Positive attitude, survival not linked

November 15, 2007|By Denise Gellene

Hoping to strengthen their stressed-out immune systems, many people with cancer join support groups, attend yoga classes or take other steps to lift their moods.

Do these mind-body interventions help prolong life? A recent study of 1,093 patients with advanced head and neck cancer suggests they do not.

The report, published in October in the journal Cancer, found no difference in life expectancy of patients with a strong sense of emotional well-being compared with those with high levels of emotional distress.

Interpreting the findings, lead author James C. Coyne, a psychologist at the University of Pennsylvania, said it was unlikely that stress-reduction activities would prolong patients' lives. The study should reassure cancer patients who blame themselves when the disease overtakes them, Coyne said.

"People are told to have a fighting spirit, and if the disease beats them, they think it's their fault," he said.

Researchers have been studying the role of emotions in cancer for more than 20 years, with mixed results. Yet many patients and their doctors are convinced that a patient's emotional state influences cancer progression, a belief reinforced by a plethora of self-help books.

In theory, the notion makes sense. Chronic worry and depression release stress hormones that tamp down the immune system.

In fact, research in healthy people has found that stress can slow wound healing. And a study published this year in The Journal of the American Geriatric Society found that practitioners of tai chi, an exercise that involves meditation, had a stronger immune response to a shingles vaccine than nonpractitioners.

It's well-accepted that stress or depression increases the risk of heart disease.

"There is a connection between what we think and feel and the immune system," said Lorenzo Cohen, director of the integrative medicine program at the University of Texas M.D. Anderson Cancer Center in Houston.

More than two dozen trials have examined effects of mind-body interventions on cancer survival, but many of the trials have been small and complicated by the fact that some study patients were sicker than others or received different treatments.

Among the first was a 1989 study that found group therapy doubled life expectancy of women with metastatic breast cancer. The report spurred a proliferation of cancer support groups, now an accepted part of cancer treatment.

However, a nearly identical study published in July failed to replicate the earlier findings. This second report, which appeared in the journal Cancer, found support groups improved quality of life and helped with mood and pain but didn't prolong their lives. The median survival in that study was 32.8 months, with no difference between the groups.

Stanford University psychiatrist Dr. David Spiegel, who led both studies, said cancer treatments had improved since the first experiment, leaving less room for improvement from psychotherapy. Some other scientists said the positive outcome of the earlier experiment probably was a fluke.

The recent study by Coyne and colleagues examined data from two trials of head- and neck-cancer patients to assess whether emotional well-being predicted survival. Before entering the trials, patients filled out surveys asking whether they agreed with such statements as "I am losing hope in my fight against my illness" and "I feel sad today." A total of 646 patients died during the two trials.

Some researchers said the study should be interpreted with caution. Janice Kiecolt-Glaser, an Ohio State University psychologist who is studying the link between emotions and skin cancer, said it was not a surprise that emotional states had little effect in patients whose disease hadn't responded to conventional treatment. "If a freight train is coming, it doesn't matter how many people stand in front of it. Nothing is going to stop it."

Spiegel said the patient surveys did not measure depression well, and researchers failed to assess mood changes over time.

"This study certainly does not support the idea that depression has anything to do with survival, but I don't think it disproves it either," he said.

Denise Gellene writes for the Los Angeles Times.

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