Relaxing to Reduce Risk?
A new study published in the journal Cancer has concluded that women who have experienced a "major stressor" and do not have an intimate social support system are at a slightly increased risk of developing breast cancer.
And yet an earlier study, published in the British Medical Journal, indicated that breast cancer risk is unrelated to stress. Still another study, published in The Lancet, found that a patient's coping style after diagnosis may have an impact on mortality.
Can stress hurt the immune system? Can it therefore affect a person's ability to fight diseases, including cancer?
Some researchers believe stress may cause the immune system to release hormones that alter the function of disease-fighting immune cells. Stress may also increase a person's smoking or drinking habits, or cause a loss of sleep, all of which may impair immune function. But the current body of research is far from conclusive.
In the Cancer study, a team of researchers led by Dr. Stewart Dunn of the Royal North Shore Hospital in New South Wales, England interviewed 514 women who underwent breast biopsy after a suspicious finding during a routine screening. They identified 239 women who were later diagnosed with breast cancer and 275 who had benign breast (non-cancerous) disease.
Of the women in the cancer group, 4.6 percent reported "an acute stressor that was rated as extremely threatening" within the previous two years, compared with 2.9 percent of those in the benign group. The researchers acknowledged that this was not a statistically significant difference.
However, they then linked this previous "stressor" with a woman's intimate emotional support system. They found that women reporting a major stressor who had no intimate emotional support were more likely to develop breast cancer than those who had a network of close personal support.
The above conclusions run counter to other studies which have found no link between stress and breast cancer risk.
For example, Dr. David Protheroe of Northern Hospital in Victoria, Australia and colleagues, writing in the British Medical Journal, interviewed 332 women seen at breast cancer clinics during routine breast cancer screenings.
They found that women who were eventually diagnosed with breast cancer were no more likely than those with a benign diagnosis to have experienced one or more "severe life events" during the preceding 5 years. Furthermore, breast cancer patients were also no more likely than patients without breast cancer to report a personal or non-personal health difficulty that lasted 2 years or more.
"Our data provide no support for the theory that severe life stresses may be concerned with the cause of breast cancer," they concluded. Protheroe suggested that breast cancer patients should therefore be advised that prior life stresses "were unlikely to have played an important part in the development of their disease."
Interestingly, another study focused on the relationship between a patient's coping style with a breast cancer diagnosis and an increased risk of mortality from the disease.
Dr. Maggie Watson of Royal Marsden Hospital NHS Trust in Surrey, England and colleagues, writing in The Lancet, concluded that women who have a "helpless/hopeless" response to being diagnosed with breast cancer have a modestly worse survival rate than women who react in a more positive way to the diagnosis.
Watson's team interviewed 578 patients with breast cancer after they were diagnosed with the disease and rated their level of anxiety and depression. They found that women with higher emotional distress levels were more likely to die of any cause within 5 years of diagnosis than were breast cancer patients with a more positive coping style.
The researchers cautioned, however, that a much larger study was needed before any clear conclusions could be made about the link between coping style and mortality risk.
Finally, a study presented at a recent National Institutes of Health conference on genetic testing demonstrated that women who undergo testing for the BRCA1 breast cancer gene experience symptoms of severe stress that can last for as long as two years-and possibly longer.
Led by Dr. Ken Smith, a team of University of Utah researchers reported that they were not surprised that stress levels spiked once it was determined that a woman carried the so-called "breast cancer gene," which indicates a significantly increased risk for the disease.
Rather, they were taken aback by how long such high stress levels were maintained-up to two years for women with the BRCA1 genetic marker.
SOURCES:
Cancer, February 15, 2001; 91:679-697
British Medical Journal, October 16, 1999; 319:1027-1030
The Lancet, October 16, 2001; 354:1320, 1331-1336
National Institutes of Health Conference, "The Ethics of Genetic Testing," January 17, 2001, Bethesda, Maryland
Journal of the National Cancer Institute, 1999; 91:1480-1486
[Table of Contents] [Archived Issues / Search] [The Breast Center]