Type D Personality and Big Five Personality Traits and the Risk of Breast Cancer: A Case-Control Study.

Objective: The goal of this study is to establish the differences in Type D personality and Big five personality traits between a group of newly diagnosed breast cancer patients and a group of controls.

Methods: A comparative study of breast cancer patients and women without previous history of cancer was carried out. We used Type D Scale-14 as an instrument for the assessment of the type-D personality pattern and NEO-FFI for the assessment of the Big Five personality traits. Conditional logistic regression models were used to estimate odds ratios and 95% confidence intervals were applied for breast cancer by personality trait factors.

Results: Negative affectivity (NA) (OR = 4.45 95% CI: 1.96-10.61), neuroticism HIGH (OR = 3.97, 95% CI: 1.08-15.81), openness to experience HIGH (OR = 3.47 95% CI: 1.11-11.49), were associated factors significantly related to an increased risk of breast cancer, whereas Social Inhibition (SI) was associated factor with a decreased risk of breast cancer (OR = 0.40 95% CI: 0.16-0.92).

Conclusions: This was the first case-control study which analyzed NA and SI traits in breast cancer patients. SI as a breast-cancer risk decreasing factor might indicate that expressing negative emotions is not always a healthy mechanism of their regulation.