Psychological Stress and Cancer
The complex relationship between physical and psychological health is not well
understood. Scientists know that many types of stress activate the body's endocrine system, which in turn can cause changes in the immune system, the body's
defense against infection and disease. However, the immune
system is a highly specialized network whose activity is affected not only by stress
but by a number of other factors. It has not been shown that stress-induced changes
in the immune system directly cause cancer.
Some studies have indicated an increased incidence of early death, including
cancer death, among people who have experienced the recent loss of a spouse or
other loved one. However, most cancers have been developing for many years and
are diagnosed only after they have been growing in the body for a long time (from
2 to 30 years). This fact argues against an association between the death of a
loved one and the triggering of cancer.
The relationship between breast cancer and stress has received particular
attention. Some studies of women with breast cancer have shown significantly
higher rates of this disease among those women who experienced traumatic life
events and losses within several years before their diagnosis. Although studies
have shown that stress factors (such as death of a spouse, social isolation, and
medical school examinations) alter the way the immune system functions, they have
not provided scientific evidence of a direct cause-and-effect relationship between
these immune system changes and the development of cancer. One NCI-sponsored
study suggests that there is no important association between stressful life events,
such as the death of a loved one or divorce, and breast cancer risk.* However, more
research to find if there is a relationship between psychological stress and the
transformation of normal cells into cancerous cells is needed.
One area that is currently being studied is the effect of stress on women
already diagnosed with breast cancer. These studies are looking at whether stress
reduction can improve the immune response and possibly slow cancer progression.
Researchers are doing this by determining whether women with breast cancer who are
in support groups have better survival rates than those not in support groups.
Many factors come into play when determining the relationship between stress
and cancer. At present, the relationship between psychological stress and cancer
occurrence or progression has not been scientifically proven. However, stress
reduction is of benefit for many other health reasons.
*"Self-Reported Stress and Risk of Breast Cancer," Felicia D. Roberts, Polly A. Newcomb, Amy Trentham-Dietz, and Barry E. Storer. Cancer, March 15, 1996.
"Stress and Immune Responses After Surgical Treatment for Regional Breast Cancer," Barbara L. Andersen, William B. Farrar, Deanna Golden-Kreutz, et al. Journal of the National Cancer Institute, January 7, 1998.