New research suggests that breast cancer patients who have little social interaction may face a worse prognosis than those who have plenty of social support.
Scientists at the University of Chicago carried out a study involving female mice, all of which were genetically prone to developing breast cancer.
They found that mice which were stressed because of social isolation after weaning tended to develop significantly larger tumours than those which were kept with other mice.
Dr Suzanne Conzen, associate professor in the University of Chicago's departments of medicine and cancer research, commented: 'Despite the genetic similarity of the mice assigned to grouped versus isolated housing, living in the stressful environment was associated with greater tumour size.'
The team's findings are published in the journal Cancer Prevention Research and suggest that women with breast cancer may benefit from a lively social environment.
However, Oliver Childs, from the charity Cancer Research UK, noted that the studies were carried out with mice and therefore 'do not prove that the stress caused by social isolation causes cancer to get worse in humans'.