NIH

Hormone therapy: A double-edged sword for younger women?

July 2, 2025

Results of a large-scale NIH study showed that hormone therapy may significantly influence breast cancer risk in women <55 years of age. Analyzing data from over 459,000 women globally, researchers found that unopposed estrogen hormone therapy (E-HT) was associated with a 14% reduction in breast cancer incidence, particularly when initiated earlier or used longer. In contrast, estrogen plus progestin therapy (EP-HT) was linked to a 10% increased risk, rising to 18% with use beyond two years. Notably, the elevated risk with EP-HT was more pronounced in women who hadn't undergone hysterectomy or oophorectomy. The findings underscore the importance of tailoring hormone therapy decisions based on individual surgical history and risk profiles.

Source:

(2025, June 30). NIH. Breast cancer risk in younger women may be influenced by hormone therapy. https://www.nih.gov/news-events/news-releases/breast-cancer-risk-younger-women-may-be-influenced-hormone-therapy