Personality-breast cancer link debunked

The idea that a woman's personality traits can make her more prone to breast cancer appears nothing more than a myth, say Dutch researchers.

Dr Eveline Bleiker of the Netherlands Cancer Institute and colleagues report their findings in the Journal of the National Cancer Institute.

Women who were unemotional, depressed or anxious were no more or less likely to get breast cancer than any other women, the study found. Nor were women who were optimistic, angry or understanding, or had any combination of personality traits.

The Dutch researchers measured 11 personality traits in 9,705 Dutch women in a survey in 1989 and 1990, then tracked them through 2003 to see who got breast cancer.

"The present results indicate that women should not worry about a possible impact of personality factors as a risk factor for breast cancer," says Bleiker.

"Moreover, women with breast cancer should not worry that their character might have contributed to the development of their disease."

Bleiker noted that some researchers in the 1980s had advanced the idea of a "cancer-prone" personality with such traits as stoicism and difficulty in expressing emotions.

"The earlier studies had a number of methodological flaws," says Bleiker, adding that more recent, large studies have not found the existence of a "cancer-prone" personality.

"In summary, there is currently no convincing evidence that such a personality profile exists."

Chance findings

In 1996, the Dutch team studied the same group of women for five years and found that one of the 11 personality traits - what they called "anti-emotionality" - actually was associated with a slight increased risk for breast cancer.

But after tracking the women for a longer time in the new study, this association vanished. This suggests it may have been only a chance finding, Bleiker says.

Women with the "anti-emotionality" trait responded negatively to survey questions such as: "In important situations, I trust my feelings," "I respond emotionally to people," and "My behaviour is influenced by my emotions."

Kevin Stein, a researcher at the American Cancer Society who was not involved in the Dutch study, says it is inappropriate and factually incorrect to blame a woman's personality for her breast cancer.

"I am pleased to see this stuff knocked down," says Stein. "There's really no support for the idea that your personality or your attitude can either cause a cancer or prevent or help avoid a cancer."

Will Dunham
Reuters