Breast Cancer and Depression - Clinical Associations

1Athena1

I came across some studies that find an association (not necessarily cause-effect relationship) between depression and length of survival in metastatic breast cancer. The reason for this association is not fully understood, and with metastaic breast cancer it may be hard to know what came first - the depression or the cancer. Still, with these caveats, here are some links that may be of interest, with excerpts of abstracts:

 http://www.ncbi.nlm.nih.gov/pubmed/21149651

 In a secondary analysis of a randomized trial of supportive-expressive group therapy, 125 women with metastatic breast cancer (MBC) completed a depression symptom measure (Center for Epidemiologic Studies-Depression Scale [CES-D]) at baseline and were randomly assigned to a treatment group or to a control group that received educational materials. At baseline and three follow-up points, 101 of 125 women completed a depression symptom measure. We used these data in a Cox proportional hazards analysis to examine whether decreasing depression symptoms over the first year of the study (the length of the intervention) would be associated with longer survival.
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Decreasing depression symptoms over the first year were associated with longer subsequent survival for women with MBC in this sample. Further research is necessary to confirm this hypothesis in other samples, and causation cannot be assumed based on this analysis.

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 Depression and cancer commonly co-occur. The prevalence of depression among cancer patients increases with disease severity and symptoms such as pain and fatigue. The literature on depression as a predictor of cancer incidence is mixed, although chronic and severe depression may be associated with elevated cancer risk. There is divided but stronger evidence that depression predicts cancer progression and mortality, although disentangling the deleterious effects of disease progression on mood complicates this research, as does the fact that some symptoms of cancer and its treatment mimic depression. There is evidence that providing psychosocial support reduces depression, anxiety, and pain, and may increase survival time with cancer, although studies in this latter area are also divided. Psychophysiological mechanisms linking depression and cancer progression include dysregulation of the hypothalamic-pituitary-adrenal axis, especially diurnal variation in cortisol and melatonin. Depression also affects components of immune function that may affect cancer surveillance. Thus, there is evidence of a bidirectional relationship between cancer and depression, offering new opportunities for therapeutic intervention.

 http://www.ncbi.nlm.nih.gov/pubmed/12893103

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 This study links sleep as well - it is worth looking at if you have endocrine problems or any disorder where the Hypothalamic-Pituitary-Adrenal gland axis is believed to be involved (as I do):

 Previous research has provided evidence of autonomic, endocrine, and immunological dysregulation in
repressors and a possible association with cancer incidence and progression. Recently published data
from the authors' laboratory demonstrated that flatter diurnal cortisol slopes were a risk factor for early
mortality in women with metastatic breast cancer. In the current analysis of this same sample (N 91),
the authors tested differences at baseline between groups scored using the Weinberger Adjustment
Inventory on diurnal cortisol slope and mean cortisol levels. When compared with self-assured and
nonextreme groups, the repressor and high-anxious groups had a significantly flatter diurnal slope.
Diurnal slope was similar for repressors and high-anxious groups. Groups did not differ on mean cortisol
levels, nor did they differ on intercept (morning) values.

http://www.chc.ucsf.edu/pdf/14. Giese-Davis, et al., Health Psych. 2004.pdf