Associations between amygdala reactivity to social threat, perceived stress and C-reactive protein in breast cancer survivors

Chronic inflammation in women diagnosed with breast cancer is critically linked with tumor progression, metastasis and survival. C-reactive protein (CRP)-a circulating marker of inflammation-is an important prognostic marker for cancer-related outcomes in breast cancer survivors (e.g. recurrence, fatigue). Psychological stress, which increases circulating markers of inflammation following sympathetic nervous system (SNS) activation, may modulate tumor-relevant inflammatory processes. However, little is known about neural mechanisms that might link stress and downstream SNS-initiated proinflammatory processes, such as elevated CRP. Past work suggests that threat-related neural regions, such as the amygdala, may be key in translating psychological stress into SNS activity and subsequent peripheral inflammation. Thus, we examined amygdala reactivity to socially threatening stimuli in association with perceived stress and plasma CRP levels to further elucidate neuro-immune pathways of social threat processing within breast cancer survivors (N=37). Significant positive correlations were found between left amygdala reactivity in response to socially threatening stimuli (e.g. angry/fearful faces vs happy faces) and perceived stress in the previous month (r=0.32, P=0.025) and between left amygdala reactivity and CRP (r=0.33, P=0.025). This work builds on prior research implicating the amygdala as a key structure in crosstalk between threat-related neural circuitries and peripheral inflammation, particularly within cancer survivors.