Based on the results of an analysis reported in JAMA Network Open by Zhang et al, preexisting depression is associated with an increased risk of mortality from prostate cancer.
The investigators commented, “Approximately one in six patients with prostate cancer experience major depression, a prevalence twice that of the general population. Studies suggest a bidirectional association between depression and prostate cancer. However, [prior to this study,] the influence of preexisting depression on prostate cancer survival remained less well defined.”
Study Details
The investigators analyzed 38,169 individuals using deidentified data from the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial, which include approximately 25 years of follow-up. The data were obtained through the National Cancer Institute. Among the participants, 205 had prostate cancer and preexisting depression (mean [standard deviation] age = 61 [5] years), 2,096 had prostate cancer without preexisting depression (mean [standard deviation] age = 61 [5] years), and 35,868 had neither cancer nor preexisting depression (mean [standard deviation] age = 61 [4] years). Preexisting depression was identified based on self-reported physician diagnosis or the use of antidepressant medication.
Cox proportional hazards models were applied. Survival comparisons were made using Kaplan-Meier curves and the log-rank test, with P > .05 suggesting no violation of the assumption. The associations of survival with prostate cancer treatment, prostate cancer stage, and specific cause of death were not assessed because of limited data.
Key Findings
Patients with prostate cancer who did vs did not have preexisting depression showed significantly lower rates of overall survival (hazard ratio = 2.14, 95% confidence interval = 1.34–3.42; log-rank P = .001). Of note, according to the investigators, the lower tail of the curve suggested poorer long-term survival associated with preexisting depression. No violation of proportional hazards assumption was found (P = .38).
The investigators concluded, “We found that preexisting depression was associated with a 2.5-fold increase in mortality risk for patients with prostate cancer, highlighting its role in exacerbating disease progression and worsening survival. However, this finding should be interpreted cautiously due to the primary limitation of unmeasured confounding factors, such as treatment and disease severity. Our findings may help physicians and patients better understand the role of depression in prostate cancer survival, supporting further studies to explore appropriate interventions for this population.”
Lei Zhang, MD, of Uniformed Services University of the Health Sciences, Bethesda, Maryland, is the corresponding author of the JAMA Network Open article.
Disclosure: For full disclosures of the study authors, visit jamanetwork.com.
