Depression May Affect Chemotherapy Efficacy

A decrease in a protein associated with depression may increase cancer mortality.

Findings from a new study suggest that patients experiencing depression may be less sensitive to chemotherapy treatments.

The investigators discovered that patients with cancer who experience depression have decreased levels of brain-derived neurotrophic factor (BDNF) in their blood, according to a study presented at ESMO Asia 2016 Congress. This protein may play a key role in how patients respond to chemotherapy.

“It's crucial doctors pay more attention to the mood and emotional state of patients,” said lead author Yufeng Wu, MD. “Depression can reduce the effects of chemotherapy and BDNF plays an important role in this process.”

Depression is common among patients with cancer, especially those diagnosed with late-stage or rare cancers that have a high mortality rate. Patients may experience anxiety and depression over their health, finances, or even their family members.

BDNF is critical for numerous processes related to healthy brain function. Previous studies have shown that a low expression of this protein is associated with mental illnesses, including depression.

In the current study, the researchers aimed to determine whether depression influences outcomes for patients with advanced lung cancer. Included in the study were 186 treatment-naïve patients who were receiving chemotherapy.

Patients were asked to rate their depression before treatment, and the investigators also gathered quality of life details, overall survival, and related data, according to the study. By compiling this information, the researchers were able to compare the patients’ health with their state of mind.

Patients whose cancer metastasized were found to be the most depressed, and also had a decrease in tolerance to chemotherapy. These patients experienced vomiting, reduction in white blood cells, and long hospital stays.

Severe depression was seen to reduce progression free survival in these patients, with many of the patients with depression progressing quicker compared with other patients, the researchers reported.

Interestingly, the investigators discovered that BDNF was able to increase the number of cancer cells that were killed by chemotherapy. Patients with severe depression were found to have low levels of this protein, which may suggest this is why these patients experienced quicker cancer progression than patients who did not have depression.

"Our aim now is to prescribe drugs such as fluoxetine to depressed patients and study their sensitivity to chemotherapy," Dr Wu said.

Fluoxetine is a selective serotonin reuptake inhibitor that can treat depression and several mental illnesses. Researchers believe that treating depression in these patients may play an important role in increasing cancer survival.

"The link between depression and poor outcomes among these patients is significant and can be associated with the downregulation of brain derived neurotrophic factor,” said oncologist Ravindran Kanesvaran, MD, who did not participate in the study. “This finding can perhaps lead to new ways to treat depression in these patients which in turn may prolong their lives. Further research is needed to establish the effects of different anti-depressant drugs on BDNF levels."