The Influence of Socioeconomic Status on Racial/Ethnic Disparities among the ER/PR/HER2 Breast Cancer Subtypes

Breast cancer insights from Northern Israel: a comprehensive analysis of survival rates among Jewish and Arab women

This study investigates breast cancer survival rates between 2000 and 2022 in northern Israel, focusing on ethnicity, socioeconomic status, age at diagnosis, and the Charlson Comorbidity Index. Analyzing data from Clalit Health Services, we studied 8,431 breast cancer patients (6,395 Jewish, 2,036 Arab). We compared five- and ten-year survival rates across different demographics. Ethnicity showed a minor impact on survival (OR 1.12, 95% CI: 0.93 - 1.35). Socioeconomic status had a significant effect, with a higher level of improving survival (OR 2.50, 95% CI: 2.04 - 3.08). Age was crucial; women 18-39 had better survival than 60-100, but no significant difference was found between the 18-39 and 40-59 age groups [OR (CI 0.90 - 1.53, p = 0.231)]. For the Charlson Comorbidity Index, women with scores of 3-10 showed lower survival compared to scores of 0 and 1-2. There was a notable improvement in five-year survival rates among patients aged 18-59 diagnosed from 2009-2018 (90.7%) compared to 2000-2008 (86.9%) (p = 0.0046), but not in patients aged 60-100. The study highlights that socioeconomic status, age, and comorbidity scores are significant in determining survival rates for breast cancer. The improvement in survival rates for younger patients diagnosed more recently reflects advancements in treatment and care. This research provides valuable insights into the factors affecting breast cancer survival rates, underscoring the role of socioeconomic status, age, and comorbidities while also highlighting the progress in breast cancer treatment over recent years.

Survival Disparities in US Black Compared to White Women with Hormone Receptor Positive-HER2 Negative Breast Cancer

Black women in the US have significantly higher breast cancer mortality than White women. Within biomarker-defined tumor subtypes, disparate outcomes seem to be limited to women with hormone receptor positive and HER2 negative (HR+/HER2-) breast cancer, a subtype usually associated with favorable prognosis. In this review, we present data from an array of studies that demonstrate significantly higher mortality in Black compared to White women with HR+/HER2-breast cancer and contrast these data to studies from integrated healthcare systems that failed to find survival differences. Then, we describe factors, both biological and non-biological, that may contribute to disparate survival in Black women.

Immune Lymphocyte Infiltrate and its Prognostic Value in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) occurs more frequently in young (<50 years) non-Hispanic black and Hispanic/Latina women. It is considered the most aggressive subtype of breast cancer, although, recently, immune infiltrate has been associated with long-term survival, lower risk of death and recurrence, and response to neoadjuvant chemotherapy. The aim of this review was to evaluate the clinical impact of the immune infiltrate in TNBC by discussing whether its prognostic value varies across different populations. A comprehensive systematic search in databases such as PubMed and Web of Science was conducted to include papers focused on tumor-infiltrating lymphocytes (TILs) in TNBC in different population groups and that were published before January 2021. TNBC patients with higher levels of TILs had longer overall survival and disease-free survival times compared with TNBC patients with low TIL levels. Similar results were observed for CD4+, CD8+ TIL populations. On the other hand, patients with high TIL levels showed a higher rate of pathological complete response regardless of the population group (Asian, European, and American). These results altogether suggest that TIL subpopulations might have a prognostic role in TNBC, but the underlying mechanism needs to be elucidated. Although the prognosis value of TILs was not found different between the population groups analyzed in the revised literature, further studies including underrepresented populations with different genetic ancestries are still necessary to conclude in this regard.

Gonadotropin-releasing hormone receptor inhibits triple-negative breast cancer proliferation and metastasis

BACKGROUND

Gonadotropin-releasing hormone receptor (GnRHR) is expressed in several malignant tumors and inhibits the proliferation and metastasis of cancer cells, but its role in triple-negative breast cancers (TNBCs) is unclear. This study investigated the biological effects of GnRHR and their influence on TNBC prognosis.

METHODS

The GSE21653 database was used to obtain information about GnRHR expression and clinicopathological factors in patients with TNBC. GnRHR was activated in cultured MDA-MB-231 and MDA-MB-468 cells by leuprolide acetate and antagonized by elagolix sodium. Cell proliferation was assessed by the cell counting kit-8 and colony formation assays. Cell metastasis was detected by the wound healing assay and Transwell assay. Apoptosis and the cell cycle were investigated by flow cytometry. GnRHR protein expression was determined by western blotting.

RESULTS

GnRHR mRNA expression was significantly higher in patients with TNBC than in hormone receptor+/human epidermal growth factor receptor (HER)2- and HER2+ patients with breast cancer. Patients with high GnRHR expression had significantly better disease-free survival than those with lower expression. Activated GnRHR significantly inhibited cell proliferation and metastasis, increased apoptosis, and enhanced GnRHR protein expression levels.

CONCLUSION

GnRHR inhibits TNBC proliferation and metastasis, suggesting it could be targeted for TNBC treatment.

Changing Trends in Estrogen Receptors/Progesterone Receptors/Human Epidermal Growth Factor Receptor 2 Prevalence Rates Among Jordanian Patients With Breast Cancer Over the Years

PURPOSE

Estrogen receptors (ERs), progesterone receptors (PRs), and human epidermal growth factor receptor 2 (HER2) are the mainstay of breast cancer management, and their prevalence rates vary among different populations possibly related to ethnic/genetic and/or socioeconomic status. In a previous study conducted at the King Hussein Cancer Center (published 2006), Jordan ER/PR/HER2 rates for patients diagnosed in 2003-2004 were 50.8%/57.5%/17.5%, respectively. The aim of this study is to revisit the prevalence rates to see if they have changed over the years with changing socioeconomic status.

MATERIALS AND METHODS

We retrieved clinicopathologic data of all patients (1,185) diagnosed with breast cancer during 2018. The data included age, histologic type, grade, and ER/PR/HER2 status as determined by immunohistochemistry and/or fluorescence in situ hybridization for HER2.

RESULTS

The mean age of patients was 52 (median = 51, range = 25-92) years, and the majority (73.2%) had invasive carcinoma of no special type. ER/PR/HER2 were 77.0%/72.4%./23.8%, respectively. Triple-negative breast cancers were 10.1%. In comparison with previous results of 2006, the changes are statistically significant. Similar changes were seen in other Middle Eastern populations. The current rates are close to those of Western populations.

CONCLUSION

Rates of ER/PR/HER2 expression have significantly changed and are close to those of Western populations for ER/PR. We propose that such changes are secondary to the adoption of a westernized lifestyle and socioeconomic changes.

Racial/ethnic disparities in risk of breast cancer mortality by molecular subtype and stage at diagnosis

PURPOSE

Previous research has found significant survival disparities between Black and White women among select stages and subtypes of breast cancer, however other racial/ethnic groups have been less well-studied. This study expands on previous research, examining differences in breast cancer-specific mortality across multiple racial and ethnic groups.

METHODS

Women diagnosed with a first primary invasive breast cancer between 2010 and 2016 who were 20-85 years of age at diagnosis were identified from 18 Surveillance, Epidemiology, and End Results (SEER) registries. Subtypes were defined by joint hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) status. Cox proportional hazards models for each stage and subtype were fit, with non-Hispanic white women as the reference group. Effect modification by age at diagnosis (< 50, ≥ 50) was found and thus analyses were age-stratified.

RESULTS

After multivariable adjustment, younger Black women had greater risks of breast cancer-specific death for all stages of HR+/HER2-, and certain stages of HR+/HER2+ , TN, and HR-/HER2 + breast cancer. Asian/Pacific Islander women generally had a lower hazard of breast cancer-specific death. Older Hispanic White women had a lower hazard of breast cancer-specific death for stages I-III HR + /HER2- and stage II TN breast cancer.

CONCLUSIONS

These findings demonstrate that different racial/ethnic groups experience different risks of breast cancer-specific mortality by stage and subtype. Efforts to address survival disparities should place additional focus on young Black women, as they experience meaningful disparities in breast cancer-specific mortality.

Overcoming disparities: Multidisciplinary breast cancer care at a public safety net hospital

PURPOSE

Public safety net hospitals (SNH) serve a disparate patient population; however, little is known about long-term oncologic outcomes of patients receiving care at these facilities. This study is the first to examine overall survival (OS) and the initiation of treatment in breast cancer patients treated at a SNH.

METHODS

Patients presenting to a SNH with stage I-IV breast cancer from 2005 to 2017 were identified from the local tumor registry. The hospital has a weekly breast tumor board and a multidisciplinary approach to breast cancer care. Kaplan-Meier survival analysis was performed to identify patient, tumor, and treatment characteristics associated with OS. Factors with a p < 0.1 were included in the Cox proportional hazards model.

RESULTS

2709 breast cancer patients were evaluated from 2005 to 2017. The patient demographics, tumor characteristics, and treatments received were analyzed. Five-year OS was 78.4% (93.9%, 87.4%, 70.9%, and 23.5% for stages I, II, III, and IV, respectively). On multivariable analysis, higher stage, age > 70 years, higher grade, and non-Hispanic ethnicity were associated with worse OS. Patients receiving surgery (HR = 0.33, p < 0.0001), chemotherapy (HR = 0.71, p = 0.006), and endocrine therapy (HR = 0.61, p < 0.0001) had better OS compared to those who did not receive these treatments.

CONCLUSION

Despite serving a vulnerable minority population that is largely poor, uninsured, and presenting with more advanced disease, OS at our SNH approaches national averages. This novel finding indicates that in the setting of multidisciplinary cancer care and with appropriate initiation of treatment, SNHs can overcome socioeconomic barriers to achieve equitable outcomes in breast cancer care.

Current Approaches to Cancer Genetic Counseling Services for Spanish-Speaking Patients

Barriers to genetic counseling services (GCS) utilization for Spanish-speaking patients (SSP) may include language barriers and limited availability of bilingual genetic counselors (GCs). The sample included GCs who: (1) practice cancer genetic counseling, (2) report a cancer practice setting, and (3) have a US mailing address. We assessed: (1) number of Spanish-speaking GCs, (2) estimated proportion of Hispanic patients, and (3) approaches used to counsel SSP. Of respondents (n = 229), 10% (n = 23) spoke Spanish. A higher proportion of GCs practicing in states with ≥ 25% Hispanics reported speaking Spanish compared to those in states with lower Hispanic populations (p = 0.02). While there was a significantly higher percentage of Spanish-speaking GCs in states with larger Hispanic populations, the absolute number was low and unlikely to meet the needs of patients. There is need to increase availability of GCS for SSPs and to understand the impact of services on patient health outcomes.

The Many Faces of Obesity and Its Influence on Breast Cancer Risk

Obesity is associated with increased risk of breast and other cancers. However, the complexity of the underlying mechanisms, together with the interplay of diet and physical activity—contributing to energy balance—and the role of adipose tissue, pose challenges to our understanding of the basis of this increased risk. Epidemiologic studies have documented a higher obesity prevalence in US black women compared to white women. Elucidation of the contribution of potential biological differences among racially distinct groups to their differences in breast cancer (BC) risk and mortality have been topics of considerable interest in recent years. The racial and ethnic variation in body fat distribution may account for at least part of the differences in breast cancer rates in these populations. Yet, while black women exhibit higher rates of obesity compared to white women, this does not translate directly into higher rates of BC. In fact, overall, BC in black women occurs with a lower incidence than BC in white women. Obesity is a known risk factor for postmenopausal breast cancer, and growing evidence suggests that abdominal obesity, also known as central obesity, may increase risk for triple negative breast cancer, which is more common in premenopausal women. The positive association of postmenopausal BC risk and specifically estrogen receptor (ER)-positive BC, is presumably due largely to accumulation of estrogen in the adipose tissue of the breast and other tissues. Of the two main types of adipose tissue—subcutaneous and visceral—visceral adipocytes are more active metabolically. Such adipose tissue harbors multiple molecular entities that promote carcinogenesis: endocrine molecules/hormones, immunologic factors, inflammatory cytokines, metabolic alterations, and other components of the microenvironment. Expression of these culpable entities is largely regulated by epigenetic mechanisms. The interrelationship between these entities and drivers of epigenetic alteration are critical to the regulation of pathways connecting obesity and cancer risk. Initiatives to counteract the carcinogenic effects of obesity have primarily involved modulation of energy balance by diet. However, targeting of specific molecular abnormalities characterizing adiposity offers an alternative approach to preventing cancer. Our goal in this review is to first discuss the major mechanisms contributing to the obesity-breast cancer link. We will also consider race, specifically black/white differences, as they relate to the association of obesity with breast cancer risk. Then we will enumerate strategies targeting these mechanisms to reduce BC risk, in large part by way of dietary interventions with potential to mitigate the cancer-promoting components of adiposity.

Neighborhood Social Determinants of Triple Negative Breast Cancer

Triple Negative Breast Cancer (TNBC) is an aggressive, heterogeneous subtype of breast cancer, which is more frequently diagnosed in African American (AA) women than in European American (EA) women. The purpose of this study is to investigate the role of social determinants in racial disparities in TNBC. Data on Louisiana TNBC patients diagnosed in 2010–2012 were collected and geocoded to census tract of residence at diagnosis by the Louisiana Tumor Registry. Using multilevel statistical models, we analyzed the role of neighborhood concentrated disadvantage index (CDI), a robust measure of physical and social environment, in racial disparities in TNBC incidence, stage at diagnosis, and stage-specific survival for the study population. Controlling for age, we found that AA women had a 2.21 times the incidence of TNBC incidence compared to EA women. Interestingly, the incidence of TNBC was independent of neighborhood CDI and adjusting for neighborhood environment did not impact the observed racial disparity. AA women were more likely to be diagnosed at later stages and CDI was associated with more advanced stages of TNBC at diagnosis. CDI was also significantly associated with poorer stage-specific survival. Overall, our results suggest that neighborhood disadvantage contributes to racial disparities in stage at diagnosis and survival among TNBC patients, but not to disparities in incidence of the disease. Further research is needed to determine the mechanisms through which social determinants affect the promotion and progression of this disease and guide efforts to improve overall survival.

Racial Disparity Among Women Diagnosed With Invasive Breast Cancer in a Large Integrated Health System

Purpose

Reasons for the well-described disparity in outcomes between African American (AA) and non-Hispanic white (NHW) women with invasive breast cancer are unclear, making it difficult to identify solutions. This study examined the effects of demographics, biomarkers, tumor characteristics, cancer stage, morphology, and treatment variables on overall and cancer-free survival in these patient populations.

Methods

We retrospectively reviewed data for 6231 patients diagnosed with invasive breast cancer throughout an integrated health system from January 2006 through March 2015. Included for analysis were 5023 NHW and 413 AA women. All category and continuous variables in the study were described in the two groups using appropriate statistics. Kaplan-Meier method of survival with log-rank test was used to compare the two racial groups (NHW and AA). Cox proportional hazards regression was used to find hazard ratios for the predictors of survival and recurrence-free survival probability. Propensity probability match method (1:1) was used to match 319 NSW women to 319 similar AA women. Matching was done using all significant predictors, including demographic variables.

Results

Compared to NHW women, AA women presented with invasive breast cancer at a younger age (P<0.001) and had a higher proportion of stage IV cancers (P<0.001), which were more often infiltrating ductal carcinoma (P<0.003) and poorly differentiated (P<0.001). Within 10-year follow-up, AA women had shorter overall and recurrence-free survival (log-rank P<0.001), were 1.4 times more likely to die (P=0.009), and were twice as likely to have recurrence (P<0.001) than NHW women. In the matched groups, overall survival was similar for AA and NHW (log-rank P=0.0793); however, recurrence-free survival was higher in NHW than in AA women (P=0.047).

Conclusions

When presenting characteristics of AA and NHW women with invasive breast cancer are matched, disparity in overall mortality and rate of recurrence appears to be reduced or perhaps eliminated, suggesting invasive breast cancers in AA and NHW women respond similarly to treatment. Further study is needed to explore the true effect of biological factors; however, rectifying delivery of and access to care might be expected to mitigate, in large part, the racial disparity currently seen in breast cancer outcomes.

The influence of marital status and race/ethnicity on risk of mortality for triple negative breast cancer

Purpose

To assess the effect of marital status and the role of race/ethnicity on breast cancer specific mortality in women with triple negative breast cancer (TNBC).

Methods

The study utilized the California Cancer Registry to identify 22,812 cases of first primary female TNBC. Unadjusted Kaplan-Meier breast cancer specific survival was computed. Cox Proportional Hazards modeling was used to compute the adjusted risk of breast cancer specific mortality for women who were single, separated, divorced, and widowed when compared with women who were married. Models were adjusted for age, stage, tumor grade, SES, and treatment with surgery, chemotherapy, hormone therapy, and radiation therapy. Hazard ratios (HR) and 95% confidence intervals (CI) were reported.

Results

Separated (HR: 1.45; 95% CI: 1.14–2.01) and widowed (HR: 1.39; 95%CI: 1.23–1.57) white women had a higher risk of mortality than white married women whereas single and divorced white women had the same risk of mortality. For Asian/Pacific Islanders (API), only single (HR: 1.55; 95% CI: 1.17–2.06) and divorced (HR:1.81; 95% CI:1.26–2.60) women had a higher risk of mortality than married women. Marital status had no influence on risk of mortality for either black or Hispanic women.

Conclusions

The risk of mortality associated with marital status is dependent on race/ethnicity. Only white and API women with TNBC have a marital advantage.

Literature review of data-based models for identification of factors associated with racial disparities in breast cancer mortality

In the United States, early detection methods have contributed to the reduction of overall breast cancer mortality but this pattern has not been observed uniformly across all racial groups. A vast body of research literature shows a set of health care, socio-economic, biological, physical, and behavioural factors influencing the mortality disparity. In this paper, we review the modelling frameworks, statistical tests, and databases used in understanding influential factors, and we discuss the factors documented in the modelling literature. Our findings suggest that disparities research relies on conventional modelling and statistical tools for quantitative analysis, and there exist opportunities to implement data-based modelling frameworks for (1) exploring mechanisms triggering disparities, (2) increasing the collection of behavioural data, and (3) monitoring factors associated with the mortality disparity across time.

Genetics, tumor features and treatment response of breast cancer in Latinas

Breast cancer is a heterogeneous and genetic disease that has variability according to ethnicity and race with respect to incidence, clinical characteristics and prognosis. The incidence of breast cancer is lower but mortality is higher in Latinas than Caucasians in the US series. Risk factors appear to have different prevalence and impact in Latinas. Breast cancer in Latinas has particular clinic-pathological features including younger age, higher rates of triple-negative subtype and advanced stages. Molecular studies find that Latinas from every region have a specific BRCA incidence and a recurrent mutation, as well as differences in activity of molecular pathways. Treatment response rates and toxicity have also been compared, and no difference was found between Latinas and other ethnic groups.

Influence of clinical, societal, and treatment variables on racial differences in ER-/PR- breast cancer survival

BACKGROUND

African American (AA) women with breast cancer have persistently higher mortality compared to whites. We evaluated racial disparities in mortality among women with estrogen receptor (ER)/progesterone receptor (PR)-negative breast cancer.

METHODS

The study population included 542 women (45% AA) diagnosed with ER/PR-negative Stage I through III breast cancer treated at the Henry Ford Health System (HFHS) between 1996 and 2005. Linked datasets from HFHS, Metropolitan Detroit Cancer Surveillance System, and the U.S. Census Bureau were used to obtain demographic, socioeconomic, and clinical information. Economic deprivation was categorized using a previously validated deprivation index, which included 5 categories based on the quintile of census tract socioeconomic deprivation. Cox proportional hazards models were used to assess the relationship between race and mortality.

RESULTS

AA women were more likely to have larger tumors, have higher Charlson Comorbidity Indices (CCI), and to reside in economically deprived areas. In an unadjusted analysis, AA women demonstrated a significantly higher risk of death compared to whites [hazard ratio (HR) 1.47, 95% confidence interval (CI) 1.09-2.00]. Following adjustment for clinical factors (age, stage, CCI) and treatment (radiation and chemotherapy), AA race continued to have a significant impact on mortality (HR 1.51, CI 1.10-2.08 and HR 1.63, CI 1.20-2.21). Only after adjusting for deprivation was race no longer significant (HR 1.26, CI 0.84-1.87).

CONCLUSIONS

Social determinants of health play a large role in explaining racial disparities in breast cancer outcomes, especially among women with aggressive subtypes.

Genomic Disparities in Breast Cancer Among Latinas

BACKGROUND

Breast cancer is the most common cancer diagnosed among Latinas in the United States and the leading cause of cancer-related death among this population. Latinas tend to be diagnosed at a later stage and have worse prognostic features than their non-Hispanic white counterparts. Genetic and genomic factors may contribute to observed breast cancer health disparities in Latinas.

METHODS

We provide a landscape of our current understanding and the existing gaps that need to be filled across the cancer prevention and control continuum.

RESULTS

We summarize available data on mutations in high and moderate penetrance genes for inherited risk of breast cancer and the associated literature on disparities in awareness of and uptake of genetic counseling and testing in Latina populations. We also discuss common genetic polymorphisms and risk of breast cancer in Latinas. In the treatment setting, we examine tumor genomics and pharmacogenomics in Latina patients with breast cancer.

CONCLUSIONS

As the US population continues to diversify, extending genetic and genomic research into this underserved and understudied population is critical. By understanding the risk of breast cancer among ethnically diverse populations, we will be better positioned to make treatment advancements for earlier stages of cancer, identify more effective and ideally less toxic treatment regimens, and increase rates of survival.

Breast and cervical cancer-screening uptake among females in Ardabil, northwest Iran: a community-based study

PURPOSE

Breast and cervical cancers are the most commonly diagnosed type of cancer and cause of cancer-related deaths in Iranian females. In contrast to previous studies, this study was carried out with a large sample size for assessment of breast self-examination (BSE)-, clinical breast examination (CBE)-, mammography-, and Pap smear-uptake rates and determination of associations among these screening behaviors with sociodemographic and cognitive variables in Azeri females.

MATERIALS AND METHODS

This was a cross-sectional, community-based study that was carried out among 1,134 females 20-60 years old during March-June 2016. Data-collection variables included sociodemographic questions, screening behaviors for breast and cervical cancer, self-efficacy, beliefs, and barriers to breast and cervical cancer screening. Collected data were analyzed by SPSS version 13 using χ2, Mann-Whitney U, and logistic regression tests.

RESULTS

Among the 1,134 participants, 53.9%, 9.8%, and 28.1% had done BSE, CBE, and Pap smear tests, respectively, and among the 625 females aged >40 years, 187 (29.9%) had done the mammography test. Moreover, 416 (36.7%), 103 (16.5%), and 64 (5.6%) females had done BSE, mammography, and CBE regularly, respectively. Beliefs, barriers, income, health insurance, number of children, and age were all important factors for BSE and regular BSE and mammography. Females who had high belief scores were more likely to undertake mammography (odds ratio [OR]: 1.2, 95% confidence interval [CI]: 1.03-1.5), regular mammography (OR: 4.2, 95% CI: 1.9-9.3), regular CBE (OR: 1.25, 95% CI: 1.2-1.3), and Pap smears (OR: 1.2, 95% CI: 1.1-1.4). Also, females who had high self-efficacy scores were more likely to perform regular BSE (OR: 1.8, 95% CI: 1.4-2.5) and mammography (OR: 2.5, 95% CI: 1.4-4.6) than females with lower self-efficacy scores.

CONCLUSION

The frequency of breast and cervical cancer screening was low in our study. The findings of this study indicated that beliefs, self-efficacy, and barriers were important predictive factors of cancer-screening behavior among the females studied.

Breast cancer subtype of French women is not influenced by socioeconomic status: A population-based-study

Context

The molecular subtype of breast tumours plays a major role in cancer prognosis and treatment options. Triple negative tumours (TN) carry the worst prognosis and affects most frequently women of low socioeconomic status (SES). Studies have shown that non-biologic factors, such as the socioeconomic status could have an influence on tumour biology. To this date no study has been done investigating this association in French women. The objective is to study the association between the SES and the molecular tumour subtype of breast cancer patients in the French county of Côte d’Or. This study benefits from the population data from the Côte d’Or breast cancer registry known for its strict quality control policy.

Methods

Invasive breast cancer cases between 2003 and 2013 were extracted from the Breast cancer registry database in Côte d’Or. A multivariate analysis was conducted using a hierarchical polytomous regression for the multinomial outcomes for the cancer subtype with HR+/HER2 as reference category.

Results

A total of 4553 cases were included in our study. There was no significant association found between SES and tumour subtype in French women at diagnosis. Women older than 75 years were less likely to have a TN and HR+/HER2+ breast cancer (OR = 0.66; CI95% = [0.46–0.94] and OR = 0.51; CI95% = [0.37–0.70] respectively). Women with TN tumour subtype had significantly less lymph node invasion when compared to HR+/HER2- subtype (OR = 0.71; CI95% = [0.54–0.92]).

Conclusion

No significant association was found between socioeconomic status and molecular subtype. Further studies are needed to clarify the mechanisms associated with developing each tumour subtype.

Regional Variation in Disparities in Breast Cancer Specific Mortality Due to Race/Ethnicity, Socioeconomic Status, and Urbanization

PURPOSE

Disparities in breast cancer mortality due to race/ethnicity, area socioeconomic status (SES), and urbanization have been documented. This study examined if disparities in the risk of breast cancer specific mortality due to race/ethnicity, SES, and urbanization varied within diverse regions of California.

METHODS

We identified 163,569 cases of first primary female invasive breast cancer from the California Cancer Registry diagnosed between January, 2000 and December, 2013. Cox regression was used to compute hazard ratios (HR) and 95 % confidence intervals for race/ethnicity, SES, and urbanization within eight regions of California.

RESULTS

Blacks had an increased risk of mortality in the San Francisco Bay Area (SFBA) (HR = 1.37; 1.22-1.55), Desert Sierra (HR = 1.27; 1.08-1.49), San Diego/Orange (HR = 1.43; 1.19-1.71), and Los Angeles (LA) (HR = 1.31; 1.20-1.44). Japanese (HR = 0.62; 0.47-0.81), Chinese (HR = 0.71; 0.58-0.87), and Filipino (HR = 0.81; 0.69-0.95) women had a decreased risk of mortality in LA. Southeast Asians had a decreased risk in San Diego/Orange (HR = 0.72; 0.57-0.90) and in the SFBA (HR = 0.81; 0.67-0.98). Hispanics had a decreased risk (HR = 0.73; 0.57-0.93) and American Indians had an increased risk (HR = 2.32; 1.08-4.98) in the Tri-County region. SES was a significant risk factor for mortality in all regions except the North and Tri-County. Urbanization was a statistically significant factor for mortality only in LA (HR = 1.32; 1.08-1.60).

CONCLUSIONS

Disparities in breast cancer mortality, due to race/ethnicity, SES, and urbanization vary by region which suggests that further research is warranted concerning the role of geographic regions and neighborhoods in cancer outcomes.

HER2 status and disparities in luminal breast cancers

National Comprehensive Care Network guidelines for adjuvant treatment of invasive breast cancer are based on HER2 and hormone receptor (HR) status, where HR+ disease encompasses all estrogen receptor (ER)+ and/or progesterone receptor (PR)+ tumors. We sought to explore clinical and demographic differences among patients with HR+ breast cancer subtypes, and the role of HER2 status, age, race/ethnicity, and socioeconomic status (SES) in disease risk. We evaluated breast cancer subtype distribution, defined by HR and HER2 status, using patient clinical, demographic, and socioeconomic characteristics. Differences in HR categories by demographic and tumor characteristics were examined using chi-squared tests. Multinomial logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) to quantify associations between breast cancer HR status and demographic factors. We found that differences in HR+ (ER-/PR+ vs. ER+/PR- or ER+/PR+) tumor biology are likely clinically significant and may play a role in breast cancer, regardless of HER2 status. While clinical and patient characteristics differed within each luminal subtype, we found disparities in SES only among Luminal A (HR+/HER2-) tumors. Among HR+/HER2- cases, we observed that ER-/PR+ patients tend to live in areas of higher poverty (OR = 1.20, 95% CI = 1.03-1.40) and are 70% more likely to be aged 50 years or older. However, this pattern was not found in women with Luminal B (HR+/HER2+) disease (Poverty OR = 0.98, 95% CI = 0.76-1.27; Age OR = 1.01, 95% CI = 0.81-1.26). Racial/ethnic disparities among non-Hispanic black and Hispanic women persisted across HR+/HER2- cases compared to non-Hispanic white women. Our findings suggest that while race/ethnicity and SES are correlated, each plays an independent role in contributing to disease among Luminal A tumors. Further study is needed to investigate how tumor biology, race/ethnicity, and socioeconomic disparities among HR+/HER2- cases may contribute to poorer patient prognosis.

Breast Cancer Mortality among Asian-American Women in California: Variation according to Ethnicity and Tumor Subtype

Purpose

Asian-American women have equal or better breast cancer survival rates than non-Hispanic white women, but many studies use the aggregate term "Asian/Pacific Islander" (API) or consider breast cancer as a single disease. The purpose of this study was to assess the risk of mortality in seven subgroups of Asian-Americans expressing the estrogen receptor (ER), progesterone receptor (PR), or human epidermal growth factor receptor 2 (HER2) tumor marker subtypes and determine whether the risk of mortality for the aggregate API category is reflective of the risk in all Asian ethnicities.

Methods

The study included data for 110,120 Asian and white women with stage 1 to 4 first primary invasive breast cancer from the California Cancer Registry. The Asian ethnicities identified were Pacific Islander, Southeast Asian (SEA), Indian Subcontinent, Chinese, Japanese, Filipino, and Korean. A Cox regression analysis was used to compute the risk of breast cancer-specific mortality in seven Asian ethnicities and the combined API category versus white women within each of the ER/PR/HER2 subtypes. Hazard ratios (HRs) and 95% confidence intervals (CIs) were computed.

Results

For the ER+/PR+/HER2- subtype, the combined API category showed a 17% (HR, 0.83; 95% CI, 0.76–0.91) lower mortality risk. This was true only for SEA (HR, 0.75; 95% CI, 0.61–0.91) and Japanese women (HR, 0.60; 95% CI, 0.45–0.81). In the ER+/PR-/HER2- subtype, SEA (HR, 0.57; 95% CI, 0.38–0.84) and Filipino women (HR, 0.71; 95% CI, 0.51–0.97) had a lower risk of mortality. Japanese (HR, 0.49; 95% CI, 0.25–0.99) and Filipino women (HR, 0.74; 95% CI, 0.58–0.94) had a lower HR for the ER-/PR-/HER2+ subtype. For triple-positive, ER+/PR+/HER2+ (HR, 0.84; 95% CI, 0.71–0.98) and triple-negative, ER-/PR-/HER2- (HR, 0.84; 95% CI, 0.74–0.94) subtypes, only the API category showed a lower risk of mortality.

Conclusion

Breast cancer-specific mortality among Asian-American women varies according to their specific Asian ethnicity and breast cancer subtype.

Racial disparities in individual breast cancer outcomes by hormone-receptor subtype, area-level socio-economic status and healthcare resources

The aim of the study is to determine the influence of area-level socio-economic status and healthcare access in addition to tumor hormone-receptor subtype on individual breast cancer stage, treatment, and mortality among Non-Hispanic (NH)-Black, NH-White, and Hispanic US adults. Analysis was based on 456,217 breast cancer patients in the SEER database from 2000 to 2010. Multilevel and multivariable-adjusted logistic and Cox proportional hazards regression analysis was conducted to account for clustering by SEER registry of diagnosis. NH-Black women had greater area-level access to healthcare resources compared with women of other races. For instance, the average numbers of oncology hospitals per million population in counties with NH-Black, NH-White, and Hispanic women were 8.1, 7.7, and 5.0 respectively; average numbers of medical doctors per million in counties with NH-Black, NH-White, and Hispanic women were 100.7, 854.0, and 866.3 respectively; and average number of Ob/Gyn in counties with NH-Black, NH-White, and Hispanic women was 155.6, 127.4, and 127.3, respectively (all p values <0.001). Regardless, NH-Black women (HR 1.39, 95 % CI 1.36-1.43) and Hispanic women (HR 1.05, 95 % CI 1.03-1.08) had significantly higher breast cancer mortality compared with NH-White women even after adjusting for hormone-receptor subtype, area-level socio-economic status, and area-level healthcare access. In addition, lower county-level socio-economic status and healthcare access measures were significantly and independently associated with stage at presentation, surgery, and radiation treatment as well as mortality after adjusting for age, race/ethnicity, and HR subtype. Although breast cancer HR subtype is a strong, important, and consistent predictor of breast cancer outcomes, we still observed significant and independent influences of area-level SES and HCA on breast cancer outcomes that deserve further study and may be critical to eliminating breast cancer outcome disparities.

Implementation of the 21-gene recurrence score test in the United States in 2011

PURPOSE

We examined hospital use of the 21-gene breast cancer test in the United States. We report state-level differences in utilization and propose a model for predicting implementation of guideline-recommended genomic testing.

METHODS

Genomic Health provided test orders for calendar year 2011.We summarized utilization at the hospital and state levels. Using logistic regression, we analyzed the association between the likelihood to order the test and the hospital's institutional and regional characteristics.

RESULTS

In 2011, 45% of 4,712 acute-care hospitals ordered the test, which suggests that 25% of newly diagnosed invasive female breast cancer cases were tested. Significant predictors of testing included participation in National Cancer Institute (NCI) clinical research cooperative groups (odds ratio (OR) 3.73; 95% confidence interval, 2.96-4.70), advanced imaging (OR, 2.19; CI, 1.78-2.68), high-complexity laboratory (OR, 2.15; CI, 1.24-3.70), affiliation with a medical school (OR, 1.57; CI, 1.31-1.88), and reconstructive surgery (OR, 1.23; CI, 1.01-1.50). Significant regional predictors included metropolitan county (OR, 3.77; CI, 2.83-5.03), above-mean income (OR, 1.37; CI, 1.11-1.69), and education (OR, 1.26; CI, 1.03-1.54). Negative predictors included designation as a critical-access hospital (OR, 0.10; CI, 0.07-0.14) and distance from an NCI cancer center (OR, 0.998; CI, 0.997-0.999), with a 15% decrease in likelihood for every 100 miles.

CONCLUSION

Despite considerable market penetration of the test, there are significant regional and site-of-care differences in implementation, particularly in rural states.Genet Med 18 10, 982-990.