A study found that women diagnosed with migraine headaches were 26% less likely to develop breast cancer compared to women never diagnosed with migraines. This finding confirms that from an earlier analysis of the same research study.
In this study, the researchers compared the medical histories -- including whether or not migraines had been diagnosed -- of over 4,500 women diagnosed with invasive breast cancer to those of over 4,600 similar women who were not diagnosed with breast cancer. The women whose medical histories were reviewed were between the ages of 35 and 64. Those who were diagnosed with breast cancer had been diagnosed between the years 1994 and 1998.
- Breast cancer risk was 26% lower in postmenopausal women and 21% lower in premenopausal women who had been diagnosed with migraines, compared to those who had not.
- The risks of both ductal and lobular breast cancer were reduced in migraine sufferers.
- The lower breast cancer risk among women with a history of migraines was not linked to any medications the migraine sufferers may have received for their migraines.
- The lower risk of breast cancer among migraine sufferers was seen regardless of a woman's race.
The researchers looked at a number of factors that are known to both trigger migraines and to increase breast cancer risk. These factors are:
- drinking alcohol
- using oral contraceptives
- using hormone replacement therapy (HRT)
They found that migraine sufferers in whom none of these factors were present had the same lowered breast cancer risk as women in whom at least one of these factors was present. So the presence or absence of these risk factors didn't alter the link between having migraines and a lower breast cancer risk.
This research found that a history of migraines mostly lowered the risk of hormone-receptor-positive breast cancers, compared to hormone-receptor-negative breast cancers. This fact led the researchers to think that estrogen may, at least in part, explain the link between migraines and reduced breast cancer risk.
Estrogen can promote the development and the growth of hormone-receptor-positive breast cancer cells. Doctors also have seen a link between estrogen levels and migraine headaches in women. When estrogen levels fall -- right before a period, for example -- women who suffer from migraines are more likely to have one. When estrogen levels rise -- during pregnancy, for example -- women who suffer from migraines are less likely to have one. While their study didn't specifically evaluate the reason for the link between migraines and breast cancer risk, the researchers think that the same changes in estrogen levels that make a woman prone to having migraines also may cause the lower breast cancer risk they saw in this study.
A better understanding of the link between migraines and breast cancer risk could help doctors improve their understanding of how breast cancer happens, and could possibly help them identify better ways to prevent or treat breast cancer in the future. Stay tuned to Breastcancer.org for the most up-to-date news on research that shapes the future of breast cancer prevention, diagnosis, and treatment.