Neighborhood Disadvantage and Breast Cancer–Specific Survival

Abstract

ImportanceNeighborhood-level disadvantage is an important factor in the creation and persistence of underresourced neighborhoods with an undue burden of disparate breast cancer–specific survival outcomes. Although studies have evaluated neighborhood-level disadvantage and breast cancer–specific survival after accounting for individual-level socioeconomic status (SES) in large national cancer databases, these studies are limited by age, socioeconomic, and racial and ethnic diversity.ObjectiveTo investigate neighborhood SES (using a validated comprehensive composite measure) and breast cancer–specific survival in a majority-minority population.Design, Setting, and ParticipantsThis retrospective multi-institutional cohort study included patients with stage I to IV breast cancer treated at a National Cancer Institute–designated cancer center and sister safety-net hospital from January 10, 2007, to September 9, 2016. Mean (SD) follow-up time was 60.3 (41.4) months. Data analysis was performed from March 2022 to March 2023.ExposuresNeighborhood SES was measured using the Area Deprivation Index (tertiles), a validated comprehensive composite measure of neighborhood SES.Main Outcomes and MeasuresThe primary outcome was breast cancer–specific survival. Random effects frailty models for breast cancer–specific survival were performed controlling for individual-level sociodemographic, comorbidity, breast cancer risk factor, access to care, tumor, and National Comprehensive Cancer Network guideline-concordant treatment characteristics. The Area Deprivation Index was calculated for each patient at the census block group level and categorized into tertiles (T1-T3).ResultsA total of 5027 women with breast cancer were included: 55.8% were Hispanic, 17.5% were non-Hispanic Black, and 27.0% were non-Hispanic White. Mean (SD) age was 55.5 (11.7) years. Women living in the most disadvantaged neighborhoods (T3) had shorter breast cancer–specific survival compared with those living in the most advantaged neighborhoods (T1) after controlling for individual-level sociodemographic, comorbidity, breast cancer risk factor, access to care, tumor, and National Comprehensive Cancer Network guideline-concordant treatment characteristics (T3 vs T1: hazard ratio, 1.29; 95% CI, 1.01-1.65; P < .04).Conclusions and RelevanceIn this cohort study, a shorter breast cancer–specific survival in women from disadvantaged neighborhoods compared with advantaged neighborhoods was identified, even after controlling for individual-level sociodemographic, comorbidity, breast cancer risk factor, access to care, tumor, and National Comprehensive Cancer Network guideline-concordant treatment characteristics. The findings suggest potential unaccounted mechanisms, including unmeasured social determinants of health and access to care measures. This study also lays the foundation for future research to evaluate whether social adversity from living in a disadvantaged neighborhood is associated with more aggressive tumor biologic factors, and ultimately shorter breast cancer-specific survival, through social genomic and/or epigenomic alterations.

Impact of Neighborhood Disadvantage on High-Risk Oncotype DX Recurrence Scores and Breast Cancer Survival

“…Prior studies have identified that neighborhood disadvantage is associated with later stage at presentation, triple negative BC, and shorter survival in women with BC 4,8,30,31 . Disadvantaged neighborhoods are associated with marginalized populations, as economic and residential segregation has roots in structural racism 32 .…”

“…As a result, most studies linking neighborhood disadvantage to shorter BC survival attribute this association to disparities in access to care 3–6 . However, recent studies have identified that disparities in BC survival remain between women living in disadvantaged compared with advantaged neighborhoods, even after controlling for multilevel access to care barriers, individual-level factors, tumor characteristics, and receipt of National Cancer Center Network guideline-concordant treatment 7,8 . This suggests unaccounted mechanisms that contribute to persistent BC survival disparities by neighborhood disadvantage.…”

Neighborhood Disadvantage and Breast Cancer–Specific Survival in the US

“…Specifically, studies have shown associations with neighborhood disadvantage, lower neighborhood socioeconomic status, and geospatial measures of economic residential segregation with shorter breast cancer survival after controlling for many of the individual-level, neighborhood-level, and structural factors that have been associated with shorter breast cancer survival in previous literature. This residual association of neighborhood disadvantage with survival suggests that there are underlying mechanisms by which neighborhood disadvantage impacts survival that have not been accounted for . Many of these studies are limited to specific geographic areas, limiting the generalizability of the study on a national level, or have limitations based on population choice, such as older Medicare patients with fee-for-service coverage, so results may not be generalizable to younger patients or those with other types of insurance …”

Area Vulnerability and Disparities in Therapy for Patients With Metastatic Renal Cell Carcinoma

“…Racial and ethnic disparities in health reflect structural differences across social factors and resources, including environmental factors and access to health care interventions . Prevailing evidence suggests that disparities in cancer treatment and mortality associated with individuals’ race and ethnicity are not fully accounted for by individual-level, clinical, and demographic factors and that neighborhood factors influencing health and health care access could be contributors …”

“…There has been growing interest in how area-level measures of socioeconomic status and environment are associated with health outcomes. Area-level measures have been associated with frailty, obesity, and cardiovascular disease as well as access to preventive health care in historically marginalized populations . In regard to cancer-specific outcomes, a higher Social Vulnerability Index (SVI) score has been associated with patients being less likely to receive neoadjuvant chemotherapy or to use high-volume centers for surgical resection and with patients being more likely to encounter fragmented postoperative care .…”