Migraine and Risk of Breast Cancer: A Systematic Review and Meta-analysis.

Migraine and breast cancer are 2 prevalent diseases with high morbidity and mortality rates world-wide. There have been inconsistent reports regarding the association between migraine and risk of breast cancer. This systematic review and meta-analysis aimed to assess the risk of breast cancer in patients with migraine. By December, 1, 2022, we searched PubMed, Web of Science, Scopus, and Cochrane Library databases. Odds ratio (OR), hazard ratio (HR), and 95% confidence intervals (CIs) were extracted or assessed to determine the pooled risk estimate using a random-effects model. We use the Newcastle-Ottawa Scale (NOS) to evaluate the quality of studies. We included 9 studies involving 393,282 participants. The pooled analysis showed that patients with migraine had a slightly low risk of breast cancer (OR 0.82, 95% CI, 0.72-0.94; P = .003), especially in case-control studies (OR 0.69, CI: 0.60-0.81, I = 74.1%, p < .001), and hormone receptor-positive breast cancer (OR 0.76, CI: 0.63-0.91; I = 88.6%; p = .003). Our findings demonstrate a slightly low risk of breast cancer, especially hormone receptor-positive breast cancer, in patients with migraine.