A brain-boosting protein plays an important role in how well people respond to chemotherapy, according to new research.
A study presented at the European Society for Medical Oncology (ESMO) Asia 2016 Congress in Singapore found that cancer patients suffering depression have decreased amounts of brain-derived neurotophic factor (BDNF) in their blood. Low levels make people less responsive to cancer drugs and less tolerant of their side effects, according to researchers.
“It’s crucial doctors pay more attention to the mood and emotional state of patients,” said lead author Yufeng Wu, head of oncology at Henan Cancer Hospital, which is affiliated with Zhengzhou University in China. “Depression can reduce the effects of chemotherapy and BDNF plays an important role in this process.”
Low mood is common among cancer patients, especially the terminally ill. BDNF is essential for healthy brain function and low levels have already been linked with mental illness, the researcher noted.
This study aimed to discover how depression influenced outcomes for people with advanced lung cancer.
Researchers recruited 186 newly diagnosed patients receiving chemotherapy. To assess their state of mind, they were asked to rate their depression levels the day before treatment began. Quality of life details, overall survival, and other data were also collected. This allowed researchers to compare this information with the patients’ mood scores.
Results showed that those whose cancer had spread to other organs were the most depressed and this severely decreased their tolerance to chemotherapy. It was associated with vomiting, a reduction in white blood cells, and prolonged hospital stays.
The impact of severe depression was even greater. It reduced the length of time that patients lived with the disease without it getting worse.
Researchers found that BDNF clearly boosted the number of tumor cells killed by chemotherapy. Patients with severe depression had lower levels of the protein in the blood, so their bodies were not as effective at fighting cancer. This reduced their chance of surviving the disease, the researchers noted.
“Our aim now is to prescribe drugs such as fluoxetine to depressed patients and study their sensitivity to chemotherapy,” Wu said.