Cancer patients who get emotional and social support through group therapy may survive up to twice as long as patients on medical treatment alone, according to a surprising new study that adds fuel to the debate over the role of psychological factors in disease.
The 10-year study of women with metastatic breast cancer, reported Wednesday by researchers from Stanford University and UC Berkeley, is believed to be the first to examine in a scientifically controlled manner the effect of psychological and social supports on cancer patients' survival.
"I must say I was quite stunned," said Dr. David Spiegel, presenting his findings at the annual meeting of the American Psychiatric Assn. Spiegel said he and his co-authors had embarked upon the study in hopes of refuting popular notions that the right mental attitude can help conquer disease.
Other researchers called Spiegel's findings marvelous and provocative--but in need of replication by other teams. Cautioned Dr. Troy Thompson, a professor of psychiatry at Jefferson Medical College in Philadelphia, "When something seems too good to be true, often it is."
The 86 middle-aged women in the study--a group considered large enough on which to base conclusions--were assigned randomly to two groups of equal size: One group received medical treatment alone, while the other received medical treatment plus one year of weekly group therapy and lessons in self-hypnosis to help them control their pain.
The women in the support group experienced fewer mood swings and less phobia and pain than their counterparts, according to patient questionnaires administered in the first year. Researchers then set about examining whether that apparent psychological benefit would have any impact on survival.
After 10 years, 83 of the 86 women had died, Spiegel reported. But the women who had received group therapy lived an average of 36.6 months after entering the study, while the others lived an average of 18.9 months.
What might account for the difference is not clear, Spiegel, an associate professor of psychiatry and behavioral sciences at Stanford Medical School, said.
Previous studies suggest that social support may influence the survival of sick people and the elderly, perhaps by serving as a buffer against stress. The opportunity to express feelings, as in group therapy, can also counter the sense of social isolation in some patients and perhaps contribute to survival, other studies suggest.
Spiegel also theorized that the group therapy might have nourished a sense of hope, enabling the women to comply better with medical treatment or perhaps improve their diet. Finally, he pointed to developing theories that the emotions may influence the immune system.
One question raised by other researchers was whether the two groups of women were truly comparable. Specifically, Thompson wondered whether the women in the group that did not receive therapy might have had more virulent forms of breast cancer.
Thompson raised that question because Spiegel's data showed that the cancers of the women in that group were more advanced when first diagnosed. The stage of a cancer at diagnosis could indicate the virulence of the disease, and predict how long the patient will survive, Thompson said.
Spiegel countered that he had taken the difference in stages into account and still found the variation in survival statistically significant. Furthermore, there was no difference between the two groups in the speed at which their disease spread throughout the body, suggesting no difference in virulence, Spiegel said.
The two groups were otherwise comparable. The average age was 54 to 55; the women were receiving similar treatment when they entered the study, and there was little difference in the time elapsed between diagnosis and the spread of the cancer beyond the breast, Spiegel said.
The group therapy the women received lasted one-and-one-half hours a week and centered on expressing fears, anger, anxiety and depression. The women were encouraged to confront their physical problems, be assertive with their physicians and to grieve the loss of friends in the group who died.
"They came to feel that they were experts in living," Spiegel said in presenting his findings Wednesday. As a result of their foreshortened lives, he said, the women felt they had learned lessons about living.
Spiegel said he undertook the study expecting to refute often overstated notions about the power of the mind over disease, which he said he had found "clinically as well as theoretically irritating, as well as destructive to many of my patients."
Thompson said he was as stunned as Spiegel by the outcome.
"This is a marvelous study, a surprising study to me as well," Thompson said. "I would have bet the mortgage of my home that it would not have come out this way."