SAN FRANCISCO – Nearly 40% of breast cancer patients experience prolonged depression lasting for at least 16 months after diagnosis of their malignancy; those at increased risk may be identifiable in a timely way by their exaggerated cortisol awakening response when measured after surgery but before adjuvant therapy, according to Kate R. Kuhlman, PhD.
“There are several psychological interventions that mitigate depressive symptoms and psychologic distress in women with breast cancer. This time period immediately following cancer diagnosis and surgery may be the optimal time to intervene,” said Dr. Kuhlman, a psychologist at the University of California, Los Angeles.
Bruce Jancin/Frontline Medical News
Dr. Kate R. Kuhlman
She presented a prospective study of 135 women with breast cancer who collected saliva samples for analysis of hypothalamic-pituitary-adrenal axis functioning on 3 consecutive days after their primary surgery but prior to starting adjuvant therapy. Samples were obtained on each of the 3 days upon awakening, 30 minutes later, 8 hours later, and at bedtime. The women also completed the Center for Epidemiologic Studies Depression Scale (CES-D) then and again 6 months after completing their breast cancer treatment.
At baseline, 45 of the 135 women scored 16 points or higher out of a possible 60 on the 20-question CES-D, indicative of clinically significant depression. Hypothalamic-pituitary-adrenal axis functioning wasn’t associated with depressive symptoms at that time. Importantly, however, one measure of baseline HPA axis functioning – the cortisol awakening response – proved to be associated with an increase in depressive symptoms over time, Dr. Kuhlman reported.
In a multivariate analysis adjusted for age, breast cancer stage, type of surgery, and forms of adjuvant therapy, a 1-standard-deviation increase above the mean in baseline cortisol awakening response was associated with a 6-point increase in CES-D score at follow-up 6 months after completion of breast cancer therapy. This association was seen only in the 90 women without significant depressive symptoms at baseline. And that’s exactly the population where a predictive biologic marker for future depression is most needed, Dr. Kuhlman said at the annual conference of the Anxiety and Depression Association of America.
“The people at highest risk of depressive symptoms in the future are the ones who have the most symptoms now. They’re easy to identify. We have good reliable measures. But then there are also people at risk whom we would miss by using those measures because they don’t have high symptoms right now,” the psychologist explained.
She and her coinvestigators zeroed in on cortisol awakening response as a potential biomarker of increased future risk of depression because it reflects the adrenal gland’s sensitivity to adrenocorticotropic hormone and the gland’s ability to signal the pituitary to produce cortisol. This action is triggered when people go from sleep to awakening.
The next steps in this research are to confirm these novel findings and hunt for an alternative marker of adrenal sensitivity to adrenocorticotropic hormone that’s simpler than sending a waking saliva sample off to a laboratory.
This ongoing longitudinal study is funded by the National Cancer Institute. Dr. Kuhlman reported having no relevant financial conflicts.