Contrary to conventional wisdom, more than 20 years of psychosocial oncology research supports only a modest association between specific psychological factors and breast cancer.
Scientists at the Roswell Park Cancer Institute, Buffalo, and the University of Illinois at Urbana-Champaign said that statistical data from 46 studies fail to support the association of breast cancer to anxiety and depression, non-supportive childhood family environments, expression of anger, or extroversion/introversion personality factors.
"Connections between personality, psychosocial factors, and physical illness do exist," said Michael A. Zevon, Ph.D., one of the authors of the study. "However, more research identifying interactions among these variables is needed before advocating the popular position that a simple interpersonal or social lifestyle change can have a significant impact on the development of cancer."
The researchers did find modest associations between breast cancer and four other psychosocial factors. Significant support was found for the hypotheses that breast cancer patients use a coping strategy based on denial and repression in response to life stressors, have experienced separation and loss, and have a history of stressful life experiences. Less support, but still significant, was found for an association between breast cancer and a personality style characterized by conflict avoidance. The research appears in the September issue of Health Psychology.
"It's important to note, however, that association is not causation, and based on the current data we should not infer that by changing these factors women can substantially alter their risk of breast cancer," said Zevon. "Overall, the current data continue to support the primacy of biology, rather than personality or life experiences, in the development of breast cancer."
The research was supported by a grant from the Roswell Park Cancer Center.