Research

Hormonal

Users of unopposed estrogen were at increased risk of breast cancer after longer-term use.

Practitioners should consider the risks of long-term unopposed estrogen therapy in postmenopausal women.

GoodSupportsmedium confidence
Users of unopposed estrogen were at increased risk of breast cancer but only after longer-term use.
Wendy Y. Chen et al. · Archives of Internal Medicine · 2006

Why this rating

Based on a prospective cohort study design.

Source

Unopposed Estrogen Therapy and the Risk of Invasive Breast Cancer

Wendy Y. Chen et al. · Archives of Internal Medicine · 2006

DOI 10.1001/archinte.166.9.1027

cohort · n=28835Cited 249×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

This is one finding among thousands. Every one is graded and traced to its source, so you can see what the evidence actually supports. Browse the research →