Background: Age is one of the strongest risk factors for breast cancer. Measures of biological age based on DNA methylation have gained popularity for their strong association with risk of many diseases, including cancer, which may help to identify high-risk subgroups for targeted prevention.
Methods: We carried out a systematic review of prospective studies that examined the association of methylation-based markers of ageing with risk of invasive breast cancer in healthy (breast cancer-free) women, published up to May 2023.