Abstract
Patients with head and neck cancer (HNC) often experience negative side effects of treatment such as oral dysfunction (eg, dry mouth, sticky saliva, or oral pain), swallowing and speech problems, insomnia, and fatigue, which are related to distress. A recent meta‐analysis demonstrated a pooled estimate of depression among patients with HNC of 11% (95% confidence interval, 3%‐34%) as measured by diagnostic interviews and 20% (95% confidence interval, 16%‐25%) as measured by screening instruments.
We read with great interest the study by Kim et al, who reported a significant association between pretreatment depression (prevalence of 25% as measured by a screening instrument) and survival in patients with HNC. Among patients with cancer, previous studies also have reported a significant association between depression and survival. In fact, several hundred studies including healthy community samples and disease‐specific populations have shown that depression is associated with survival. A recent meta‐analysis of 293 studies again demonstrated that there is a significant association between depression and excess mortality, but to our knowledge there are only a few indications that this association is stronger in community or specific patient samples. This meta‐analysis also included 29 studies on cancer, including one regarding HNC. Thus, the study by Kim et al adds to the large amount of evidence regarding a significant association between depression and survival. However, it is not justified to state that “the results demonstrate a close relation between pretreatment depression and treatment outcome,” and therefore suggest that depression is related to the outcome of treatment. The study by Kim et al only confirms what has been found in hundreds of earlier observational studies, nothing more.
However, to the best of our knowledge, the mechanisms underlying the association between depression and survival remain unclear and may well be cancer‐ or tumor‐specific. There are several reasons why depression may enhance mortality risk in patients with HNC. Depressed patients with HNC may use ineffective coping strategies, and they are at risk of suicide. Unhealthy lifestyle is a risk factor for excess mortality and in patients with HNC continued alcohol use after diagnosis is reported to have an adverse effect on survival. Empirical evidence has suggested that tumor‐related and patient‐related biomarkers of endocrine, immune, and autonomic (dys)function also may be associated with depression and survival. There is growing evidence that dysregulation of hypothalamic‐pituitary‐adrenal axis function is associated with depression and cancer survival. Neuroimmunological explanations include increased immune responses and increased levels of proinflammatory cytokines (eg, interleukin 6), which were found to be associated with depression and survival among patients with HNC. Another study has suggested that a common functional promoter polymorphism of the neurotransmitter serotonin transporter gene (serotonin transporter‐linked polymorphic region [5‐HTTLPR]) may be associated with depression in patients with HNC.
Comprehensive insight into all these factors is necessary to unravel these complex associations. To the best of our knowledge, previous studies investigating the relation between depression and survival in patients with (head and neck) cancer included relatively small cohorts and/or a limited number of possible confounders. Consequently, the association between depression and survival among patients with cancer may have inadequately adjusted for potentially relevant confounders. In the Netherlands, a prospective, multicenter cohort study, the Netherlands Quality of Life and Biomedical Cohort Study in Head and Neck Cancer (NET‐QUBIC) (available at: researchers.kubusproject.nl/home), currently is ongoing. The data from this study will allow investigation of the course of depression and the association between changes in depression and survival in patients with HNC, controlling for cancer‐related and treatment‐related, personal, biological, psychobehavioral, physical, lifestyle‐related, and social factors.
We read with great interest the study by Kim et al, who reported a significant association between pretreatment depression (prevalence of 25% as measured by a screening instrument) and survival in patients with HNC. Among patients with cancer, previous studies also have reported a significant association between depression and survival. In fact, several hundred studies including healthy community samples and disease‐specific populations have shown that depression is associated with survival. A recent meta‐analysis of 293 studies again demonstrated that there is a significant association between depression and excess mortality, but to our knowledge there are only a few indications that this association is stronger in community or specific patient samples. This meta‐analysis also included 29 studies on cancer, including one regarding HNC. Thus, the study by Kim et al adds to the large amount of evidence regarding a significant association between depression and survival. However, it is not justified to state that “the results demonstrate a close relation between pretreatment depression and treatment outcome,” and therefore suggest that depression is related to the outcome of treatment. The study by Kim et al only confirms what has been found in hundreds of earlier observational studies, nothing more.
However, to the best of our knowledge, the mechanisms underlying the association between depression and survival remain unclear and may well be cancer‐ or tumor‐specific. There are several reasons why depression may enhance mortality risk in patients with HNC. Depressed patients with HNC may use ineffective coping strategies, and they are at risk of suicide. Unhealthy lifestyle is a risk factor for excess mortality and in patients with HNC continued alcohol use after diagnosis is reported to have an adverse effect on survival. Empirical evidence has suggested that tumor‐related and patient‐related biomarkers of endocrine, immune, and autonomic (dys)function also may be associated with depression and survival. There is growing evidence that dysregulation of hypothalamic‐pituitary‐adrenal axis function is associated with depression and cancer survival. Neuroimmunological explanations include increased immune responses and increased levels of proinflammatory cytokines (eg, interleukin 6), which were found to be associated with depression and survival among patients with HNC. Another study has suggested that a common functional promoter polymorphism of the neurotransmitter serotonin transporter gene (serotonin transporter‐linked polymorphic region [5‐HTTLPR]) may be associated with depression in patients with HNC.
Comprehensive insight into all these factors is necessary to unravel these complex associations. To the best of our knowledge, previous studies investigating the relation between depression and survival in patients with (head and neck) cancer included relatively small cohorts and/or a limited number of possible confounders. Consequently, the association between depression and survival among patients with cancer may have inadequately adjusted for potentially relevant confounders. In the Netherlands, a prospective, multicenter cohort study, the Netherlands Quality of Life and Biomedical Cohort Study in Head and Neck Cancer (NET‐QUBIC) (available at: researchers.kubusproject.nl/home), currently is ongoing. The data from this study will allow investigation of the course of depression and the association between changes in depression and survival in patients with HNC, controlling for cancer‐related and treatment‐related, personal, biological, psychobehavioral, physical, lifestyle‐related, and social factors.
Original language | English |
---|---|
Pages (from-to) | 971-972 |
Number of pages | 2 |
Journal | Cancer |
Volume | 122 |
Issue number | 6 |
Early online date | 22 Dec 2015 |
DOIs | |
Publication status | Published - 15 Mar 2016 |
Keywords
- Carcinoma, Squamous Cell
- Comment
- Depression
- Female
- Head and Neck Neoplasms
- Humans
- Letter
- Male
- Research Support, Non-U.S. Gov't