PROSTATE cancer patients suffer more anxiety than patients with other forms of cancer – with high stress levels reducing the effectiveness of their treatment, according to a new study.
Researchers found stress is not just an emotional side-effect of the diagnosis, but that it reduces the effectiveness of drugs and can accelerate the development of prostate cancer.
They tested the effects of behavioural stress in two different mouse models of prostate cancer.
One model used mice implanted with human prostate cancer cells and treated with a drug in clinical trials for prostate cancer treatment.
When the mice were kept calm and free of stress, the drug destroyed prostate cancer cells and inhibited tumour growth.
However, when the mice were stressed, the cancer cells did not die and the drug did not inhibit tumour growth.
In the second model, mice genetically modified to develop prostate cancer were used. When these mice were repeatedly stressed, the size of prostate tumours increased.
When the mice were treated with bicalutamide, a drug used to treat prostate cancer, their prostate tumours decreased in size.
However, if these mice were subjected to repeated stress, the prostate tumours did not respond as well to the drug.
The researchers, from Wake Forest Baptist Medical Centre in North Carolina in the US, identified the cell signalling pathway by which epinephrine, a hormone also known as adrenaline, sets off the cellular chain reaction controlling cell death.
Study leader Doctor George Kulik, associate professor of cancer biology, said: “We hope components of this signalling pathway could be used as biomarkers to predict whether and how a given tumour will respond to stress and anti-stress therapies.”
The findings were published in the Journal of Clinical Investigation.