Life events and the risk of breast cancer: a case-control study

A case-control study was undertaken to investigate the possibility of an association between stressful life events and the development of breast cancer. Ninety-nine breast cancer cases, and 99 controls matched by age and area of residence, completed a life events inventory to measure life change and distress scores over a 2-year and a 10-year period. Study subjects were also interviewed to establish potential breast cancer risk factors; their height and weight were measured; they completed a food frequency questionnaire and provided a fasting blood sample for hormonal assay. After adjusting for potential confounders, women with a 10-year life change score greater than 210 (i.e. the highest quartile) had 4.67 times the risk of developing breast cancer, compared with those in the lowest quartile (P < 0.05).