Effect of hormone replacement therapy on breast cancer risk: estrogen versus estrogen plus progestin
A study published in the Journal of the National Cancer Institute in 2000 (PMID: 10675382) examined the effects of hormone replacement therapy (HRT) on breast cancer risk among postmenopausal women aged 55-72. The analysis of 1,897 breast cancer cases and 1,637 controls found that combined HRT (estrogen plus progestin) increased