The Role of Race/Ethnicity on the Association between Neighborhood Deprivation and Breast Cancer Outcomes among Kentucky Breast Cancer Patients years 2010-2022.

Background: Kentucky is within the top five leading states for breast mortality nationwide. This study investigates the association between neighborhood socioeconomic disadvantage and breast cancer outcomes, including surgical treatment, radiation therapy, chemotherapy, and survival, and how associations vary by race and ethnicity in Kentucky.

Methods: We conducted a retrospective cohort analysis using data from the Kentucky Cancer Registry (KCR) for breast cancer patients diagnosed between 2010 and 2017, with follow-up through December 31, 2022. We linked KCR data with census tract data to examine the relationship of Area Deprivation Index (ADI) on breast cancer outcomes. Logistic regression and Cox Proportional Hazards models analyzed binary outcomes and time-to-event data, respectively.

Results: Women in the most disadvantaged (ADI 4th quartile) neighborhoods were more likely to be diagnosed at later stages (OR: 1.26, 95% CI: 1.12-1.41) and 34% more likely to die from breast cancer (HR: 1.34, 95% CI: 1.14-1.57) after adjusting for age, race, tobacco use, tobacco pack years, marital status, insurance status, family history, stage at diagnosis, breast cancer subtype, and residence in Appalachia when compared to women living in the least disadvantaged neighborhoods (ADI 1st quartile).

Conclusions: Women in disadvantaged neighborhoods had significantly higher odds of late-stage diagnosis and breast cancer death, regardless of race, indicating that neighborhood factors contribute to breast cancer disparities.

Impact: Socioeconomic and neighborhood factors may contribute to breast cancer outcomes, suggesting the necessity for targeted interventions. Future research should explore the effectiveness of such interventions and investigate additional social determinants contributing to disparities.