Breast cancer and hormone-replacement therapy in the Million Women Study

06 Aug 2003Million Women Study Collaborators,

Current use of hormone-replacement therapy is associated with an increased risk of incident and fatal breast cancer; the effect is substantially greater for oestrogen-progestagen combinations than for other types of hormone-replacement therapy.

Cohort Study
1 effect
5 years
1084110 subjects

Reported Outcomes

CausesOutcomeCertainty

Hormone Replacement Therapy Manufactured risk & protective factor

Breast Cancer Reproductive outcome
Increased risk of Breast Cancer
Reproductive system

High evidence
66.0%