Individual- and neighborhood-level socioeconomic status and risk of aggressive breast cancer subtypes in a pooled cohort of women from Kaiser Permanente Northern California.

BACKGROUND: Low socioeconomic status (SES) has been associated with a higher risk of aggressive breast cancer (BC) subtypes, but few studies have examined the independent effects of both neighborhood-level socioeconomic status (nSES) and individual-level SES measures. METHODS: This study included 5547 women from the Pathways and Life After Cancer Epidemiology cohorts who were diagnosed with invasive BC. Generalized estimating equation models were used to examine associations of nSES (a composite score based on income, poverty, education, occupation, employment, rent, and house value) and individual-level SES (income and education) with BC subtypes: luminal B (LumB), Her2-enriched (Her2-e), and triple-negative breast cancer (TNBC) relative to luminal A (LumA). Models controlled for age, race, nativity, stage, days from diagnosis to survey, and study cohort and simultaneously for nSES and individual-level SES. RESULTS: In fully adjusted models, low nSES was significantly associated with the LumB (odds ratio for quartile 1 vs quartile 4 [ORQ1vQ4 ], 1.31; 95% confidence interval [CI], 1.11-1.54; P for trend = .005) and TNBC subtypes (ORQ1vQ4 , 1.32; 95% CI, 1.02-1.71; P for trend = .037) relative to LumA. Conversely, individual education was significantly associated with only the Her2-e subtype (odds ratio for high school degree or less vs postgraduate, 1.68; 95% CI, 1.03-2.75; P for trend = .030) relative to LumA. Individual income was not significantly associated with any BC subtype. CONCLUSIONS: nSES and individual-level SES are independently associated with different BC subtypes; specifically, low nSES and individual-level education are independent predictors of more aggressive BC subtypes relative to LumA.

A validation study for measuring Asian- and Hispanic-serving sociocultural institutions in neighborhoods using business listing data and potential implications for health.

Ethnic enclaves influence the health of Asian American and Hispanic or Latinx/a/o populations, likely via neighborhood social, economic, and built environments. To facilitate studies aiming to disentangle these specific neighborhood mechanisms, we describe the creation and validation of two novel measures-Asian-serving and Hispanic-serving sociocultural institutions (SCIs)-to estimate the social, cultural, and economic character of ethnic enclaves in California. Business listing data were used to identify SCIs or businesses that promote cultural and social identity, including arts, civic, historical, religious, social service, and membership organizations. Keyword searches of business names were used to identify potential Asian- or Hispanic-serving SCIs. An online audit of 1,627 businesses within 12 cities confirmed the validity of using keyword searches to assess whether census tracts were high or low in Asian- or Hispanic-serving SCIs (sensitivity: 63%-100%, specificity: 86%-95%; positive predictive value: 63%-89%). In exploratory regression analyses, high presence of SCIs (compared to low presence) may be associated with neighborhood-level health indicators, including greater percentages of residents who had an annual checkup in majority Asian census tracts and lower percentages of residents who were current smokers in majority Asian and Hispanic census tracts. This approach advances methodology in measurement of neighborhood sociocultural environments.