Breast Cancer Mortality in African-American and Non-Hispanic White Women by Molecular Subtype and Stage at Diagnosis: A Population-Based Study

Racial Differences in Breast Cancer Survival Between Black and White Women According to Tumor Subtype: A Systematic Review and Meta-Analysis

PURPOSE

Despite effective early-detection approaches and innovative treatments, Black women in the United States have higher breast cancer mortality rates compared with White women. The purpose of this systematic review and meta-analysis is to determine the extent of disparities in breast cancer survival between Black and White women according to tumor subtype.

METHODS

A comprehensive database search was performed for full-text, English-language articles published from January 1, 2000, to December 31, 2022. Included studies compared survival between Black and White female patients with breast cancer within subtypes defined by hormone receptor and human epidermal growth factor receptor 2 (HER2)/neu (HER2; now known as ERBB2) status. Random-effects models were used to combine study-specific results and generate pooled relative risks (RRs) and 95% CIs for breast cancer-specific or overall survival (OS). A protocol for this review was registered in PROSPERO (CRD42021268212).

RESULTS

Eighteen studies including 228,885 (34,262 Black; 182,466 White) patients with breast cancer were identified. Compared with White women, Black women had a higher risk of breast cancer death for all tumor subtypes. The summary risk of breast cancer death was 50% higher among hormone receptor-positive HER2-negative [HER2-] tumors (RR, 1.50 [95% CI, 1.30 to 1.72]), 34% higher for hormone receptor+/HER2+ (RR, 1.34 [95% CI, 1.10 to 1.64]), 20% higher for hormone receptor-negative (-)/HER2+ (RR, 1.29 [95% CI, 1.00 to 1.43]), and 17% higher among individuals with hormone receptor-/HER2- tumors (hazard ratio, 1.17; 95% CI, 1.10 to 1.25). Black women also had poorer OS than White women for all subtypes.

CONCLUSION

These results suggest there are both subtype-specific and subtype-independent mechanisms that contribute to disparities in breast cancer survival between Black and White women, which require multilevel interventions to address and achieve health equity.

Spatial N-glycomics of the normal breast microenvironment reveals fucosylated and high-mannose N-glycan signatures related to BI-RADS density and ancestry

Higher breast cancer mortality rates continue to disproportionally affect black women (BW) compared to white women (WW). This disparity is largely due to differences in tumor aggressiveness that can be related to distinct ancestry-associated breast tumor microenvironments (TMEs). Yet, characterization of the normal microenvironment (NME) in breast tissue and how they associate with breast cancer risk factors remains unknown. N-glycans, a glucose metabolism-linked post-translational modification, has not been characterized in normal breast tissue. We hypothesized that normal female breast tissue with distinct Breast Imaging and Reporting Data Systems (BI-RADS) categories have unique microenvironments based on N-glycan signatures that varies with genetic ancestries. Profiles of N-glycans were characterized in normal breast tissue from BW (n = 20) and WW (n = 20) at risk for breast cancer using matrix assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI). A total of 176 N-glycans (32 core-fucosylated and 144 noncore-fucosylated) were identified in the NME. We found that certain core-fucosylated, outer-arm fucosylated and high-mannose N-glycan structures had specific intensity patterns and histological distributions in the breast NME dependent on BI-RADS densities and ancestry. Normal breast tissue from BW, and not WW, with heterogeneously dense breast densities followed high-mannose patterns as seen in invasive ductal and lobular carcinomas. Lastly, lifestyles factors (e.g. age, menopausal status, Gail score, BMI, BI-RADS) differentially associated with fucosylated and high-mannose N-glycans based on ancestry. This study aims to decipher the molecular signatures in the breast NME from distinct ancestries towards improving the overall disparities in breast cancer burden.

Racial/ethnic differences in 21-gene recurrence score and survival among patients with estrogen receptor-positive breast cancer

BACKGROUND

Despite numerous studies on racial/ethnic disparities among patients with breast cancer, there is a paucity of literature evaluating racial/ethnic differences in 21-gene recurrence score (RS) and survival differences stratified by RS risk categories. We thus performed an observational cohort study to examine racial/ethnic disparities in the context of RS.

METHODS

The National Cancer Database (NCDB) was queried for female patients diagnosed between 2006 and 2018 with estrogen receptor (ER)-positive, pT1-3N0-1aM0 breast cancer who received surgery followed by adjuvant endocrine therapy and had RS data available. Logistic multivariable analysis (MVA) was built to evaluate variables associated with RS ≥ 26. Cox MVA was used to evaluate OS. Subgroup analyses were performed to compare the magnitude of racial/ethnic differences stratified by RS. P values less than 0.017 were considered statistically significant based on Bonferroni correction.

RESULTS

A total of 140,133 women were included for analysis. Of these, 115,651 (82.5%), 8,213 (5.9%), 10,814 (7.7%), and 5,455 (3.9%) were NHW, Hispanic, Black, and API women, respectively. Median (IQR) follow up was 66.2 months (48.0-89.8). Logistic MVA showed that, compared with NHW women, Black women were associated with higher RS (≥ 26 vs < 26: adjusted odds ratio [aOR] 1.19, 95% confidence interval [CI] 1.12-1.26, p < 0.001), while HW (aOR 0.93, 95% CI 0.86-1.00, p = 0.04) and API women (aOR 1.03, 95% CI 0.95-1.13, p = 0.45) were not. Cox MVA showed that, compared with NHW women, Black women had worse OS (adjusted hazards ratio [aHR] 1.10, 95% CI 1.02-1.19, p = 0.012), while HW (aHR 0.85, 95% CI 0.77-0.94, p = 0.001) and API (aHR 0.66, 95% CI 0.56-0.77, p < 0.001) women had better OS. In subgroup analysis, similar findings were noted among those with RS < 26, while only API women were associated with improved OS among others with RS ≥ 26.

CONCLUSION

To our knowledge, this is the largest study using nationwide oncology database to suggest that Black women were associated with higher RS, while HW and API women were not. It also suggested that Black women were associated with worse OS among those with RS < 26, while API women were associated with improved OS regardless of RS when compared to NHW women.

Tumor-infiltrating lymphocytes and breast cancer mortality in racially and ethnically diverse participants of the Northern California Breast Cancer Family Registry

Stromal tumor-infiltrating lymphocyte (sTIL) enrichment in pretreatment breast tumors has been associated with superior response to neoadjuvant treatment and survival. In a population-based cohort, we studied sTIL-survival associations by race and ethnicity. We assessed associations of continuous sTIL scores and sTIL-enriched breast cancers (defined as percent lymphocytic infiltration of tumor stroma or cell nests at cutoffs of 30%, 50%, and 70%) with clinical and epidemiologic characteristics and conducted multivariable survival analyses. Although we identified no difference in sTIL score by race and ethnicity, higher continuous sTIL score was associated with lower breast cancer-specific mortality only among non-Hispanic White and Asian American but not African American and Hispanic women. This finding suggests that complex factors influence treatment response and survival, given that sTIL enrichment was not associated with a survival advantage among women from minoritized groups, who more often experience health disparities. Further study of patient selection for sTIL-guided treatment strategies is warranted.

Translational Epidemiology: Genetic Ancestry in Breast Cancer: What Is the Role of Genetic Ancestry and Socioeconomic Status in Triple-Negative Breast Cancer?

Racial/ethnic and socioeconomic disparities seen in triple-negative breast cancer (TNBC) have prompted questions regarding the role of genetic ancestry in breast cancer (BC) subtype development, tumor biology, and ultimately prognosis. The causes of disparities in TNBC are influenced greatly by both sociopolitical factors and genetic ancestry, and now, the potential genomic underpinnings of social factors. To comprehensively understand disparities in TNBC, it is critical to take a translational epidemiologic approach that takes into account genomic and non-genomic factors. Understanding the interplay between genetic ancestry and social genomics and their proportional influence on outcomes can guide our priorities for screening, diagnosis, and interventions for this aggressive BC subtype.

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

Importance

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.

Objective

To jointly examine associations between African genetic ancestry, social environment, and mortality from any cause and BC in Black BC survivors.

Design, Setting, and Participants

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.

Exposures

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.

Main Outcomes and Measures

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.

Results

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).

Conclusions and Relevance

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.

Clinical outcomes and prognostic factors in triple-negative invasive lobular carcinoma of the breast

PURPOSE

Triple-negative invasive lobular carcinoma (TN-ILC) of breast cancer is a rare disease and the clinical outcomes and prognostic factors are not well-defined.

METHODS

Women with stage I-III TN-ILC or triple-negative invasive ductal carcinoma (TN-IDC) of the breast undergoing mastectomy or breast-conserving surgery between 2010 and 2018 in the National Cancer Database were included. Kaplan-Meier curves and multivariate Cox proportional hazard regression were used to compare overall survival (OS) and evaluate prognostic factors. Multivariate logistic regression was performed to analyze the factors associated with pathological response to neoadjuvant chemotherapy.

RESULTS

The median age at diagnosis for women with TN-ILC was 67 years compared to 58 years in TN-IDC (p < 0.001). There was no significant difference in the OS between TN-ILC and TN-IDC in multivariate analysis (HR 0.96, p = 0.44). Black race and higher TNM stage were associated with worse OS, whereas receipt of chemotherapy or radiation was associated with better OS in TN-ILC. Among women with TN-ILC receiving neoadjuvant chemotherapy, the 5-year OS was 77.3% in women with a complete pathological response (pCR) compared to 39.8% in women without any response. The odds of achieving pCR following neoadjuvant chemotherapy were significantly lower in women with TN-ILC compared to TN-IDC (OR 0.53, p < 0.001).

CONCLUSION

Women with TN-ILC are older at diagnosis but have similar OS compared to TN-IDC after adjusting for tumor and demographic characteristics. Administration of chemotherapy was associated with improved OS in TN-ILC, but women with TN-ILC were less likely to achieve complete response to neoadjuvant therapy compared to TN-IDC.

Clinical Outcomes and Prognostic Factors in Triple-Negative Invasive Lobular Carcinoma of the Breast

Purpose: Triple-negative invasive lobular carcinoma (TN-ILC) of breast cancer is a rare disease and the clinical outcomes and prognostic factors are not well-defined. Methods: Women with stage I-III TN-ILC or triple-negative invasive ductal carcinoma (TN-IDC) of the breast undergoing mastectomy or breast-conserving surgery between 2010 and 2018 in the National Cancer Database were included. Kaplan-Meier curves and multivariate Cox proportional hazard regression were used to compare overall survival (OS) and evaluate prognostic factors. Multivariate logistic regression was performed to analyze the factors associated with pathological response to neoadjuvant chemotherapy. Results: The median age at diagnosis for women with TN-ILC was 67 years compared to 58 years in TN-IDC (p<0.001). There was no significant difference in the OS between TN-ILC and TN-IDC in multivariate analysis (HR 0.96, p=0.44). Black race and higher TNM stage were associated with worse OS, whereas receipt of chemotherapy or radiation was associated with better OS in TN-ILC. Among women with TN-ILC receiving neoadjuvant chemotherapy, the 5-year OS was 77.3% in women with a complete pathological response (pCR) compared to 39.8% in women without any response. The odds of achieving pCR following neoadjuvant chemotherapy were significantly lower in women with TN-ILC compared to TN-IDC (OR 0.53, p<0.001). Conclusion: Women with TN-ILC are older at diagnosis but have similar OS compared to TN-IDC after adjusting for tumor and demographic characteristics. Administration of chemotherapy was associated with improved OS in TN-ILC, but women with TN-ILC were less likely to achieve complete response to neoadjuvant therapy compared to TN-IDC.

Lower breast cancer survival among Black women in Brazil: a population-based retrospective study

OBJECTIVES

To analyze the rates of breast cancer survival among Black and White women according to age and stage at diagnosis.

STUDY DESIGN

A retrospective cohort study.

METHODS

The study examined women registered in the population-based cancer registry of Campinas in 2010-2014. The primary variable was the declared race (White or Black). Other races were excluded. Data were linked with the Mortality Information System, and missing information was accessed by active search. Overall survival (OS) was calculated by the Kaplan-Meier method, comparisons were done by chi-squared tests, and hazard ratios were examined by Cox regression.

RESULTS

The total numbers of new cases of staged breast cancer among Black and White women were 218 and 1522 cases, respectively. The rates of stages III/IV were 35.5% among White women and 43.1% among Black women (P = 0.024). The frequencies among White and Black women under 40 years old were 8.0% and 12.4% (P = 0.031), 19.6% and 26.6% (P = 0.016) for ages of 40-49 years, and 23.8% and 17.4% (P = 0.037) for ages of 60-69 years, respectively. The mean OS was 7.5 years (7.0; 8.0) among Black women and 8.4 years (8.2; 8.5) among White women. The 5-year OS was 72.3% among Black women and 80.5% among White women (P = 0.001). Black women had an age-adjusted risk of death that was 1.7 times higher (1.33; 2.20). The risk was 6.4 times higher for diagnoses in stage 0 (1.65; 24.90) and 1.5 times for diagnoses in stage IV (1.04; 2.17).

CONCLUSION

The 5-year OS for women with breast cancer was significantly lower among Black women than White women. Black women were more frequently diagnosed in stages III/IV, and their age-adjusted risk of death was 1.7 times higher. Differences in access to care may explain these differences.

Incidence trends in triple-negative breast cancer among women in the United States from 2010 to 2019 by race/ethnicity, age and tumor stage

There were substantial ethnic disparities in the incidence rates of triple-negative breast cancer, but few studies were conducted on the incidence trend of triple-negative breast cancer by race/ethnicity. This study aimed to address the longer trends in the incidence of triple-negative breast cancer by race/ethnicity in women from 2010 to 2019, examine the incidence trends by patient age, tumor stage and time periods, and explore the changing proportions of three component receptors over time for triple-negative breast cancer. Our study identified 573,168 women with incident breast cancer at age ≥20 years between 2010 and 2019 in 18 SEER (Surveillance, Epidemiology, and End Results) registries. Of them, 62,623 (10.9%) were incident triple-negative breast cancer and 510,545 were non-triple negative breast cancer cases. The denominator of population included 320,117,009 women aged ≥20 in the same SEER areas. The study found that overall age-adjusted incidence rate of triple-negative breast cancer in women aged ≥20 years was 18.3 cases per 100,000 women. Age-adjusted incidence rate of triple-negative breast cancer was the highest in black women (33.8 cases per 100,000 women), followed by white (17.5), American Indian and Alaska Native (AIAN) (14.7), Hispanic (14.7), and Asian women (12.4). The significantly higher age-adjusted incidence of triple-negative breast cancer in black women as compared to white women appeared to be limited in younger women aged 20-44 only. Annual percentage changes in age-adjusted incidence of triple-negative breast cancer slightly decreased insignificantly in white, black and Asian women aged 20-44 and 45-54 years. There was a statistically significant annual percentage increase in age-adjusted incidence of triple-negative breast cancer in Asian and black women aged ≥55 years. In conclusion, there was a significantly higher incidence of triple-negative breast cancer in black women aged 20-44 years. From 2010 to 2019, there were no significant annual percentage changes in age-adjusted incidence of triple-negative breast cancer in all ethnic groups of women aged <55 years, with the exception of a significant decrease among AIAN women aged 45-54 years. However, there was a statistically significant annual percentage increase in age-adjusted incidence of triple-negative breast cancer in Asian and black women aged ≥55 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.

Exosomal miR-1304-3p promotes breast cancer progression in African Americans by activating cancer-associated adipocytes

Breast cancer displays disparities in mortality between African Americans and Caucasian Americans. However, the exact molecular mechanisms remain elusive. Here, we identify miR-1304-3p as the most upregulated microRNA in African American patients. Importantly, its expression significantly correlates with poor progression-free survival in African American patients. Ectopic expression of miR-1304 promotes tumor progression in vivo. Exosomal miR-1304-3p activates cancer-associated adipocytes that release lipids and enhance cancer cell growth. Moreover, we identify the anti-adipogenic gene GATA2 as the target of miR-1304-3p. Notably, a single nucleotide polymorphism (SNP) located in the miR-1304 stem-loop region shows a significant difference in frequencies of the G allele between African and Caucasian American groups, which promotes the maturation of miR-1304-3p. Therefore, our results reveal a mechanism of the disparity in breast cancer progression and suggest a potential utility of miR-1304-3p and the associated SNP as biomarkers for predicting the outcome of African American patients.

NURR1 Is Differentially Expressed in Breast Cancer According to Patient Racial Identity and Tumor Subtype

Breast carcinoma (BCa) remains the second most common cause of cancer-related death among American women. Whereas estrogen receptor (ER) expression is typically regarded as a favorable prognostic indicator, a significant proportion of ER(+) patients still experience either de novo or acquired endocrine resistance. Previously, we have shown that the loss of orphan nuclear receptor NURR1 expression is associated with neoplastic transformation of the breast epithelium and shorter relapse-free survival (RFS) among systemically treated breast cancer (BCa) patients. Here, we further ascertain the prognostic value of NURR1 in BCa, and its differential expression among Black and White female BCa patients. We assessed the expression of NURR1 mRNA in BCa patients using the Cancer Genome Atlas (TGCA) and compared the occurrence of basal-like cancer and luminal A breast cancer subtypes. Expression levels were further stratified according to racial identity of the patient. We next assessed the correlation of NURR1 expression with Oncotype DX prognostic markers, and the association of NURR1 expression with relapse free survival in patients treated with endocrine therapy. Our study shows that NURR1 mRNA expression is differentially correlated with luminal A vs. basal-like cancer BCa and is predictive of poor relapse-free survival, confirming a similar trend observed in our previous studies using microarray data. NURR1 expression was positively correlated with expression of Oncotype DX biomarkers associated with estrogen responsiveness, while being inversely correlated with biomarkers associated with cell proliferation. Furthermore, we observed that NURR1 expression was positively associated with greater relapse-free survival at 5 years among patients treated with endocrine therapy. Interestingly, we found that among Black women with luminal A BCa, NURR1 expression was repressed in comparison to White women with the same subtype.

Insulin resistance and racial disparities in breast cancer prognosis: a multi-center cohort study

The survival for breast cancer (BC) is improving but remains lower in Black women than White women. A number of factors potentially drive the racial differences in BC outcomes. The aim of our study was to determine if insulin resistance (defined as homeostatic model assessment for insulin resistance (HOMA-IR)), mediated part of the relationship between race and BC prognosis (defined by the improved Nottingham prognostic index (iNPI)). We performed a cross-sectional study, recruiting self-identified Black and White women with newly diagnosed primary invasive BC from 10 US hospitals between March 2013 and February 2020. Survey, anthropometric, laboratory, and tumor pathology data were gathered, and we compared the results between Black and White women. We calculated HOMA-IR as well as iNPI scores and examined the associations between HOMA-IR and iNPI. After exclusions, the final cohort was 1206: 911 (76%) White and 295 (24%) Black women. Metabolic syndrome and insulin resistance were more common in Black than White women. Black women had less lobular BC, three times more triple-negative BC, and BCs with higher stage and iNPI scores than White women (P < 0.001 for all comparisons). Fewer Black women had BC genetic testing performed. HOMA-IR mediated part of the association between race and iNPI, particularly in BCs that carried a good prognosis and were hormone receptor (HR)-positive. Higher HOMA-IR scores were associated with progesterone receptor-negative BC in White women but not Black women. Overall, our results suggest that HOMA-IR contributes to the racial disparities in BC outcomes, particularly for women with HR-positive BCs.

Breast Cancer Statistics, 2022

This article is the American Cancer Society's update on female breast cancer statistics in the United States, including population-based data on incidence, mortality, survival, and mammography screening. Breast cancer incidence rates have risen in most of the past four decades; during the most recent data years (2010-2019), the rate increased by 0.5% annually, largely driven by localized-stage and hormone receptor-positive disease. In contrast, breast cancer mortality rates have declined steadily since their peak in 1989, albeit at a slower pace in recent years (1.3% annually from 2011 to 2020) than in the previous decade (1.9% annually from 2002 to 2011). In total, the death rate dropped by 43% during 1989-2020, translating to 460,000 fewer breast cancer deaths during that time. The death rate declined similarly for women of all racial/ethnic groups except American Indians/Alaska Natives, among whom the rates were stable. However, despite a lower incidence rate in Black versus White women (127.8 vs. 133.7 per 100,000), the racial disparity in breast cancer mortality remained unwavering, with the death rate 40% higher in Black women overall (27.6 vs. 19.7 deaths per 100,000 in 2016-2020) and two-fold higher among adult women younger than 50 years (12.1 vs. 6.5 deaths per 100,000). Black women have the lowest 5-year relative survival of any racial/ethnic group for every molecular subtype and stage of disease (except stage I), with the largest Black-White gaps in absolute terms for hormone receptor-positive/human epidermal growth factor receptor 2-negative disease (88% vs. 96%), hormone receptor-negative/human epidermal growth factor receptor 2-positive disease (78% vs. 86%), and stage III disease (64% vs. 77%). Progress against breast cancer mortality could be accelerated by mitigating racial disparities through increased access to high-quality screening and treatment via nationwide Medicaid expansion and partnerships between community stakeholders, advocacy organizations, and health systems.

Risk of Presenting with Poor-Prognosis Metastatic Cancer in Adolescents and Young Adults: A Population-Based Study

Having metastatic disease at diagnosis poses the great risk of death among AYAs with cancer from all sociodemographic subgroups. This “landscape” study utilized United States Surveillance, Epidemiology, and End Results Program data from 2000−2016 to identify subgroups of AYAs at highest risk for presenting with metastases across twelve cancer sites having a poor-prognosis (5-year survival <50% with metastases). Adjusted odds ratios for risk of metastatic disease presentation were compared for AYAs in aggregate and by sociodemographic subgroup (race/ethnicity, sex, socioeconomic status [SES]). In general, AYAs who were male, racial/ethnic minorities, or low SES were at consistently greatest risk of metastases. Strikingly, having metastatic melanoma was independently associated with multiple AYA sociodemographic subgroups, including males (aOR 3.11 [95% CI 2.64−3.66]), non-Hispanic Blacks (4.04 [2.32−7.04]), Asian Pacific Islanders (2.99 [1.75−5.12]), Hispanics (2.37 [1.85−3.04]), and low SES (2.30 [1.89−2.80]). Non-Hispanic Blacks were more likely to present with metastatic cancer in all sites, except for bone, rhabdomyosarcoma, and stomach. Low SES AYAs are more likely to present with metastatic melanoma, bone tumors, soft tissue sarcomas, breast, cervical, lung, and stomach carcinomas. Building on these results, future cancer-specific studies should investigate the connection between sociodemographic risk factors and biological drivers of metastases. This line of research has potential to inform targeted public health and screening efforts to facilitate risk reduction and earlier detection of these deadly diseases.

Are there differences in outcomes by race among women with metastatic triple-negative breast cancer?

PURPOSE

Black women have higher breast cancer mortality rates than other groups, with Triple-negative breast cancer (TNBC) being more common among AAs with a worse prognosis. Our study seeks to explore differences among Non-Hispanic Black (NHB) vs. White (NHW) women, with Stage IV TNBC, focusing on survival and treatment patterns.

METHODS

SEER database was queried for TNBC patients diagnosed with metastatic disease from 2012 to 2016. Neighborhood socioeconomic status (nSES) was defined using the Yost index based on income, education, housing, and employment. Univariate and multivariate analyses were performed to evaluate receipt of surgery, radiation, and chemotherapy. Overall survival was evaluated using Kaplan-Meier curve and Cox proportional hazards model analysis.

RESULTS

25,761 TNBC cases were identified with 1420 being metastatic (5.5%). Bone was the most common site for metastasis, with patients' age being 63.7 years for NHW vs. 59.5 years for NHB. NHB women had the highest percentage of low nSES (62.3% vs 29.3%; p value = 0.001). On univariate analysis, fewer NHBs received radiation compared to NHWs (27.1 vs. 32.6%; p value = 0.040). On multivariate analysis, all women were less likely to undergo treatment if unmarried (p value < 0.01). NHB women had lower median survival compared to NHW women (13 vs. 15 months; p value < 0.01). Receipt of surgery and chemotherapy reduced the risk of mortality (p value < 0.01).

CONCLUSION

NHB women had lower median survival with metastatic TNBC. Race was associated with different treatment utilization. With a mortality differential between NHW and NHB women with metastatic TNBC, more investigation is needed to inform strategies to reduce this disparity.

Metabolic Links to Socioeconomic Stresses Uniquely Affecting Ancestry in Normal Breast Tissue at Risk for Breast Cancer

A primary difference between black women (BW) and white women (WW) diagnosed with breast cancer is aggressiveness of the tumor. Black women have higher mortalities with similar incidence of breast cancer compared to other race/ethnicities, and they are diagnosed at a younger age with more advanced tumors with double the rate of lethal, triple negative breast cancers. One hypothesis is that chronic social and economic stressors result in ancestry-dependent molecular responses that create a tumor permissive tissue microenvironment in normal breast tissue. Altered regulation of N-glycosylation of proteins, a glucose metabolism-linked post-translational modification attached to an asparagine (N) residue, has been associated with two strong independent risk factors for breast cancer: increased breast density and body mass index (BMI). Interestingly, high body mass index (BMI) levels have been reported to associate with increases of cancer-associated N-glycan signatures. In this study, we used matrix assisted laser desorption/ionization (MALDI) imaging mass spectrometry (IMS) to investigate molecular pattern changes of N-glycosylation in ancestry defined normal breast tissue from BW and WW with significant 5-year risk of breast cancer by Gail score. N-glycosylation was tested against social stressors including marital status, single, education, economic status (income), personal reproductive history, the risk factors BMI and age. Normal breast tissue microarrays from the Susan G. Komen tissue bank (BW=43; WW= 43) were used to evaluate glycosylation against socioeconomic stress and risk factors. One specific N-glycan (2158 m/z) appeared dependent on ancestry with high sensitivity and specificity (AUC 0.77, Brown/Wilson p-value<0.0001). Application of a linear regression model with ancestry as group variable and socioeconomic covariates as predictors identified a specific N-glycan signature associated with different socioeconomic stresses. For WW, household income was strongly associated to certain N-glycans, while for BW, marital status (married and single) was strongly associated with the same N-glycan signature. Current work focuses on understanding if combined N-glycan biosignatures can further help understand normal breast tissue at risk. This study lays the foundation for understanding the complexities linking socioeconomic stresses and molecular factors to their role in ancestry dependent breast cancer risk.

A Contemporary Analysis of Racial and Ethnic Disparities in Diagnosis of Early-Stage Breast Cancer and Stage-Specific Survival by Molecular Subtype

BACKGROUND

Prior studies of breast cancer disparities have focused primarily on differences between Black and White women, yet contemporary patterns of disparity for other groups are not well understood. We examine breast cancer disparities by stage at diagnosis across nine racial and ethnic groups.

METHODS

The SEER 18 registries identified 841,975 women diagnosed with breast cancer from 2000 to 2017. Joinpoint models assessed trends in diagnosis stage and survival. Multivariable logistic regression evaluated associations between race/ethnicity and diagnosis stage. Multivariable Cox models compared survival of groups by stage and molecular subtype.

RESULTS

Black, American Indian, Southeast Asian, South Asian, Pacific Islander, and Hispanic women were less likely than white women to be diagnosed with early stage breast cancer. Among those diagnosed at early stage, Hispanic, American Indian, Pacific Islander and Black women were 9%, 14%, 22%, and 39% (respectively) more likely than White women to die from breast cancer, whereas Asian subgroups had lower risk of death. Among those diagnosed at late stage, Black women were 18% more likely than White counterparts to die from breast cancer, and survival disparities for Black women persisted across all subtypes and stages, (except late stage HR-/HER2-). East Asian women with early stage HR+/HER2- tumors had better survival than White women.

CONCLUSIONS

Persistent disparities in early detection and survival of breast cancer demand further work to address and reduce disparities across the cancer continuum.

IMPACT

Results have implications for efforts to reduce entrenched racial and ethnic disparities in breast cancer early detection and survival.

Systematic review of neighborhood socioeconomic indices studied across the cancer control continuum

BACKGROUND

There is extensive interest in understanding how neighborhood socioeconomic status (nSES) may affect cancer incidence or survival. However, variability regarding items included and approaches used to form a composite nSES index presents challenges in summarizing overall associations with cancer. Given recent calls for standardized measures of neighborhood sociodemographic effects in cancer disparity research, the objective of this systematic review was to identify and compare existing nSES indices studied across the cancer continuum (incidence, screening, diagnosis, treatment, survival/mortality) and summarize associations by race/ethnicity and cancer site to inform future cancer disparity studies.

METHODS

Using PRISMA guidelines, peer-reviewed articles published between 2010 and 2019 containing keywords related to nSES and cancer were identified in PubMed.

RESULTS

Twenty-four nSES indices were identified from 75 studies. In general, findings indicated a significant association between nSES and cancer outcomes (n = 64/75 studies; 85.33%), with 42/64 (65.63%) adjusting for highly-correlated individual SES factors (e.g., education). However, the direction of association differed by cancer site, race/ethnicity, and nSES index.

CONCLUSIONS

This review highlights several methodologic and conceptual issues surrounding nSES measurement and potential associations with cancer disparities. Recommendations pertaining to the selection of nSES measures are provided, which may help inform disparity-related disease processes and improve the identification of vulnerable populations in need of intervention.

Oncobiology and treatment of breast cancer in young women

Female breast cancer emerged as the leading cancer type in terms of incidence globally in 2020. Although mortality due to breast cancer has improved during the past three decades in many countries, this trend has reversed in women less than 40 years since the past decade. From the biological standpoint, there is consensus among experts regarding the clinically relevant definition of breast cancer in young women (BCYW), with an age cut-off of 40 years. The idea that breast cancer is an aging disease has apparently broken in the case of BCYW due to the young onset and an overall poor outcome of BCYW patients. In general, younger patients exhibit a worse prognosis than older pre- and postmenopausal patients due to the aggressive nature of cancer subtypes, a high percentage of cases with advanced stages at diagnosis, and a high risk of relapse and death in younger patients. Because of clinically and biologically unique features of BCYW, it is suspected to represent a distinct biologic entity. It is unclear why BCYW is more aggressive and has an inferior prognosis with factors that contribute to increased incidence. However, unique developmental features, adiposity and immune components of the mammary gland, hormonal interplay and crosstalk with growth factors, and a host of intrinsic and extrinsic risk factors and cellular regulatory interactions are considered to be the major contributing factors. In the present article, we discuss the status of BCYW oncobiology, therapeutic interventions and considerations, current limitations in fully understanding the basis and underlying cause(s) of BCYW, understudied areas of BCYW research, and postulated advances in the coming years for the field.

Survival of Adolescents and Young Adults with Prevalent Poor-Prognosis Metastatic Cancers: A Population-Based Study of Contemporary Patterns and Their Implications

BACKGROUND

Although survival has improved dramatically for most adolescents and young adults (AYA; 15-39 years old) with cancer, it remains poor for those presenting with metastatic disease. To better characterize this subset, we conducted a landscape survival comparison with older adults (40-79 years).

METHODS

Using Surveillance, Epidemiology, and End Results Program data from 2000 to 2016, we examined incident cases of poor-prognosis metastatic cancers (5-year survival < 50%) among AYAs (n = 11,518) and older adults (n = 345,681) and compared cause-specific survival by sociodemographic characteristics (race/ethnicity, sex, and socioeconomic status). Adjusted HRs (aHR) for death from metastatic disease [95% confidence intervals (95% CI)] were compared between AYAs and older adults (Pint).

RESULTS

AYAs had significantly better survival than older adults for every cancer site except kidney, where it was equivalent (range of aHRs = 0.91; 95% CI, 0.82-1.02 for kidney cancer to aHR = 0.33; 95% CI, 0.26-0.42 for rhabdomyosarcoma). Compared with their older adult counterparts, greater survival disparities existed for AYAs who were non-Hispanic Black with uterine cancer (aHR = 2.20; 95% CI, 1.25-3.86 versus aHR = 1.40; 95% CI, 1.28-1.54; Pint = 0.049) and kidney cancer (aHR = 1.51; 95% CI, 1.15-1.98 versus aHR = 1.10; 95% CI, 1.03-1.17; Pint = 0.04); non-Hispanic Asian/Pacific Islanders with ovarian cancer (aHR = 1.47; 95% CI, 1.12-1.93 versus aHR = 0.89; 95% CI, 0.84-0.95; Pint<0.001); and males with colorectal cancer (aHR = 1.21; 95% CI, 1.10-1.32 versus aHR = 1.08; 95% CI, 1.06-1.10; Pint = 0.045).

CONCLUSIONS

AYAs diagnosed with these metastatic cancers have better survival than older adults, but outcomes remain dismal.

IMPACT

Overcoming the impact of metastasis in these cancers is necessary for continuing progress in AYA oncology. Sociodemographic disparities affecting AYAs within kidney, uterine, ovarian, and colorectal cancer could indicate plausible effects of biology, environment, and/or access and should be explored.

Nomograms for Predicting Specific Distant Metastatic Sites and Overall Survival of Breast Invasive Ductal Carcinoma Patients After Surgery: A Large Population-Based Study

Background

Breast cancer (BC) has become the most common malignancy worldwide, accounting for 11.7% of newly diagnosed cancer cases last year. Invasive ductal carcinoma (IDC) is the most common pathological type of BC. However, there were few studies to predict distant metastatic sites and overall survival (OS) of IDC patients.

Methods

Post-operative IDC patients from 2010 to 2016 in the Surveillance, Epidemiology, and End Results (SEER) database were reviewed. Nomograms were developed to predict the specific distant metastatic sites and OS of IDC patients. The performance of nomograms was evaluated with the calibration curves, area under the curve (AUC), and decision curve analysis (DCA). Kaplan-Meier analysis and log-rank tests were used to estimate the survival times of IDC patients with distant metastases.

Results

A total of 171,967 post-operative IDC patients were enrolled in our study. Univariate and multivariate analyses were used to establish the nomograms of significant variables. The AUC of the nomograms for the prediction of liver, lung, bone, and brain metastases was 0.903, 0.877, 0.863, and 0.811, respectively. In addition, the AUC of the nomogram for the prediction of 1-, 3-, and 5-year OS was 0.809, 0.813, 0.787, respectively. Calibration curves and DCA showed good consistency and clinical benefits, respectively.

Conclusions

We constructed new predictive models for liver, lung, brain, bone metastases and 1-, 3-, and 5-year OS in IDC patients. These can help clinicians to individualize the treatment of IDC patients, so that patients can get the more appropriate treatment options.

Racial disparities in health insurance, triple‑negative breast cancer diagnosis, tumor stage, treatment and survival in a large nationwide SEER cohort in the United States

It remains unclear whether there are racial disparities in mortality between women of different races who have the same subtype of breast cancer when tumor stage and size and treatment are controlled for. The present study aimed to investigate whether racial disparities in mortality existed between women of different races who had the same subtype of breast cancer when health insurance, tumor stage and size and treatment were controlled for in a large cohort of women with breast cancer in the United States. This study identified 399,564 women who were diagnosed with incident breast cancer at age ≥20 years between 2010 and 2016 in 17 Surveillance, Epidemiology and End Results (SEER) registries, including 277,319 non-Hispanic white (white), 44,149 non-Hispanic black (black), 34,141 non-Hispanic Asian or Pacific Islander (Asian) and 43,955 Hispanic women. White and Asian women exhibited a lower proportion of triple-negative breast cancer (9.8 and 9.1% respectively) than black (20.8%) and Hispanic women (12.6%). Black women had a significantly higher risk of all-cause mortality compared with white women in only those with triple-negative breast cancer (hazard ratio: 1.39, 95% CI: 1.29-1.51) and those with hormone receptor-negative/human epidermal growth factor receptor 2 (HER2)-positive breast cancer (1.53, 1.48-1.58) after adjusting for confounders. In those with hormone receptor-positive breast cancer, regardless of HER2 receptor status, the risk of all-cause mortality was not statistically different between black and white women, while the risk of breast cancer-specific mortality was significantly higher in all subtypes of breast cancer among black women. There were racial disparities in the presentation of triple-negative breast cancer and in all-cause and breast cancer specific mortality following stratification by triple-negative status and adjusting for tumor stage, size, grade and treatment.

Palbociclib plus endocrine therapy significantly enhances overall survival of HR+/HER2- metastatic breast cancer patients compared to endocrine therapy alone in the second-line setting-a large institutional study

Cyclin-dependent-kinase-4/6 inhibitor (CDKi) plus endocrine therapy (ET) is standard of care for patients with advanced hormone receptor (HR)-positive, HER2-negative breast cancer (BC). The Breast Medical Oncology database at MD Anderson Cancer Center (MDACC) was analyzed to assess effectiveness of the CDKi palbociclib plus ET compared to ET alone. From a total of 5402 advanced HR+ HER2- BC patients referred to MDACC between 1997 and 2020, we identified eligible patients who received palbociclib in combination with first- (n=778) and second-line (n=410) ET. We further identified "control" patients who received ET alone in the first- (n=2452) and second-line (n=1183) settings. Propensity score matching analysis was conducted to balance baseline demographic and clinical characteristics between palbociclib and control cohorts to assess the effect of palbociclib treatment on progression-free survival (PFS) and overall survival (OS). For propensity-matched-cohort in the first-line setting (n=708), palbociclib group had significantly longer median PFS (17.4 vs. 11.1 months; p<0.0001) compared to controls. Median OS (44.3 vs. 40.2 months) did not show a statistically significant benefit in the first line setting. However, in the second-line setting, with 380 propensity-matched-cohort, the palbociclib group had significantly longer PFS (10 vs 5 months, p<0.0001) as well as OS (33 vs 24 months; p < 0.022), compared to controls. We conclude that in this single center analysis of a large cohort of metastatic HR+ HER2- BC patients, palbociclib in combination with ET was associated with improved PFS in both first- and second-line settings and OS in the second-line setting compared with ET alone cohort.

Identifying Equitable Screening Mammography Strategies for Black Women in the United States Using Simulation Modeling

BACKGROUND

Screening mammography guidelines do not explicitly consider racial differences in breast cancer epidemiology, treatment, and survival.

OBJECTIVE

To compare tradeoffs of screening strategies in Black women versus White women under current guidelines.

DESIGN

An established model from the Cancer Intervention and Surveillance Modeling Network simulated screening outcomes using race-specific inputs for subtype distribution; breast density; mammography performance; age-, stage-, and subtype-specific treatment effects; and non-breast cancer mortality.

SETTING

United States.

PARTICIPANTS

A 1980 U.S. birth cohort of Black and White women.

INTERVENTION

Screening strategies until age 74 years with varying initiation ages and intervals.

MEASUREMENTS

Outcomes included benefits (life-years gained [LYG], breast cancer deaths averted, and mortality reduction), harms (mammographies, false positives, and overdiagnoses), and benefit-harm ratios (tradeoffs) by race. Efficiency (benefits per unit resource), mortality disparity reduction, and equity in tradeoffs were evaluated. Equitable strategies for Black women were defined as those with tradeoffs closest to benchmark values for screening White women biennially from ages 50 to 74 years.

RESULTS

Biennial screening from ages 45 to 74 years was most efficient for Black women, whereas biennial screening from ages 40 to 74 years was most equitable. Initiating screening 10 years earlier in Black versus White women reduced Black-White mortality disparities by 57% with similar LYG per mammogram for both populations. Selection of the most equitable strategy was sensitive to assumptions about disparities in real-world treatment effectiveness: The less effective treatment was for Black women, the more intensively Black women could be screened before tradeoffs fell short of those experienced by White women.

LIMITATION

Single model.

CONCLUSION

Initiating biennial screening in Black women at age 40 years reduces breast cancer mortality disparities and yields benefit-harm ratios that are similar to tradeoffs of White women screened biennially from ages 50 to 74 years.

PRIMARY FUNDING SOURCE

National Cancer Institute at the National Institutes of Health.

Patient-reported treatment toxicity and adverse events in Black and White women receiving chemotherapy for early breast cancer

PURPOSE

It is not known whether chemotherapy-related symptom experiences differ between Black and White women with early breast cancer (Stage I-III) receiving current chemotherapy regimens and, in turn, influences dose delay, dose reduction, early treatment discontinuation, or hospitalization.

METHODS

Patients self-reported their race and provided symptom reports for 17 major side effects throughout chemotherapy. Toxicity and adverse events were analyzed separately for anthracycline and non-anthracycline regimens. Fisher's exact tests and two-sample t-tests compared baseline patient characteristics. Modified Poisson regression estimated relative risks of moderate, severe, or very severe (MSVS) symptom severity, and chemotherapy-related adverse events.Please check and confirm that the authors and their respective affiliations have been correctly identified and amend if necessary.no changes RESULTS: In 294 patients accrued between 2014 and 2020, mean age was 58 (SD13) and 23% were Black. For anthracycline-based regimens, the only significant difference in MSVS symptoms was in lymphedema (41% Black vs 20% White, p = .04) after controlling for axillary surgery. For non-anthracycline regimens, the only significant difference was MSVS peripheral neuropathy (41% Blacks vs. 23% White) after controlling for taxane type (p = .05) and diabetes (p = .05). For all other symptoms, severity scores were similar. Dose reduction differed significantly for non-anthracycline regimens (49% Black vs. 25% White, p = .01), but not for anthracycline regimens or in dose delay, early treatment discontinuation, or hospitalization for either regimen.

CONCLUSION

Except for lymphedema and peripheral neuropathy, Black and White patients reported similar symptom severity during adjuvant chemotherapy. Dose reductions in Black patients were more common for non-anthracycline regimens. In this sample, there were minimal differences in patient-reported symptoms and other adverse outcomes in Black versus White patients.

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.

Breast Tumor Microenvironment in Black Women: A Distinct Signature of CD8+ T-Cell Exhaustion

BACKGROUND

Blacks tend to have a stronger inflammatory immune response than Whites. We hypothesized that racial differences in host immunity also manifest in the tumor microenvironment, constituting part of a distinct aggressive tumor biology underlying higher mortality in Black women.

METHODS

Pathological and gene expression profiling approaches were used for characterizing infiltrating immune cells in breast tumor microenvironment from 1315 patients from the Women's Circle of Health Study. Racial differences in tumor immune phenotypes were compared, with results validated in a publicly accessible dataset. Prognostic associations of immune phenotypes were assessed in 3 independent cohorts.

RESULTS

We found marked and consistent differences in tumor immune responses between Black and White patients. Not only did tumors from Blacks display a stronger overall immune presence but also the composition and quality of immune infiltrates differed, regardless of tumor subtypes. Black patients had a stronger CD4+ and B-cell response, and further, a more exhausted CD8+ T-cell profile. A signature indicating a higher ratio of exhausted CD8+ T cells to total CD8+ T cells (ExCD8-r) was consistently associated with poorer survival, particularly among hormone receptor-positive patients. Among hormone receptor-negative patients, combinations of the absolute fraction of CD8+ T cells and ExCD8-r signature identified the CD8lowExCD8-rhigh subgroup, the most prevalent among Blacks, with the worst survival.

CONCLUSIONS

Our findings of a distinct exhausted CD8+ T-cell signature in Black breast cancer patients indicate an immunobiological basis for their more aggressive disease and a rationale for the use of immune checkpoint inhibitors targeting the exhaustion phenotype.

Disparities in Surgical Oncology: Management of Advanced Cancer

Significant variations in the patterns of care, incidence, and mortality rates of several common cancers have been noted. These disparities have been attributed to a complex interplay of factors, including genetic, environmental, and healthcare-related components. Within this review, primarily focusing on commonly occurring cancers (breast, lung, colorectal), we initially summarize the burden of these disparities with regard to incidence and screening patterns. We then explore the interaction between several proven genetic, epigenetic, and environmental influences that are known to contribute to these disparities.

Evaluation of Racial/Ethnic Differences in Treatment and Mortality Among Women With Triple-Negative Breast Cancer

Importance

To our knowledge, there is no consensus regarding differences in treatment and mortality between non-Hispanic African American and non-Hispanic White women with triple-negative breast cancer (TNBC). Little is known about whether racial disparities vary by sociodemographic, clinical, and neighborhood factors.

Objective

To examine the differences in clinical treatment and outcomes between African American and White women in a nationally representative cohort of patients with TNBC and further examine the contributions of sociodemographic, clinical, and neighborhood factors to TNBC outcome disparities.

Design, Setting, and Participants

This population-based, retrospective cohort study included 23 123 women who received a diagnosis of nonmetastatic TNBC between January 1, 2010, and December 31, 2015, followed up through December 31, 2016, and identified from the Surveillance, Epidemiology, and End Results data set. The study was conducted from July 2019 to November 2020. The analyses were performed from July 2019 to June 2020.

Exposures

Race and ethnicity, including non-Hispanic African American and non-Hispanic White race.

Main Outcomes and Measures

Using logistic regression analysis and competing risk regression analysis, we estimated odds ratios (ORs) of receipt of treatment and hazard ratios (HRs) of breast cancer mortality in African American patients compared with White patients.

Results

Of 23 213 participants, 5881 (25.3%) were African American women and 17 332 (74.7%) were White women. Compared with White patients, African American patients had lower odds of receiving surgery (OR, 0.69; 95% CI, 0.60-0.79) and chemotherapy (OR, 0.89; 95% CI, 0.81-0.99) after adjustment for sociodemographic, clinicopathologic, and county-level factors. During a 43-month follow-up, 3276 patients (14.2%) died of breast cancer. The HR of breast cancer mortality was 1.28 (95% CI, 1.18-1.38) for African American individuals after adjustment for sociodemographic and county-level factors. Further adjustment for clinicopathological and treatment factors reduced the HR to 1.16 (95% CI, 1.06-1.25). This association was observed in patients living in socioeconomically less deprived counties (HR, 1.26; 95% CI, 1.14-1.39), urban patients (HR, 1.21; 95% CI, 1.11-1.32), patients having stage II (HR, 1.19; 95% CI, 1.02-1.39) or III (HR, 1.15; 95% CI, 1.01-1.31) tumors that were treated with chemotherapy, and patients younger than 65 years (HR, 1.24; 95% CI, 1.12-1.37).

Conclusions and Relevance

In this retrospective cohort study, African American women with nonmetastatic TNBC had a significantly higher risk of breast cancer mortality compared with their White counterparts, which was partially explained by their disparities in receipt of surgery and chemotherapy.

Reflecting on 20 years of breast cancer modeling in CISNET: Recommendations for future cancer systems modeling efforts

Since 2000, the National Cancer Institute’s Cancer Intervention and Surveillance Modeling Network (CISNET) modeling teams have developed and applied microsimulation and statistical models of breast cancer. Here, we illustrate the use of collaborative breast cancer multilevel systems modeling in CISNET to demonstrate the flexibility of systems modeling to address important clinical and policy-relevant questions. Challenges and opportunities of future systems modeling are also summarized. The 6 CISNET breast cancer models embody the key features of systems modeling by incorporating numerous data sources and reflecting tumor, person, and health system factors that change over time and interact to affect the burden of breast cancer. Multidisciplinary modeling teams have explored alternative representations of breast cancer to reveal insights into breast cancer natural history, including the role of overdiagnosis and race differences in tumor characteristics. The models have been used to compare strategies for improving the balance of benefits and harms of breast cancer screening based on personal risk factors, including age, breast density, polygenic risk, and history of Down syndrome or a history of childhood cancer. The models have also provided evidence to support the delivery of care by simulating outcomes following clinical decisions about breast cancer treatment and estimating the relative impact of screening and treatment on the United States population. The insights provided by the CISNET breast cancer multilevel modeling efforts have informed policy and clinical guidelines. The 20 years of CISNET modeling experience has highlighted opportunities and challenges to expanding the impact of systems modeling. Moving forward, CISNET research will continue to use systems modeling to address cancer control issues, including modeling structural inequities affecting racial disparities in the burden of breast cancer. Future work will also leverage the lessons from team science, expand resource sharing, and foster the careers of early stage modeling scientists to ensure the sustainability of these efforts.

Since 2000, our research teams have used computer models of breast cancer to address important clinical and policy-relevant questions as part of the National Cancer Institute’s Cancer Intervention and Surveillance Modeling Network (CISNET). Our 6 CISNET breast cancer models embody the key features of systems modeling by incorporating numerous data sources and reflecting tumor, person, and health system factors that change over time and interact to represent the burden of breast cancer. We have used our models to investigate questions related to breast cancer biology, compare strategies to improve the balance of benefits and harms of screening mammography, and support insights into the delivery of care by modeling outcomes following clinical decisions about breast cancer treatment. Moving forward, our research will continue to use systems modeling to address issues related to reducing the burden of breast cancer including modeling structural inequities affecting racial disparities. Our future work will also leverage lessons from engaging multidisciplinary scientific teams, expand efforts to share modeling resources with other researchers, and foster the careers of early stage modeling scientists to ensure the sustainability of these efforts.

Poor-Prognosis Metastatic Cancers in Adolescents and Young Adults: Incidence Patterns, Trends, and Disparities

Background

For adolescents and young adults (AYAs, aged 15-39 years) with cancer, metastatic disease at diagnosis is the strongest predictor of mortality, but its associations with age and sociodemographic factors are largely unexplored.

Methods

Using Surveillance, Epidemiology, and End Results Program data from 2000 to 2016, we collected incident cases of poor-prognosis metastatic cancer (5-year survival < 50%) and compared the proportion, incidence, time trends, and incidence rate ratios for race and ethnicity, sex, and socioeconomic status among AYAs, middle-aged adults (aged 40-64 years) and older adults (aged 65-79 years).

Results

From 2000 to 2016, a total of 17 210 incident cases of poor-prognosis metastatic cancer were diagnosed in AYAs, 121 274 in middle-aged adults, and 364 228 in older adults. Compared with older patients, the proportion of AYAs having metastatic disease was equivalent or substantially lower in nearly every site except stomach and breast cancers, which were statistically significantly higher for AYAs compared with middle-aged and older adults (stomach: 57.3% vs 46.4% and 39.5%; breast: 6.6% vs 4.4% and 5.6%, respectively; 2-sided P < .001 for all comparisons). Incidence rates rose significantly faster among AYAs for breast, stomach, and kidney cancers and among AYAs and middle-aged adults for colorectal cancer. Markedly higher incidence rate ratios were noted for AYA racial and ethnic minorities with breast, stomach, and especially kidney cancer, where only non-Hispanic Black AYAs were at considerably higher risk. For most sites, incidence rate ratios were higher among male patients and individuals of low socioeconomic status across age groups.

Conclusions

For most cancers, AYAs are not more likely to present with metastases than middle-aged and older adults. Further investigation is warranted for the disproportionate rise in incidence of metastatic breast, stomach, and kidney cancer among AYAs and their excess burden among AYA racial and ethnic minorities. The rising incidence of colorectal cancer among AYAs and middle-aged adults remains an additional concern.

Differences in Breast Cancer Presentation at Time of Diagnosis for Black and White Women in High Resource Settings

This paper provides a narrative review of the existing literature on differences in demographic and biological features of breast cancer at time of diagnosis between Black and White women in Canada, the United Kingdom and the United States. Electronic database searches for published peer-reviewed articles on this topic were conducted, and 78 articles were included in the final narrative review. Differences between Black and White women were compared for eight categories including age, tumour stage, size, grade, lymph node involvement, and hormone status. Black women were significantly more likely to present with less favourable tumour features at the time of diagnosis than White women. Significant differences were reported in age at diagnosis, tumour stage, size, grade and hormone status, particularly triple negative breast cancer. Limitations on the generalizability of the review findings are discussed, as well as the implications of these findings on future research, especially within the Canadian context.

Racial/Ethnic Disparities in All-Cause Mortality among Patients Diagnosed with Triple-Negative Breast Cancer

It is unclear whether racial/ethnic disparities in triple-negative breast cancer (TNBC) mortality remain after accounting for clinical characteristics, treatment, and access-to-care-related factors. In this study, women with a primary diagnosis of TNBC during 2010-2014 were identified from the National Cancer Database. Hazard ratios (HR) and 95% confidence intervals (CI) for 3- and 5-year all-cause mortality associated with race/ethnicity were estimated using Cox proportional hazards models with stepwise adjustments for age, clinical characteristics, treatment, and access-to-care-related factors. Of 78,708 patients, non-Hispanic (NH) black women had the lowest 3-year overall survival rates (79.4%), followed by NH-whites (83.1%), Hispanics (86.0%), and Asians (87.1%). After adjustment for clinical characteristics, NH-blacks had a 12% higher risk of dying 3 years post-diagnosis (HR, 1.12; 95% CI, 1.07-1.17), whereas Hispanics and Asians had a 24% (HR, 0.76; 95% CI, 0.70-0.83) and 17% (HR, 0.83; 95% CI, 0.73-0.94) lower risk than their NH-white counterparts. The black-white disparity became non-significant after combined adjustment for treatment and access-to-care-related factors (HR, 1.04; 95% CI, 0.99-1.09), whereas the white-Hispanic and white-Asian differences remained. Stratified analyses revealed that among women aged less than or equal to 50 with stage III cancer, the elevated risk among NH-blacks persisted (HR, 1.20; 95% CI, 1.04-1.39) after full adjustments. Similar results were seen for 5-year mortality. Overall, clinical characteristics, treatment, and access-to-care-related factors accounted for most of the white-black differences in all-cause mortality of TNBC but explained little about Hispanic- and Asian-white differences. SIGNIFICANCE: These findings highlight the need for equal healthcare to mitigate the black-white disparity and for investigations of contributors beyond healthcare for lower mortality among Asians and Hispanics.

Targeting the purinergic pathway in breast cancer and its therapeutic applications

Breast cancer (BC) is the most frequent cause of death among women, representing a global public health problem. Here, we aimed to discuss the correlation between the purinergic system and BC, recognizing therapeutic targets. For this, we analyzed the interaction of extracellular nucleotides and nucleosides with the purinergic receptors P1 and P2, as well as the influence of ectonucleotidase enzymes (CD39 and CD73) on tumor progression. A comprehensive bibliographic search was carried out. The relevant articles for this review were found in the PubMed, Scielo, Lilacs, and ScienceDirect databases. It was observed that among the P1 receptors, the A1, A2A, and A2B receptors are involved in the proliferation and invasion of BC, while the A3 receptor is related to the inhibition of tumor growth. Among the P2 receptors, the P2X7 has a dual function. When activated for a short time, it promotes metastasis, but when activated for long periods, it is related to BC cell death. P2Y2 and P2Y6 receptors are related to BC proliferation and invasiveness. Also, the high expression of CD39 and CD73 in BC is strongly related to a worse prognosis. The receptors and ectonucleotidases involved with BC become possible therapeutic targets. Several purinergic pathways have been found to be involved in BC cell survival and progression. In this review, in addition to analyzing the pathways involved, we reviewed the therapeutic interventions already studied for BC related to the purinergic system, as well as to other possible therapeutic targets.

In modern times, how important are breast cancer stage, grade and receptor subtype for survival: a population-based cohort study

Background

In breast cancer, immunohistochemistry (IHC) subtypes, together with grade and stage, are well-known independent predictors of breast cancer death. Given the immense changes in breast cancer treatment and survival over time, we used recent population-based data to test the combined influence of IHC subtypes, grade and stage on breast cancer death.

Methods

We identified 24,137 women with invasive breast cancer aged 20 to 74 between 2005 and 2015 in the database of the Cancer Registry of Norway. Kaplan-Meier curves, mortality rates and adjusted hazard ratios for breast cancer death were estimated by IHC subtypes, grade, tumour size and nodal status during 13 years of follow-up.

Results

Within all IHC subtypes, grade, tumour size and nodal status were independent predictors of breast cancer death. When combining all prognostic factors, the risk of death was 20- to 40-fold higher in the worst groups compared to the group with the smallest size, low grade and ER+PR+HER2− status. Among node-negative ER+HER2− tumours, larger size conferred a significantly increased breast cancer mortality. ER+PR−HER2− tumours of high grade and advanced stage showed particularly high breast cancer mortality similar to TNBC. When examining early versus late mortality, grade, size and nodal status explained most of the late (> 5 years) mortality among ER+ subtypes.

Conclusions

There is a wide range of risks of dying from breast cancer, also across small breast tumours of low/intermediate grade, and among node-negative tumours. Thus, even with modern breast cancer treatment, stage, grade and molecular subtype (reflected by IHC subtypes) matter for prognosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13058-021-01393-z.

Racial Disparities in Triple Negative Breast Cancer: A Review of the Role of Biologic and Non-biologic Factors

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer that lacks expression of the estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor (HER2). TNBC constitutes about 15–30 percent of all diagnosed invasive breast cancer cases in the United States. African-American (AA) women have high prevalence of TNBC with worse clinical outcomes than European-American (EA) women. The contributing factors underlying racial disparities have been divided into two major categories based on whether they are related to lifestyle (non-biologic) or unrelated to lifestyle (biologic). Our objective in the present review article was to understand the potential interactions by which these risk factors intersect to drive the initiation and development of the disparities resulting in the aggressive TNBC subtypes in AA women more likely than in EA women. To reach our goal, we conducted literature searches using MEDLINE/PubMed to identify relevant articles published from 2005 to 2019 addressing breast cancer disparities primarily among AA and EA women in the United States. We found that disparities in TNBC may be attributed to racial differences in biological factors, such as tumor heterogeneity, population genetics, somatic genomic mutations, and increased expression of genes in AA breast tumors which have direct link to breast cancer. In addition, a large number of non-biologic factors, including socioeconomic deprivation adversities associated with poverty, social stress, unsafe neighborhoods, lack of healthcare access and pattern of reproductive factors, can promote comorbid diseases such as obesity and diabetes which may adversely contribute to the aggression of TNBC biology in AA women. Further, the biological risk factors directly linked to TNBC in AA women may potentially interact with non-biologic factors to promote a higher prevalence of TNBC, more aggressive biology, and poor survival. The relative contributions of the biologic and non-biologic factors and their potential interactions is essential to our understanding of disproportionately high burden and poor survival rates of AA women with TNBC.

Racial/Ethnic Disparities in Survival after Breast Cancer Diagnosis by Estrogen and Progesterone Receptor Status: A Pooled Analysis

BACKGROUND

Limited studies have investigated racial/ethnic survival disparities for breast cancer defined by estrogen receptor (ER) and progesterone receptor (PR) status in a multiethnic population.

METHODS

Using multivariable Cox proportional hazards models, we assessed associations of race/ethnicity with ER/PR-specific breast cancer mortality in 10,366 California women diagnosed with breast cancer from 1993 to 2009. We evaluated joint associations of race/ethnicity, health care, sociodemographic, and lifestyle factors with mortality.

RESULTS

Among women with ER/PR⁺ breast cancer, breast cancer-specific mortality was similar among Hispanic and Asian American women, but higher among African American women [HR, 1.31; 95% confidence interval (CI), 1.05-1.63] compared with non-Hispanic White (NHW) women. Breast cancer-specific mortality was modified by surgery type, hospital type, education, neighborhood socioeconomic status (SES), smoking history, and alcohol consumption. Among African American women, breast cancer-specific mortality was higher among those treated at nonaccredited hospitals (HR, 1.57; 95% CI, 1.21-2.04) and those from lower SES neighborhoods (HR, 1.48; 95% CI, 1.16-1.88) compared with NHW women without these characteristics. Breast cancer-specific mortality was higher among African American women with at least some college education (HR, 1.42; 95% CI, 1.11-1.82) compared with NHW women with similar education. For ER^-/PR^- disease, breast cancer-specific mortality did not differ by race/ethnicity and associations of race/ethnicity with breast cancer-specific mortality varied only by neighborhood SES among African American women.

CONCLUSIONS

Racial/ethnic survival disparities are more striking for ER/PR⁺ than ER^-/PR^- breast cancer. Social determinants and lifestyle factors may explain some of the survival disparities for ER/PR⁺ breast cancer.

IMPACT

Addressing these factors may help reduce the higher mortality of African American women with ER/PR⁺ breast cancer.

Obesity, comorbidities, and treatment selection in Black and White women with early breast cancer

BACKGROUND

This study investigates obesity and comorbidity in Black and White women with early breast cancer (stages I-III) and their potential impact on treatment decisions for patients with hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) tumors.

METHODS

In this retrospective chart review, comparisons of frequencies for Black and White patients were calculated with the Fisher exact test. Log binomial regression was used to estimate prevalence ratios (PRs) with 95% confidence intervals for total and individual comorbidities, and multivariable modeling was used to estimate PRs adjusted for age and body mass index (BMI).

RESULTS

In a sample of 548 patients, 26% were Black, and 74% were White. Sixty-two percent of Black patients and 32% of White patients were obese (BMI ≥ 30 kg/m² ; P < .0001). Seventy-five percent of Black patients and 87% of White patients had HR+ tumors (P = .001). Significant intergroup differences were seen for 2 or more total comorbidities (62% of Blacks vs 47% of Whites; P = .001), 2 or more obesity-related comorbidities (33% vs 10%; P < .0001), hypertension (60% vs 32%; P < .0001), diabetes mellitus (23% vs 6%; P < .0001), hypercholesterolemia or hyperlipidemia (28% vs 18%; P = .02), and hypothyroidism (4% vs 11%; P = .012). In women with HR+/HER2- tumors, there were no intergroup differences in treatment decisions regarding the type of surgery, chemotherapy regimen, radiation, or endocrine treatment despite significant differences in the prevalence of obesity and comorbidities.

CONCLUSIONS

This study documents significant disparities between Black and White women with early breast cancer with regard to high rates of obesity, overall comorbidities, and obesity-related comorbidities, and it highlights the prevalence of competing risks that may complicate outcomes in breast cancer.

Management of the axilla with sentinel lymph node biopsy after neoadjuvant chemotherapy for breast cancer: A single-center study

The neoadjuvant chemotherapy (NAC) is the gold standard initial treatment of the locally advanced breast cancer (LABC). However, the reliability of methods that used to assess response the NAC is still controversial. In this study, patients with LABC who underwent NAC were evaluated retrospectively. The assessment of response to NAC and the effect of axillary approach were investigated on LABC course.The study comprised 94 patients who received NAC with an LABC diagnosis between 2008 and 2020. In our center, magnetic resonance imaging, ultrasonography, and F-flouro deoxyglucose positron emission tomography/computed tomography, and, for some patients, fine-needle aspiration biopsy of suspicious axillary lymph nodes have been performed to assess the effects of NAC. Patients with positive hormone receptor status received adjuvant hormonotherapy, and those with human epidermal growth factor receptor 2 gene expression were treated with trastuzumab. Adjuvant radiotherapy was applied to all patients undergoing breast conserving surgery. Radiotherapy was applied to the peripheral lymphatic areas in the clinical N1 to N3 cases regardless of the response to NAC.The clinical response to the NAC was found that partial in 59% and complete in 19% of the patients. However, 21.2% of the patients were unresponsive. The mean of lymph nodes that excised with the procedure of sentinel lymph node biopsy (SLNB) was 2.4 (range 1-7). In 22 of the 56 patients who underwent SLNB, axillary dissection (AD) was added to the procedure upon detection of metastasis in frozen section examinations. There was no difference between the SLNB and AD groups regarding overall survival (OS; P = .472) or disease-free survival (DFS) rates (P = .439). However, there were differences in the OS (P < .05) and DFS (P = .05) rates on the basis of the LABC histopathological subtypes.The study found that a relationship between molecular subtypes and LABC survival. However, the post-NAC axillary approach had no effect on OS or DFS. Therefore, multiple imaging and interventional methods are needed for the evaluation of NAC response. In addition, morbidity can be avoided after AD by the use of SLNB in cN0 patients.

Breast Cancer-Specific Mortality in Small-Sized Tumor with Stage IV Breast Cancer: A Population-Based Study

BACKGROUND

Small-sized primary tumor does not always indicate a better prognosis. We hypothesized that very small primary breast tumors with extensive lymph node (LN) metastases represented an aggressive biologic behavior in stage IV disease.

MATERIALS AND METHODS

Data between 2010 and 2015 were retrieved retrospectively from the Surveillance, Epidemiology, and End Results database with inclusion criteria of female sex, unilateral, metastatic, and T1/2 invasive ductal carcinoma. Primary study variables included T stage, N stage, grade, metastatic sites, number of involved sites, estrogen receptor status, progesterone receptor status, and human epidermal growth factor receptor 2 status. Kaplan-Meier and adjusted Cox proportional hazards models with interaction terms were used. One-, 2- and 3-year breast cancer-specific mortality (BCSM) was examined according to tumor size.

RESULTS

We identified 5,340 eligible patients with breast cancer. In multivariate analysis, race, age, grade, molecular subtype, surgery, brain metastases, and liver metastases were found to be independently associated with BCSM. For T1 tumors, the N0, N1, and N2+ groups had the same BCSM. In tumors smaller than 50 mm, the 1-, 2-, and 3-year BCSM did not decline with the decrease of tumor size. For triple-negative breast cancers (TNBCs), the T1a/T1bN2+ group had significantly worse BCSM than any other group did.

CONCLUSION

Patients with stage IV cancer with small-sized tumors may have BCSM as high as those with larger tumors. In TNBCs, very small tumors with severe LN involvement are associated with the worst BCSM. Continued efforts are needed to further investigate Ta1/T1bN2 + M1 TNBCs and individualize the treatment for affected patients.

IMPLICATIONS FOR PRACTICE

This study revealed that for stage IV breast cancer, smaller primary tumors were not always associated with better breast cancer-specific mortality. This study illustrated that very small triple-negative breast cancers (TNBCs) with extensive regional lymph node involvement may be a surrogate for biologically aggressive disease. Because of poor prognosis of T1a/T1bN2+ TNBCs, there might be an urgent need of more individualized treatment for affected patients. Future correlative studies ought to focus on the genetic and molecular differences in Ta1/T1bN2+ TNBCs that contribute to the biological behavior. Clarification of the regulation mechanism of very small-sized primary TNBCs with metastatic outgrowth in nodes and distant sites will play an integral role in developing targeted therapies.

Racial disparities in survival outcomes among breast cancer patients by molecular subtypes

PURPOSE

Differences in tumor biology, genomic architecture, and health care delivery patterns contribute to the breast cancer mortality gap between White and Black patients in the US. Although this gap has been well documented in previous literature, it remains uncertain how large the actual effect size of race is for different survival outcomes and the four breast cancer subtypes.

METHODS

We established a breast cancer patient cohort at the University of Chicago Comprehensive Cancer Center. We chose five major survival outcomes to study: overall survival, recurrence-free survival, breast-cancer-specific survival, time-to-recurrence and post-recurrence survival. Cox proportional hazards models were used to estimate the hazard ratios between Black and White patients, adjusting for selected patient, tumor, and treatment characteristics, and also stratified by the four breast cancer subtypes.

RESULTS

The study included 2795 stage I-III breast cancer patients (54% White and 38% Black). After adjusting for selected patient, tumor and treatment characteristics, Black patients still did worse than White patients in all five survival outcomes. The racial difference was highest within the HR-/HER2+ subgroup, in both overall survival (hazard ratio = 4.00, 95% CI 1.47-10.86) and recurrence-free survival (hazard ratio = 3.00, 95% CI 1.36-6.60), adjusting for age at diagnosis, cancer stage, and comorbidities. There was also a significant racial disparity within the HR+/HER2- group in both overall survival and recurrence-free survival.

CONCLUSIONS

Our study confirmed that racial disparity existed between White and Black breast cancer patients in terms of both survival and recurrence, and found that this disparity was largest among HR-/HER2+ and HR+/HER2- patients.

Menstrual and reproductive characteristics and breast cancer risk by hormone receptor status and ethnicity: The Breast Cancer Etiology in Minorities study

We pooled multiethnic data from four population-based studies and examined associations of menstrual and reproductive characteristics with breast cancer (BC) risk by tumor hormone receptor (HR) status [defined by estrogen receptor (ER) and progesterone receptor (PR)]. We estimated odds ratios and 95% confidence intervals using multivariable logistic regression, stratified by age (<50, ≥50 years) and ethnicity, for 5,186 HR+ (ER+ or PR+) cases, 1,365 HR- (ER- and PR-) cases and 7,480 controls. For HR+ BC, later menarche and earlier menopause were associated with lower risk in non-Hispanic whites (NHWs) and Hispanics, and higher parity and longer breast-feeding were associated with lower risk in Hispanics and Asian Americans, and suggestively in NHWs. Positive associations with later first full-term pregnancy (FTP), longer interval between menarche and first FTP and shorter time since last FTP were limited to younger Hispanics and Asian Americans. Except for nulliparity, reproductive characteristics were not associated with risk in African Americans. For HR- BC, lower risk was associated with later menarche, except in African Americans and older Asian Americans and with longer breast-feeding in Hispanics and Asian Americans only. In younger African Americans, HR- BC risk associated with higher parity (≥3 vs. 1 FTP) was increased fourfold in women who never breast-fed, but not in those with a breast-feeding history, suggesting that breast-feeding may mitigate the adverse effect of higher parity in younger African American women. Further work needs to evaluate why menstrual and reproductive risk factors vary in importance according to age and ethnicity.

21-gene recurrence score testing utilization among older women from different races: A population-based study

OBJECTIVES

The influence of older age at diagnosis in combination with race/ethnicity on utilization and results of the 21-gene recurrence score (RS) assay for breast cancer (BC) patients is not fully understood. Our objectives were to evaluate the utilization of RS among older women with BC, the likelihood of a high-risk RS, and factors associated with breast cancer-specific mortality (BCSM) among older patients across different races.

MATERIALS AND METHODS

We utilized the Surveillance, Epidemiology, and Results (SEER) database with linked RS results to evaluate women with estrogen receptor-positive BC diagnosed 2004-2015. Multivariable logistic regression was used to describe the differences in utilization of RS testing and the association of high-risk RS according to patient characteristics. The Cox proportional hazards model was used to analyze factors associated with BCSM.

RESULTS

We found that 20.4% (109,244/536,555) of all women ≥18 and 14.3% (33,584/235,171) of women ≥65 underwent RS testing. Non-whites had lower odds of RS testing at younger ages whereas among women ≥65 there was no significant difference. After taking into account stage and grade, being ≥65 reduced the odds of high-risk RS in all races except American Indian/Alaskan Native. Age ≥ 65 was independently associated with increased hazard BCSM. Among women ≥65 with high-risk RS, chemotherapy was associated with lower hazard of BCSM in all races.

CONCLUSIONS

Older women are less likely to be tested for RS, but also less likely to have high-risk RS. Older women with high-risk RS, when given chemotherapy have reduced BCSM across all races.