Depression’s influence on breast cancer treatment and survival

Up to one‐quarter of breast cancer survivors experience depression at some point in their lives. Research has shown that depression may be an important risk factor for poor treatment outcomes or worse survival rates.

But are treatment adherence and survival affected by the timing of the depression diagnosis?

Feitong Lei, Ph.D., with the University of Kentucky College of Public Health’s Department of Biostatistics, is part of a team that looked at data surrounding female patients diagnosed with primary invasive breast cancer in Kentucky and who also had a depression diagnosis before their cancer diagnosis, after cancer diagnosis, or before and after (persistent depression).

“When we state that the depression diagnosis was only pre-breast cancer diagnosis, we mean that patients have a record of depression only before receiving a cancer diagnosis, not after it,” said Lei, who earned her master’s in public health from the UK College of Public Health. “Considering that depression is a chronic disease requiring long-term management, patients who experienced depression before a cancer diagnosis are likely to continue experiencing it, especially after being diagnosed with breast cancer.

“Therefore, patients having a depression diagnosis recorded only before the cancer diagnosis does not imply that the depression was resolved after the cancer diagnosis. It may instead suggest that the patients did not engage in any depression management following their cancer diagnosis, resulting in no further records of a depression diagnosis.” 

Lei and her research team accessed Kentucky Cancer Registry (KCR) data to identify female patients who had been diagnosed with primary invasive breast cancer and were 20 years of age or older in 2007–2011. KCR data include information on patient demographics, tumor characteristics, initial treatment regimens, and survival.

Of 6,054 eligible patients, 4.1% had persistent depression, 3.7% had depression pre‐diagnosis only, and 6.2% had depression post‐diagnosis only. A total of 1,770 (29.2%) of the patients did not receive guideline-recommended cancer treatment — a combination of surgery, chemotherapy, radiation therapy, etc., tailored to a patient’s cancer stage. Lei said, “Most patients identified as not having received guideline-recommended treatment did receive some extent of treatment but did not meet the standard treatment level.”

Compared to patients with no depression, patients with pre-diagnosis depression were the only subset to be less likely to receive guideline‐recommended treatment.

As for survival, depression post‐diagnosis only and depression pre‐diagnosis only were associated with worse survival rates. No significant difference in survival was found between patients with persistent depression and patients with no depression.

The study, “Influence of depression on breast cancer treatment and survival: A Kentucky population-based study,” was recently published in the journal Cancer.

Lei hopes that the results of the study emphasize the need for proper depression diagnosis and treatment, especially when paired with a life-altering physical issue.

“We want to make both the provider and patients aware of the importance of depression screening and management after a breast cancer diagnosis, especially for those who have a prior depression diagnosis,” she said. “Neglecting depression management after a breast cancer diagnosis may result in poorer cancer treatment concordance and worse chances of survival.”

To learn more about the University of Kentucky College of Public Health’s people, programs, and passion for public health, visit cph.uky.edu.  

Research reported in this publication was supported by the National Center for Advancing Translational Sciences of the National Institutes of Health under Award Number KL2TR001996, and the National Cancer Institute of the National Institutes of Health under Award Numbers HHSN2612018 and P30CA1777558. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.