Preexisting Mental Illness and All-Cause and Breast Cancer Mortality in Elderly Breast Cancer Patients
A study using linked Surveillance, Epidemiology, and End Results–Medicare data has shown a significantly increased risk of all-cause mortality and a nonsignificantly increased risk of breast cancer–specific mortality in elderly breast cancer patients with preexisting severe mental illness. The study was reported by Iglay et al in the Journal of Clinical Oncology.
Study Details
The retrospective cohort study included data on 19,028 women aged ≥ 68 years diagnosed with stage I to IIIA breast cancer between 2005 and 2007. Patients were categorized as having severe mental illness if the International Classification of Diseases, 9th Edition, Clinical Modification code for bipolar disorder, schizophrenia, or other psychotic disorder was recorded on at least one inpatient or two outpatient claims in the 3 years preceding breast cancer diagnosis. Patients were followed for up to 5 years after breast cancer diagnosis.
Associations With Mortality
Overall, 496 patients (2.6%) had preexisting severe mental illness; 80.1% had no preexisting mental health diagnosis, 7.7% had depression, 6.0% had anxiety, and 3.6% had both anxiety and depression. In an analysis adjusting for age, income, race, ethnicity, geographic location, and marital status, patients with severe mental illness had a greater than twofold increase in risk for all-cause mortality vs those without preexisting mental illness (cumulative incidence = 38.0% vs 19.4%; adjusted hazard ratio [HR] = 2.19, 95% confidence interval [CI] = 1.84–2.60). An increased hazard ratio was observed for breast cancer–specific mortality, but it did not reach statistical significance (cumulative incidence = 7.2% vs 6.2%; adjusted HR = 1.20, 95% CI = 0.82–1.74). Patients with severe mental illness were more likely to be diagnosed with advanced breast cancer and to have aggressive tumor characteristics.
Depression only (HR = 1.39, 95% CI = 1.22–1.58) and anxiety and depression (HR = 1.26, 95% CI = 1.03–1.53) were associated with a significantly increased risk of all-cause mortality but not breast cancer–specific mortality vs patients with no mental illness.
The investigators concluded: “Patients with severe mental illness may need assistance with coordinating medical services.”
Melissa L. Santorelli, PhD, of Rutgers School of Public Health, is the corresponding author of the Journal of Clinical Oncology article.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
