Evaluation of relationship between breast cancer and migraine.

Background: Frequency of migraine changes at different times of a woman's reproductive cycle because of fluctuation of estrogen levels. Breast cancer has also a link with hormonal changes. Given this fact that both migraine and breast cancer are affected by estrogen, the prevalence of migraine may be different in breast cancer patients compared to the normal population.

Materials And Methods: In this case-control study, two groups of women with and without breast cancer were compared regarding the prevalence of migraine. Each group consisted of 400 women. The diagnosis of different types of headache was made based on The International Headache Society (IHS) guidelines. Type of headache, type and receptor status of breast cancer, as well as history of taking hormonal medications was recorded. Independent t-test and Chi-square tests were used for data analysis.

Results: Relative frequency of migraine headache in the normal woman was 38% compared to 19% in the breast cancer group (P < 0.0001). Tension headache was also significantly more prevalent in the normal group (P < 0.001). The frequency of migraine was significantly lower in estrogen receptor (ER)+/progesterone receptor (PR)- women compared to ER-/PR+ (26 and 43 women, respectively; P = 0.04); however, this difference was not significant for tension headache (P = 0.68).

Conclusion: This study confirmed the lower frequency of migraine, as well as tension headache, in breast cancer sufferers. This could be contributed to several non-hormonal factors, such as a history of long term use of nonsteroidal anti-inflammatory drugs (NSAIDs), and hormonal factors, although only migraine showed a strong link with hormone status.