In a randomized trial, early palliative care (EPC) in patients with metastatic non-small-cell lung cancer (NSCLC) was observed to improve survival. In a secondary analysis, we explored the hypothesis that the survival benefit resulted from improving depression.

In total, 151 patients with newly diagnosed metastatic NSCLC participated in a randomized trial of EPC integrated with standard oncology care versus standard oncology care alone. Depression was assessed at baseline and at 12 weeks with the Patient Health Questionnaire-9 (PHQ-9) and was scored diagnostically by using Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, criteria for major depression syndrome (MDS). Depression response was considered ≥ 50% reduction in PHQ-9 scores at 12 weeks. Survival differences were tested with log-rank and Cox proportional hazards models.

At baseline, 21 patients (14%) met MDS criteria. MDS significantly predicted worse survival (hazard ratio, 1.82; P = .02). Patients assigned to EPC had greater improvements in PHQ-9 scores at 12 weeks (P < .001); among patients with MDS, those receiving EPC had greater rates of depression response at 12 weeks (P = .04). However, improvement in PHQ-9 scores was not associated with improved survival, except in a sensitivity analysis in which patients who died before 12 weeks were modeled to have worse depression. The group randomly assigned to EPC remained independently associated with survival after adding improvement in PHQ-9 scores to the survival model.

Depression predicted worse survival in patients with newly diagnosed metastatic NSCLC. Although EPC was associated with greater improvement in depression at 12 weeks, the data do not support the hypothesis that treatment of depression mediated the observed survival benefit from EPC.