Psychological group therapy for women with breast cancer may help them not only to cope better with their disease but also live longer, U.S. researchers said on Monday.

The idea that such therapy can extend survival in cancer patients has been controversial for two decades. Past studies have yielded conflicting results.

Researchers led by Ohio State University's Barbara Andersen studied 227 women with breast cancer. About half took part in a year of therapy in groups of eight to 12 patients led by two clinical psychologists, while the others did not.

After 11 years, the women who participated in the group therapy were 56 percent less likely to die of breast cancer and 45 percent less likely to have their cancer return, the researchers wrote in the journal Cancer.

"Survival is kind of the bottom line when it comes to cancer. So we have people being healthy, productive people for longer — and that's a huge health outcome," Andersen, who helped lead the therapy groups, said in a telephone interview.

Michael Stefanek, an American Cancer Society behavioral research expert, expressed wariness.

"Psychological interventions have been found in the majority of well-controlled studies to enhance quality of life and reduce distress. It would not be reasonable for patients to participate in psychological interventions with the goal of extending survival," he said in a statement.

BETTER IMMUNE FUNCTION

The women had Stage II or Stage III breast cancer in which the tumor may have spread to the lymph nodes near the breast or chest wall or skin, but not to more distant parts of the body.

Andersen said the group sessions, among other things, aimed to reduce the women's distress, train them how to relax and improve coping skills, improve their diet and exercise habits and discourage smoking and drinking alcohol.

The improved survival may stem from better immune function resulting from stress reduction, the researchers said.

The therapy sessions began after the women had breast cancer surgery but before they started chemotherapy and radiation treatments. They took part in weekly sessions for four months and monthly sessions for another eight months.

Among the 54 women who died during the study period, those who took part in group therapy lived longer than the others. And among the women whose cancer came back, the recurrence happened later in those who had done the therapy sessions.

Lois Friedman, a psychologist at University Hospitals Case Medical Center's Ireland Cancer Center in Cleveland, said too few cancer patients take part in therapy.

Friedman, who was not involved in the study, said there is clear evidence that such psychological interventions can improve mood and quality of life, help with adherence to medical regimens and improve general well-being.

"But I think we need to be cautious before we say it's going to increase survival," Friedman said in a telephone interview.