Hormone therapy in the menopause and breast cancer risk--a review.
OBJECTIVE
To evaluate the association between use of hormones in the menopause and breast cancer risk.


METHODS
A qualitative review of reports published between 1970 and 1995.


RESULTS
The risk of breast cancer starts to increase after 5 or more years of hormone use and remains elevated while taking hormones. Use for 10 or more years may be associated with a 30-80% increase in risk. From 2 to 5 years after stopping taking hormones, the risk seems to return to unity. There is no difference in risk between different types of oestrogens and the addition of progestins does not lower the risk.


CONCLUSIONS
Short term use (less than 5 years) seems safe with respect to breast cancer risk, while longer durations of use may be associated with a small, but significant increase in risk.
Ewertz
M
M
Danish Cancer Society, Division for Cancer Epidemiology, Copenhagen, Denmark.
D000328:Adult; D017677:Age Distribution; D000368:Aged; D001943:Breast Neoplasms / Q000453:epidemiology / Q000209:etiology*; D015914:Estrogen Replacement Therapy / Q000009:adverse effects; D004967:Estrogens / Q000009:adverse effects / Q000494:pharmacology / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008593:Menopause / Q000187:drug effects* / Q000502:physiology; D008875:Middle Aged; D017698:Postmenopause / Q000187:drug effects / Q000502:physiology; D011372:Progestins / Q000627:therapeutic use; D012307:Risk Factors; D013997:Time Factors
D004967:Estrogens; D011372:Progestins