Group therapy sessions helped breast cancer patients eat better, stop smoking and may have boosted their immune systems, U.S. researchers reported on Wednesday.

A study of women with stage II or III breast cancer showed counseling sessions helped breast cancer patients feel more relaxed and also raised the activity of immune cells called T-cells.

Writing in the Journal of Clinical Oncology, the researchers at Ohio State University Comprehensive Cancer Center say they now want to study group therapy in other cancers.

“We were so surprised with the findings about immunity that we repeated the tests over and over again as more patients entered the trial,” said Barbara Andersen, a professor of psychology who led the study.

They studied 227 women, who were randomly assigned either to get a simple psychological assessment or to enter group counseling sessions.

The patients, who were all receiving chemotherapy or radiation for their cancer, discussed ways to lower their stress, improve their mood, stop smoking, eat better and follow their treatment plans.

Their blood was tested for activity of two types of immune cells - natural killer cells and T-cells. Radiation and chemotherapy can both suppress immune cells.

The researchers found no significant change in the numbers of T-cell or killer cells, but found the women in group therapy had an increase in the proliferative capacity of T-cells, meaning they could respond quickly when needed for an immune defense.

The women who were not in the groups had decreased T-cell proliferative capacity.

“These findings are important because there has only been one other study linking stress reduction and changes in immunity,” said Dr. William Carson, an associate professor of medicine and molecular virology, immunology and medical genetics at Ohio State.

“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 they are consistent with other improvements, we simply have to do more to fully understand what is going on.”

SOURCE: Journal of Clinical Oncology, September 1, 2004.