Stress Of Breast Cancer Surgery, Diagnosis Weakens Immune System

COLUMBUS, Ohio -- In the largest study of its kind to date, Ohio State University researchers have shown that the stress women experience after breast cancer diagnosis and surgery can weaken their immune response, based on at least three different biochemical indicators.

The findings, reported in the Jan 7, 1998 issue of the Journal of the National Cancer Institute, are the latest in a series of studies documenting the link between conditions of high stress and low immunity.

Barbara Andersen, professor of psychology and researcher with Ohio State’s Comprehensive Cancer Center and Institute of Behavioral Medicine Research, said the results were the strongest evidence she’s seen of a stress-linked immune reduction in cancer patients.

Andersen and her colleagues studied 116 women who underwent surgery for stage II or stage III invasive breast cancer. Before the women began follow-up adjuvant therapy, they completed an extensive questionnaire intended to gauge their stress levels. Based on how they responded to the questionnaire, they were placed in either a high- or low-stress group.

Blood was drawn from women in both groups and tested for three different indicators of immune status. The first test measured the extent to which natural killer (NK) cells were breaking down. NK cells are essential components of the immune system’s search for tumors and virally infected cells.

Andersen’s team also checked how well the NK cells responded to gamma interferon, a compound naturally produced by the body that enhances NK cell activity, as well as inhibiting replication of a virus.

The researchers then tested how well the women’s T-lymphocytes -- white blood cells that are key to the immune response -- responded to two plant chemicals (PHA and Con-A), as well as to monoclonal antibodies.

Their analyses showed the following:

• 15.4 percent more of the NK cells in women in the high-stress group were destroyed than were in the low-stress group.
• The response to gamma interferon in the high-stress women was 20.1 percent less than it was in the low-stress women.
• And the T-cell response to PHA, Con-A and the monoclonal antibodies was 19.8 percent less in the high-stress group than it was in the low-stress group.

“I think this is the most reliable effect I’ve seen so far in any of the scientific literature,” Andersen said. “And it’s occurred in the largest stress and immunity study so far that’s focused on cancer patients.”

Andersen said this kind of study is very difficult to do.

“We were literally recruiting women (into the study) on what they described as the worst day of their lives. Not only had they just had surgery but they’d also been told they had positive nodes (the cancer had spread to the patient’s lymphatic tissue), cutting their prospects for survival in half,” Andersen said.

The new findings are the first real results from Andersen’s six-year, $4.2 million project. The study was funded by the National Institute of Mental Health and the Department of the Army. Initial grant support came from the American Cancer Society.

The study will eventually involve 235 breast cancer patients, Andersen said, and include additional testing of other immune system components. A comparable report citing changes in hormone levels key to immune response is expected later next year.

Andersen and her colleagues are also randomly assigning women in the study to one of two groups. The first will only be monitored and assessed for stress levels while women in the second group will be taught strategies for lowering their stress levels, improving their diets and increasing their exercise. At the end of six years, the researchers will compare the immune and endocrine responses, health and survival of women in both groups.

Other members of the research team included William Farrar, associate professor of surgery; Robert MacCallum, professor of psychology and preventive medicine; Ronald Glaser, professor of microbiology and immunology and of internal medicine; Deanna Golden-Kreutz, project coordinator; Leigh Ann Kutz, laboratory technician, and Mary Elizabeth Courtney, a research associate.