What did the media say?
The media reported that women who suffer regular migraines may be at lower risk of developing breast cancer in the future.
What does the research show?
US researchers looked at data from two population studies involving 3,412 postmenopausal women. Of these, 1,199 women had been diagnosed with ductal carcinoma, 739 with lobular carcinoma and 1,474 had no history of breast cancer.
The subjects were all aged 55–79 years. They were asked to self-report their history of migraine that had been diagnosed by a health professional.
Women with a clinical diagnosis of migraine had a 33% reduced relative risk of ductal carcinoma (odds ratio of 0.67) and a 32% reduced relative risk of lobular carcinoma (odds ratio of 0.68). These observed risk reductions were primarily limited to hormone receptor-positive tumours. It is the first study to identify such a link.
What did the authors say?
‘Overall, women who had a history of migraines had a 30% lower risk of breast cancer compared with women who did not have a history of such headaches,’ said study author Christopher Li, a breast cancer epidemiologist and associate member of the Hutchinson Cancer Research Center in Seattle.
‘While these results need to be interpreted with caution, they point to a possible new factor that may be related to breast cancer risk.’
What does it mean for nursing practice?
Dr Andy Dowson, chairperson of the Migraine Action Association medical advisory board, said: ‘This study samples a highly selected population of women which does not necessarily represent the much larger population of female migraneurs who never see a doctor.’
He added: ‘The authors do not seem to consider important facts that we already know about both migraine and breast cancer when creating their theory.’
He said that, while it was known that migraine was affected by fluctuations in oestrogen, the latest findings from a major study, the Women’s Health Initiative, suggested that progestogens, not oestrogen, were the ‘culprits in breast cancer’.
Cancer Epidemiology, Biomarkers and Prevention (2008) 17: 3116–3122