Abstract A52: Disparities in psychosocial stress and breast cancer survival by race/ethnicity
Authors: Sánchez-Díaz Carola T. , Rasucher Garth H. 
Published: February 2019

Abstract
Background: Greater levels of stress, anxiety, or isolation (psychosocial stress) have been hypothesized to negatively alter the sympathetic-parasympathetic autonomic nervous system, suppress immune function, and have other physiologic effects that, in turn, might impact survival in breast cancer patients. Prior research in a variety of contexts has documented greater levels of psychosocial stress among non-Latina (nL) Black and Latina women when comparted to nL White women in the United States. We examined associations between patient-reported psychosocial stress and survival (breast cancer-specific and overall) in the Breast Cancer Care in Chicago (BCCC) study, a cross-sectional study of 989 recently diagnosed breast cancer patients, including 397 non-Hispanic White (white), 411 non-Hispanic Black (black), and 181 Latina patients.
Methods: Eligible patients were between 30 and 79 years of age at diagnosis, resided in Chicago, and were diagnosed with a first primary breast cancer (in situ or invasive) between 2005 and 2008. Psychosocial stress was defined based on three existing scales. The four items from the Cohen perceived stress subscale were summed to create a measure with an inter-item reliability (Cronbach's alpha of 0.74). The three items from the UCLA felt loneliness scale (alpha=0.79) and the 12 items from the Cockburn psychological consequences scale (alpha=0.93) were also summed. The probability of death due to breast cancer was modeled in multivariable logistic regression followed by conditional standardization, separately for each psychosocial stress measure while controlling for age, race/ethnicity, insurance, mode of detection, socioeconomic status, and treatment variables.
Results: Compared to white patients, black and Latina patients reported greater levels of stress, loneliness, and psychological consequences (p=0.001 for each). When comparing patients one SD above vs. one SD below the mean for each psychosocial stress measure, perceived stress and psychological consequences were associated or marginally associated with increased risk of death from breast cancer (RR =1.90, 95% CI: 1.21, 3.12 and RR=1.42, 95%CI: 0.84, 2.36, respectively), whereas loneliness was not (RR=1.08, 95%CI: 0.61, 1.68). With respect to death from all causes, RRs for perceived stress, psychological consequences, and loneliness were 1.77 (95% CI: 1.24, 2.46), 1.37 (95%CI: 0.94, 2.04) and 1.17 (95%CI: 0.78, 1.63), respectively. The black-white disparity in breast cancer-specific death (HR=3.63, 95%CI: 2.08, 6.34) was slightly attenuated with control for all three psychosocial stress variables (HR=3.46, 95%CI: 1.98, 6.06). The black-white disparity in death from any cause (HR=2.41, 95%CI: 1.60, 3.62) was again slightly attenuated with control for all three psychosocial stress variables (HR=2.30, 95%CI: 1.53, 3.47). Additional mediation analyses confirmed that these three psychosocial stress variables did not appear to mediate black-white survival disparities.
Conclusions: Psychosocial stress was associated with increased mortality from breast cancer among recently diagnosed patients. Although it seems to not be very meaningful in the context of black-white survival disparities, elevated stress could lead to detrimental effects on immune function, or could adversely affect patient adherence and completion of recommended treatment, in addition to other mental health illnesses, such as depression. For this reason, further analysis and interventions at the extent of multilevel contributing factors may be needed in order to address survival disparities in breast cancer.
Citation Format: Carola T. Sánchez-Díaz, Garth H. Rasucher. Disparities in psychosocial stress and breast cancer survival by race/ethnicity [abstract]. In: Proceedings of the Tenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2017 Sep 25-28; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2018;27(7 Suppl):Abstract nr A52.