SEATTLE--Breast cancer patients who report high levels of personal stress score lower on three measures of immune function than less stressed women with the disease, said Barbara L. Andersen, PhD, professor of psychology and obstetrics and gynecology, Ohio State University, Columbus.
In her presentation at the annual meeting of the American Association for the Advancement of Science (AAAS), Dr. Andersen reported preliminary findings from an ongoing study she is conducting with Ronald Glaser, PhD, and William Farrar, MD.
Women enrolled in the trial are tested for the ability of their natural killer (NK) cells to find and destroy target cells; the reaction of NK cells to gamma interferon, which normally stimulates these cells; and how well their blood cells replicate in the presence of two plant chemicals, ConA and PHA.
"The results were surprisingly strong and clearly suggested an association between high stress and lower levels of immunity in breast cancer patients," Dr. Andersen said.
Low-stress women showed greater NK cell activity than did women assessed as high stress. However, she pointed out, "high levels of stress did not reduce the number of NK cells; rather, stress seemed to make the NK cells less effective."
The immune system findings held up when the Ohio State University team controlled for factors known to influence the immune systems of breast cancer patients, including age, disease severity, and days since cancer surgery.
The findings are consistent with work by Dr. Glaser and others at Ohio State's Institute for Behavioral Medicine Research that has linked stress with reduced immune system functioning in relatively healthy people.
"We're showing that the same relationship between stress and immune function occurs in people with cancer," Dr. Andersen said.
The preliminary report included immune function data from 115 women with stage II or III breast cancer. The women were treated at Ohio State's James Cancer Hospital and Research Institute or by collaborating physicians in the Columbus, Ohio, region. The researchers expect to enroll a total of 230 breast cancer patients and follow them for up to five years.
Women enter the study between their surgery and their adjuvant therapy. They answer questionnaires designed to reveal evidence of stress, such as intrusive thoughts about their breast cancer or attempts to avoid thinking or talking about the cancer.
The women are randomized to two groups: one groups is assessed only for stress and serves as the control; the second is assessed and receives psychological intervention.
The Intervention Program
In this intervention program, the women meet in structured group sessions that target reducing stress, increasing positive and decreasing negative health behaviors, improving treatment compliance, and enhancing quality of life (by improving coping skills, mobilizing a social support network, and dealing with breast-specific problems such as sexual functioning).
Preliminary findings suggest that the women receiving intervention have significantly better adjustment and enhanced quality of life than those in the assessment-only group, and show much higher patient compliance.
What remains unanswered is whether reducing stress can actually prolong the life of patients. Thus, the Ohio State University team is also assessing outcomes in these patients, although no data are yet available.
"Psychological interventions may play an important role, not just in improving quality of life but also in improving the health of breast cancer patients," Dr. Andersen said. "That's what we're exploring now."