Abstract
Background/Objectives: Breast cancer (BC) represents a major public health problem that is influenced by social and systemic factors. This study evaluates disparities in the BC care continuum based on health insurance type and determines whether these patterns differ according to neighborhood-level deprivation. Methods: Using the Puerto Rico Central Cancer Registry-Health Insurance Linkage Database, we conducted a retrospective cohort study of women aged ≥18 years and diagnosed with BC in Puerto Rico between 2012 and 2016. The main outcomes were diagnostic delay (>60 days) and six-year mortality. Insurance type (private, Medicare, Medicaid, and dual enrollment in Medicare and Medicaid) was the main predictor, with neighborhood deprivation as a modifier. Logistic and Cox models assessed delay and survival, adjusting for key covariates. Results: Disparities in diagnostic delays and risk of death across insurance types were most evident in areas with low to average deprivation, whereas, in neighborhoods with above-average to highest deprivation, these differences diminished for diagnostic delay and disappeared for risk of death. Conclusions: These findings reveal that neighborhood environment, an intermediary social determinant of health, may affect the timeliness and quality of care provided to women diagnosed with BC.