Association of depression with all-cause and cancer-specific mortality in older adults with cancer: Systematic review, meta-analysis, and meta-regression

Introduction: The incidence and mortality of cancer is increasing worldwide with studies reporting that cumulative risk of cancer rises as age increases. Against the backdrop of the increasing prevalence of cancer amongst older patients, we conducted a systematic review and meta-analysis examining the depression-mortality relationship in older adults with cancer (OAC). Materials and Methods: This PRISMA-adherent systematic review involved a systematic search of PubMed, Medline, EMBASE, and PsycINFO for prospective and retrospective cohort studies comparing the risk of all-cause and cancer-related mortality among OAC with depression. Random effects meta-analyses and meta-regressions were used for the primary analysis. Results: From 5,280 citations, we included 14 cohort studies. Meta-analyses of hazard ratios (HRs) showed an increased incidence of all-cause mortality in OAC with depression (pooled HR: 1.40; 95% confidence interval [CI]: 1.25, 1.55). Subgroup analyses of other categorical study-level characteristics were insignificant. While risk of cancer-related mortality in OAC with depression was insignificantly increased with a pooled HR of 1.21 (95% CI: 0.98, 1.49), subgroup analysis indicated that risk of cancer-related mortality in OAC with depression significantly differed with cancer type. Our systematic review found that having fewer comorbidities, a higher education level, greater socioeconomic status, and positive social supportive factors lowered risk of all-cause mortality in OAC with depression. Discussion: Depression in OAC significantly increases risk of all-cause mortality and cancer-related mortality among different cancer types. It is imperative for healthcare providers and policy makers to recognize vulnerable subgroups among older adults with cancer to individualize interventions.