Depressive symptoms predict head and neck cancer survival: Examining plausible behavioral and biological pathways

Abstract

Background: Head and neck cancers are associated with high rates of depression, which may increase the risk for poorer immediate and long-term outcomes. Here it was hypothesized that greater depressive symptoms would predict earlier mortality, and behavioral (treatment interruption) and biological (treatment response) mediators were examined.

Methods: Patients (n = 134) reported depressive symptomatology at treatment planning. Clinical data were reviewed at the 2-year follow-up.

Results: Greater depressive symptoms were associated with significantly shorter survival (hazard ratio, 0.868; 95% confidence interval [CI], 0.819-0.921; P < .001), higher rates of chemoradiation interruption (odds ratio, 0.865; 95% CI, 0.774-0.966; P = .010), and poorer treatment response (odds ratio, 0.879; 95% CI, 0.803-0.963; P = .005). The poorer treatment response partially explained the depression-survival relation. Other known prognostic indicators did not challenge these results.

Conclusions: Depressive symptoms at the time of treatment planning predict overall 2-year mortality. Effects are partly influenced by the treatment response. Depression screening and intervention may be beneficial. Future studies should examine parallel biological pathways linking depression to cancer survival, including endocrine disruption and inflammation. Cancer 2018;124:1053-60. © 2018 American Cancer Society.

Keywords: depression; head and neck cancer; residual tumor; survival.

Figure 1

To aid understanding of the statistically significant interaction between depressive symptoms and treatment response (i.e., for descriptive and not statistical purposes), patients were split into six groups according to their depressive symptom scores (none, mild/moderate, or above clinical cutoff) and the response of their tumor to radiation/combined treatment (complete response or poor response). Kaplan-Meier curves depict all-cause mortality for each of these groups. Depressive symptoms were measured at the treatment planning visit using the Hospital Anxiety and Depression Scale. Scores were: No symptoms (0), Mild to Moderate (1–7), and Clinically Significant (≥ 8). Response to treatment was assessed after completion of radiotherapy or combined treatment, and categorized as complete (no evidence of disease), or poor (some evidence of disease present). No deaths occurred among patients who reported no depressive symptoms. Thus, the two survival curves for these patients (no depression + complete response, no depression + poor treatment response) overlap.