The "cancer prone" personality

In the past, researchers have tried to find out if some women have a personality that makes them more prone to develop breast cancer. Results have been mixed¹, and it appears likely that some past studies showing the "cancer prone" personality were not valid because they surveyed women who were already showing symptoms of the disease. If women know they have cancer, they are likely to experience strong emotions that can influence memories and the way they respond to survey questions about their personalities. This Australian study was the first to look at the personalities of women before they were diagnosed with breast cancer - and researchers found no link between personality style and development of breast cancer.

Past researchers have thought that women with a "cancer prone", or "Type C" personality, show three main traits²:

1. a tendency to defer one's own needs for the needs of others
2. difficulty expressing emotion
3. a helpless or hopeless attitude

This study considered all three personality traits.

Scope and aim of the study

Australian women who participated in this study were all over 40 years old, with an average age of 56. The 2,224 women were recruited for the study from routine screening programs in their communities. Women were divided into four groups, based on the results of their screening:

1. women with normal breast tissue
2. women with benign (non-cancerous) lesions that did not require a biopsy
3. women with benign lesions that required a biopsy (using a needle)
4. women with breast cancer

Participants in the study completed the research questionnaires before being told their diagnosis.

Participants were also asked about some well-established risk factors for developing breast cancer such as family history of breast cancer, age when starting menopause, and whether or not women first gave birth after the age of 29. Women were excluded from the study if they had a prior history of breast cancer, were already showing symptoms of the disease, or if they had already been told they had developed cancer.

No link between personality style and breast cancer

The researchers made comparisons of personality style and the development of breast cancer based on (1) the woman's overall personality style and (2) each of the three traits of the "cancer prone" personality. No association was found between personality style and the development of breast cancer. This was true even when taking well-known risk factors (e.g. age, family history of breast cancer, etc.) into account.

These results are similar to those found in a large study of Dutch women, who were also chosen as participants while undergoing breast cancer screening in their community³. Although the Dutch researchers looked at only one personality trait - the ability of women to express emotion - they too found no link between women's emotional expression and development of breast cancer.

Comment

This study provided strong evidence that personality does not directly affect a woman's risk of developing breast cancer. Researchers made great strides in improving the way they looked for links between personality and cancer - for this study, they surveyed women in the community who were having routine screening for breast cancer. By looking at women's personality styles before they knew their diagnosis, researchers avoided the kind of bias that can occur when people with an illness look back to see what they may have done to contribute to the illness.

Why is this study important for women over 40? There are a couple of reasons. First, it is one less thing for women to worry about, especially if they are already at increased risk of developing breast cancer due to other well-known factors (such as family history). Second, it removes the element of false "blame" that can sometime comes from misinformed people around her. A woman is not responsible for developing cancer because of her personality style.

This research was part of a larger, more complex study that looked at combinations of factors that might influence a woman's risk of developing breast cancer, including stress and the amount of social support available. Please see below for link to further results of the study in Part 2 of this article.