Pre-existing and new-onset depression among patients undergoing esophageal cancer surgery: a nationwide cohort study in South Korea.

Background: Esophageal cancer is believed to be related to psychological stress. This study aimed to examine the prevalence and risk factors for new-onset depression after esophageal cancer surgery among patients who had no pre-existing depression. In addition, we examined whether pre-existing depression affected postoperative 1-year mortality.

Methods: The National Health Insurance Service database in South Korea was used for data extraction in this population-based cohort study. This study included all adult patients diagnosed with esophageal cancer who underwent esophageal surgery between January 1, 2011, and December 31, 2018.

Results: A total of 7039 adult patients who underwent esophageal cancer surgery at 95 South Korean hospitals were included in the analyses. Of the total, 608 patients (8.6%) were diagnosed with new-onset depression within 1 year after esophageal cancer surgery. Female sex, adjuvant chemotherapy, increased Charlson comorbidity index, pre-existing anxiety disorder, and pre-existing insomnia disorder were potential risk factors for new-onset depression. In multivariable Cox regression analysis, the pre-existing depression group showed a 1.27-fold (hazard ratio: 1.27; 95% confidence interval: 1.08-1.48; P = 0.004) higher risk of 1-year all-cause mortality than those who had no pre-existing depression.

Conclusion: In South Korea, 8.6% of patients are newly diagnosed with depression after esophageal cancer surgery, and some potential risk factors have been identified. Moreover, pre-existing depression was associated with increased 1-year all-cause mortality. Patients with esophageal cancer and pre-existing depression may be at high risk, requiring interventions after esophageal cancer surgery.