Socioeconomic Status and Disparities in Breast Cancer Outcomes

Objectives: There is a need to evaluate the link between socioeconomic status (SES) and breast cancer outcomes to explain the growing disparity that exists between African American and Caucasian breast cancer patients. This project aimed to create a measure of SES and evaluate disparities in breast cancer outcomes by SES. Methods: Data from 2,000 female breast cancer patients diagnosed and recorded at Jefferson University between 1995 and 2002 were analyzed in this retrospective study. An extensive literature review was completed to update a previously published deprivation index. Additional census variables were selected based on the literature review and the updated SES index was created using Principal Components Analysis (PCA) using all zip codes in Southeastern Pennsylvania. New Jersey, and Delaware. The SES index t was merged with the Jefferson University Hospital cohort by zip code. The relationship between SES and breast cancer mortality was assessed through survival analysis. Results: Initial results indicate that the all-site (Pennsylvania, New Jersey, Delaware) confirmatory first principal component accounts for 38.7% of the variance observed in SES. The exploratory PCA created for this study better explains SES within the study sites, accounting for 42.3% of SES variance, indicating that the modified index is more appropriate for the designated study areas. Component loadings were consistent within sites and across sites, indicating that each indicator contributed relatively evenly to the index and across the region. The index was statistically associated with breast cancer mortality, with the most deprived areas demonstrating the poorest survival across sites. Conclusions: The persistent disparities in breast cancer outcomes, despite advancements in treatment and screening policies, indicate that additional barriers exist to healthy outcomes. SES is one such barrier. The results illustrate the effectiveness of using an index measure to measure SES in order to quantify the effect of SES on breast cancer mortality. Policies and interventions that target SES at the neighborhood level may reduce the overall mortality rates of breast cancer.