Prevalence and determinants of headaches in Hawaii: the Hilo Women's Health Study

Migraine and possible etiologic heterogeneity for hormone-receptor-negative breast cancer

Migraine headache is often timed with the menstrual cycle. Some studies have reported reduced risk of breast cancer in migraineurs but most of those did not distinguish menstrually-related from non-menstrually-related migraine. To examine the possible associations between breast cancer and migraine overall and between cancer subcategories and the two migraine subtypes, we used a cohort study of 50,884 women whose sister had breast cancer and a sister-matched case-control study including 1,418 young-onset (<50 years) breast cancer cases. We analyzed the two studies individually and also in tandem via a hybrid Cox model, examining subcategories of breast cancer in relation to menstrually-related and non-menstrually-related migraine. History of migraine was not associated with breast cancer overall. Migraine showed an inverse association with ductal carcinoma in situ (HR = 0.77; 95% CI (0.62,0.96)). Also, women with non-menstrually-related migraine had increased risk (HR = 1.30, 95% CI (0.93,1.81)) while women with menstrually-related migraine had decreased risk (HR = 0.63, 95% CI (0.42,0.96)) of hormone-receptor-negative (ER-/PR-) cancer, with a significant contrast in estimated effects (P = 0.005). While replication of these subset-based findings will be needed, effect specificity could suggest that while migraine has little overall association with breast cancer, menstrual migraine may be associated with reduced risk of ER-/PR- breast cancer.

Epidemiology and cultural differences in tension-type headache

Tension-type headache (TTH) is the most prevalent headache worldwide Stovner et al. (Cephalalgia 27:193-210, 2007••); Robbins and Lipton (Semin Neurol 30:107-19, 2010••); Jensen and Stovner (Lancet Neurol 7:354-361, 2008). Despite being the most prevalent primary headache type, there is still a relative lack of epidemiologic data when compared to that for migraine Robbins and Lipton (Semin Neurol 30:107-19, 2010••). Out of the available data, it is apparent that there are wide variations and differences in tension-type headache epidemiology across different cultures Stovner et al. (Cephalalgia 27:193-210, 2007••). This review will focus on reviewing and comparing the epidemiology of episodic and chronic TTH in adult populations across varying continental regions. This will include prevalence, cultural variations and differences in study methodologies, common precipitants and prognosis. Possible explanations for such widely varying prevalence rates among different cultures and regions will also be discussed.