Recent research indicates that unopposed estrogen therapy may lower the risk of developing young-onset breast cancer (diagnosed before age 55), while long-term use of estrogen plus progestin therapy is correlated with an increased risk. In a comprehensive analysis of data from nearly 460,000 women across multiple regions, the study found that 15% of participants used hormone therapy. Notably, unopposed estrogen therapy showed a significant risk reduction for long-term users and those who started treatment before age 45. In contrast, estrogen plus progestin therapy was linked to higher breast cancer risks, especially for specific subtypes. Findings suggest critical implications for hormone therapy recommendations among younger women.

Source: The Lancet Oncology