Social environment can play an important role in the biology of disease, including breast cancer, and lead to significant differences in health outcome, according to results of a study published in Cancer Prevention Research, a journal of the American Association for Cancer Research.
"This study uses an elegant preclinical model and shows that social isolation alters expression of genes important in mammary gland tumor growth," said the journal's Deputy Editor Caryn Lerman, Ph.D. "It further elucidates the molecular mechanisms linking environmental stress with breast cancer development and progression."
These findings suggest novel targets for chemoprevention, and future studies should evaluate whether these molecular processes can be reversed by chemopreventive agents, according to Lerman, who is the Mary W. Calkins professor of psychiatry and scientific director of the Abramson Cancer Center at the University of Pennsylvania, Philadelphia.
Previous results from clinical studies have indicated that social support can improve the health outcome of patients with breast cancer. Epidemiological studies have suggested that social isolation increases the mortality risk from several chronic diseases.
Suzanne D. Conzen, M.D., associate professor in the department of medicine and the Ben May department for cancer research at the University of Chicago, along with colleagues from the Institute of Mind and Biology at the University of Chicago, evaluated whether an unfavorable social environment could influence tumor growth in mice that are genetically predisposed to mammary gland cancer.
They found that female mice that were chronically stressed because of social isolation (from the time they were first separated from their mothers) developed significantly larger mammary gland tumors compared to those mice that were group-housed.
Additionally, the isolated mice developed a heightened corticosterone stress hormone response.