Objective: This study examined the effects of a cognitive-behavioral stress management (CBSM) group intervention on serum cortisol levels in women being treated for stage I or II breast cancer.
Methods: Participants were randomly assigned to undergo a 10-week intervention (N = 24) within 8 weeks after surgery or were placed on a waiting list (N = 10). Cortisol was assessed by means of a radioimmunoassay of blood samples collected at the same time of day just before the start of the intervention and immediately after its completion. The women also reported the degree to which breast cancer had made positive contributions to their lives.
Results: Intervention participants showed increased benefit finding and reduced serum cortisol levels, whereas control subjects experienced neither change. Path analysis suggested that the effect of CBSM on cortisol was mediated by increases in benefit finding.
Conclusions: These findings suggest that positive growth enhanced during a time-limited intervention can influence physiological parameters such as cortisol among women with early stage breast cancer.