Study: Does prior antidepressant use affect the treatment breast cancer patients receive?

IN DEPTH REVIEW OF RESEARCH

Study background:

Previous studies found an association between depression and survival after breast cancer, with people who have a history of depression experiencing worse rates of survival than those who do not. Nis Suppli and colleagues from the Danish Cancer Society Research Center published work in the Journal of Clinical Oncology in January 2017 to try to understand this association.

Researchers of this study wanted to know:

Do women who have previously been prescribed antidepressants receive different breast cancer treatments than women who have not taken antidepressants?

Population(s) looked at in the study:

This study included 45,325 women from Denmark who were diagnosed with early-stage breast cancer between April 1998 through December 2011: 6,068 (13%) of the women had previously used antidepressants. Women with a previous cancer diagnosis or other major psychiatric disorders were excluded. The study authors used national cancer treatment guidelines and clinical data from the Danish Breast Cancer Group. Information on which women had been prescribed antidepressants was retrieved from the Danish Psychiatric Central Research Register.

Study findings: 

1. Women in Denmark who were diagnosed with early-stage breast cancer and who had previously taken antidepressants had increased risk of:
   • receiving cancer treatment that did not follow national guidelines.
   • having worse overall survival.
   • having worse breast cancer-specific survival.
   • While these risks were increased, the overall differences were small between women who were treated with antidepressants and those who had not.  

Limitations:

Because the researchers used existing data from registries and did not collect it themselves, they were unable to differentiate between women who had undiagnosed or untreated depression and those who had depression but only had psychotherapy without antidepressants. (The registry information was collected over a 13½-year period during which treatment for both breast cancer and depression has evolved.) Nor did researchers take into account lifestyle factors such as alcohol use, smoking, and access to care. Another problem was the use of antidepressant prescriptions as a measure of the women with depression—this number could include patients who didn’t necessarily have depression, as antidepressants are often prescribed to treat anxiety, pain and other conditions; the number may have also missed people with depression who chose to treat it with other methods. Finally, because of the study design, researchers were unable to understand why treatment for patients who had been prescribed antidepressants was less likely to follow recommended national guidelines. Several reasons are possible, including patient preference, health care providers not offering guideline-based treatments, patients may not have been compliant, or a combination of these and/or other reasons.

It is also important to note that this study was conducted in the Danish health care system and does not necessarily reflect what is happening in the United States.

Conclusions:

This study suggests that early-stage breast cancer patients who were previously treated for depression are more likely to receive cancer treatment other than treatment that is recommended by national guidelines. This is an interesting study that generates ideas for further research, but it should not cause alarm for patients who face both depression and cancer.  Breast cancer patients or survivors with depression or a history of depression should discuss any concerns with their health care providers.

Posted 1/24/17

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