Variation In Breast Cancer Incidence Research Articles

Disparities in Breast Cancer Mortality Rates in Israel among Urban and Rural Women

Breast cancer is a leading cause of death. There are a number of risk factors for breast cancer mortality including parity, age, ethnicity, genetic history, and place of residence. This study examined the disparities in breast cancer-related mortality rates among women from urban areas compared to rural areas in Israel. This was a retrospective, follow-up study on mortality from breast cancer among 894,608 Israeli women born between the years of 1940 and 1960. Data was collected from the Israeli Central Bureau of Statistics, the Population Authority, the Education Ministry, and the Health Ministry. Over 80% of women lived in urban areas. A higher incidence of mortality from breast cancer in Israel was found among urban women compared to rural women (1047.8/100,000 compared to 837/100,000, respectively). Even after adjusting for sociodemographic variables, higher mortality rates were found among women from urban areas in Israel compared to women from rural areas in Israel. It is believed that environmental factors can partially explain the geographic variation of breast cancer incidence, and that breast cancer incidence is likely a complex interaction between genetic, environmental, and health factors.

Associations of Obesity, Physical Activity, and Screening With State-Level Trends and Racial and Ethnic Disparities of Breast Cancer Incidence and Mortality in the US

Breast cancer causes disproportionate disease burden among various racial and ethnic groups in the US. However, state-level temporal trends and racial and ethnic disparities and whether metabolic and lifestyle factors and screening access are associated with temporal changes remain largely unknown. To investigate temporal trends and racial and ethnic variations at the state level and ecological correlations between obesity, physical activity, and mammography screening and breast cancer incidence and mortality trends among women in the US. A cross-sectional study was conducted to analyze breast cancer incidence and mortality trends among women in the US from January 1, 1999, to December 31, 2017, whereas an ecological analysis was performed to assess the associations. Data were analyzed from March 1, 2021, to September 30, 2021. Population-based cancer registry data were obtained from US Cancer Statistics incidence and mortality data. Prevalence of obesity, physical activity, and mammography screening were obtained from the Behavioral Risk Factor Surveillance System. Prevalence of obesity, physical activity, and mammography screening. Breast cancer incidence and mortality trends from 1999 to 2017 in the 50 US states and the District of Columbia. A total of 4 136 123 breast cancer cases and 782 454 deaths were included in the analysis, with a significant reduction in incidence (average annual percent change [AAPC], -0.4% [95% CI, -0.6% to -0.2%)]) and mortality (AAPC, -1.7% [95% CI, -1.8% to -1.5%]) during the study period. A significant state-level variation in breast cancer incidence and mortality between White women and those of other races and ethnicities was observed. A significant positive correlation was found between obesity and breast cancer incidence (r = 0.316; P = .02) and mortality (r = 0.400; P = .004) and an inverse correlation was found between physical activity and incidence (r = -0.577; P < .001) in women 55 years or older and mammography screening and mortality trends (r = -0.644; P < .001) in women 40 years or older. The findings of this cross-sectional study suggest that racial and ethnic disparities exist at the state level with regard to breast cancer incidence and mortality among women in the US. Metabolic and lifestyle factors and screening access were associated with the observed trends and racial and ethnic disparities. Interventions targeting these factors may help reduce the incidence of breast cancer and related deaths.

Revisiting the MMTV Zoonotic Hypothesis to Account for Geographic Variation in Breast Cancer Incidence.

Human breast cancer incidence varies by geographic location. More than 20 years ago, we proposed that zoonotic transmission of the mouse mammary tumor virus (MMTV) from the western European house mouse, Mus musculus domesticus, might account for the regional differences in breast cancer incidence. In the intervening years, several developments provide additional support for this hypothesis, including the limited impact of genetic factors for breast cancer susceptibility revealed by genome-wide association studies and the strong effect of antiretroviral therapy to reduce breast cancer incidence. At the same time, economic globalization has further expanded the distribution of M. m. domesticus to Asia, leading to a significant increase in breast cancer incidence in this region. Here, we revisit this evidence and provide an update to the MMTV zoonotic hypothesis for human breast cancer at a time when the world is recovering from the global COVID-19 zoonotic pandemic. We present evidence that mouse population outbreaks are correlated with spikes in breast cancer incidence in Australia and New Zealand and that globalization has increased the range of M. m. domesticus and MMTV. Given the success of global vaccination campaigns for HPV to eradicate cervical cancer, a similar strategy for MMTV may be warranted. Until breast cancer incidence is reduced by such an approach, zoonotic transmission of MMTV from mice to humans as an etiologic factor for breast cancer will remain controversial.

The Role of Stress in Breast Cancer Incidence: Risk Factors, Interventions, and Directions for the Future.

Stress is a common belief among breast cancer patients and the public to explain variation in breast cancer incidence. Epidemiological studies interrogating the relationship between stress and cancer have reported mixed results. The impact of the topic and the lack of consensus has sparked this review of the literature to investigate gaps in knowledge and identify areas of research. We first present a brief summary of the biopsychosocial model generally used to conduct research on stress. We then divide the overview of the literature into areas of research focus. These include the role of distressing life events in breast cancer incidence, the role of adverse childhood events in later breast cancer incidence, the importance of race and socioeconomic status (SES) as social determinants of breast cancer incidence, and the specific role of chronic stress in relation to breast cancer. For each topic, we discuss the potential of stress as a risk factor and possible intervention strategies that could reduce the effects of stress. We then identify further research questions to be probed to fill the gaps in knowledge. We conclude with a discussion of future research directions for stress research as it relates to breast cancer incidence.

International variation in breast cancer incidence and mortality in young women.

Breast cancer in young women (< 40 years) is rare and carries a poor prognosis relative to breast cancer in older women. Most studies examining global breast cancer patterns do not describe the trends in young women specifically. Data from GLOBOCAN 2018 were used to compare breast cancer incidence and mortality rates among younger (ages 0-39) vs. older (ages 40+) women across 185 countries. The coefficient of variation (the ratio of the standard deviation to the mean) was used to quantify relative variability. The risk of developing breast cancer to age 39 ranged from 0.13% in Guinea to 0.95% in South Korea (coefficient of variation: 46%), and the risk of death from breast cancer to age 39 ranged from 0.02% in China to 0.72% in Cameroon (coefficient of variation: 81%). In contrast, the risk of developing breast cancer to age 74 ranged from 1.5% in Mozambique to 12.2% in Belgium (coefficient of variation: 50%), and the risk of death from breast cancer to age 74 ranged from 0.65% in South Korea to 3.0% in Somalia (coefficient of variation: 36%). Among young women, breast cancer mortality rates varied more worldwide than breast cancer incidence. In contrast, among older women/women of all ages, breast cancer incidence varied more than breast cancer mortality. Further research is required to examine the impact of stage at diagnosis, clinicopathologic features, and treatments received, on variations in the survival and mortality of breast cancer in young women around the world.

Assessing Endogenous and Exogenous Hormone Exposures and Breast Development in a Migrant Study of Bangladeshi and British Girls.

Timing of breast development (or thelarche) and its endogenous and exogenous determinants may underlie global variation in breast cancer incidence. The study objectives were to characterize endogenous estrogen levels and bisphenol A (BPA) exposure using a migrant study of adolescent girls and test whether concentrations explained differences in thelarche by birthplace and growth environment. Estrogen metabolites (EM) and BPA-glucuronide (BPA-G) were quantified in urine spot samples using liquid chromatography tandem mass spectrometry (LC-MS/MS) from a cross-sectional study of Bangladeshi, first- and second-generation Bangladeshi migrants to the UK, and white British girls aged 5–16 years (n = 348). Thelarche status at the time of interview was self-reported and defined equivalent to Tanner Stage ≥2. We compared geometric means (and 95% confidence interval (CIs)) of EM and BPA-G using linear regression and assessed whether EM and BPA-G explained any of the association between exposure to the UK and the age at thelarche using hazard ratios and 95% confidence intervals. Average EM decreased with exposure to the UK, whereas BPA-G increased and was significantly higher among white British (0.007 ng/mL, 95% CI: 0.0024–0.0217) and second-generation British-Bangladeshi girls (0.009 ng/mL, 95% CI: 0.0040–0.0187) compared to Bangladeshi girls (0.002 ng/mL, 95% CI: 0.0018–0.0034). Two of four EM ratios (16-pathway/parent and parent/all pathways) were significantly associated with thelarche. The relationship between exposure to the UK and thelarche did not change appreciably after adding EM and BPA-G to the models. While BPA-G is often considered a ubiquitous exposure, our findings suggest it can vary based on birthplace and growth environment, with increasing levels for girls who were born in or moved to the UK. Our study did not provide statistically significant evidence that BPA-G or EM concentrations explained earlier thelarche among girls who were born or raised in the UK.

Assessing and Explaining Geographic Variations in Mammography Screening Participation and Breast Cancer Incidence.

Investigating geographic variations in mammography screening participation and breast cancer incidence help improve prevention strategies to reduce the burden of breast cancer. This study examined the suitability of health insurance claims data for assessing and explaining geographic variations in mammography screening participation and breast cancer incidence at the district level. Based on screening unit data (1,181,212 mammography screening events), cancer registry data (13,241 incident breast cancer cases) and claims data (147,325 mammography screening events; 1,778 incident breast cancer cases), screening unit and claims-based standardized participation ratios (SPR) of mammography screening as well as cancer registry and claims-based standardized incidence ratios (SIR) of breast cancer between 2011 and 2014 were estimated for the 46 districts of the German federal state of Lower Saxony. Bland-Altman analyses were performed to benchmark claims-based SPR and SIR against screening unit and cancer registry data. Determinants of district-level variations were investigated at the individual and contextual level using claims-based multilevel logistic regression analysis. In claims and benchmark data, SPR showed considerable variations and SIR hardly any. Claims-based estimates were between 0.13 below and 0.14 above (SPR), and between 0.36 below and 0.36 above (SIR) the benchmark. Given the limited suitability of health insurance claims data for assessing geographic variations in breast cancer incidence, only mammography screening participation was investigated in the multilevel analysis. At the individual level, 10 of 31 Elixhauser comorbidities were negatively and 11 positively associated with mammography screening participation. Age and comorbidities did not contribute to the explanation of geographic variations. At the contextual level, unemployment rate was negatively and the proportion of employees with an academic degree positively associated with mammography screening participation. Unemployment, income, education, foreign population and type of district explained 58.5% of geographic variations. Future studies should combine health insurance claims data with individual data on socioeconomic characteristics, lifestyle factors, psychological factors, quality of life and health literacy as well as contextual data on socioeconomic characteristics and accessibility of mammography screening. This would allow a comprehensive investigation of geographic variations in mammography screening participation and help to further improve prevention strategies for reducing the burden of breast cancer.

Spatial Clusters of Breast Cancer Mortality and Incidence in the Contiguous USA: 2000-2014.

Clusters of breast cancer with varied incidence or mortality are known to exist. No national scale of analysis of geographical variation in breast cancer incidence has been published before for the contiguous USA. This was a spatial cluster analysis of incidence and mortality data on breast cancer in the contiguous USA at the county resolution. Data for the years 2000-2014 were downloaded and analyzed with the software SaTScan with the goal to identify significant spatial clusters of breast cancer. Regression analysis was used to then adjust breast cancer incidence and mortality for several key risk factors such as age, smoking, particulate matter air pollution, physical inactivity, urban living, education level, and race. Spatial clusters of counties for higher than expected breast cancer incidence and also for breast cancer mortality were identified. All identified clusters have p < 0.05. The mortality clusters show the mean breast cancer rates inside the cluster, while the incidence clusters show the relative risk inside each cluster. This is the first study of the contiguous USA for breast cancer mortality and incidence together. The clustering for mortality is quite different from the clustering for incidence. Using the software JOINPOINT, it is shown that the annual US downward trend for breast cancer mortality slowed down in recent years. There exist several significant clusters in the contiguous USA, both for breast cancer incidence and for breast cancer mortality. Some of the clusters persisted even after adjusting for several key risk factors. These geographic areas warrant further investigation to potentially identify additional local concerns or needs to further address female breast cancer in those specific sites.

Impact of Chemotherapy Treatments on Dietary Intakes of Macro and Micronutrients among Jordanian Women with Breast Cancer

Background: Breast cancer (BC) is the leading cause of cancer related deaths among women worldwide. Nutritional factors may account for the large variation in BC incidence around the world. Most studies have shown no link between dietary intakes and increased risk of BC.Objective: To evaluate the dietary intake of macro and some micronutrients among BC patients with respect to chemotherapy treatment.Methods: A total of 168 BC patients aged 20-70 years attending BC clinics at the Jordanian Royal Medical Services, Jordan were evaluated for dietary intake. The study design permitted to include 60 newly-diagnosed BC patients who were not exposed to any type of interventions and 108 recently-diagnosed BC patients (up to three months). Recently group member were sub-divided in two sub-groups to control exposure to chemotherapy. The Chemo group (have exposed to chemotherapy) and the non-chemo group (have exposed to other types of treatments interventions). Calculations were based on the computerized nutrient analysis program (the food processor nutrition and fitness analysis software (ESHA), version 10.6/.3, Salem, USA).Results: Energy, macronutrients and micronutrients intakes were not significantly different considering exposure to chemotherapy. However, they were less than recommended in all BC patients.Conclusion: The possible risk of dietary undernutrition among BC patients that need a careful monitoring, evaluation and managements care plan.

Are Global Breast Cancer Incidence and Mortality Patterns Related to Country-Specific Economic Development and Prevention Strategies?

PurposeThere remains considerable international variation in breast cancer incidence and mortality, but a comprehensive examination of rates by country level economic, development and cancer prevention policies is lacking.Materials and MethodsWe compared GLOBOCAN 2012 age-specific breast cancer incidence and mortality rates for 177 countries by using development and policy data available from the WHO Global Cancer Country Profiles data base. We classified each country on the basis of gross national income per capita from the World Development Indicators data base, as follows: low-income country (LIC), lower-middle–income country (LMIC), upper-middle–income country (UMIC), and high-income country (HIC).ResultsThere were 1,651,326 breast cancer cases and 516,868 breast cancer deaths estimated in 2012. Approximately three quarters of all breast cancer cases and 60% of the breast cancer deaths were in women from HICs and UMICs. Age and country-level income explained approximately 60% of the international variation in breast cancer incidence and mortality in women of all ages (adjusted R2 = 58% and 60%, respectively). Economic development indicators additionally increased the overall variation in incidence and mortality by approximately 5%. In women younger than age 50 years, country-level income explained 68% of incidence and 59% of mortality; economic development indicators additionally increased this percentage by approximately 4%. Country-level cancer prevention policy indicators contributed little to explanation of the overall variation in incidence and mortality after analysis accounted for age and country-level income; however, an overall resource summary index of greater economic development and cancer prevention policies was related to lower mortality within each major income level.ConclusionAlthough breast cancer incidence increases with higher income levels in all ages, women in the poorest countries bear a relatively higher burden of breast cancer mortality, particularly women younger than age 50 years.

Ambient air emissions of polycyclic aromatic hydrocarbons and female breast cancer incidence in US.

To examine ambient air pollutants, specifically polycyclic aromatic hydrocarbons (PAHs), as a factor in the geographic variation of breast cancer incidence seen in the US, we conducted an ecological study involving counties throughout the US to examine breast cancer incidence in relation to PAH emissions in ambient air. Age-adjusted incidence rates of female breast cancer from the surveillance, epidemiology, and end results (SEER) program of the US National Cancer Institute were collected and analyzed using SEER*Stat 8.3.2. PAH emissions data were obtained from the Environmental Protection Agency. Linear regression analysis was performed using SPSS 23 software for Windows to analyze the association between PAH emissions and breast cancer incidence, adjusting for potential confounders. Age-adjusted incidence rates of female breast cancer were found being significantly higher in more industrialized metropolitan SEER regions over the years of 1973-2013 as compared to less industrialized regions. After adjusting for sex, race, education, socioeconomic status, obesity, and smoking prevalence, PAH emission density was found to be significantly associated with female breast cancer incidence, with the adjusted β of 0.424 (95% CI 0.278, 0.570; p < 0.0001) for emissions from all sources and of 0.552 (95% CI 0.278, 0.826; p < 0.0001) for emissions from traffic source. This study suggests that PAH exposure from ambient air could play a role in the increased breast cancer risk among women living in urban areas of the US. Further research could provide insight into breast cancer etiology and prevention.

Differences in breast cancer incidence among young women aged 20-49years by stage and tumor characteristics, age, race, and ethnicity, 2004-2013.

Younger women diagnosed with breast cancer have poorer prognoses and higher mortality compared to older women. Young black women have higher incidence rates of breast cancer and more aggressive subtypes than women of other races/ethnicities. In this study, we examined recent trends and variations in breast cancer incidence among young women in the United States. Using 2004-2013 National Program of Cancer Registries and Surveillance, Epidemiology, and End Results Program data, we calculated breast cancer incidence rates and trends and examined variations in stage, grade, and tumor subtype by age and race/ethnicity among young women aged 20-49years. The majority of breast cancer cases occurred in women aged 40-44 and 45-49years (77.3%). Among women aged<45years, breast cancer incidence was highest among black women. Incidence trends increased from 2004 to 2013 for Asian or Pacific Islander (API) women and white women aged 20-34years. Black, American Indian or Alaska Native, and Hispanic women had higher proportions of cases diagnosed at later stages than white and API women. Black women had a higher proportion of grade III-IV tumors than other racial/ethnic groups. Across all age groups, incidence rates for triple-negative breast cancer were significantly higher in black women than women of other races/ethnicities, and this disparity increased with age. Breast cancer among young women is a highly heterogeneous disease. Differences in tumor characteristics by age and race/ethnicity suggest opportunities for further research into personal and cultural factors that may influence breast cancer risk among younger women.

Geographic variations in female breast cancer incidence in relation to ambient air emissions of polycyclic aromatic hydrocarbons.

A significant geographic variation of breast cancer incidence exists, with incidence rates being much higher in industrialized regions. The objective of the current study was to assess the role of environmental factors such as exposure to ambient air pollution, specifically carcinogenic polycyclic aromatic hydrocarbons (PAHs) that may be playing in the geographic variations in breast cancer incidence. Female breast cancer incidence and ambient air emissions of PAHs were examined in the northeastern and southeastern regions of the USA by analyzing data from the Surveillance, Epidemiology, and End Results (SEER) Program and the State Cancer Profiles of the National Cancer Institute and from the Environmental Protection Agency. Linear regression analysis was conducted to evaluate the association between PAH emissions and breast cancer incidence in unadjusted and adjusted models. Significantly higher age-adjusted incidence rates of female breast cancer were seen in northeastern SEER regions, when compared to southeastern regions, during the years of 2000-2012. After adjusting for potential confounders, emission densities of total PAHs and four carcinogenic individual PAHs (benzo[a]pyrene, dibenz[a,h]anthracene, naphthalene, and benzo[b]fluoranthene) showed a significantly positive association with annual incidence rates of breast cancer, with a β of 0.85 (p=0.004), 58.37 (p=0.010), 628.56 (p=0.002), 0.44 (p=0.041), and 77.68 (p=0.002), respectively, among the northeastern and southeastern states. This study suggests a potential relationship between ambient air emissions of carcinogenic PAHs and geographic variations of female breast cancer incidence in the northeastern and southeastern US. Further investigations are needed to explore these interactions and elucidate the role of PAHs in regional variations of breast cancer incidence.

Survey of Breast Cancer Incidence in the Middle East and the United States

Breast cancer is the most frequent cancer and the leading cause of cancer deaths in women worldwide. Regional comparisons of breast cancer incidence can shed light on population and health care factors that contribute to differences between countries. We surveyed breast cancer incidence in four population based cancer registries in the Middle East to identify factors associated with regional variations in breast cancer incidence.

Geography of breast cancer incidence according to age & birth cohorts

PurposeGeographic variation in breast cancer incidence across Connecticut was examined according to age and birth cohort –specific groups. MethodsWe assigned each of 60,937 incident breast cancer cases diagnosed in Connecticut, 1986–2009, to one of 828 census tracts around the state. Global and local spatial statistics estimated rate variation across the state according to age and birth cohorts. ResultsWe found the global distribution of incidence rates across places to be more heterogeneous for younger women and later birth cohorts. Concurrently, the spatial scan identified more locations with significantly high rates that pertained to larger proportions of at-risk women within these groups. Geographic variation by age groups was more pronounced than by birth cohorts. ConclusionGeographic patterns of cancer incidence exhibit differences within and across age and birth cohorts. With the continued insights from descriptive epidemiology, our capacity to effectively limit spatial disparities in cancer will improve.

Comparison of Bayesian Spatial Ecological Regression Models for Investigating the Incidence of Breast Cancer in Iran, 2005- 2008

Breast cancer is the most prevalent kind of cancer among women in Iran. Regarding the importance of cancer prevention and considerable variation of breast cancer incidence in different parts of the country, it is necessary to recognize regions with high incidence of breast cancer and evaluate the role of potential risk factors by use of advanced statistical models. The present study focussed on incidence of breast cancer in Iran at the province level and also explored the impact of some prominent covariates using Bayesian models. All patients diagnosed with breast cancer in Iran from 2005 to 2008 were included in the study. Smoking, fruit and vegetable intake, physical activity, obesity and the Human Development Index (HDI), measured at the province level, were considered as potential modulating factors. Gamma-Poisson, log normal and BYM models were used to estimate the relative risk of breast cancer in this ecological investigation with and without adjustment for the covariates. The unadjusted BYM model had the best fit among applied models. Without adjustment, Isfahan, Yazd, and Tehran had the highest incidences and Sistan- Baluchestan and Chaharmahal-Bakhtiari had the lowest. With the adjusted model, Khorasan-Razavi, Lorestan and Hamedan had the highest and Ardebil and Kohgiluyeh-Boyerahmad the lowest incidences. A significantly direct association was found between breast cancer incidence and HDI. BYM model has better fit, because it contains parameters that allow including effects from neighbors. Since HDI is a significant variable, it is also recommended that HDI should be considered in future investigations. This study showed that Yazd, Isfahan and Tehran provinces feature the highest crude incidences of breast cancer.

Exposures To Hazardous Air Pollutants And The Risk Of Incident Breast Cancer

Background: There is increasing concern that environmental exposures, such as hazardous air pollutants (HAPS), may be related to breast cancer and may explain some of the geographic variation in breast cancer incidence. A recent analysis in the California Teachers Study identified a few HAPs that were associated with an increased risk of incident breast cancer. We examined the association of exposures to these HAPS with risk of incident breast cancer in the prospective nationwide Nurses' Health Study II (NHSII) cohort. Methods: The NHSII cohort began in 1989 and is followed biennially to obtain time-varying information on disease incidence and potential risk factors (e.g. demographics, lifestyle and reproductive factors). Self-reported breast cancer diagnoses are confirmed by medical record review. Census tract-level information on 38 HAPS was obtained from the USEPA and assigned to each residential address throughout follow-up. Multivariate time-varying Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (95%CIs). Results: From 1989-2011, 1,926 incident cases of breast cancer occurred among 67,021 NHSII participants with exposure information available. Only 24 of the HAPS examined had values =0 for at least 75% of the participants, and there was little evidence of an increased risk of overall breast cancer with any of the HAPs in multivariate adjusted models using linear exposure-response functions. Elevated risks were noted, however, for women in the upper three quartiles of exposure to 1,2-dibromo-3-chloropropane (HRs=1.24, 1.50, 1.58), 2,4-dinitrotoluene (HRs=2.76, 2.77, 2.46), ethylene dichloride (HRs=1.17, 1.18, 1.12), vinyl chloride (HRs=1.19, 1.11, 1.09), and diesel exhaust (HRs=1.06, 1.05, 1.13), when compared to women in the lowest quartile of each exposure. Conclusions: These results add to a growing body of literature suggesting that HAPS may be associated with increased risk of breast cancer.

Ethnicity differences in breast cancer stage at the time of diagnosis in Norway.

Several studies have demonstrated that breast cancer survival rates differ with ethnicity. Most of these studies analyzed discrepancies between African-American and Caucasian-American women and were performed in the United States. There are increasing concerns about differences in breast cancer survival among immigrants from Asia and Africa living in Europe, including those living in Scandinavian countries. There are few data on breast cancer survival in relation to race or ethnicity in Scandinavian countries, even though immigrants from Asia and Africa have lived in Scandinavian countries for decades. The aim of this study was to identify variations in breast cancer incidence, treatment modalities, relapse, and survival among women from Pakistan, Sri Lanka, and Somalia compared to ethnic Norwegian women. The incidence, treatment modalities, relapse, and survival of breast cancer were analyzed in women from Pakistan, Sri Lanka, and Somalia in a nation-based study over a period of 7 ears. Results for women from Pakistan, Sri Lanka, and Somalia were compared with those from a group of ethnic Norwegian women during the same period. In our study, 63 patients from Pakistan, Sri Lanka, and Somalia were diagnosed with breast cancer during the period 2002-2009 in Norway. Comparison between women from Pakistan, Sri Lanka, and Somalia and ethnic women from Norway revealed significant differences in cancer stage at the time of diagnosis, age at diagnosis, type of surgical treatment, and relapse and breast cancer mortality rates. The findings of this study demonstrate that the outcome after a breast cancer diagnosis is significantly worse for women from Pakistan, Sri Lanka, and Somalia than for ethnic Norwegian women. In addition, the mean age at the breast cancer diagnosis was lower for women from Pakistan, Sri Lanka, and Somalia, especially those from Sri Lanka and Somalia, than for ethnic Norwegian women.

Ethnic variation in breast cancer incidence and outcomes—the debate continues

Ethnic variation in breast cancer outcomes has been known for many decades. Much of the data derives from the US, whereas disparities seen in the United Kingdom are less well studied. Epidemiologic data suggest that the incidence of breast cancer in black women is less than that of white women, while their outcomes are significantly worse (Bowen et al, 2006). Despite advances in the treatment and detection of breast cancer, these ethnic disparities have persisted over recent years (Colditz et al, 2006). Causative factors are complex and multifaceted but those suggested to be influential include biologic variations in tumour characteristics, differential presentation, variations in co-morbidities, differences in treatment and of course socioeconomic status.

Abstract B65: Profiling and characterization of ethnicity-associated metabolic pathways in breast cancer.

Abstract Large variations in breast cancer incidence and survival among the various population groups in the United States continue to exist and differences in the clinical presentation of the disease between African American (AA) and European-American women have been recognized. Specifically, AA develop breast cancer at a relatively younger age, have a two-fold increased risk of developing triple-negative (TN) tumors and present more commonly with the stage IV disease, when compared with EA women. While the precise reasons for this disparity are still debated, genetic, environmental, and health care access/utilization factors may all contribute to the excessive burden of breast cancer among the AA patients. We therefore asked the question whether metabolomic differences in either breast tissue or body fluids may exist between AA and EA women that could help explain the substantial inequality in TN breast cancer-related outcomes. Metabolomics describes the science of quantifying the levels of metabolites (e.g., small molecules &amp;lt;1kDa) that are the byproducts of cellular metabolism. Metabolomic analysis is less complex than genomic, transcriptomic and proteomic studies (i.e., ~3,000 metabolites vs. 40,000 genes, 150,000 transcripts and 1x106 proteins) and may accentuate subtle upstream gene/protein level alterations. To date, a systematic breast cancer metabolomic analysis focusing on the distinction between AA and EA women has not been reported. Furthermore, a metabolomically derived prognostic model for TN in each of these ethnic groups has not yet been defined. The presentation will discuss our results on profiling and validating the levels of 120 metabolites in both TN breast tumors from AA and EA women and in cell lines representing the two patient groups. A subset of the functional pathways has been characterized for their activity using BIOLOG-based flux assays to identify their role in TN breast cancer. The information gleaned from this study could reveal the biochemical underpinnings of TN breast cancer health disparity Citation Format: Atsushi Terunuma, Nagireddy Putluri, Susmita Samanta, Prachi Mishra, Ewy Mathe, Tiffany H. Dorsey, Rick Kittles, Stefan Ambs. Profiling and characterization of ethnicity-associated metabolic pathways in breast cancer. [abstract]. In: Proceedings of the Fifth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2012 Oct 27-30; San Diego, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2012;21(10 Suppl):Abstract nr B65.