Influence of depression on breast cancer treatment and survival: A Kentucky population-based study

Background: Depression is common among breast cancer patients and can affect concordance with guideline-recommended treatment plans. Yet, the impact of depression on cancer treatment and survival is understudied, particularly in relation to the timing of the depression diagnosis. Methods: The Kentucky Cancer Registry data was used to identify female patients diagnosed with primary invasive breast cancer who were 20 years of age or older in 2007–2011. Patients were classified as having no depression, depression pre-cancer diagnosis only, depression post- cancer diagnosis only, or persistent depression. The impact of depression on receiving guideline-recommended treatment and survival was examined using multivariable logistic regression and Cox regression, respectively. Results: Of 6054 eligible patients, 4.1%, 3.7%, and 6.2% patients had persistent depression, depression pre-diagnosis only, and depression post-diagnosis only, respectively. A total of 1770 (29.2%) patients did not receive guideline-recommended cancer treatment. Compared to patients with no depression, the odds of receiving guideline-recommended treatment were decreased in patients with depression pre-diagnosis only (odds ratio [OR], 0.75; 95% confidence interval [CI], 0.54–1.04) but not in patients with post-diagnosis only or persistent depression. Depression post-diagnosis only (hazard ratio, 1.51; 95% CI, 1.24–1.83) and depression pre-diagnosis only (hazard ratio, 1.26; 95% CI, 0.99–1.59) were associated with worse survival. No significant difference in survival was found between patients with persistent depression and patients with no depression (p >.05). Conclusions: Neglecting depression management after a breast cancer diagnosis may result in poorer cancer treatment concordance and worse survival. Early detection and consistent management of depression is critical in improving patient survival.