Breast cancer-specific intrusions are associated with increased cortisol responses to daily life stressors in healthy women without personal or family histories of breast cancer.

Studies indicate that women fear breast cancer more than any other disease and that women's levels of breast cancer-specific intrusions are related to their perceived risk of breast cancer. Here, we explore possible biological consequences of higher breast cancer risk perceptions and intrusions in healthy women without personal or family histories of the disease. We hypothesized that women with higher perceived risk would have more intrusions about breast cancer, which would constitute a background stressor sufficient to increase hypothalamus-pituitary-adrenal axis (HPA) responsivity to daily stress. HPA responses to an ordinary life stressor (work) were assessed in 141 employed women (age = 37.2+/-9.2) without personal or family histories of breast cancer. Urinary cortisol excretion rates were assessed with timed sample collections at work, home, and during sleep. Repeated measures ANOVA revealed a significant Group by Time interaction with higher work cortisol levels in women with breast cancer-specific intrusions compared to women without intrusions (p < 0.02). Regression analyses revealed a significant association between risk perceptions and intrusions (p < 0.001). Regression analysis with intrusions and risk perceptions predicting work cortisol indicated a significant contribution of intrusions (p < 0.04), but not risk perceptions (p = 0.53). Overestimation of breast cancer risk is associated with higher levels of breast cancer-specific intrusions that can result in increased cortisol responsivity to daily stressors. This heightened responsivity could have long-term negative health implications.