Disparities In Breast Cancer Survival Research Articles

Understanding breast cancer patient pathways and their impact on survival in Mexico

BackgroundUnderstanding patient pathways from discovery of breast symptoms to treatment start can aid in identifying ways to improve access to timely cancer care. This study aimed to describe the patient pathways experienced by uninsured women from detection to treatment initiation for breast cancer in Mexico City and estimate the potential impact of earlier treatment on patient survival. MethodsWe used process mining, a data analytics technique, to create maps of the patient pathways. We then compared the waiting times and pathways between patients who initially consulted a private service versus those who sought care at a public health service. Finally, we conducted scenario modelling to estimate the impact of early diagnosis and treatment on patient survival. ResultsOur study revealed a common pathway followed by breast cancer patients treated at the two largest public cancer centres in Mexico City. However, patients who initially sought care in private clinics experienced shorter mean wait times for their first medical consultation (66 vs 88 days), and diagnostic confirmation of cancer (57 vs 71 days) compared to those who initially utilized public clinics. Our scenario modelling indicated that improving early diagnosis to achieve at least 60% of patients starting treatment at early stages could increase mean patient survival by up to two years. ConclusionOur study highlights the potential of process mining to inform healthcare policy for improvement of breast cancer care in Mexico. Also, our findings indicate that reducing diagnostic and treatment intervals for breast cancer patients could result in substantially better patient outcomes. Policy summaryThis study revealed significant differences in time intervals along the pathways of women with breast cancer according to the type of health service first consulted by the patients: whether public primary care clinics or private doctors. Policies directed to reduce these inequities in access to timely cancer care are desperately needed to reduce socioeconomic disparities in breast cancer survival.

Barriers to endocrine therapy adherence: perspectives of Black breast cancer survivors and their providers.

Adherence to oral endocrine therapy (ET) remains an issue for up to half of women prescribed these medications. There is emerging data that Black breast cancer survivors (BCS) have lower rates of ET adherence. Given the disparities in breast cancer recurrence and survival for Black BCS compared to their White counterparts, the goal of this study is to better understand barriers to ET adherence among Black BCS from the patient and provider perspectives. In this qualitative study, we conducted semi-structured interviews between October 29, 2021, and March 1, 2023. Interviews were recorded and transcribed, and coded data were organized into primary and secondary themes. Participants were recruited from a single academic cancer center. A convenience sample of 24 Black BCS and 9 medical oncology providers was included. Eligible BCS were 18years or older, English-speaking, diagnosed with stage I-III hormone receptor-positive breast cancer, who had initiated ET. Mean age of the BCS was 55years (interquartile range, IQR 17years). About one-fourth had a high school diploma or less (26.1%) and 47% completed a college education or higher. Approximately one-third of participants had annual household incomes of $40,000 or less (30.4%) or more than $100,000 (30.4%). Forty-three percent of the patient participants had private insurance; 11% were insured through Medicaid or the federal healthcare exchange; 26.1% had Medicare; and 13% were uninsured. Of the 9 medical oncology providers interviewed, 2 were advanced practice providers, and 7 were medical oncologists. We found 3 major themes: (1) Black BCS often had concerns about ET before initiation; (2) after initiation, both BCS and providers reported side effects as the most impactful barrier to ET adherence; and (3) survivors experienced challenges with managing ET side effects. Our results suggest that multifaceted support interventions for managing ET-related symptoms may lead to improved adherence to ET among Black women and may reduce disparities in outcomes. Multifaceted support interventions for managing ET-related symptoms may lead to improved adherence to ET among Black breast cancer survivors.

Unmet Social Needs and Breast Cancer Screening Utilization and Stage at Presentation

Unmet social needs in local populations may hinder the development of targeted cancer control interventions aimed at improving screening utilization and early-stage breast cancer diagnosis to ultimately improve breast cancer survival disparities. To evaluate if (1) city-funded screening mammography is associated with utilization of screening mammography, (2) unmet social needs are associated with utilization of screening mammography, and (3) unmet social needs are associated with later-stage disease at diagnosis. This cohort study included patients with stages I-IV invasive ductal or lobular carcinoma treated at an academic medical center (including both an underserved safety-net hospital [SNH] and a National Cancer Institute-designated academic cancer center [ACC]) from 2020 to 2023. Eligible patients were aged 18 years or older and able to consent. Data were analyzed between July 2023 and September 2023. The Health Leads Social Needs Screening Toolkit, a screening tool that gathers information on the most common social need domains affecting patient health. Univariable and multivariable logistic regression was utilized to evaluate the following primary outcomes: (1) routine screening mammography and (2) American Joint Committee on Cancer 8th edition clinical stage at presentation. Of the 322 women who completed the Health Leads Social Needs Screening Toolkit, 201 (62%) self-identified as Hispanic, 63 (19%) as non-Hispanic Black, and 63 (19%) as non-Hispanic White. Two hundred fifty-five (76%) patients with access to city-funded screening mammography completed a screening mammogram. Patients who presented to the SNH were more likely to present with late-stage disease compared with early-stage disease (15 of 48 [31%] vs 50 of 274 [18%]; P = .04). On multivariable logistic regression, not completing a screening mammography was associated with having an increasing number of unmet social needs (OR, 0.74; 95% CI, 0.55-0.99; P = .047) and an increasing age at diagnosis (OR, 0.92; 95% CI, 0.89-0.96; P < .001). Moreover, increasing unmet social needs was significantly associated with late-stage diagnosis above and beyond screening mammography (OR, 1.38; 95% CI, 1.01-1.89; P = .04). In this cohort study, access to screening mammography did not translate to utilization of screening mammography, increasing unmet social needs were significantly associated with lower rates of screening mammography, and those with increasing unmet social needs were more likely to present with late-stage disease. This association transcended recruitment site (SNH vs ACC), indicating that patients in either hospital setting may benefit from unmet social needs screening to overcome access to care barriers associated with late-stage disease at diagnosis.

Bayesian mediation analysis for time-to-event outcome: Investigating racial disparity in breast cancer survival

Mediation analysis is conducted to make inferences on the effects of mediators that intervene in the relationship between an exposure variable and an outcome. Bayesian mediation analysis (BMA) naturally considers the hierarchical structure of the effects from the exposure variable to mediators and then to the outcome. We propose three BMA methods on survival outcomes, where mediation effects are measured in terms of hazard rate, survival time, or log of survival time respectively. In addition, we allow setting a limited survival time in the time-to-event analysis. The methods are validated by comparing the estimation precision at different scenarios through simulations. The three methods all give effective estimates. Finally, the methods are applied to the Surveillance, Epidemiology, and End Results Program (SEER) supported special studies to explore the racial disparity in breast cancer survival. The included variable completely explained the observed racial disparities. We provide visual aids to help with the result interpretations.

Racial disparities in breast cancer survival after treatment initiation in Brazil: a nationwide cohort study

Breast cancer is a public health priority in Brazil and ensuring equity in health care is one of the cancer control plan goals. Our aim was to present the first assessment on the influence of race or skin colour on breast cancer survival at the national level. In this nationwide cohort study, data on women who initiated treatment for breast cancer in the public health-care system (Sistema Unico de Saúde), Brazil, were assembled through record linkage of administrative and mortality information systems. The administrative information systems were the Outpatient Information System (data from high complexity procedure authorisations) and the Hospital Information System (data from hospitalisation authorisations). We included women aged 19 years or older who started treatment between Jan 1, 2008, and Nov 30, 2010; self-identified as having White, Black, or Brown race or skin colour; had tumour stage I-IV; and were treated with chemotherapy or radiotherapy, or both. Patients were followed up until Dec 31, 2015. Patients with only hormone therapy records or who underwent only surgery were excluded. The Kaplan-Meier method was used to estimate crude overall survival for race or skin colour by time since treatment initiation, and Cox regression to estimate all-cause mortality hazard ratios (HRs) before and after adjustment for other covariates. We identified 59 811 women treated for stage I-IV breast cancer. 37 318 (62·4%) women identified themselves as White, 18 779 (31·4%) as Brown, and 3714 (6·2%) as Black. 5-year overall survival probability was higher for White women (74% [95% CI 73-74]) than Black women (64% [62-65]; p<0·0001). In adjusted regression models stratified by the absence of hormone therapy, Black women had a 24% (HR 1·24 [95% CI 1·16-1·34]; p<0·0001) higher risk of all-cause death than White women, and in the presence of hormone therapy Black women had a 25% (1·25 [1·14-1·38]; p<0·0001) higher risk of all-cause death than White women. Black skin colour was identified as a statistically significant risk marker for lower 5-year survival probability and higher risk of all-cause death among women treated for breast cancer by the Sistema Unico de Saúde. Actions to understand and mitigate this unfair difference in health results are urgently needed. Conselho Nacional de Desenvolvimento Científico e Tecnológico and Coordenação de Aperfeiçoamento de Pessoal de Nível Superior and Pró-Reitoria de Pesquisa da Universidade Federal de Minas Gerais.

Abstract B087: Racial disparities in breast cancer survival: Examining the potential role of neighborhood deprivation and breast adipose tissue inflammation

Abstract Background: Previous studies have found the Black-White disparity in breast cancer survival is greatest among women living in neighborhoods of high socioeconomic status (i.e., low % poverty). This study aimed to examine the association between race and breast cancer mortality according to neighborhood deprivation, a more comprehensive measure of neighborhood socioeconomic status. We also explored the association between neighborhood deprivation and the presence of breast adipose tissue inflammation as a potential biologic mechanism underlying the association. Methods: We examined Black-White disparities in breast cancer mortality overall and stratified by neighborhood deprivation status among 37,369 Black and White women in the Georgia Cancer Registry who were diagnosed with a first primary Stage I-IIIA breast cancer between 2010 and 2017 and followed until December 31, 2019. Cox proportional hazards regression models were used to calculate hazard ratios (HR) and 95% confidence intervals (CI). In a separate analysis, we examined the presence of crown-like structures in breast adipose tissue (CLS-B), detected by CD68 immunohistochemistry, among 342 women with stage I–III breast cancer who underwent mastectomy at Emory University Hospitals in Atlanta, Georgia (2007–2012). Logistic regression models were used to estimate odds ratios (OR) and 95% CIs. For both cohorts of breast cancer patients, neighborhood deprivation was assessed dichotomously using census tract at diagnosis and the neighborhood deprivation index (NDI), which was computed using American Community Survey 5-year estimates for census tracts in Georgia. Results: In Georgia, we found Black women with breast cancer had ~1.8 times higher rate of breast cancer mortality than their White counterparts (age-adj. HR=1.78, 95% CI: 1.63, 1.94). The disparity was attenuated after adjusting for stage and molecular subtype but was not eliminated (multivariable (MV)-adj. HR=1.32, 95% CI: 1.21, 1.45). When stratified by NDI, the disparity was greater among women living in neighborhoods of low deprivation (MV-adj. HR=1.44, 95% CI: 1.26, 1.64) compared to high deprivation (MV-adj. HR=1.17, 95% CI: 1.03, 1.33). Among Emory breast cancer patients, we found high neighborhood deprivation was inversely associated with CLS-B (age- and race-adj. OR=0.48, 95% CI; 0.26, 0.87). We also found Black patients were more likely than their White counterparts to have CLS-B in low deprivation neighborhoods (age-adj. OR=1.79, 95% CI: 0.98, 3.25) but not in high deprivation neighborhoods (age-adj. OR=0.73, 95% CI: 0.24, 2.20), albeit estimates were imprecise. Conclusion: Our study using a population-based cohort of breast cancer patients in Georgia adds to the evidence that racial disparities in breast cancer survival are worse among women living in higher socioeconomic (i.e., low deprivation) neighborhoods. Additionally, we provide evidence of a potential underlying mechanism, finding the prevalence of CLS-B higher for women in low rather than high deprivation neighborhoods, particularly Black women in this group. Citation Format: Maret L. Maliniak, Lauren E. Barber, Jasmine M. Miller-Kleinhenz, Leah Moubadder, Lauren E. McCullough. Racial disparities in breast cancer survival: Examining the potential role of neighborhood deprivation and breast adipose tissue inflammation [abstract]. In: Proceedings of the 16th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2023 Sep 29-Oct 2;Orlando, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2023;32(12 Suppl):Abstract nr B087.

Using a disparities dashboard to identify racial/ethnic differences in breast cancer treatment: Implications for improving cancer care delivery.

161 Background: Delays in the initiation of breast cancer treatment (e.g., surgery, chemotherapy, adjuvant endocrine therapy) contributes to breast cancer survival disparities. Yet, the use of a cancer dashboard to assess and inform real time assessments of the timing of surgery and systemic treatment by race/ethnicity is unclear. The purpose of this study is to investigate whether a cancer disparities dashboard can be used to assess racial/ethnic differences in the initiation of first line of treatment and timeliness of breast cancer surgery. Methods: A disparities dashboard was built using data from the tumor registry and the electronic medical record’s Data Warehouse. Key fields assessing patient race/ethnicity, cancer stage, receptor status, surgery type, treatments received and dates of surgery. This retrospective analysis included women diagnosed with a new primary breast cancer who underwent definitive surgery at Mount Sinai Hospital (2010-2020). We defined delays as &gt;8 weeks to treatment initiation, and delay to breast surgery as &gt; 6 weeks from diagnosis. Chi-square and t tests were used to assess independent variables (e.g., stage, age) by race/ethnicity. Patient-level multivariable logistic regression was used to evaluate the association between race/ethnicity and delays to initiation of first treatment and surgical delays. Results: Of 8,403 women identified (46.5% non-Hispanic White, 17.7% Black, 16.9% Hispanic), 64.5% had stage I cancer, 80.8% had estrogen receptor cancer. 18.5% of the sample had delays to initial treatment and 42.6% experienced delays to surgery. After adjusting for stage, age and receptor status Black patients compared to non-Hispanic White patients had the greatest likelihood of delayed initial treatment (OR: 3.03; 95% CI:2.6-3.5) or surgery delays (OR:2.45; 95% CI:2.1-2.8). With regards to clinical/sociodemographic factors younger patients (22-39 vs. 40-64; p&lt;0.001), mastectomy surgery type (; p=0.031), higher stage (stage 3 vs.1; p&lt;0.0001), HER2 and TNBC receptor status (vs. ER; p&lt;0.0001),) were more likely to experience surgery delays. Conclusions: Breast cancer treatment delays were more common among minoritized patients compared to White counterparts. A Disparities Dashboard can be used to assess differences in care. These data can be used to inform quality initiatives to improve cancer care delivery for at-risk patient populations who experience worse cancer outcomes.

Age, Body Mass Index, Tumor Subtype, and Racial and Ethnic Disparities in Breast Cancer Survival

Black women in the United States have higher breast cancer (BC) mortality rates than White women. The combined role of multiple factors, including body mass index (BMI), age, and tumor subtype, remains unclear. To assess the association of race and ethnicity with survival among clinical trial participants with early-stage BC (eBC) according to tumor subtype, age, and BMI. This cohort study analyzed survival data, as of November 12, 2021, from participants enrolled between 1997 and 2010 in 4 randomized adjuvant chemotherapy trials: Cancer and Leukemia Group B (CALGB) 9741, 49907, and 40101 as well as North Central Cancer Treatment Group (NCCTG) N9831, legacy groups of the Alliance of Clinical Trials in Oncology. Median follow-up was 9.8 years. Non-Hispanic Black and Hispanic participants were compared with non-Hispanic White participants within subgroups of subtype (hormone receptor positive [HR+]/ERBB2 [formerly HER2] negative [ERBB2-], ERBB2+, and HR-/ERBB2-), age (<50, 50 to <65, and ≥65 years), and BMI (<18.5, 18.5 to <25.0, 25.0 to <30.0, and ≥30.0). Recurrence-free survival (RFS) and overall survival (OS). Of 9479 participants, 436 (4.4%) were Hispanic, 871 (8.8%) non-Hispanic Black, and 7889 (79.5%) non-Hispanic White. The median (range) age was 52 (19.0-89.7) years. Among participants with HR+/ERBB2- tumors, non-Hispanic Black individuals had worse RFS (hazard ratio [HR], 1.49; 95% CI, 1.04-2.12; 5-year RFS, 88.5% vs 93.2%) than non-Hispanic White individuals, although the global test for association of race and ethnicity with RFS was not significant within any tumor subtype. There were no OS differences by race and ethnicity in any subtype. Race and ethnicity were associated with OS in young participants (age <50 years; global P = .008); young non-Hispanic Black participants (HR, 1.34; 95% CI, 1.04-1.71; 5-year OS, 86.6% vs 92.0%) and Hispanic participants (HR, 1.62; 95% CI, 1.16-2.29; 5-year OS, 86.2% vs 92.0%) had worse OS than young non-Hispanic White participants. Race and ethnicity were associated with RFS in participants with BMIs of 25 to less than 30, with non-Hispanic Black participants having worse RFS (HR, 1.81; 95% CI, 1.23-2.68; 5-year RFS, 83.2% vs 87.3%) than non-Hispanic White participants. In this cohort study, racial and ethnic survival disparities were identified in patients with eBC receiving standardized initial care, and potentially at-risk subgroups, for whom focused interventions may improve outcomes, were found.

Neighborhood Disadvantage, African Genetic Ancestry, Cancer Subtype, and Mortality Among Breast Cancer Survivors.

Racial disparities in breast cancer (BC) survival arise from multilevel causes, which may exert influence at different stages of BC progression. Clarifying the importance of genetic and social factors could help prioritize interventions. To jointly examine associations between African genetic ancestry, social environment, and mortality from any cause and BC in Black BC survivors. This population-based cohort study enrolled self-identified Black women aged 20 to 75 years with histologically confirmed BC from June 2005 to May 2019 and followed them up until death or censoring in September 2021. Participants lived in 10 New Jersey counties. Data were analyzed between December 2022 and April 2023. A neighborhood socioeconomic status (nSES) index composed of census tract measures (education, income, wealth, employment status, and occupation) was linked to residential addresses at diagnosis. Percentage African ancestry was estimated using the ADMIXTURE program. Sequentially adjusted (age adjusted: age and interview year; fully adjusted: age adjusted with individual SES, lifestyle factors, and comorbidities) logistic regression models were fit to estimate associations with tumor subtypes (estrogen receptor-negative [ER-] vs estrogen receptor-positive [ER+]; triple-negative breast cancer [TNBC] vs luminal A), and Cox models were fit for associations with all-cause mortality (ACM) and breast cancer-specific mortality (BCSM). Models for BCSM were fit using Fine-Gray competing risks models, and robust standard errors were used to account for census tract-level clustering. Among 1575 participants, median (IQR) African ancestry was 85% (76%-90%), and median (IQR) age was 55 (46-63) years. A 10-percentage point increase in African ancestry was associated with higher odds of ER- vs ER+ (adjusted odds ratio [aOR], 1.08; 95% CI, 0.98-1.18) and TNBC vs luminal (aOR, 1.15; 95% CI, 1.02-1.31) tumors, but not with ACM or BCSM. A 1-IQR increase in nSES was associated with lower ACM (adjusted hazard ratio [aHR], 0.76; 95% CI, 0.63-0.93), and the HR for BCSM was less than 1 but not statistically significant (aHR, 0.81; 95% CI, 0.62-1.04) in age-adjusted models, but associations attenuated following further adjustment for potential mediators (individual SES, lifestyles, comorbidities). In this cohort study of Black female BC survivors, higher African ancestry was associated with aggressive tumor subtypes. Compared with genetic ancestry, mediating pathways related to social environments may be more important for survival in these patients.

The contribution of prognostic factors to socio-demographic inequalities in breast cancer survival in Victoria, Australia.

Breast cancer survival in Australia varies according to socio-economic status (SES) and between rural and urban places of residence. Part of this disparity may be due to differences in prognostic factors at the time of diagnosis. Women with invasive breast cancer diagnosed from 2008 until 2012 (n = 14,165) were identified from the Victorian Cancer Registry and followed up for 5 years, with death from breast cancer or other causes recorded. A prognostic score, based on stage at diagnosis, cancer grade, whether the cancer was detected via screening, reported comorbidities and age at diagnosis, was constructed for use in a mediation analysis. Five-year breast cancer mortality for women with breast cancer who were in the lowest quintile of SES (10.3%) was almost double that of those in the highest quintile (5.7%). There was a small survival advantage (1.7% on average, within each socio-economic quintile) of living in inner-regional areas compared with major cities. About half of the socio-economic disparity was mediated by prognostic factors, particularly stage at diagnosis and the presence of comorbidities. The inner-regional survival advantage was not due to differences in prognostic factors. Part of the socio-economic disparity in breast cancer survival could be addressed by earlier detection in, and improved general health for, more disadvantaged women. Further research is required to identify additional causes of socio-economic disparities as well as the observed inner-regional survival advantage.

Health insurance and neighborhood poverty as mediators of racial disparities in advanced disease stage at diagnosis and nonreceipt of surgery for women with breast cancer.

In our recent study, advanced disease stage and nonreceipt of surgery were the most important mediators of the racial disparity in breast cancer survival. The purpose of this study was to quantify the racial disparity in these two intermediate outcomes and investigate mediation by the more proximal mediators of insurance status and neighborhood poverty. This was a cross-sectional study of non-Hispanic Black and non-Hispanic White women diagnosed with first primary invasive breast cancer in Florida between 2004 and 2015. Log-binomial regression was used to obtain prevalence ratios (PR) with 95% confidence intervals (CIs). Multiple mediation analysis was used to assess the role of having Medicaid/being uninsured and living in high-poverty neighborhoods on the race effect. There were 101,872 women in the study (87.0% White, 13.0% Black). Black women were 55% more likely to be diagnosed with advanced disease stage at diagnosis (PR, 1.55; 95% CI, 1.50-1.60) and nearly twofold more likely to not receive surgery (PR, 1.97; 95% CI, 1.90-2.04). Insurance status and neighborhood poverty explained 17.6% and 5.3% of the racial disparity in advanced disease stage at diagnosis, respectively; 64.3% remained unexplained. For nonreceipt of surgery, insurance status explained 6.8% while neighborhood poverty explained 3.2%; 52.1% was unexplained. Insurance status and neighborhood poverty were significant mediators of the racial disparity in advanced disease stage at diagnosis with a smaller impact on nonreceipt of surgery. However, interventions designed to improve breast cancer screening and receipt of high-quality cancer treatment must address additional barriers for Black women with breast cancer.

Impact of endocrine therapy adherence on racial disparities in breast cancer survival.

541 Background: Black women have worse breast cancer outcomes compared to their White counterparts, even for hormone receptor positive (HR+) HER2 negative (HER2-) breast cancer (BC). This tumor type is usually treated with 5-10 years of adjuvant endocrine therapy (ET) to reduce risk of BC recurrence and improve survival. We investigated the impact of adherence to ET on racial differences in survival for HR+ HER2- BC survivors. Methods: We conducted a population-based, retrospective cohort study using the Surveillance, Epidemiology, and End Results (SEER)-Medicare database, which links demographic and clinical data with cause of death for persons with cancer and Medicare claims for covered health services. We examined 9,039 women with HR+ HER2- stage I-III BC diagnosed between 2007 and 2016, who received primary breast surgery and initiated ET. Adherence to ET was measured using the medication possession ratio (MPR), which assesses the proportion of time a patient has medication available via filled prescriptions. As in established literature, we defined ET adherence as MPR &gt; = 80%. Causal mediation analysis was performed to measure to impact of adherence on survival disparities between Black and White BC survivors. Results: Mean age at diagnosis was 72 years, 6.5% were Black, and 20.9% were dual eligible for Medicaid (a surrogate for socioeconomic hardship). Most had stage I or II breast cancer (69.3%) and mastectomy as primary surgery (69.7%). Nineteen percent received chemotherapy and 62.5% received radiation. In univariate analyses, factors associated with ET adherence were Black race (OR 0.62, 95% CI 0.54-0.75), insured by Medicaid (OR 0.72, 95% CI 0.65-0.81), being married (OR 1.14, 95% CI 1.03-1.25), and increased comorbidities (Charlson score &gt; = 2) (OR 0.88, 95% CI 0.78-0.99). Age, BC stage, type of surgery, and receipt of chemotherapy or radiation were not associated with ET adherence. In multivariable models adjusting for age, race, marital status, Medicaid eligibility, and Charlson score, Black race and Medicaid eligibility remained inversely associated with ET adherence (OR 0.70, 95% CI 0.59-0.83 and OR 0.77, 95% CI 0.69-0.87 respectively). Among those who were adherent to ET, Black women had 43% higher risk of mortality compared to White women (HR 1.43, 95% CI 1.17-1.76). In mediation analysis, 4.25% of the observed survival disparity between Black and White women can be explained by differences in ET adherence. Conclusions: We identified racial disparities in ET adherence and overall survival among women with BC. Adherence to ET accounted for a small percentage of racial disparities in survival. Further research is needed to delineate other factors contributing to ET non-adherence among Black women and to investigate additional factors contributing to known disparities in BC survival.

Abstract 6493: Ethnic disparities in breast cancer survival in Guam

Abstract Background: Breast cancer is the second leading cause of cancer-related death among women in Guam. The breast cancer mortality rate is higher in Guam than in the U.S. (27.3 vs 20.3 per 100,000 women, age-adjusted, 2013-2017 data); even though the incidence rate remains lower (86.6 vs 126.8 respectively). Guam has major ethnic disparities in breast cancer survival with CHamoru (indigenous people) and Micronesian (immigrants from other Micronesian Islands) faring much worse than other ethnic groups. The purpose of this study was to determine the survival rates of breast cancer patients in Guam and examine the effects of demographic and other mortality risk factors on breast cancer survival. Methods: This study included 1105 women diagnosed with primary invasive breast cancer and reported to the Guam Cancer Registry from 1998-2020. Five-year and 10-year survival rates were calculated using the Kaplan-Meier method and were compared using the log-rank test across different ethnic groups: CHamoru (N = 528), Filipino (N = 336), Asian (N = 66), Micronesian (N = 51), and Caucasian (N = 71). The Cox proportional hazards regression was used to investigate the effects of age, year of diagnosis, ethnicity, breast cancer staging, and cancer treatment status on the risk of all-cause mortality. Results: Mean age at diagnosis was 58.2 years. Significant differences in the 5-year and 10-year survival rates were found across ethnic groups. Micronesians had the lowest 5-year and 10-year survival rates (55.9% and 48.5%) followed by CHamorus (81.1% and 68.1%, respectively). All-cause mortality was higher among CHamoru (HR = 2.28, 95% CI: 1.65, 3.16) and Micronesian women (HR=5.33, 95% CI: 3.30, 8.61) compared with Filipino women after adjusting for age, year of diagnosis, staging, and cancer treatment status. All-cause mortality among White and Asian women was not statistically significantly different from that among Filipino women. Cancer staging also indicated significantly higher hazard rate for late-stage patients when compared to early-stage patients (HR = 3.62, 95% CI: 2.70, 4.85). Conclusion: The analysis suggests significant differences in breast cancer 5-year and 10-year survival rates across different ethnic groups, with Micronesian women exhibiting the highest hazard rate among women in Guam. Acknowledgement: This study was supported by the PIPCHE/U54 Grant (U54CA143728), a partnership between the University of Hawai'i Cancer Center and the University of Guam. Citation Format: Grazyna Badowski, Rodney Teria, Louis Dulana, Cabrini Aguon, Lynne Wilkens, Yurii Shvetsov, Rachel Novotny, Rachael T. Leon Guerrero. Ethnic disparities in breast cancer survival in Guam. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6493.

Association of Social Determinants and Tumor Biology With Racial Disparity in Survival From Early-Stage, Hormone-Dependent Breast Cancer

Black women with hormone receptor-positive breast cancer experience the greatest racial disparity in survival of all breast cancer subtypes. The relative contributions of social determinants of health and tumor biology to this disparity are uncertain. To determine the proportion of the Black-White disparity in breast cancer survival from estrogen receptor (ER)-positive, axillary node-negative breast cancer that is associated with adverse social determinants and high-risk tumor biology. A retrospective mediation analysis of factors associated with the racial disparity in breast cancer death for cases diagnosed between 2004 and 2015 with follow-up through 2016 was carried out using the Surveillance, Epidemiology, and End Results (SEER) Oncotype registry. The study included women in the SEER-18 registry who were aged 18 years or older at diagnosis of a first primary invasive breast cancer tumor that was axillary node-negative and ER-positive, who were Black (Black), non-Hispanic White (White), and for whom the 21-gene breast recurrence score was available. Data analysis took place between March 4, 2021, and November 15, 2022. Census tract socioeconomic disadvantage, insurance status, tumor characteristics including the recurrence score, and treatment variables. Death due to breast cancer. The analysis with 60 137 women (mean [IQR] age 58.1 [50-66] years) included 5648 (9.4%) Black women and 54 489 (90.6%) White women. With a median (IQR) follow-up time of 56 (32-86) months, the age-adjusted hazard ratio (HR) for breast cancer death among Black compared with White women was 1.82 (95% CI, 1.51-2.20). Neighborhood disadvantage and insurance status together mediated 19% of the disparity (mediated HR, 1.62; 95% CI, 1.31-2.00; P < .001) and tumor biological characteristics mediated 20% (mediated HR, 1.56; 95% CI, 1.28-1.90; P < .001). A fully adjusted model that included all covariates accounted for 44% of the racial disparity (mediated HR, 1.38; 95% CI, 1.11-1.71; P < .001). Neighborhood disadvantage mediated 8% of the racial difference in the probability of a high-risk recurrence score (P = .02). In this study, racial differences in social determinants of health and indicators of aggressive tumor biology including a genomic biomarker were equally associated with the survival disparity in early-stage, ER-positive breast cancer among US women. Future research should examine more comprehensive measures of socioecological disadvantage, molecular mechanisms underlying aggressive tumor biology among Black women, and the role of ancestry-related genetic variants.

Impact of Patient Navigation on Reducing Breast Imaging Disparities and Applications in the COVID-19 Era.

The coronavirus (COVID-19) pandemic has impacted breast cancer screening with concerns that this may lead to increased overall breast cancer mortality and worsened racial and ethnic disparities in breast cancer survival. As pandemic recovery efforts are underway, we must be prepared to address barriers to timely access of breast imaging services, including those that existed prior to the pandemic, as well as any new barriers that may arise as a result of the pandemic. Patient navigation is an important tool that has been shown to address barriers to timely breast imaging access and help reduce disparities. Patient navigation programs can serve as a key part of the strategy to mitigate the impact of the COVID-19 pandemic on timely breast cancer diagnosis. These programs have been shown to be successful in promoting adherence to breast cancer screening guidelines as well as encouraging timely diagnostic follow-up, particularly in underserved communities. Further research is needed to explore the role of using a telehealth platform for patient navigation and evaluate the cost-effectiveness of patient navigator programs as well as more randomized controlled trials to further explore the impact of patient navigation programs.

Abstract C086: A summary of findings from the Breast Cancer, Race and Place (BCRP) study on structural racism and breast cancer survival disparities in the United States, based in Milwaukee, WI

Abstract Racial disparities in breast cancer survival are significant, with only 68% of US Black women diagnosed with breast cancer remaining alive 10 years post-diagnosis, compared to 84% of White women. However, the size of racial disparities in breast cancer mortality varies geographically across the US. Such geographical variation suggests that disparities are not inevitable, and this variation has not been explained. Structural racism and racial residential segregation are widely considered to contribute to health disparities and may partially explain geographical variation in the size of the disparities. While some studies have shown that segregation is related to poor survival, others have found that this is not always the case, and some studies highlight the case of ethnic enclaves, which may be protective. The NCI funded Breast Cancer, Race and Place (BCRP) study is a national study of structural racism and breast cancer survival with three aims: (1) Construct new metrics of structural racism at the local level for the largest US metropolitan areas, (2) Determine whether these measures are related to breast cancer survival disparities among Black, Hispanic and Non-Hispanic White women, and whether relationships are mediated by local stressors, social resources, or opportunities, and (3) Explore the ways in which Black and Hispanic breast cancer survivors in a highly segregated metropolitan area (Milwaukee, WI) navigate cancer survivorship in the context of segregation. The project is supported by an interdisciplinary research team and a community advisory board. We have published several studies based on this work with others in review or in preparation and share an overview of this body of work here. This summary of findings includes: (1) a description of new measures of contemporary racial bias and property location based bias (redlining) in mortgage lending, (2) a direct association between redlining and breast cancer survival in older women diagnosed with breast cancer in the US, (3) collaborative work using these metrics in other cohorts and locations, (4) a clear gradient association between historic redlining and contemporary redlining, (5) new evidence of potential mediating factors, (6) qualitative evidence of lived experience of Black and Hispanic survivors in Milwaukee, WI, and (7) a new web-based tool to explore and download mortgage lending bias metrics. We hope that this work will support the development of multi-sectoral interventions to reduce cancer disparities by targeting local systems and policies, including in the housing sector. Citation Format: Kirsten M. M. Beyer, BCRP Team. A summary of findings from the Breast Cancer, Race and Place (BCRP) study on structural racism and breast cancer survival disparities in the United States, based in Milwaukee, WI [abstract]. In: Proceedings of the 15th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2022 Sep 16-19; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr C086.

Abstract C003: Insurance status and neighborhood poverty as mediators of the racial disparity in advanced disease stage at diagnosis and nonreceipt of surgery for women with breast cancer in Florida

Abstract Background: In our previous study investigating mediators of the Black vs. White disparity in breast cancer survival for women in Florida, the two most important factors explaining the disparity were advanced disease stage at diagnosis and nonreceipt of surgery. Model assumptions of the multiple mediation approach used in that study prohibited examination causally prior (proximal) mediators. The purpose of this study was to: 1) quantify the excess risk of advanced disease stage at diagnosis and nonreceipt of surgery for Black vs. White women, and 2) use multiple mediation analysis to investigate the degree to which insurance status and high neighborhood poverty explain the racial disparity in these two outcomes. Methods: The study population was comprised of women in Florida diagnosed with breast cancer between 2004 and 2015 and who were reported to the Florida Cancer Data System. The potential mediators consisted of insurance status (Medicaid/Uninsured: yes/no) and census tract poverty level (High poverty [≥ 20% of households in poverty]: yes/no). The two outcomes of interest were advanced stage of disease at diagnosis (stages III/IV) and nonreceipt of surgery. The log-binomial model was used to obtain risk ratios (RR) with 95% confidence interval (CI) for the association of race with these two outcomes, adjusted for age. The multiple mediation approach of Yu et. al. was used to obtain log odds ratios (OR) to quantify direct effects, indirect effects, and the relative % of the total effect mediated. Results: There were 101,872 women available for analysis. African American women were 55% more likely to be diagnosed with advanced disease stage (RR = 1.55: 95% CI, 1.50-1.60) and 97% more likely more likely to not receive surgery (RR = 1.97: 95% CI, 1.90-2.04). The results of the multiple mediation analysis revealed that insurance status and high poverty explained 20.2% and 6.8%, respectively, of the racial disparity in advanced stage of disease at diagnosis. For the disparity in nonreceipt of surgery, insurance status explained 14.4% of the race effect and high poverty explained 5.2% of the race effect. Conclusions: Mediation analysis can provide insight into the mechanisms by which racial disparities in health outcomes occur. As was the case in this study, mediation analysis can also lead to new hypotheses concerning the most important factors causing disparities. To wit, contrary to our initial hypothesis, neither insurance status nor high poverty mediated the majority of the racial disparity in advanced disease stage at diagnosis or nonreceipt of surgery. Future research is required to obtain a better understanding of the barriers to screening mammography and receipt surgical treatment in Black women diagnosed with breast cancer. Citation Format: Robert B. Hines, Xiang Zhu, Eunkyung Lee, Bradley Eames, Karolina Chmielewska, Asal Johnson. Insurance status and neighborhood poverty as mediators of the racial disparity in advanced disease stage at diagnosis and nonreceipt of surgery for women with breast cancer in Florida [abstract]. In: Proceedings of the 15th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2022 Sep 16-19; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr C003.

Abstract IA039: The breast cancer biomarkers as predictors of survival: Do they vary by race and ethnicity?

Abstract Introduction: Racial/ethnic disparities in cancer survival in the United States are well documented, but the underlying biology is not well understood. Compared with European American (EA) counterparts, African American (AA) women are more likely to die from breast cancer in the United States. Our recent studies were aimed to evaluate trends in survival, by race-ethnicity, for women diagnosed with breast cancer. We uncovered some biological factors underlying this disparity by comparing functional expression and prognostic significance of several biomarkers including master transcriptional regulators of luminal differentiation. Materials &amp; Methods: We used a ML approach to assess a cohort of racially diverse 555 primary BC patients who underwent surgery in Greenville, NC and develop proteomics-based genomics (PbG) signatures. We apply quantitative automated image processing and computational methods to profile the subcellular distribution of the multi-functional transcriptional regulator, Kaiso (ZBTB33), and GP78. The cross-validated models were developed on a BC pooled dataset of (N= 845) samples (primarily taxane and anthracycline based) and chemotherapy cohort (N=415) including racial disparities. Results: Multiplex multivariate analysis of the association of Kaiso’s subcellular distribution with other breast cancer biomarkers reveals novel functional and predictive linkages between Kaiso and the autophagy-related proteins, LC3A/B, that are associated with features of the tumor immune microenvironment, survival, and race. Univariate or multivariate HRs for overall survival, estimated from digital IHC scoring of nuclear antigen, show distinct differences in the magnitude and significance of these biomarkers to predict survival based on race: ESR1 [EA HR 0.47; 95% confidence interval (CI), 0.31–0.72 and AA HR 0.77; 95% CI, 0.48–1.18]; FOXA1 (EA HR 0.38; 95% CI, 0.23–0.63 and AA HR 0.53; 95% CI, 0.31–0.88), and GATA3 (EA HR 0.36; 95% CI, 0.23–0.56; AA HR 0.57; CI, 0.56–1.4). In addition, elevated levels of gp78 in patient breast cancer cells predict poor survival. Moreover, high levels of gp78 are associated with poor outcomes in both ER+ and ER– tumors, and breast cancers expressing elevated amounts of gp78 protein are enriched in gene expression pathways that influence cell cycle, metabolism, receptor-mediated signaling, and cell stress response pathways. Conclusion: Understanding these biomarkers and their downstream regulons will elucidate the intrinsic mechanisms that drive racial disparities in breast cancer survival. These findings identify effective modalities of Kaiso biomarker assessment and uncover unanticipated insights into Kaiso’s role in breast cancer progression. Even within clinically homogeneous tumor groups, regulatory networks that drive mammary luminal differentiation reveal race-specific differences in their association with clinical out- come. Our findings implicate a prominent role for gp78 in tumor progression and offer insights into our understanding of racial differences in breast cancer outcomes. Citation Format: Sandeep K. Singhal, Kevin L. Gardner. The breast cancer biomarkers as predictors of survival: Do they vary by race and ethnicity? [abstract]. In: Proceedings of the 15th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2022 Sep 16-19; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr IA039.

Racial and ethnic disparities in breast cancer survival: critical appraisal of the data emerging from the randomized TAILORx

Racial and ethnic disparities in breast cancer survival: critical appraisal of the data emerging from the randomized TAILORx

Racial Disparity in Quadruple Negative Breast Cancer: Aggressive Biology and Potential Therapeutic Targeting and Prevention.

Simple SummaryQuadruple negative breast cancer (QNBC), a subgroup of triple negative BC, has emerged as a highly aggressive BC subtype that disproportionately afflicts and impacts Black/African-American (AA) women. In this article, we review molecular distinctions in Black/AA and White/European-American (EA) QNBC biology as well as address potential non-genetic risk factors that could be underlying this racially disparate burden. We aim to provide deeper insight and provide a framework for novel discovery of actionable therapeutic targets and identify lifestyle changes to improve outcomes for Black/AA QNBC patients.Black/African-American (AA) women, relative to their White/European-American (EA) counterparts, experience disproportionately high breast cancer mortality. Central to this survival disparity, Black/AA women have an unequal burden of aggressive breast cancer subtypes, such as triple-negative breast cancer (ER/PR-, HER2-wild type; TNBC). While TNBC has been well characterized, recent studies have identified a highly aggressive androgen receptor (AR)-negative subtype of TNBC, quadruple-negative breast cancer (ER/PR-, HER2-wildtype, AR-; QNBC). Similar to TNBC, QNBC disproportionately impacts Black/AA women and likely plays an important role in the breast cancer survival disparities experienced by Black/AA women. Here, we discuss the racial disparities of QNBC and molecular signaling pathways that may contribute to the aggressive biology of QNBC in Black/AA women. Our immediate goal is to spotlight potential prevention and therapeutic targets for Black/AA QNBC; ultimately our goal is to provide greater insight into reducing the breast cancer survival burden experienced by Black/AA women.