Society for Neuroscience Jun 8 2026 Most breast cancers are worsened by estrogens. To combat the recurrence of these cancers, clinicians treat patients with inhibitors for estrogen production, like letrozole. But many patients do not adhere to this treatment due to negative side effects. Preclinical work in rodents suggests that a drug called 10β,17β-dihydroxyestra-1,4-dien-3-one (DHED), which delivers estrogen only to the brain, may be an effective, safe way to reduce these side effects. New