Personality doesn't affect breast cancer risk

NEW YORK (Reuters Health) - A woman's personality does not seem to influence her risk of developing breast cancer, according to a new study.

Some past research has found that personality may sway cancer risk, fueling the idea that there are certain cancer-prone personality types, but "consistent scientific evidence ... is lacking," Dr. Eveline M. A. Bleiker, of The Netherlands Cancer Institute, Amsterdam, and colleagues note in the Journal of the National Cancer Institute.

In a 1996 study, the researchers found a weak link between the development of breast cancer and high levels of "antiemotionality," defined as the lack of emotional behavior or trust in one's own feelings. However, they failed to find a connection between breast cancer and any of the 10 other personality traits studied, including anxiety, anger and depression.

The 1996 study was based on 131 women with breast cancer and 771 without the disease, who were part of a larger surveillance group of 9,705 women who completed personality questionnaires between 1989 and 1990.

Bleiker and colleagues conducted a follow-up with 217 women enrolled in the original group who developed breast cancer within 5 to 13 years after completing the personality questionnaire. The new study also included 868 women who remained free of breast cancer.

The researchers were unable to confirm the previously reported association between antiemotionality and breast cancer. This suggests that it might have been only a "chance finding," they note.

Bleiker's group also could not link any personality trait, alone or in combination with other personality traits or medical risk factors, to increased breast cancer risk.

These findings may help to reassure women that their personality is unlikely to influence their odds of developing breast cancer, Bleiker and colleagues conclude.

SOURCE: Journal of the National Cancer Institute, February 6, 2008.