Stress history and breast cancer recurrence

Background: There is mixed evidence regarding the possible association between a history of stressful or traumatic life events and more rapid breast cancer progression. Method: Retrospective reports of past experiences of traumatic life events were assessed among 94 women with metastatic or recurrent breast cancer. A traumatic event assessment was conducted using the event-screening question from the posttraumatic stress disorder (PTSD) module of the Structured Clinical Interview for the DSM-IV-TR (SCID; 2002). Each reported event was judged by two independent raters to determine whether it met DSM-IV-TR PTSD A1 criteria for a traumatic event. Those events that did not meet such criteria were designated "stressful events.". Results: Nearly 42% of the women in the sample were judged to have experienced one or more traumatic events; 28.7% reported only stressful events. A Kruskal-Wallis test found significant differences in disease-free interval among the three groups [χ² (2, N=94)=6.09, P<.05]. Planned comparisons revealed a significantly longer disease-free interval among women who had reported no traumatic or stressful life events (median=62 months) compared to those who had experienced one or more stressful or traumatic life events (combined median=31 months). Conclusions: A history of stressful or traumatic life events may reduce host resistance to tumor growth. These findings are consistent with a possible long-lasting effect of previous life stress on stress response systems such as the hypothalamic-pituitary-adrenal (HPA) axis.