disease progression, and are more targeted to this patient population. Potential treatments include poly (ADP-ribose) polymerase inhibitors, and therapies that target cancer stem cells could also have an important impact in these patients. This article will focus on the molecular stratification of triple-negative breast cancers and the therapeutic implications of these classifications.

Pathological features of Breast Cancer seen in Northwestern Tanzania: a nine years retrospective study

BACKGROUND

Breast cancer is more common in Western Countries compared to African populations. However in African population, it appears that the disease tends to be more aggressive and occurring at a relatively young age at the time of presentation. The aim of this study was to describe the trend of Breast Cancer in Northwestern Tanzania.

METHODS

This was a retrospective study which involved all cases of breast cancer diagnosed histologically at Bugando Medical Center from 2002 to 2010. Histological results and slides were retrieved from the records in the Pathology department, clinical information and demographic data for patients were retrieved from surgical wards and department of medical records. Histology slides were re-evaluated for the histological type, grade (By modified Bloom-Richardson score), and presence of necrosis and skin involvement. Data was entered and analyzed by SPSS computer software version 15.

FINDINGS

There were 328 patients histologically confirmed to have breast cancer, the mean age at diagnosis was 48.7 years (+/- 13.1). About half of the patients (52.4%) were below 46 years of age, and this group of patients had significantly higher tendency for lymph node metastasis (p = 0.012). The tumor size ranged from 1 cm to 18 cm in diameter with average (mean) of 5.5 cm (+/- 2.5), and median size of 6 cm. Size of the tumor (above 6 cm in diameter) and presence of necrosis within the tumor was significantly associated with high rate of lymph node metastasis (p = 0.000). Of all patients, 64% were at clinical stage III (specifically IIIB) and 70.4% had lymph node metastasis at the time of diagnosis. Only 4.3% of the patients were in clinical stage I at the time of diagnosis. Majority of the patients had invasive ductal carcinoma (91.5%) followed by mucinous carcinoma (5.2%), Invasive lobular carcinoma (3%) and in situ ductal carcinoma (0.3%). In all patients, 185 (56.4%) had tumor with histological grade 3.

CONCLUSION

Breast cancer in this region show a trend towards relative young age at diagnosis with advanced stage at diagnosis and high rate of lymph node metastasis. Poor Referral system, lack of screening programs and natural aggressive biological behavior of tumor may contribute to advanced disease at the time of diagnosis.