Effects of Stress on Immune System Studied in Breast Cancer

HOUSTON—Stress is an immediate reaction to cancer that generally becomes more intensified during the course of the disease. Barbara L. Andersen, PhD, Department of Psychology, Ohio State University, Columbus, and her colleagues are conducting a study to examine the effects of stress on the immune system in cancer patients.

“Acute stress sets in at the very moment the disease is diagnosed, and the experience of stress becomes more chronic as the patient undergoes treatment and recovery, adjusts to lifestyle changes, and copes with social and relationship issues,” Dr. Andersen said. “We are examining how high levels of stress might affect an ovarian cancer patient’s immune system, using breast cancer patients as a model, and whether interventions to reduce stress can improve quality of life.”

Dr. Andersen discussed the study at the First Annual International Conference for Ovarian Cancer, co-sponsored by The University of Texas M.D. Anderson Cancer Center and Memorial Sloan-Kettering Cancer Center.

A number of studies over the years have shown that stress downregulates immunity. “The relationship between stress and immunity has been documented in spouses of Alzheimer’s patients, individuals going through bereavement, and even in medical students taking medical exams,” Dr. Andersen said.

Emotional distress brought on by a disturbance of a person’s psychological, physiological, and social well-being can create or compound an unhealthy condition, she added.

The current study is exploring the possibility that biobehavioral interventions may not only reduce stress and enhance the patient’s quality of life but also have other important biologic benefits.

Women with stage II or III breast cancer are being recruited for the study because of their difficult prognosis, the high rate of disease recurrence, and the aggressiveness of adjuvant therapy. “We felt this group provided a relative model for a study of quality of life in ovarian cancer patients,” Dr. Andersen said. Patients are randomized to assessment only or assessment and intervention.

The multicomponent biobehavioral intervention model is designed to reduce stress, improve quality of life, increase positive health behaviors, and improve compliance with medical treatment. Assessment and intervention are begun when the patient is about to begin chemotherapy, a time when, as Dr. Andersen explained, “anxiety and feelings of inadequacy are particularly high.”

One of the components of the intervention model is progressive muscle relaxation, in which patients are taught skills to help them release physical tensions and emotional distress.

Another component of the program involves cognitive coping strategies, in which patients are taught to cope with their situation by redirecting their energies, restructuring their expectations, and readjusting socially.

Patients are also taught how to mobilize their avenues of support, which can be realized through friends, family members, and other patients.

The model also attempts to increase positive health behaviors, Dr. Andersen said. “We recommend a low-fat, high-fiber diet and a regular program of moderate exercise, such as a walking plan,” she said. “The goal is to encourage a healthy lifestyle by decreasing negative mood, reducing fatigue, and increasing the patient’s energy level.”

Improving Compliance

To improve compliance with treatment, patients are encouraged to learn more about their disease condition and their treatment. “We give them information about the disease and train them how to communicate better with doctors and nurses so that they get better mileage out of appointments and consultations,” she said.

Other, more focused components of the intervention are used to address disease-specific problems that may affect the patient’s overall quality of life, such as sexual issues, concerns about body image, and hormonal changes.

“The disease-specific concern we encounter most often is sexuality,” she said. In another study, Dr. Andersen and her colleagues found that sexual self-concept was an independent, predictive variable for sexual morbidity in women with gynecologic cancer.

“How women perceive of themselves sexually has a huge bearing on their sexual well-being,” Dr. Andersen said. “Some of these women have sexual difficulties or a negative sexual self-image before cancer. This group seems to be at higher risk for sexual problems after disease occurrence.”

Reduced Natural Killer Cell Lysis

The researchers plan to accrue 235 patients for the study. Dr. Andersen reported that a relationship between stress and downregulation of immunity has been seen in the first group of patients.

“After only 40 patients, we began to detect trends that showed some relationship between high levels of stress and low levels of immunity,” she said. “We found that high levels of stress lower natural killer cell lysis and have an adverse effect on some other cellular functions.”

Using a gamma-interferon assay, the researchers found that some natural killer cells remained in lysis after the addition of gamma-interferon and that this process was affected by the patient’s level of stress. “We knew that high levels of stress correlated with downregulation of immunity,” Dr. Andersen commented.

Future studies will focus on determining which immunologic mechanism accounts for the lower levels of natural killer cell lysis seen with increased stress.