Emotional State Doesn't Affect Cancer Survival

But positivity or negativity are not the issue, suggested Dr. David Spiegel, associate chairman of psychiatry and behavioral sciences at Stanford University School of Medicine in California. What matters is the way in which a cancer patient approaches the stresses in his or her life, Spiegel said.

"The authors vastly overstate the quality of their data and the findings," said Spiegel. "They used a subscale of a quality-of-life measure which is hardly a reliable measure of depression and provides, by definition, limited variance in mood, making it, by design, difficult to show a relationship with any other variable."

Spiegel also noted that head and neck cancers generally have a "very poor prognosis," are not hormone-sensitive, and usually require serious surgery and radiotherapy -- all of which has social and psychological consequences.

"Our research shows that it is not a positive attitude but rather facing and dealing well with the ups and downs of life with cancer that is, at the least, psychologically helpful," Spiegel said.

But an Australian study released in the February issue ofCancershowed similar results for lung cancer patients. Patients in that study also completed questionnaires about their outlook before treatment and after treatment.

As with the current study, the Australian research team found no relationship between attitude, positive or negative, and outcome.

Another study released in the Nov. 1 issue of theBritish Medical Journalanalyzed data from 26 studies of emotional outlook and cancer survival and came to the same conclusion: A positive outlook may be a good thing in general but has no impact on cancer outcomes. The same was true for negativity.

But more research is needed, argued Spiegel. The connection between true depression and the course of cancer is still not well understood.

"Patients in my support group joke, 'Am I living longer yet?' They grieve deaths when they occur, but feel they grow stronger doing so," said Spiegel. "They joke about the prison of positive thinking. The connection between mood and cancer is not about 'positive thinking,' it is about managing the very real stressors of life-threatening illness."

Another expert said he wasn't surprised by the Pennsylvania findings.

"People are more likely to find this news a relief than a disappointment," said Dr. Michael Fisch, an associate professor of gastrointestinal medical oncology at the University of Texas M.D. Anderson Cancer Center, in Houston.

Survival depends on the location of the cancer, the risk factors for the cancer, and how advanced the cancer is when it's diagnosed, said Fisch.