Social support moderates the impact of neighborhood disadvantage on serum cortisol levels in post-surgical breast cancer patients.

INTRODUCTION

Neighborhood disadvantage generates chronic adversity and negatively impacts breast cancer (BCa) survival. Greater social support may correspond with less adversity in BCa patients via physiological stress mechanisms. We evaluated the association between neighborhood disadvantage and serum cortisol, a physiologic marker of stress, and whether social support moderates this relationship in BCa patients.

METHODS

Women diagnosed with stage 0-III BCa post-surgery and before adjuvant treatment provided a late afternoon-evening serum cortisol sample and completed the Social Provisions Scale (SPS). Area Deprivation Index (ADI), a validated measure of neighborhood disadvantage, was determined using home addresses. Multivariable regression tested the relationship between SPS scores, ADI, and cortisol controlling for age, surgery type, and receptor status.

RESULTS

Of 178 participants, 24.7 % lived in disadvantaged neighborhoods (ADI 4 -10). High ADI (4-10) predicted greater cortisol (B = 0.417, 95 % CI [0.35, 0.800], p = 0.033). There was a significant interaction effect between ADI and SPS on cortisol levels (B= -1.776, 95 % CI [-2.974, -0.559], p = 0.004). Simple slope test showed the conditional effect of ADI on cortisol was statistically significant at low (M = 0.23; p < 0.001) and middle (M = 0.51; p < 0.05) but not high (M = 0.80; p = 0.901) SPS levels.

CONCLUSION

Social support moderates the relationship between neighborhood disadvantage and serum cortisol levels in women with BCa undergoing treatment. While the neighborhood may generate elevated stress, social support is a modifiable element that may be protective. Secondary analyses indicated that perceiving higher levels of social attachment may confer this protective effect, suggesting future targets for interventions.