COLUMBUS, Ohio – Regular psychological counseling for breast cancer patients may do more than just lower their stress and anxiety. A new study says the right kind of intervention can also mean healthier diets, reduced smoking, and most surprising of all – a stronger immune system.
The findings, published in the Sept.1 issue of the Journal of Clinical Oncology, are the first to come from a long-term study at the Ohio State University Comprehensive Cancer Center (OSUCCC) of the impact of stress on immunity among breast cancer patients. They also add more evidence to one side of a longstanding debate over the value of psychological intervention in cancer treatment.
"We were so surprised with the findings about immunity that we repeated the tests over and over again as more patients entered the trial," says Barbara Andersen, a professor of psychology at Ohio State University and lead investigator in the study.
Ten years ago, Andersen and her colleagues at Ohio State began studying women with stage II or stage III breast cancer to find out if reducing stress and changing health habits have any impact on the incidence and timing of recurrence. While it is too soon to answer that question, researchers say interim data clearly show that the intervention itself offers powerful psychological, behavioral and biological benefits for patients.
Two hundred and twenty-seven women enrolled in the study after surgery but before continuing additional treatment with chemotherapy or radiation. They were randomized to one of two groups – one that received psychological intervention and one that received only a psychological assessment. All participants completed interviews and questionnaires designed to measure emotional distress, social adjustment and health behaviors. Researchers also took blood samples for immunity studies.
Patients in the intervention group met weekly in small-group sessions to learn ways to lower their stress, improve their mood, modify key health behaviors and follow their treatment plans. Researchers used the same interview process and questionnaires to reassess them four months later at the end of the intervention period.
Women in the assessment-only group received no psychological intervention, but they were also reevaluated at the end of the four-month period using identical measures.
As expected, the intervention helped patients in the treatment group. Overall, they reported lower stress and improved mood and said they felt they were getting more support from friends and family, compared to those who were only assessed. In addition, a significant number of patients in the intervention group developed healthier eating habits and quit smoking, while women in the assessment-only group made no significant changes in their diets and actually increased their cigarette use.
Researchers also examined two key markers of the patients' immune systems, the activity of natural killer (NK) cells and the capacity of certain T-cells to grow and multiply. T-cells and NK cells are critical to the body's immune system – they help identify and destroy infectious or mutated cells that might lead to cancer and other diseases.
In assessing the strength of the patients' immune systems, scientists measured the numbers of T-cells and certain T-cell subsets (CD3, CD4 and CD8) in both groups. They also evaluated the ability of the T-cells to grow and multiply.
After controlling for all other variables, researchers found no significant change in the numbers of T-cell or NK cells present. They discovered, however, that women in the intervention group showed a stable or improved T-cell proliferative capacity.
On the other hand, women in the assessment-only group had decreased T-cell proliferative capacity across all measures.
William Carson, an associate professor of medicine and molecular virology, immunology and medical genetics at Ohio State and co-author of the study, says while it is not clear what is prompting the improved immune response among the patients in the intervention arm, the findings are intriguing and merit additional study.
"These findings are important because there has only been one other study linking stress reduction and changes in immunity. It found no changes in the immune system at the end of the intervention, but it did find changes six months later. Given the strength of our results and the fact that are consistent with other improvements, we simply have to do more to fully understand what is going on."
Carson, who is also associate director for clinical research and co-leader of the Immunology Program at the OSUCCC and a surgeon at the Arthur J. James Cancer Hospital and Richard J. Solove Research Institute, notes that some types of cancers appear to stimulate the immune system more than others – a phenomenon known as "immunogenicity." He adds that breast cancer is only moderately immunogenic, suggesting an immune response to the psychological intervention might be even more pronounced when tested in other malignancies, like renal cell carcinoma or basal cell carcinoma.
"Our findings spark more questions than answers, at this point," he says.
Andersen's research team is already compiling patient data from one and two years into the study and says early indications suggest these early findings will remain consistent over time.
"Ours is the first study to use an experimental design to discover what, if any, relationship exists between psychological intervention and risk of recurrence. Statistically, we just don't have enough data yet to determine that, but so far, we know that the intervention is beneficial and the findings are robust, and that gives us greater confidence we have a strong test regarding impact on recurrence," says Andersen.
Source: Eurekalert & othersLast reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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