Impact of socioeconomic status and rurality on cancer-specific survival among women with de novo metastatic breast cancer by race/ethnicity

Subdivision of M1 category and prognostic stage for de novo metastatic breast cancer to enhance prognostic prediction and guide the selection of locoregional therapy

BACKGROUND

Although de novo metastatic breast cancer (dnMBC) is acknowledged as a heterogeneous disease, the current staging systems do not distinguish between patients within the M1 or stage IV category. This study aimed to refine the M1 category and prognostic staging for dnMBC to enhance prognosis prediction and guide the choice of locoregional treatment.

METHODS

We selected patients with dnMBC from the SEER database (2010-2019), grouping them into training (N = 8048) and internal validation (N = 3450) cohorts randomly at a 7:3 ratio. An independent external validation cohort (N = 660) was enrolled from dnMBC patients (2010-2023) treated in three hospitals. Nomogram-based risk stratification was employed to refine the M1 category and prognostic stage, incorporating T/N stage, histologic grade, subtypes, and the location and number of metastatic sites. Both internal and external validation sets were used for validation analyses.

RESULTS

Brain, liver, or lung involvement and multiple metastases were independent prognostic factors for overall survival (OS). The nomogram-based stratification effectively divided M1 stage into three groups: M1a (bone-only involvement), M1b (liver or lung involvement only, with or without bone metastases), and M1c (brain metastasis or involvement of both liver and lung, regardless of other metastatic sites). Only subtype and M1 stage were included to define the final prognostic stage. Significant differences in OS were observed across M1 and prognostic subgroups. Patients with the M1c stage benefited less from primary tumor surgery in comparison with M1a stage.

CONCLUSION

Subdivision of the M1 and prognostic stage could serve as a supplement to the current staging guidelines for dnMBC and guide locoregional treatment.

Racialized economic segregation and inequities in treatment initiation and survival among patients with metastatic breast cancer

PURPOSE

Racialized economic segregation, a form of structural racism, may drive persistent inequities among patients with breast cancer. We examined whether a composite area-level index of racialized economic segregation was associated with real-world treatment and survival in metastatic breast cancer (mBC).

METHODS

We conducted a retrospective cohort study among adult women with mBC using a US nationwide electronic health record-derived de-identified database (2011-2022). Population-weighted quintiles of the index of concentration at the extremes were estimated using census tract data. To identify inequities in time to treatment initiation (TTI) and overall survival (OS), we employed Kaplan-Meier methods and estimated hazard ratios (HR) adjusted for clinical factors.

RESULTS

The cohort included 27,459 patients. Compared with patients from the most privileged areas, those from the least privileged areas were disproportionately Black (36.9% vs. 2.6%) or Latinx (13.2% vs. 2.6%) and increasingly diagnosed with de novo mBC (33.6% vs. 28.9%). Those from the least privileged areas had longer median TTI than those from the most privileged areas (38 vs 31 days) and shorter median OS (29.7 vs 39.2 months). Multivariable-adjusted HR indicated less timely treatment initiation (HR 0.87, 95% CI 0.83, 0.91, p < 0.01) and worse OS (HR 1.19, 95% CI 1.13, 1.25, p < 0.01) among those from the least privileged areas compared to the most privileged areas.

CONCLUSION

Racialized economic segregation is a social determinant of health associated with treatment and survival inequities in mBC. Public investments directly addressing racialized economic segregation and other forms of structural racism are needed to reduce inequities in cancer care and outcomes.

Neighborhood Deprivation and Breast Cancer Mortality Among Black and White Women

Importance

Neighborhood deprivation has been associated with increased breast cancer mortality among White women, but findings are inconsistent among Black women, who experience different neighborhood contexts. Accounting for interactions among neighborhood deprivation, race, and other neighborhood characteristics may enhance understanding of the association.

Objective

To investigate whether neighborhood deprivation is associated with breast cancer mortality among Black and White women and whether interactions with rurality, residential mobility, and racial composition, which are markers of access, social cohesion, and segregation, respectively, modify the association.

Design, Setting, and Participants

This population-based cohort study used Georgia Cancer Registry (GCR) data on women with breast cancer diagnosed in 2010 to 2017 and followed-up until December 31, 2022. Data were analyzed between January 2023 and October 2023. The study included non-Hispanic Black and White women with invasive early-stage (I-IIIA) breast cancer diagnosed between 2010 and 2017 and identified through the GCR.

Exposures

The Neighborhood Deprivation Index (NDI), assessed in quintiles, was derived through principal component analysis of 2011 to 2015 block group-level American Community Survey (ACS) data. Rurality, neighborhood residential mobility, and racial composition were measured using Georgia Public Health Department or ACS data.

Main Outcomes and Measures

The primary outcome was breast cancer-specific mortality identified by the GCR through linkage to the Georgia vital statistics registry and National Death Index. Cox proportional hazards regression was used to estimate age-adjusted and multivariable-adjusted hazard ratios (HRs) and 95% CIs for the association between neighborhood deprivation and breast cancer mortality.

Results

Among the 36 795 patients with breast cancer (mean [SD] age at diagnosis, 60.3 [13.1] years), 11 044 (30.0%) were non-Hispanic Black, and 25 751 (70.0%) were non-Hispanic White. During follow-up, 2942 breast cancer deaths occurred (1214 [41.3%] non-Hispanic Black women; 1728 [58.7%] non-Hispanic White women). NDI was associated with an increase in breast cancer mortality (quintile 5 vs 1, HR, 1.36; 95% CI, 1.19-1.55) in Cox proportional hazards models. The association was present only among non-Hispanic White women (quintile 5 vs 1, HR, 1.47; 95% CI, 1.21-1.79). Similar race-specific patterns were observed in jointly stratified analyses, such that NDI was associated with increased breast cancer mortality among non-Hispanic White women, but not non-Hispanic Black women, irrespective of the additional neighborhood characteristics considered.

Conclusions and Relevance

In this cohort study, neighborhood deprivation was associated with increased breast cancer mortality among non-Hispanic White women. Neighborhood racial composition, residential mobility, and rurality did not explain the lack of association among non-Hispanic Black women, suggesting that factors beyond those explored here may contribute to breast cancer mortality in this racial group.

Risk of contralateral breast cancer among Asian/Pacific Islander women in the United States

PURPOSE

While breast cancer studies often aggregate Asian/Pacific Islander (API) women, as a single group or exclude them, this population is heterogeneous in terms of genetic background, environmental exposures, and health-related behaviors, potentially resulting in different cancer outcomes. Our purpose was to evaluate risks of contralateral breast cancer (CBC) among subgroups of API women with breast cancer.

METHODS

We conducted a retrospective cohort study of women ages 18 + years diagnosed with stage I-III breast cancer between 2000 and 2016 in the Surveillance, Epidemiology and End Results registries. API subgroups included Chinese, Japanese, Filipina, Native Hawaiian, Korean, Vietnamese, Indian/Pakistani, and other API women. Asynchronous CBC was defined as breast cancer diagnosed in the opposite breast 12 + months after first primary unilateral breast cancer. Multivariable-adjusted subdistribution hazard ratios (SHR) and 95% confidence intervals (CI) were estimated and stratified by API subgroups.

RESULTS

From a cohort of 44,362 API women with breast cancer, 25% were Filipina, 18% were Chinese, 14% were Japanese, and 8% were Indian/Pakistani. API women as an aggregate group had increased risk of CBC (SHR 1.15, 95% CI 1.08-1.22) compared to NHW women, among whom Chinese (SHR 1.23, 95% CI 1.08-1.40), Filipina (SHR 1.37, 95% CI 1.23-1.52), and Native Hawaiian (SHR 1.69, 95% CI 1.37-2.08) women had greater risks.

CONCLUSION

Aggregating or excluding API patients from breast cancer studies ignores their heterogeneous health outcomes. To advance cancer health equity among API women, future research should examine inequities within the API population to design interventions that can adequately address their unique differences.

Prognostic implications of HER2NEU-low in metastatic breast cancer

INTRODUCTION

We explored characteristics and clinical outcomes of HER2-negative and HER2-low metastatic breast cancers using real-world data.

METHODS

We queried the National Cancer Database to identify MBC patients that were HER2-low or HER2-negative per immunohistochemical staining. A binomial regression analysis identified demographic and clinical correlates of each subtype. A Cox multivariable regression analysis (MVA) and propensity-match analysis were performed to identify correlates of survival.

RESULTS

Excluding missing data, 24,636 MBC patients diagnosed between 2008 and 2015 were identified; 27.9% were HER2-negative and 72.1% were HER2-low. There were no relevant demographic differences between the groups. HER2-low tumors were half as likely to have concomitant hormone receptor-positive status (p < 0.01). The 3-year survival rate among hormone receptor-negative patients was 33.8% for HER2-low and 32.2% for HER2-negative (p < 0.05), and 60.9% and 55.6% in HER2-low and HER2-negative cases among hormone receptor-positive patients (p < 0.05), respectively. HER2-low cases were associated with better survival on MVA (HR =0.95, 95% CI 0.91-0.99) and remained superior with propensity-matching (HR = 0.92, 95% CI 0.89-0.96). In a subset analysis isolated to hormone receptor-positive cases, HER2-low remained correlated with improved survival (HR = 0.93, 95% CI 0.89-0.98) with propensity-matched MVA. Correlates of worse survival include older age as a continuous variable (HR = 1.02, 95% CI 1.02-1.02) and Black race (HR = 1.26, 95% CI 1.20-1.32) [all p < 0.01].

CONCLUSIONS

In the largest such analysis performed to date, our study demonstrates a small but statistically significant association with improved survival for HER2-low tumors compared to HER2-negative tumors in MBC.

Inequities in referrals to a breast cancer risk assessment and prevention clinic: a mixed methods study

BACKGROUND

Inequitable access to personalized breast cancer screening and prevention may compound racial and ethnic disparities in outcomes. The Breast Cancer Personalized Risk Assessment, Education and Prevention (B-PREP) program, located within the Brigham and Women's Hospital (BWH) Comprehensive Breast Health Center (BHC), provides care to patients at high risk for developing breast cancer. We sought to characterize the differences between BWH primary care patients referred specifically to B-PREP for risk evaluation and those referred to the BHC for benign breast conditions. Through interviews with primary care clinicians, we sought to explore contributors to potentially inequitable B-PREP referral patterns.

METHODS

We used electronic health record data and the B-PREP clinical database to identify patients referred by primary care clinicians to the BHC or B-PREP between 2017 and 2020. We examined associations with likelihood of referral to B-PREP for risk assessment. Semi-structured interviews were conducted with nine primary care clinicians from six clinics to explore referral patterns.

RESULTS

Of 1789 patients, 78.0% were referred for benign breast conditions, and 21.5% for risk assessment. In multivariable analyses, Black individuals were less likely to be referred for risk than for benign conditions (OR 0.38, 95% CI:0.23-0.63) as were those with Medicaid/Medicare (OR 0.72, 95% CI:0.53-0.98; OR 0.52, 95% CI:0.27-0.99) and those whose preferred language was not English (OR 0.26, 95% CI:0.12-0.57). Interviewed clinicians described inconsistent approaches to risk assessment and variable B-PREP awareness.

CONCLUSIONS

In this single-site evaluation, among individuals referred by primary care clinicians for specialized breast care, Black, publicly-insured patients, and those whose preferred language was not English were less likely to be referred for risk assessment. Larger studies are needed to confirm these findings. Interventions to standardize breast cancer risk assessment in primary care may improve equity.

A narrative review of heart failure with preserved ejection fraction in breast cancer survivors

Advances in breast cancer (BC) treatment have contributed to improved survival, but BC survivors experience significant short-term and long-term cardiovascular mortality and morbidity, including an elevated risk of heart failure with preserved ejection fraction (HFpEF). Most research has focused on HF with reduced ejection fraction (HFrEF) after BC; however, recent studies suggest HFpEF is the more prevalent subtype after BC and is associated with substantial health burden. The increased HFpEF risk observed in BC survivors may be explained by treatment-related toxicity and by shared risk factors that heighten risk for both BC and HFpEF. Beyond risk factors with physiological impacts that drive HFpEF risk, such as hypertension and obesity, social determinants of health (SDOH) likely contribute to HFpEF risk after BC, impacting diagnosis, management and prognosis.Increasing clinical awareness of HFpEF after BC and screening for cardiovascular (CV) risk factors, in particular hypertension, may be beneficial in this high-risk population. When BC survivors develop HFpEF, treatment focuses on initiating guideline-directed medical therapy and addressing underlying comorbidities with pharmacotherapy or behavioural intervention. HFpEF in BC survivors is understudied. Future directions should focus on improving HFpEF prevention and treatment by building a deeper understanding of HFpEF aetiology and elucidating contributing risk factors and their pathogenesis in HFpEF in BC survivors, in particular the association with different BC treatment modalities, including radiation therapy, chemotherapy, biological therapy and endocrine therapy, for example, aromatase inhibitors. In addition, characterising how SDOH intersect with these therapies is of paramount importance to develop future prevention and management strategies.

Racial disparities in overall survival after the introduction of cyclin-dependent kinase 4/6 inhibitors for patients with hormone receptor-positive, HER2-negative metastatic breast cancer

PURPOSE

CDK4/6 inhibitors (CDK4/6i) combined with endocrine therapy have improved HR + /HER2- metastatic breast cancer (MBC) outcomes. However, it is still unclear whether the response to CDK4/6i is similar for all races. Therefore, we aimed to assess overall survival (OS) trends stratified by race in patients with HR + /HER2- MBC after the approval of CDK4/6i, as part of the standard of care, in 2015.

METHODS

We performed a population-based study using the SEER database. Patients with HR + /HER2- MBC were divided into two time-based cohorts: 1) pre-CDK4/6i era (diagnosed in 2011-2013) and 2) post-CDK4/6i era (diagnosed in 2015-2017). We used propensity score matching and identified 2,684 patients in each cohort that matched in several characteristics. Kaplan-Meier methods were used to estimate 2-year OS. Association between cohort and OS was evaluated using marginal Cox proportional hazards models with robust sandwich variance estimator. We conducted competing risk analysis to estimate the risk of breast cancer death in both cohorts.

RESULTS

The 2-year OS rate was 65% for the post-CDK4/6i era and 62% for the pre-CDK4/6i era (stratified log-rank p = 0.025). The 2-year OS for non-Hispanic White (NHW) patients improved in the post-CDK4/6i era compared to the pre-CDK4/6i era (67% vs. 63%, p = 0.033). However, OS did not improve for non-Hispanic Black (NHB) (54% vs. 54%, p = 0.876) or Hispanic (67% vs. 65%, p = 0.617) groups. The risk of breast cancer death decreased in the post-CDK4/6i era as compared to the pre-CDK4/6i era (2-year risk of breast cancer death: 33% vs. 30%, p = 0.015); however, this effect was observed only in NHW (sHR 0.84, p = 0.005) women, but not in NHB (sHR 0.94, p = 0.630) or Hispanic (sHR 0.91, p = 0.550) women.

CONCLUSIONS

Our study confirms that outcomes for HR + /HER2- MBC have improved after CDK4/6i were introduced in 2015. However, this effect is primarily driven by the improved OS in NHW patients, without significant improvement in OS in NHB or Hispanics.

Disparities in peripheral artery disease care: A review and call for action

Peripheral artery disease (PAD), the pathophysiologic narrowing of arterial blood vessels of the lower leg due to atherosclerosis, is a highly prevalent disease that affects more than 6 million individuals 40 years and older in the United States, with sharp increases in prevalence with age. Morbidity and mortality rates in patients with PAD range from 30% to 70% during the 5- to 15-year period after diagnosis and PAD is associated with poor health outcomes and reduced functionality and quality of life. Despite advances in medical, endovascular, and open surgical techniques, there is striking variation in care among population subgroups defined by sex, race and ethnicity, and socioeconomic status, with concomitant differences in preoperative medication optimization, amputation risk, and overall health outcomes. We reviewed studies from 1995 to 2021 to provide a comprehensive analysis of the current impact of disparities on the treatment and management of PAD and offer action items that require strategic partnership with primary care providers, researchers, patients, and their communities. With new technologies and collaborative approaches, optimal management across all population subgroups is possible.