Adverse life events and breast cancerBMJ 1996; 312 doi: https://doi.org/10.1136/bmj.312.7034.845 (Published 30 March 1996) Cite this as: BMJ 1996;312:845
Other studies have found no association
- Jennifer Barraclough
- Consultant in psychological medicine Sir Michael Sobell House, Palliative Care Unit, Churchill Hospital, Oxford OX3 7LJ
EDITOR,—The latest interview study about adverse life events and breast cancer, by C C Chen and colleagues, reports a positive link,1 but wider review of the literature shows a contradictory picture.2 Retrospective interview studies on this topic are hampered by unavoidable problems. A diagnosis of cancer has often been correctly predicted by the patient or interviewer before the results of biopsy are known, which increases the likelihood of overreporting of stress in an effort to explain the illness. The temporal relation of previous life events to the onset of cancer is impossible to assess because the onset of cancer cannot be dated. Furthermore, patients with benign breast disease may not be a suitable comparison group.
These limitations can be overcome by large population record studies in which the focus of interest is restricted to two major adverse life events—widowhood and divorce—which can be objectively verified and dated. Such studies yield little or no evidence that widowhood or divorce is related to the onset or outcome of breast cancer.3 4 5
Interactions among external stress, psychoneuroimmunological responses, and the breast cancer process are complex and fascinating, but their clinical importance remains in doubt. Chen and colleagues have carried out a careful study, but their claim to have shown “a significant aetiological association between life events and development of breast cancer” goes beyond their data and could be misleading and unhelpful for the patients concerned.