Dysregulation of the hypothalamo-pituitary-adrenal (HPA) axis activity has been commonly observed among breast cancer patients and has been linked to adverse health consequences. However, whether these alterations persist long after the cancer diagnosis has not been well-documented.
In the first study, the diurnal cortisol rhythms and the cortisol stress response of breast cancer survivors who had completed all local and/or systemic adjuvant therapy with the exception of hormonal therapy were compared to those of women without a history of cancer. The Trier Social Stress Test was used to elicit a moderate stress response and the subjective levels of stress of participants were recorded using visual analog scales. The results indicate similar diurnal patterns in both groups; however, significant differences in stress reactivity were noted, with breast cancer survivors displaying a relatively flat profile following the acute stress induction. Subjective levels of psychological stress were similar in both groups, indicating that the subjective appraisal did not account for the blunted cortisol stress response.
In the second study, the impact of the stressful life events that happened during the previous year on the cortisol stress response was analyzed in the same groups of participants. The frequency of stressful life events as well as their subjective impact was documented using the Life Experience Survey. Results suggest no group differences between the total number of stressful life events and their perceived effect. However, the number of stressful life events and their perceived impact correlated negatively with the peak cortisol concentration in breast cancer survivors. The results suggest that the cumulative effect of stressful life events contribute significantly to the low levels of cortisol reported in breast cancer survivors following a stressful situation.
Together, these studies emphasize that breast cancer survivors are at risk of presenting a subtle alteration of their HPA axis activity when their system is challenged and that an accumulation of stressors plays a role in this dysregulation. These results reinforce the need for interventions intended to reduce the levels of psychological stress experienced by breast cancer survivors.
| Identifer | oai:union.ndltd.org:uottawa.ca/oai:ruor.uottawa.ca:10393/34539 |
| Date | January 2016 |
| Creators | Couture-Lalande, Marie-Ève |
| Contributors | Bielajew, Catherine |
| Publisher | Université d'Ottawa / University of Ottawa |
| Source Sets | Université d’Ottawa |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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