Background: Aberrant diurnal cortisol rhythms are one of the biological risk factors for cancer progression. We have previously shown that greater expression of negative emotions during a first session of supportive-expressive group therapy (SET) was associated with salutary, steep cortisol rhythms among women with metastatic breast cancer.

Objectives: We examined whether time spent storytelling shared in SET (personal storytelling vs. direct communication with other group members) are associated with cortisol rhythms, and whether expression of negative affect is associated with cortisol rhythms regardless of story types. We also explored whether women who shared many stories and those who shared few stories exhibit differential relationships between their emotion expression and cortisol rhythms.  

Methods: Prior to the initial SET session, 29 women with metastatic breast cancer donated four saliva samples per day for three consecutive days.  We coded emotional expression using Specific Affect Coding System-Cancer and story types from video-recorded SET. We collapsed the 23 emotion-categories into defensive, hostile, primary negative, high arousal positive, constrained anger, compassion, and neutral categories.

Results: The overall duration of storytelling was not associated with diurnal cortisol rhythms. However, greater expression of primary negative affect and defensiveness were associated with steep diurnal cortisol slopes only during direct conversation.  Also, greater expression of hostility was associated with aberrant slopes, while greater expression of positive affect was associated with steep slopes only among women who shared many stories throughout the year of SET.  

Conclusions: While expressing primary negative affect through direct conversation may be salutary, expressing hostility through personal narratives is not. Our results provide preliminary evidence for how emotional expression in spoken narratives is associated with a disease-relevant physiological marker.