The stress of interacting with others causes tumours to shrink, and even go into remission, according to a study published in the journal Cell.

The study suggests that people with cancer could see an improvement if they change their lifestyle to include more company, rather than less.

Stress is widely considered to be damaging to health, although the latest findings suggest that manageable levels of stress could help the immune system fight disease.

The findings conflict with many recent studies which have linked high stress levels to a higher susceptibility to cancer and lower survival rates.

The mice-based study was led by Matthew During of the Ohio State University, who said it had implications for the optimal lifestyle for cancer patients.

Traditional clinical treatments like chemotherapy, radiation treatment and surgery should be complemented with attention to the living conditions of cancer patients, During said.

The goal was to live a life that was physically and socially richer, and more challenging, not to minimise stress in an attempt to combat the disease, he said.

During said lifestyle issues and brain reactions had been regarded traditionally by clinicians as a ‘soft area’ of cancer care programmes.

Instead, During's paper suggests focusing more on people's perceptions of disease, their social interactions and environment, in the treatment of cancer.

Mice with cancer that were moved from their standard laboratory living quarters which were shared by groups of five animals to larger cages with up to 20 other mice saw a huge boost to their condition.

Tumours in these mice saw their tumours shrink by an average of 77% (43% by volume), and 5% had no signs of cancer at all after three weeks under the new conditions, which included more space to play in and more toys.

However, the stress of social interaction was highlighted as the main factor prompting the beneficial effects on cancer.

The changes are linked to a stress-linked protein called brain-derived neurotrophic factor (BDNF). It inhibits the growth of tumours by shutting down the production of the hormone, leptin.

Researchers concluded that there was no reason why the findings should not apply to humans as well, and could pave the way for new drugs based on the same protein and hormones.