Breast cancer screening needs assessment in 19 Northern California counties: geography, poverty, and racial/ethnic identity composition

Purpose: To describe the area-level rate of breast cancers, the percentage of early-stage diagnoses (stage I-IIa), and associations between area-level measures of poverty, racial/ethnic composition, primary care shortage, and urban/rural/frontier status for the UC Davis Comprehensive Cancer Center (UCDCCC) catchment area.

Methods: Using data from the SEER Cancer Registry of Greater California (2014-2018) and the California Department of Health Care Access and Information Medical Service Study Area, we conducted an ecological study in the UCDCCC catchment area to identify geographies that need screening interventions and their demographic characteristics.

Results: The higher the percentage of the population identifying as Hispanic/Latino/Latinx, and the higher the percentage of the population below the 100% poverty level, the lower the odds of being diagnosed at an early-stage (OR = 0.98, 95% CI 0.96-0.99 and OR = 0.96, 95% CI 0.93-0.99, respectively). The association with poverty level was attenuated in the multivariable model when the Hispanic/Latino/Latinx population percentage was added. Several California counties had high poverty levels and differences in cancer stage distribution between racial/ethnic category groups. For all individuals combined, 65% was the lowest proportion of early-stage diagnoses for any geography. However, when stratified by racial/ethnic category, 11 geographies were below 65% for Hispanic/Latino/Latinx individuals, six for non-Hispanic Asian and Pacific Islander individuals, and seven for non-Hispanic African American/Black individuals, in contrast to one for non-Hispanic White individuals.

Conclusions: Areas with lower percentages of breast cancers diagnosed at an early-stage were characterized by high levels of poverty. Variation in the proportion of early-stage diagnosis was also observed by race/ethnicity where the proportion of Hispanic/Latino/Latinx individuals was associated with fewer early-stage diagnoses.

Impact: Results will inform the implementation of the UCDCCC mobile cancer prevention and early detection program, providing specific locations and populations to prioritize for tailored outreach, education, and screening.