Even mild depressive symptoms can reduce the chances of survival in patients with head and neck cancer, a study has warned.
The findings, published in the journal Cancer, indicate that patients should be screened and treated for depressive symptoms at the time of diagnosis.
In addition, studies should examine parallel biological pathways linking depression to cancer survival.
Many patients diagnosed with head and neck cancer experience symptoms of depression, which can make it difficult for them to manage treatment side effects, quit smoking, or maintain adequate nutrition or sleep habits.
Researchers led by Elizabeth Cash of the University of Louisville in the US, wanted to find if depressive symptoms might also affect patients' health outcomes.
They studied 134 patients with head and neck cancers who reported depressive symptoms during the planning of their treatment.
When researchers examined the patients' clinical data over the following two years, they found that patients with greater depressive symptoms had shorter survival, higher rates of chemoradiation interruption, and poorer treatment response.
"We observed that head and neck cancer patients who reported more depressive symptoms at their initial appointment were more likely to miss scheduled treatment appointments and were more likely to have tumours that persisted after medical treatment," said Cash.
"We also observed that patients with depressive symptoms suffered greater two-year overall mortality rates, and this was especially true for those who did not achieve optimal response to medical treatment," she said.
Poorer treatment response partially explained the depression-survival relationship; however, there were no significant effects from factors commonly used to determine cancer prognosis--such as the patient's age, the stage of tumour advancement, or extent of smoking history.
"This suggests that depressive symptoms may be as powerful as the clinical features that physicians typically use to determine the prognosis of patients with head and neck cancer," said Cash.
Cash noted that most patients in the study did not meet criteria for diagnosis of major depressive disorder, suggesting that even mild symptoms of depression may interfere with head and neck cancer treatment outcomes.
She also stressed that the findings need to be replicated in a larger study but suggest that depressive symptoms may affect head and neck cancer patients' survival through mechanisms that potentially coincide with the activities of their tumour.
"We want patients to know that it is normal to get depressed when they are diagnosed, but it is important to seek help for any depression symptoms because they may lead to poorer outcomes related to their cancer treatment," said Cash.
