Examining the Intersection between Drivers of Disparities: Social Determinants and Stress Reactivity in African American Breast Cancer Survivors.

Responses to social stressors are important drivers of cancer risk and outcomes; however, current studies focus on neighborhood-level social determinants of health (SDOH). We evaluated within-subject trajectories in stress reactivity (i.e., change in salivary cortisol) among 60 African American patients with breast cancer and examined the moderating effects of social stressors on cortisol responses. SDOHs were obtained by self-report and were included in linear mixed-effects regression models that were generated for cortisol levels, including time (primary regressor) adjusting for time-invariant covariates. Significant increases in cortisol levels were observed at 12- and 24-minute post-Trier Social Stress Test tasks. Significant interactions between time and SDOHs on cortisol were identified. Higher and escalating stress reactivity was observed in patients with greater financial strain, social isolation, negative life events, and perceived stress. Social risk factors moderated stress reactivity; however, additional research is needed to understand the effects of physiologic stress reactivity on tumor etiology and progression, especially among patients who have greater exposure to social stressors. SIGNIFICANCE: Chronic stress exposure promotes breast cancer initiation and progression; however, current studies focus on neighborhood-level deprivation even though individual variability in stress reactivity is an important driver of cancer risk and outcomes, especially among those who experience the greatest burden of disease. Self-reported data on social risk factors can be used to enhance the precision of cancer care by identifying patients who should be prioritized for referral to socially informed care and who are likely to experience dysregulated cortisol response to SDOHs.