DEATH OF A HUSBAND OR MARITAL DIVORCE RELATED TO RISK OF BREAST-CANCER IN MIDDLE-AGED WOMEN - A NESTED CASE-CONTROL STUDY AMONG NORWEGIAN WOMEN BORN 1935-1954

A topic of general interest is whether important life changes may play a role in the onset of cancer. The hypothesis of this study was that death of a husband or marital divorce, is associated with an increased risk of breast cancer. The study included 4491 incident breast cancer cases and 44 910 controls, matched on age, in a population-based nest ed case-control study, among Norwegian women born between 1935 and 195 4. The risk of breast cancer among widowed compared to married women s howed an odds ratio (OR) of 1.13 [95% confidence interval (CI) 0.94-1. 36], after adjusting for age at first birth and parity. For divorced w omen the analogous OR was 0.83 (95% CI 0.75-0.92), after adjusting for age at first birth, parity and place of residence. Thus, the results did not show any clear evidence that death of a husband or marital div orce was associated with an increased risk of breast cancer.