Timing and Type of Hormone Therapy Affect Breast Cancer Risk

British study suggests early initiation is riskier; findings on estrogen-only therapy contrast with WHI findings.

Hormone therapy (HT) initiated in recently menopausal women seems to lower risk for coronary artery disease and dementia (JW Womens Health Apr 8 2010 and JW Neurol Jan 4 2011). Now, U.K. investigators for the observational Million Women Study (MWS) have assessed whether timing of HT initiation affects breast cancer risk.

Compared with never use, initiation of estrogen-only HT within 5 years of menopause onset was associated with modestly elevated risk for breast cancer (relative risk, 1.43), whereas initiation ≥5 years after onset of menopause was not associated with excess risk for breast cancer (RR, 1.05). Initiation of combination estrogen-progestin HT within 5 years of menopause also was associated with greater risk (RR, 2.04) than was l…

Reviewing Author

Andrew M. Kaunitz, MD

Disclosures

RoyaltiesUpToDate

Grant/Research SupportMerck, Mithra, Medicines360

Editorial BoardsContraception; Menopause; Contraceptive Technology Update; OBG Management; Medscape OB/GYN & Women’s Health

Andrew M. Kaunitz, MD

Disclosures

RoyaltiesUpToDate

Grant/Research SupportMerck, Mithra, Medicines360

Editorial BoardsContraception; Menopause; Contraceptive Technology Update; OBG Management; Medscape OB/GYN & Women’s Health

Timing and Type of Hormone Therapy Affect Breast Cancer Risk

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Reviewing Author