A review of the ethnic differences in breast cancer

Whole-genome analysis of Nigerian patients with breast cancer reveals ethnic-driven somatic evolution and distinct genomic subtypes

Black women across the African diaspora experience more aggressive breast cancer with higher mortality rates than white women of European ancestry. Although inter-ethnic germline variation is known, differential somatic evolution has not been investigated in detail. Analysis of deep whole genomes of 97 breast cancers, with RNA-seq in a subset, from women in Nigeria in comparison with The Cancer Genome Atlas (n = 76) reveal a higher rate of genomic instability and increased intra-tumoral heterogeneity as well as a unique genomic subtype defined by early clonal GATA3 mutations with a 10.5-year younger age at diagnosis. We also find non-coding mutations in bona fide drivers (ZNF217 and SYPL1) and a previously unreported INDEL signature strongly associated with African ancestry proportion, underscoring the need to expand inclusion of diverse populations in biomedical research. Finally, we demonstrate that characterizing tumors for homologous recombination deficiency has significant clinical relevance in stratifying patients for potentially life-saving therapies.

Breast cancer heterogeneity and tumour evolutionary trajectories remain largely unknown among women of African ancestry. Here, the authors perform whole genome and transcriptome sequencing of Nigerian breast cancer patients and identify unique evolutionary phenomena.

Overview of Breast Cancer and Implications of Overtreatment of Early-Stage Breast Cancer: An Indian Perspective

The prevalence and mortality of breast cancer is increasing in Asian countries, including India. With advances in medical technology leading to better detection and characterization of the disease, it has been possible to classify breast cancer into various subtypes using markers, which helps predict the risk of distant recurrence, response to therapy, and prognosis using a combination of molecular and clinical parameters. Breast cancer and its therapy, mainly surgery, systemic therapy (anticancer chemotherapy, hormonal therapy, targeted therapy, and immunotherapy), and radiation therapy, are associated with significant adverse influences on physical and mental health, quality of life, and the economic status of the patient and her family. The fear of recurrence and its devastating effects often leads to overtreatment, with a toxic cost to the patient financially and physically in cases in which this is not required. This article discusses some aspects of a breast cancer diagnosis and its impact on the various facets of the life of the patient and her family. It further elucidates the role of prognostic factors, the currently available biomarkers and prognostic signatures, and the importance of ethnically validating biomarkers and prognostic signatures.

Assessment of clinical outcome and health insurance coverage among patients with breast cancer

Breast cancer is a global health concern in terms of morbidity and mortality. Risksharing mechanisms such as health insurance provide resources and promote access to healthcare. The aim of the study was to assess the relationship between health insurance coverage and clinical outcome of breast cancer patients. The study employed retrospective design involving the use of secondary data from the patients diagnosed with breast cancer. Between the period of 2015 to 2019, 250 patients' records were reviewed from a sample size of 300 patients over 5 year patients' follow-up period. A descriptive and Kaplan Meier survival analysis was performed to determine the patients' survival rate. Seventy-two percent of the patients had health insurance cover at the time of diagnosis. Insurance status was found to be significantly associated with survival (p-values= 0.036). Insurance cover had 1.42 hazard ratio (p=0.036, 95% CI: 1.023-1.980). Patients with health insurance coverage at the time of diagnosis had a higher survival rate. No significant association was found among the demographic characteristics and the patients' clinical outcomes.

Endocrine Therapy Nonadherence and Discontinuation in Black and White Women

BACKGROUND

Differential use of endocrine therapy (ET) by race may contribute to breast cancer outcome disparities, but racial differences in ET behaviors are poorly understood.

METHODS

Women aged 20-74 years with a first primary, stage I-III, hormone receptor-positive (HR+) breast cancer were included. At 2 years postdiagnosis, we assessed nonadherence, defined as not taking ET every day or missing more than two pills in the past 14 days, discontinuation, and a composite measure of underuse, defined as either missing pills or discontinuing completely. Using logistic regression, we evaluated the relationship between race and nonadherence, discontinuation, and overall underuse in unadjusted, clinically adjusted, and socioeconomically adjusted models.

RESULTS

A total of 1280 women were included; 43.2% self-identified as black. Compared to white women, black women more often reported nonadherence (13.7% vs 5.2%) but not discontinuation (10.0% vs 10.7%). Black women also more often reported the following: hot flashes, night sweats, breast sensitivity, and joint pain; believing that their recurrence risk would not change if they stopped ET; forgetting to take ET; and cost-related barriers. In multivariable analysis, black race remained statistically significantly associated with nonadherence after adjusting for clinical characteristics (adjusted odds ratio = 2.72, 95% confidence interval = 1.75 to 4.24) and after adding socioeconomic to clinical characteristics (adjusted odds ratio = 2.44, 95% confidence interval = 1.50 to 3.97) but was not independently associated with discontinuation after adjustment. Low recurrence risk perception and lack of a shared decision making were strongly predictive of ET underuse across races.

CONCLUSIONS

Our results highlight important racial differences in ET-adherence behaviors, perceptions of benefits/harms, and shared decision making that may be targeted with culturally tailored interventions.

Low-Frequency Mutational Heterogeneity of Invasive Ductal Carcinoma Subtypes: Information to Direct Precision Oncology

Information regarding the role of low-frequency hotspot cancer-driver mutations (CDMs) in breast carcinogenesis and therapeutic response is limited. Using the sensitive and quantitative Allele-specific Competitor Blocker PCR (ACB-PCR) approach, mutant fractions (MFs) of six CDMs (PIK3CA H1047R and E545K, KRAS G12D and G12V, HRAS G12D, and BRAF V600E) were quantified in invasive ductal carcinomas (IDCs; including ~20 samples per subtype). Measurable levels (i.e., ≥ 1 × 10-5, the lowest ACB-PCR standard employed) of the PIK3CA H1047R, PIK3CA E545K, KRAS G12D, KRAS G12V, HRAS G12D, and BRAF V600E mutations were observed in 34/81 (42%), 29/81 (36%), 51/81 (63%), 9/81 (11%), 70/81 (86%), and 48/81 (59%) of IDCs, respectively. Correlation analysis using available clinicopathological information revealed that PIK3CA H1047R and BRAF V600E MFs correlate positively with maximum tumor dimension. Analysis of IDC subtypes revealed minor mutant subpopulations of critical genes in the MAP kinase pathway (KRAS, HRAS, and BRAF) were prevalent across IDC subtypes. Few triple-negative breast cancers (TNBCs) had appreciable levels of PIK3CA mutation, suggesting that individuals with TNBC may be less responsive to inhibitors of the PI3K/AKT/mTOR pathway. These results suggest that low-frequency hotspot CDMs contribute significantly to the intertumoral and intratumoral genetic heterogeneity of IDCs, which has the potential to impact precision oncology approaches.

Metabolic Syndrome and the Risk of Breast Cancer and Subtypes by Race, Menopause and BMI

The objective of this study was to investigate the association of metabolic syndrome (MetS) with the risk of invasive breast cancer and molecular subtypes across race, menopause, and body mass index (BMI) groups. We examined the association of metabolic syndrome and its components with risk of invasive breast cancer among 94,555 female participants of the National Institute of Health-American Association of Retired Persons (NIH-AARP) Diet and Health Study, accounting for ductal carcinoma in situ as a competing risk. Cox proportional hazard regression with the Fine and Gray method was used to generate hazard ratios (HR) and 95% confidence intervals (CI) adjusting for baseline sociodemographic, behavioral, and clinical covariates. During a mean follow-up of 14 years, 5380 (5.7%) women developed breast cancer. Overall, MetS at baseline was associated with a 13% increased risk of breast cancer compared to women without MetS (HR: 1.13, 95% CI: 1.00, 1.27); similar estimates were obtained among postmenopausal women (HR: 1.14, 95% CI: 1.01, 1.29). MetS was associated with a slight but non-significantly increased risk of breast cancer among those with both normal weight and overweight/obesity, and those with estrogen receptor positive breast cancer subtype. In the NIH-AARP cohort, MetS was associated with an increased risk of breast cancer. Further studies are needed to definitively evaluate the association of MetS with triple negative breast cancer subtypes across all levels of BMI.

A three-year national follow-up study on the development of community-level cancer rehabilitation in Denmark

Aims: Scandinavian cancer care policies emphasise community-level rehabilitation services, but little is known about changes in service provision over time. This follow-up study explores development in these services in Danish municipalities, focusing on availability, utilisation and organisation of services, including existing opportunities and challenges. Methods: A national survey among all 98 Danish municipalities was conducted in 2013 (baseline) and repeated in 2016 (follow-up). The electronic questionnaire comprised closed- and open-ended questions. Data were analysed using descriptive statistics and content analysis. Results: A total of 93 municipalities responded (95% response rate) and the services offered primarily comprised group physical activity, dietary advice, smoking cessation and individual counselling on physical activity. The number of patients enrolled was below the estimated number needing rehabilitation in Denmark. Inequality in utilisation by ethnicity, age and gender was reported. Key challenges for the delivery of services were: inadequate referral and recruitment procedures; lack of needs assessment tools; obstacles to ensuring collaboration and referral of patients between hospitals and municipalities; and inadequate evidence on the rehabilitation's effect. Key recommendations include ensuring collaboration between municipalities; provision of diagnosis-specific group-based activities; services focusing on physical activity; and gender-specific activities directed particularly at men. Conclusions: This study, which highlights improvements in the provision of community-level cancer rehabilitation, recommends that more effort be made to ensure equality in utilisation across patient groups, improved integration of municipal-level services into cancer care trajectories, more uniform documentation of service delivery and the enforcement of patient outcomes to gradually build a more robust evidence base for community-level cancer rehabilitation.

State of the evidence 2017: an update on the connection between breast cancer and the environment

BACKGROUND

In this review, we examine the continually expanding and increasingly compelling data linking radiation and various chemicals in our environment to the current high incidence of breast cancer. Singly and in combination, these toxicants may have contributed significantly to the increasing rates of breast cancer observed over the past several decades. Exposures early in development from gestation through adolescence and early adulthood are particularly of concern as they re-shape the program of genetic, epigenetic and physiological processes in the developing mammary system, leading to an increased risk for developing breast cancer. In the 8 years since we last published a comprehensive review of the relevant literature, hundreds of new papers have appeared supporting this link, and in this update, the evidence on this topic is more extensive and of better quality than that previously available.

CONCLUSION

Increasing evidence from epidemiological studies, as well as a better understanding of mechanisms linking toxicants with development of breast cancer, all reinforce the conclusion that exposures to these substances - many of which are found in common, everyday products and byproducts - may lead to increased risk of developing breast cancer. Moving forward, attention to methodological limitations, especially in relevant epidemiological and animal models, will need to be addressed to allow clearer and more direct connections to be evaluated.

African American Race is an Independent Risk Factor in Survival from Initially Diagnosed Localized Breast Cancer

BACKGROUND: African American race negatively impacts survival from localized breast cancer but co-variable factors confound the impact.

METHODS: Data sets were analyzed from the Surveillance, Epidemiology and End Results (SEER) directories from 1973 to 2011 consisting of patients with designated diagnosis of breast adenocarcinoma, race as White or Caucasian, Black or African American, Asian, American Indian or Alaskan Native, Native Hawaiian or Pacific Islander, age, stage I, II or III, grade 1, 2 or 3, estrogen receptor or progesterone receptor positive or negative, marital status as single, married, separated, divorced or widowed and laterality as right or left. The Cox Proportional Hazards Regression model was used to determine hazard ratios for survival. Chi square test was applied to determine the interdependence of variables found significant in the multivariable Cox Proportional Hazards Regression analysis. Cells with stratified data of patients with identical characteristics except African American or Caucasian race were compared.

RESULTS: Age, stage, grade, ER and PR status and marital status significantly co-varied with race and with each other. Stratifications by single co-variables demonstrated worse hazard ratios for survival for African Americans. Stratification by three and four co-variables demonstrated worse hazard ratios for survival for African Americans in most subgroupings with sufficient numbers of values. Differences in some subgroupings containing poor prognostic co-variables did not reach significance, suggesting that race effects may be partly overcome by additional poor prognostic indicators.

CONCLUSIONS: African American race is a poor prognostic indicator for survival from breast cancer independent of 6 associated co-variables with prognostic significance.

Hormone receptor expression and clinicopathologic features in male and female breast cancer

BACKGROUND

Male and female breast cancers were investigated for variation in the clinicopathologic characteristics and expression of steroid hormone receptors in the northeast of Iran.

MATERIALS AND METHODS

Tumor specimens of 17 males and 338 females with breast cancer were collected at the hospitals of Mashhad University of Medical Sciences. Immunohistochemical expression of hormone receptors and clinicopathologic features of breast cancer were compared between two groups.

RESULTS

The mean age in men was 15 years higher than women (p=0.000). Males and females were mainly in stage II and III respectively (p=0.007). Although more than 60% of male and female patients were grade II, the respective figures for grade I and III were 25% and 12.5% in men but 7.1% and 27.2% in women respectively (p=0.025). ER was significantly more positive in men against women; 82.3% versus 53.4% (p=0.016). The related measures for PR was 58.8% and 50.3%, respectively (p=0.424). Males also showed significantly more ER expression than postmenopausal females; 82.3% versus 48.9% (p=0.010).

CONCLUSIONS

Breast cancer in males and females contrasted in age at diagnosis, histological type, stage, grade and ER expression which emphasize they are separate diseases with different behaviors.

Health disparities across the breast cancer continuum

OBJECTIVES

To provide a brief overview of disparities across the spectrum of breast cancer incidence, treatment, and long-term care during the survivorship period.

DATA SOURCES

Review of the literature including research reports, review articles, and clinically based articles available through PubMed and CINAHL.

CONCLUSION

Minority women generally experience worse breast cancer outcomes despite a lower incidence of breast cancer than whites. A variety of factors contribute to this disparity, including advanced stage at diagnosis, higher rates of aggressive breast cancer subtypes, and lower receipt of appropriate therapies including surgery, chemotherapy, and radiation. Disparities in breast cancer care also extend into the survivorship trajectory, including lower rates of endocrine therapy use among some minority groups, as well as differences in follow-up and survivorship care.

IMPLICATIONS FOR NURSING PRACTICE

Breast cancer research should include improved minority representation and analyses by race, ethnicity, and socioeconomic status. While we cannot yet change the biology of this disease, we can encourage adherence to screening and treatment and help address the many physical, psychological, spiritual, and social issues minority women face in a culturally sensitive manner.

Quality of Care, Including Survivorship Care Plans

With the expectation of prolonged survival in the vast majority of women diagnosed with breast cancer, making initial treatment decisions that minimize or prevent late complications, and maximize the quality as well as quantity of life, is absolutely critical. Unfortunately, such care is not uniformly delivered. Patient, provider, and system barriers contribute to delays in cancer care, lower quality of care, and poorer outcomes in vulnerable populations, including low income, underinsured, and racial/ethnic minority populations. Covering the costs of cancer care is a major concern for many cancer survivors, and as a result, a major challenge will be to provide cost-effective follow-up care by reducing overuse of unnecessary tests and procedures so that access to effective medications can be preserved. One of the recently promoted means of improving the coordination of care for breast cancer survivors has been the use of survivorship care planning, as coordination of care will be absolutely essential to deliver high-quality care. Patient navigation is another approach to help overcome healthcare system barriers and facilitate timely access to quality medical care. Understanding the challenges and opportunities in delivering high-quality cancer care is one of the most critical issues of the day. With the large numbers of breast cancer patients and the tremendous advances in our understanding of the disease and treatments (leading to large numbers of survivors), breast cancer will likely be the focus of new models for the delivery of better and more efficient cancer care.

HER2-enriched tumors have the highest risk of local recurrence in Chinese patients treated with breast conservation therapy

PURPOSE

The purpose of this study was to investigate the recurrence pattern and characteristics of patients based on the 2013 St. Gallen surrogate molecular subtypes after breast-conserving surgery (BCS) in Chinese women.

METHODS

This retrospective analysis included 709 consecutive breast cancer patients undergoing BCS from 1999-2010 at our institution. Five different surrogate subtypes were created using combined expression of the estrogen receptor, progesterone receptor, and human epidermal growth factor receptor-2. Locoregional relapse-free survival (LRRFS), distant metastasis-free survival (DMFS), and disease-free survival (DFS) rates were calculated.

RESULTS

The 5-year LRRFS, DMFS, and DFS rates were 90.5%, 88.2%, and 81.5%, respectively. Multivariate analysis revealed that young age, node-positive disease, and HER2 enrichment were independent prognostic factors in LRRFS patients. There was also an independent prognostic role of lymph node-positive disease in DMFS and DFS patients. Patients with luminal A tumors had the most favorable prognosis, with LRRFS, DMFS, and DFS rates of 93.2%, 91.5%, and 87.5% at 5 years, respectively. Conversely, HER-2-enriched tumors exhibited the highest rate of recurrence (27.5%) and locoregional recurrence (11.4%).

CONCLUSION

Surrogate subtypes present with significant differences in RFS, DMFS, and LRRFS. Luminal A tumors have the best prognosis, whereas HER2-enriched tumors have the poorest.

Survival rate of breast cancer patients in Malaysia: a population-based study

Breast cancer is the most common cancer among Malaysian women. Other than hospital-based results, there are no documented population-based survival rates of Malaysian women for breast cancers. This population- based retrospective cohort study was therefore conducted. Data were obtained from Health Informatics Centre, Ministry of Health Malaysia, National Cancer Registry and National Registration Department for the period from 1st Jan 2000 to 31st December 2005. Cases were captured by ICD-10 and linked to death certificates to identify the status. Only complete data were analysed. Survival time was calculated from the estimated date of diagnosis to the date of death or date of loss to follow-up. Observed survival rates were estimated by Kaplan- Meier method using SPSS Statistical Software version 17. A total of 10,230 complete data sets were analysed. The mean age at diagnosis was 50.6 years old. The overall 5-year survival rate was 49% with median survival time of 68.1 months. Indian women had a higher survival rate of 54% compared to Chinese women (49%) and Malays (45%). The overall 5-year survival rate of breast cancer patient among Malaysian women was still low for the cohort of 2000 to 2005 as compared to survival rates in developed nations. Therefore, it is necessary to enhance the strategies for early detection and intervention.

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.

Relationship between tumor DNA methylation status and patient characteristics in African-American and European-American women with breast cancer

Aberrant DNA methylation is critical for development and progression of breast cancer. We investigated the association of CpG island methylation in candidate genes and clinicopathological features in 65 African-American (AA) and European-American (EA) breast cancer patients. Quantitative methylation analysis was carried out on bisulfite modified genomic DNA and sequencing (pyrosequencing) for promoter CpG islands of p16, ESR1, RASSF1A, RARβ2, CDH13, HIN1, SFRP1 genes and the LINE1 repetitive element using matched paired non-cancerous and breast tumor specimen (32 AA and 33 EA women). Five of the genes, all known tumor suppressor genes (RASSF1A, RARβ2, CDH13, HIN1 and SFRP1), were found to be frequently hypermethylated in breast tumor tissues but not in the adjacent non-cancerous tissues. Significant differences in the CDH13 methylation status were observed by comparing DNA methylation between AA and EA patients, with more obvious CDH13 methylation differences between the two patient groups in the ER- disease and among young patients (age<50). In addition, we observed associations between CDH13, SFRP1, and RASSF1A methylation and breast cancer subtypes and between SFRP1 methylation and patient's age. Furthermore, tumors that received neoadjuvant therapy tended to have reduced RASSF1A methylation when compared with chemotherapy naïve tumors. Finally, Kaplan Meier survival analysis showed a significant association between methylation at 3 loci (RASSF1A, RARβ2 and CDH13) and reduced overall disease survival. In conclusion, the DNA methylation status of breast tumors was found to be significantly associated with clinicopathological features and race/ethnicity of the patients.

Implications of HER2 amplification in small, node-negative breast cancers: do Asians differ?

BACKGROUND

We investigated the implications of HER2 amplification in Asian women with small, node-negative breast cancer in low- and middle-income countries (LMCs).

METHODS

We reviewed the charts patients treated between 1989 and 2009 with breast conservation therapy for node-negative breast cancers measuring ≤ 2 cm. Disease-free survival (DFS), ipsilateral breast tumor recurrence (IBTR), distant disease-free survival (DDFS), and overall survival (OS) rates were estimated using the Kaplan-Meier method and were compared by the log-rank test. Potential covariates-age, tumor grade, hormone receptor status--were analyzed by multivariate analysis.

RESULTS

A total of 519 patients were studied including 204 (39%) and 315 (61%) patients diagnosed with pT1ab and pT1c tumors, respectively. Median follow-up was 57 months. HER2 amplification was found in 17.1% of all patients and in 16.7% patients with pT1ab tumors. Among patients with T1ab tumors, 73.0 and 9.3% underwent adjuvant hormonal and chemotherapy, respectively; 3 of 34 T1ab patients with HER2-amplified tumors received trastuzumab. HER2 amplification was associated with poorer 5-year DFS (83.7% vs. 95.5%, P < 0.0001), DDFS (87.5% vs. 97.9%, P < 0.0001), and IBTR (8.6% vs. 2.1%, P < 0.0001) rates in patients with pT1 tumors. Multivariate analysis showed that HER2 amplification remained a significant negative prognostic factor for DFS [hazard ratio (HR) 4.1, 95% confidence interval (CI) 2.1-7.8, P < 0.0001], DDFS (HR 6.3, 95% CI 2.4-17.0, P < 0.0001), and IBTR (HR 4.5, 95% CI 2.0-10.0, P < 0.0001) rates. In the pT1ab subgroup, univariate analysis showed that HER2 amplification prognosticated for DFS (85.1% vs. 95.7%, P = 0.022) and IBTR (14.9% vs. 3.5%, P = 0.004) rates but not for the OS (100% vs. 99.2%, P = 0.487) rate. Similar results were obtained after excluding patients given trastuzumab.

CONCLUSIONS

The decision to use trastuzumab in HER2-amplified pT1ab tumors must balance their poor outcome against intrinsic financial limitations in LMCs. Patient selection criteria needs fine-tuning, and resource-sensitive regimens must be explored.

LMTK3 expression in breast cancer: association with tumor phenotype and clinical outcome

Interactions between kinases and the estrogen receptor α (ERα) are thought to be a critical signaling pathway in the majority of human breast cancers. We have recently identified a previously uncharacterized molecule, lemur tyrosine kinase-3 (LMTK3) as a prognostic and predictive oncogenic ERα regulator with a central role in endocrine resistance. Unusually this protein has undergone Darwinian positive selection between Chimpanzees and humans suggesting it may contribute to human susceptibility to ERα-positive tumors. Using over 600 European primary breast cancer cases, we wished to establish tumor characteristics associated with both cytoplasmic and nuclear LMTK3 expression, and then externally validate our observed European clinical outcomes with samples from Asian individuals receiving chemotherapy. Both nuclear and cytoplasmic expression correlated with tumor grade (P < 0.001) and in the Asian cohort, independent blinded analyses demonstrated that high basal LMTK3 expression was associated with advanced stage of primary breast cancers as well as decreased overall (P = 0.03) and disease-free survival (P = 0.006). In summary, higher LMTK3 expression is associated with more aggressive cancers. These data support our previous findings and suggest LMTK3 expression may be a reliable new biomarker in breast cancer.

Breast cancer: a neglected disease for the majority of affected women worldwide

Recent progress with declines in mortality in some high-income countries has obscured the fact that for the majority of women worldwide who are newly diagnosed, breast cancer is a neglected disease in the context of other numerically more frequent health problems. For this growing majority, it is also an orphan disease, in that detailed knowledge about tumor characteristics and relevant host biology necessary to provide even basic care is absent. With the possible exception of nutritional recommendations, current international cancer policy and planning initiatives are irrelevant to breast cancer. The progress that has occurred in high-income countries has come at extraordinary fiscal expense and patient toxicity, which of themselves suggest nonrelevance to women and healthcare practitioners in middle- and low-income countries. The implications of these circumstances appear clear: if the promise of the now 60-year-old Declaration of Human Rights that the fruits of medical science accrue to all mankind is to be realized with respect to breast cancer, a basic and translational global research initiative should be launched.

Hormone Receptors and HER-2 Status as Surrogates for Breast Cancer Molecular Subtypes Prognosticate for Disease Control in Node Negative Asian Patients Treated with Breast Conservation Therapy

Introduction: Our study investigates whether an approximation of breast cancer molecular subtypes using the hormone receptors and HER-2 status prognosticates for disease control after breast conservation therapy (BCT) in node-negative Asian breast cancer patients. Methods and Materials: We retrospectively reviewed 541 women with node-negative breast cancers treated with BCT between 1989 and 2007. Hormone receptors and HER-2 status were obtained from patients’ histological report. All patients received radiotherapy. Thirty-six percent and 68% of women received chemotherapy and hormonal treatment respectively. Results: Median follow-up of patients is 72 months. Five-year local recurrence free survival (LRFS) is 97.2% for the cohort but differs between subtypes: luminal A, 0.8%; luminal B, 1.4%; HER-2, 3.6% and basal-like, 12.7% (P = 0.047). The 5-year distant disease free survival (DDFS) is 96.4% for the cohort but differs between subtypes: luminal A, 98.2%; luminal B, 92.6%; HER-2, 89.5% and basal-like, 91.5% (P = 0.019). The 5-year disease free survival (DFS) is 94.4% for the cohort but differs between subtypes: luminal A, 97.4%; luminal B, 92.7%; HER-2, 86.3% and basal-like, 85.0% (P = 0.007). Univariate analysis with luminal A as baseline revealed an association of the other 3 subtypes with decreased DFS (P = 0.007), Hazard Ratio (HR) of 2.2, 4.4 and 3.3 to Luminal B, HER-2 and basal subtypes, respectively. On multivariate analysis, HER-2 subtype (AHR = 3.3, 95% CI, 1.1 to 9.8, P = 0.036) and basal-like subtype (HR = 3.5, 95% CI, 1.2 to 9.9, P = 0.019) prognosticate adversely for DFS. Conclusion: The combination of hormone receptors and HER-2 status can be used as surrogates for molecular subtypes in Asian breast cancer patients with node-negative disease to prognosticate LRFS, DFS and DDFS. Keywords: Histological subtypes, Lumpectomy, Outcomes, Prognostic factors

A profile of prognostic and molecular factors in European and Māori breast cancer patients

Background

New Zealand Māori have a poorer outcome from breast cancer than non-Māori, yet prognostic data are sparse. The objective of this study was to quantify levels of prognostic factors in a cohort of self-declared Māori and European breast cancer patients from Christchurch, New Zealand.

Methods and Results

Clinicopathological and survival data from 337 consecutive breast cancer patients (27 Māori, 310 European) were evaluated. Fewer tumours were high grade in Māori women than European women (p = 0.027). No significant ethnic differences were detected for node status, tumour type, tumour size, human epidermal growth factor receptor, oestrogen and progesterone receptor (ER/PR) status, or survival.

In addition, tumour and serum samples from a sub-cohort of 14 Māori matched to 14 NZ European patients were analyzed by immunohistochemistry and enzyme linked immunosorbent assay for molecular prognostic factors. Significant correlations were detected between increased grade and increased levels of hypoxia inducible factor-1 (HIF-1α), glucose transporter-1 (GLUT-1), microvessel density (MVD) and cytokeratins CK5/6 (p < 0.05). High nodal status correlated with reduced carbonic anhydrase IX (CA-IX). Negative ER/PR status correlated with increased GLUT-1, CA-IX and MVD. Within the molecular factors, increased HIF-1α correlated with raised GLUT-1, MVD and CK5/6, and CK5/6 with GLUT-1 and MVD (p < 0.05). The small number of patients in this sub-cohort limited discrimination of ethnic differences.

Conclusions

In this Christchurch cohort of breast cancer patients, Māori women were no more likely than European women to have pathological or molecular factors predictive of poor prognosis. These data contrast with data from the North Island NZ, and suggest potential regional differences.

A pilot trial of spirituality counseling for weight loss maintenance in African American breast cancer survivors

A continuing challenge in weight loss treatment is attaining maintenance of weight loss. The goal of this study was to develop a counseling method that would assist African American breast cancer survivors with weight loss maintenance. In this pilot study, 31 obese breast cancer survivors were recruited. Individualized, dietitian-led counseling by telephone and free Weight Watchers coupons were provided to all participants for 18 months. At the 6-month time point, women were randomized to receive spirituality counseling or not in addition to the standard program. The spirituality counseling was delivered via telephone using an 8-step framework. Subjects were asked to utilize daily meditation or prayer, daily readings, and the recording of thoughts in a journal. Mean weight loss from baseline to 6 months was a modest 2.0% of baseline weight. From 6 to 18 months, there was no further weight change in the spirituality arm and a gain of 0.7% in the dietitian-only arm. Despite little effect on weight loss, it did appear that spirituality counseling positively affected spiritual well-being (FACIT-Sp) scores and dietary quality. The spirituality counseling framework therefore may be further refined and useful for other health promotion studies with African American populations.

Associations between polycyclic aromatic hydrocarbon-related exposures and p53 mutations in breast tumors

BACKGROUND

Previous studies have suggested that polycyclic aromatic hydrocarbons (PAHs) may be associated with breast cancer. However, the carcinogenicity of PAHs on the human breast remains unclear. Certain carcinogens may be associated with specific mutation patterns in the p53 tumor suppressor gene, thereby contributing information about disease etiology.

OBJECTIVES

We hypothesized that associations of PAH-related exposures with breast cancer would differ according to tumor p53 mutation status, effect, type, and number.

METHODS

We examined this possibility in a population-based case-control study using polytomous logistic regression. As previously reported, 151 p53 mutations among 859 tumors were identified using Surveyor nuclease and confirmed by sequencing.

RESULTS

We found that participants with p53 mutations were less likely to be exposed to PAHs (assessed by smoking status in 859 cases and 1,556 controls, grilled/smoked meat intake in 822 cases and 1,475 controls, and PAH-DNA adducts in peripheral mononuclear cells in 487 cases and 941 controls) than participants without p53 mutations. For example, active and passive smoking was associated with p53 mutation-negative [odds ratio (OR) = 1.55; 95% confidence interval (CI), 1.11-2.15] but not p53 mutation-positive (OR = 0.77; 95% CI, 0.43-1.38) cancer (ratio of the ORs = 0.50, p < 0.05). However, frameshift mutations, mutation number, G:C-->A:T transitions at CpG sites, and insertions/deletions were consistently elevated among exposed subjects.

CONCLUSIONS

These findings suggest that PAHs may be associated with specific breast tumor p53 mutation subgroups rather than with overall p53 mutations and may also be related to breast cancer through mechanisms other than p53 mutation.

The influence of common polymorphisms on breast cancer

Breast cancer is one of the most frequently diagnosed cancers in the Western world and a significant cause of mortality worldwide. A small proportion of cases are accounted for by high-penetrance monogenic predisposition genes; however, this explains only a small fraction (less than 5%) of all breast cancers. Increasingly with advances in molecular technology and the development of large research consortia, the locations and identities of many low-penetrance genetic variants are being discovered. However, each variant has a very small effect similar to or smaller than many of the known environmental risk factors. It is therefore unlikely that these variants will be appropriate for predictive genetic testing, although they may identify novel pathways and genes which provide new insights and targets for therapeutic intervention. The future challenges will be identifying causal variants and determining how these low-penetrance alleles interact with each other and with environmental factors in order to usefully implement them in the practice of clinical medicine. Furthermore, it is clear that breast cancer comes in many forms with the tumour pathology and immunohistochemical profile already being used routinely as prognostic indicators and to inform treatment decisions. However, these indicators of prognosis are imperfect; two apparently identical tumours may have very different outcomes in different individuals. Inherited genetic variants may well be one of the other factors that need to be taken into account in assessing prognosis and planning treatment.

African American-preponderant single nucleotide polymorphisms (SNPs) and risk of breast cancer

BACKGROUND

African American women more often present with more aggressive types of breast cancer than Caucasian women, but little is known whether genetic polymorphisms specific to or disproportionate in African Americans are associated with their risk of breast cancer.

METHODS

A population-based case-control study was conducted including 194 cases identified through the Metropolitan Detroit Cancer Surveillance System and 189 controls recruited through random digit dialing to examine polymorphisms in genes involved in estrogen metabolism and action.

RESULTS

The African American-specific CYP1A1 5639C allele was associated with an increased risk of breast cancer (odds ratio (OR)=2.34, 95% confidence interval (CI) 1.23-4.44) and this association with the CYP1A1 5639 locus was dependent on another polymorphism in the CYP3A4 gene (P=0.043 for the interaction). In addition, African American-predominant CYP1B1 432 Val allele was significantly more often found in the cases than in the controls overall and the HSD17B1 312 Gly allele was specifically associated with premenopausal breast cancer risk (OR=3.00, 95%CI 1.29-6.99).

CONCLUSION

These observations need to be confirmed in larger studies due to the limited statistical power of the study based on a small number of cases.

Increased risk for second primary malignancies in women with breast cancer diagnosed at young age: a population-based study in Taiwan

Studies conducted in Western countries have reported excess risks for second primary malignancies after breast cancer. However, there is little documentation of ethnic differences in these excess risks. Asian women are characterized by younger age at diagnosis of breast cancer, but very few reports are available on the incidences and risks for second primary cancers in this region. Using population-based data from the Taiwan National Cancer Registry (TNCR) for the period 1979 to 2003, we quantified standardized incidence ratios and cumulative incidence of second cancers among 53,783 women with initial diagnoses of breast cancer. Age-specific incidences showed peaks among women in their 40s, and 1,085 cases (2.02%) developed nonbreast second primary cancers. The risk for second cancers differs significantly according to age at diagnosis of breast cancer. In comparison with women diagnosed when >or=50 years (standardized incidence ratio, 0.96; 95% confidence interval; 0.89-1.04), there were significantly greater risks for bone, corpus uterine, ovarian, thyroid, esophageal, kidney and lung cancers, nonmelanoma skin cancer, and leukemia or lymphoma in women diagnosed when <50 years (standardized incidence ratio, 1.43; 95% confidence interval, 1.29-1.58). The survival probabilities differed between breast cancer patients with and without second cancers (P<0.001). After diagnosis of the second cancer, the median survival time was only 2.87 years. In conclusion, we confirmed that young age at diagnosis of breast cancer predicted a subsequently increased risk for second malignancies, and the second cancers indeed worsen survivorship in patients who survived breast cancer.

Evaluation of genetic variation contributing to differences in gene expression between populations

Gene expression is a complex quantitative trait partially regulated by genetic variation in DNA sequence. Population differences in gene expression could contribute to some of the observed differences in susceptibility to common diseases and response to drug treatments. We characterized gene expression in the full set of HapMap lymphoblastoid cell lines derived from individuals of European and African ancestry for 9156 transcript clusters (gene-level) evaluated with the Affymetrix GeneChip Human Exon 1.0 ST Array. Gene expression was found to differ significantly between these samples for 383 transcript clusters. Biological processes including ribosome biogenesis and antimicrobial humoral response were found to be enriched in these differential genes, suggesting their possible roles in contributing to the population differences at a higher level than that of mRNA expression and in response to environmental information. Genome-wide association studies for local or distant genetic variants that correlate with the differentially expressed genes enabled identification of significant associations with one or more single-nucleotide polymorphisms (SNPs), consistent with the hypothesis that genetic factors and not simply population identity or other characteristics (age of cell lines, length of culture, etc.) contribute to differences in gene expression in these samples. Our results provide a comprehensive view of the genes differentially expressed between populations and the enriched biological processes involved in these genes. We also provide an evaluation of the contributions of genetic variation and nongenetic factors to the population differences in gene expression.

The HapMap Resource is Providing New Insights into Ourselves and its Application to Pharmacogenomics

The exploration of quantitative variation in complex traits such as gene expression and drug response in human populations has become one of the major priorities for medical genetics. The International HapMap Project provides a key resource of genotypic data on human lymphoblastoid cell lines derived from four major world populations of European, African, Chinese and Japanese ancestry for researchers to associate with various phenotypic data to find genes affecting health, disease and response to drugs. Recent progress in dissecting genetic contribution to natural variation in gene expression within and among human populations and variation in drug response are two examples in which researchers have utilized the HapMap resource. The HapMap Project provides new insights into the human genome and has applicability to pharmacogenomics studies leading to personalized medicine.

Triple negative breast carcinoma and the basal phenotype: from expression profiling to clinical practice

Triple negative breast carcinomas (TNBCs) are a group of primary breast tumors with aggressive clinical behavior. Most TNBCs possess a basal phenotype (BP) and show varying degrees of basal cytokeratin and myoepithelial marker expression. The importance of recognizing these tumors came to light largely as the result of gene expression profiling studies that categorized breast cancer into 3 major groups. Two of these groups are defined by their respective expression of estrogen receptor and HER2. TNBCs represent a third group and are defined by negativity for hormone receptors and HER2. TNBCs currently lack effective targeted therapies and are frequently resistant to standard chemotherapeutic regimens. These tumors tend to occur in premenopausal women and members of specific ethnic groups and a subset are associated with heritable BRCA1 mutations. For patients with sporadic TNBCs and BP tumors, BRCA1 dysfunction seems to play a major role in the development and progression of disease. The pathologist's role in the diagnosis and characterization of TNBCs and BP tumors is currently being defined as we are acquiring knowledge of the biologic and genetic underpinnings that drive this heterogeneous group of diseases. This review will provide a historical prospective on TNBCs and tumors that express basal cytokeratins and myoepithelial makers. Additionally, we will discuss the molecular biologic, genetic and pathologic aspects of these tumors. Guidelines will be provided on how to best approach the diagnosis of these cases and on what input pathologists should provide clinicians to help develop optimal therapeutic and preventative strategies against this aggressive group of breast cancers.