Study: Women With Breast Cancer in Racially, Ethically Diverse Neighborhoods Have Worse Cancer-Specific Survival Outcomes

Majority-minority women with breast cancer in disadvantaged neighborhoods in South Florida had shorter breast cancer-specific survival than women in advantaged neighborhoods, according to a study published in JAMA Network Open.

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Experts recognize the association between breast cancer survival and neighborhood-level measures like socioeconomic status (SES), but many previous studies do not account for the complexities of this disadvantage, such as age and racial and ethnic diversity.

“Neighborhood-level disadvantage is an important factor in the creation and persistence of under-resourced neighborhoods with an undue burden of disparate breast cancer–specific survival outcomes,” the study authors wrote.

Recent advancements in breast cancer screening, diagnosis, and treatment have decreased rates of cancer across the country, but not every local geographic area, or neighborhood, experiences these benefits.

“Neighborhood disadvantage remains a fundamental cause of health disparities in the US and contributes to the creation and persistence of underresourced neighborhoods with an undue burden of disparate health outcomes,” the study authors wrote. “Neighborhood disadvantage, therefore, warrants consideration as a significant ecologic risk factor when studying breast cancer survival inequities.”

Investigators aimed to add more context to previous studies by finding an association between Area Deprivation Index (ADI)—which measures SES to discern magnitude of neighborhood disadvantage—and breast cancer-specific survival (the time from primary diagnosis to death because of a cancer-related event). The ADI ranks neighborhoods on a scale of 1 to 10, with 10 being more disadvantaged. Neighborhoods were also categorized into 1 of 3 tertiles (T1 through T3), with T3 being the highest ADI score.

Investigators focused on a majority-minority racially/ethnically diverse cohort of 5027 women with breast cancer (55.8% Hispanic, 17.5% non-Hispanic Black, and 27.0% non-Hispanic White) from South Florida. This is an area of many socially disadvantaged neighborhoods due to its history of segregation. The primary endpoint was breast cancer-specific survival.

Neighborhood disadvantage was independently associated with shorter breast cancer-specific survival among the socioeconomically, racially, and ethnically, and age-diverse cohort. Women living in T3 neighborhoods had shorter breast cancer–specific survival compared to women in more advantaged T1 neighborhoods.

These disparities were recognized after considering individual-level characteristics that were not in national database studies (sociodemographic, comorbidity, breast cancer risk factor, access to care, tumor, and National Comprehensive Cancer Network guideline-concordant treatment), “suggesting unaccounted mechanisms through which neighborhood disadvantage may be associated with shorter breast cancer–specific survival,” the study authors wrote.

Including a cohort of majority racial and ethnic minority populations takes focus away from individual-level race and ethnicity, according to the study. Importantly, this may show that geography, not biology, can impact breast-cancer specific survival rates.

“This study found that neighborhood disadvantage independently associated with shorter breast cancer–specific survival in a socioeconomically, racially and ethnically, and age-diverse majority-minority population,” the study authors wrote. “These disparities remained even after accounting for individual-level sociodemographic, comorbidity, breast cancer risk factor, access to care, tumor, and NCCN guideline-concordant treatment characteristics, not available in national database studies, suggesting unaccounted mechanisms through which neighborhood disadvantage may be associated with shorter breast cancer–specific survival.”

The study contains some limitations. It excludes data about Charlson Comorbidity Index levels and potential treatments administered at other facilities. The study took place in 2 facilities and is not fully generalizable, and investigators did not consider all nonbiologic pathways that could contribute to disparities in breast cancer survival.

“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,” the study authors wrote.

Reference

Goel N, Hernandez A, Thompson C, et al. Neighborhood Disadvantage and Breast Cancer–Specific Survival. JAMA Netw Open. 2023. doi:10.1001/jamanetworkopen.2023.8908