Keeping in close contact with friends and family and maintaining an active social life can help control cancer, recent research has revealed.

Cancerous growths have been found shrinking dramatically, even disappearing completely, among mice when the animals were brought into contact with many more of their ilk than under normal circumstances, says a study published in the journal Cell.

Tests on diseased mice indicated that those who were around other mice and had access to games and exercise had more success with fighting cancer.

The research offers powerful new evidence of the critical role that social connection and an individual's mental state may play in cancer, says Geneticist Professor Matthew During, who led the research and published the findings.

`'Animals' interaction with the environment has a profound influence on the growth of cancer - more than we knew was possible,'' Prof During of Ohio State University has stated.

For the lab experiments, the mice were typically housed in small groups of five or so in confinements. But Prof. During and his team placed the mice with cancer in what they called 'enriched environments' with 15 or 20 of them together.

The mice with tumours were provided with more space and more things to play with including toys, hiding places and running wheels. To their surprise, the researchers found the tumours often going into spontaneous remission over a period of time. The size of the tumour shrunk by an average 77 per cent, while volumes declined by 43 per cent.

One out of 20 cancer-affected mice showed no evidence of the disease after three weeks in their new more sociable environment compared to others mice kept in conventional captivity. Also, the mice did show lower levels of a hormone leptin that indicated there was a significant progressive shift in metabolism.

When traced to a brain chemical known as BDNF (brain-derived neurotrophic factor), the researchers came to the conclusion that the immune system of the mice had also turned robust. Increased levels of BDNF, which can be increased by exercise, had a positive effect on reducing their tumours.

`'A lot of people think stress is bad, but our data show the animals aren't just happy. Antidepressants won't give you the same effect,' Prof. During said.