Researchers are having second thoughts about a long-trusted piece of conventional wisdom: that a positive attitude can help patients beat cancer.

Until now, cancer care has included trying to find ways to improve a patient's attitude. Self-help books, cancer Web sites and loved ones often urge patients to stay positive, arguing that an optimistic outlook is a critical tool in overcoming the disease.

But a new body of work examining the biological underpinnings of attitude suggests that its connection to fighting cancer may be more complex. So far, the findings indicate that successful coping isn't necessarily about having a positive outlook.

More important may be coping in a way a patient is used to, which could involve anything from stress relief to exercise rather than simply striving for a cheery disposition. Indeed, if someone is a natural curmudgeon, then continuing to be a curmudgeon may be the very thing to help lower stress, bolster the immune system and, possibly, influence the success of the cancer treatment.

"Many pessimists cope well with cancer," says Jimmie Holland, the chair of psychiatric oncology at Memorial Sloan-Kettering Hospital in New York. "You can be as curmudgeonly or angry or whiny as you want and still survive cancer, as long as it doesn't cause your doctor to throw you out of the office."

The current work is being driven by what Dr. Holland calls "the tyranny of positive thinking" and its impact on patients. Many patients fear they are lowering their chances of survival if they don't feel positive, creating an additional burden at a time when they are overwhelmed by their diagnosis.

The research doesn't focus so much on patients' tendencies to look at the glass as half-full or half-empty and how they may influence survival outcomes. Instead, researchers are examining how different coping styles may affect indicators of disease-fighting ability, such as cortisol rhythms (a measure of stress levels) and natural killer cell counts (a measure of immune response). With better understanding of these variables, doctors and researchers hope to find ways, such as muscle relaxation or problem solving, to help patients keep stress and natural killer cells at levels that improve their chances of extending survival.

Cindy Miller, 46, was diagnosed in 2000 with breast cancer and had a mastectomy, eight rounds of chemotherapy and drugs. She says that she had many bad days when she felt angry, sad and scared. "Telling someone to feel positive makes you feel like you are not being understood," says the mother of two, who lives outside Philadelphia.

Ultimately, Ms. Miller says she did maintain an optimistic view that she could survive, but she doesn't believe that simply being positive improved her survival odds. More important, she says, was staying true to her regular coping style, which involved actively seeking out complementary care to bolster what her doctor was doing. She changed her diet to only organic foods, did massage to ease the pain and ran as much as she could. "I'm a naturally optimistic person," she says. "You are who you are, and you bring that to cancer."

The new approach also stems from the realization that after more than a decade of research trying to link optimism with improved cancer survival, the data haven't revealed much evidence of a connection. In February, the American Cancer Society journal, Cancer, published a report about 179 patients newly diagnosed with non-small-cell lung cancer who were followed for five years.

The investigators found that a patient's level of optimism didn't affect survival time. A British Medical Journal review in 2002 of 37 other studies on the effect of psychological coping styles found most also showed no connection between positive attitude and improved survival.

Mark Petticrew, a public-health researcher at the University of Glasgow in Scotland who helped lead the review, says positive thinking can still help. In a number of studies, it was associated with better compliance with the doctors' orders, improved mood and less pain. "But positive thinking is often sold as a cure all to cancer and it isn't," he said.

The latest work is different in that it is based on "a more complex measure of optimism," says David Spiegel, a psychiatrist at Stanford University School of Medicine, who is heading one of the studies. Back in 1989, he was the lead author on a seminal paper published in Lancet that looked at the effect of participating in support groups on 86 women with metastatic breast cancer. At the 10-year follow up, only three patients were alive -- all support group members -- and death records were obtained for the other 83 women. The study reported that women who participated in the group survived 36.6 months from entry into the study, compared with 18.9 months for the control group.

The results caused a stir, generating huge public and academic interest. Cancer patients were urged to join support groups. But in follow-up studies, the results weren't easily duplicated. In one major study designed to replicate Dr. Spiegel's original findings with metastatic breast-cancer patients, women assigned to a support group showed improved mood and the perception of less pain but didn't survive any longer than women not in the group. Dr. Spiegel says that some randomized trials looking at cancers besides breast cancer, such as melanoma, did find that effective psychological support could predict longer survival. But there were just as many that found it didn't.

As a result, he says his group is now in the 12th year of a similar study but taking a different approach. In the previous study, the only thing measured was length of survival time based on death certificates. In the current one, researchers are assessing the effects of stress and its management on the body, guided by the idea that the stress that cancer patients feel while coping may weaken their immune systems. Researchers are measuring the women's cortisol concentrations in their saliva, an indicator of stress, and counting their circulating natural-killer cells, a measure of immune response.

Although the study is ongoing, in a preliminary report published in 2000 in the Journal of the National Cancer Institute, the researchers found that patients whose cortisol levels were flat and didn't follow the typical pattern of declining throughout the day, died sooner than women with normal cortisol patterns. The finding, researchers believe, indicates that there may be psychological interventions that can boost disease-fighting ability, a notion that in the past has driven the focus on staying positive.

But what if the pressure to be upbeat raised someone's stress level? Researchers are now realizing that people cope with stress in vastly different ways, and that they need to find solutions that match someone's natural temperament and personality. The next step is finding the mechanisms that enable patients to keep their cortisol patterns and natural killer cells at optimum levels and hopefully extend their survival. "For some patients this may happen by being uncooperative and unpleasant rather than positive," Dr. Spiegel says.

At Ohio State University, an ongoing study is measuring not only survival rates but also endocrine responses and biological markers of immunity. Women participating in the study, all of whom share similar diagnoses for breast cancer, are learning muscle relaxation, problem solving, and time management techniques. They are making dietary changes, such as reducing fat and increasing fiber, and exercising, all in the hope that some methods will bolster the women's ability to fight and ultimately beat the disease.