Cancer ‘hijacks’ patient’s brain, finds US research, city docs see silver lining
Times of India | 15 April 2025
Kolkata: Doctors have long associated advanced-stage cancer patients' tendency to withdraw from life as a psychological response to physical deterioration. Now, a study published in Science magazine — by US researchers — says cancer "hijacks" a part of the brain that controls motivation. The withdrawal from life is not merely a psychological response to physical decline, but a fallout of the disease itself.
Oncologists in Kolkata believe this could be true in most cases, since a large number of patients fail to cling to their favourite activities or daily routine, despite being physically fit to carry on with such activities. They also pointed out that Bengal has a significantly large number of cancer patients suffering from depression.
The symptom is part of a syndrome called "cachexia", which affects 80% of late-stage cancer patients.
This finding could be an eye-opener and lead to major changes in cancer therapy, said Manipal Hospital oncologist Subir Ganguly. "A clinical option to treat depression could help many cancer patients respond to treatment better and comply with prescribed treatment," he said, adding, "This will improve survival rate and treatment outcomes. But other than the clinical aspect, there are psychological and emotional reasons that trigger depression, which is why we have many giving up on life. For instance, a cancer patient with disabilities is bound to be more frequently demotivated than others. Then, there are financial issues and constraints that act as triggers for depression. Many lack family support and caregivers. These patients will require a support system."
Diptendra Sarkar, professor of oncology at IPGMER, said: "We frequently come across patients who turn apathetic towards life despite efforts to motivate them. This happens even to those who show considerable improvement and have several years to live. This study reveals that neurotransmitters are responsible for this and the condition is perhaps clinically treatable. This will benefit millions of cancer patients and add to the number of survivors. More importantly, their quality of life will improve."
Using brain-mapping techniques on mice, researchers identified an area in the brain called the postrema, which acts as the brain's inflammation detector. As a tumour grows, it releases cytokines — molecules that trigger inflammation — into the bloodstream. Postrema lacks the blood-brain barrier, allowing it to sample the circulating inflammatory signals. Once this happens, the postrema triggers a neural cascade across several brain regions, eventually suppressing dopamine release in the brain's motivation centre, the nucleus accumbens. The research says that dopamine is wrongly identified as the brain's "pleasure chemical" but is actually associated with a willingness to put in effort for gain.
Anti-depressants are already used to treat distraught cancer patients, said Sanjoy Roy, a senior radiation oncologist at Ruby General Hospital. "This research makes it more specific and now we know that dopamine in the postrema can be regulated to curb depression and motivation loss. This is a major issue with cancer patients across all age groups. While some amount of anxiety and depression is inevitable, many fail to get over it, which negates treatment," Roy said.
The good news is that the researchers have managed to identify ways to restore motivation in mice suffering from cancer cachexia, even when the disease was progressing. It was done by genetically switching off the inflammation-sensing neurons in postrema or by directly stimulating dopamine.