The risk of breast cancer linked to menopausal hormone therapy.

Results. 226 (26 %) of the women were using hormone replacement at the time of the survey. The average time of use was ten years. Current users had a higher risk of breast cancer than never-users: adjusted OR 2.1 (95 % CI 1.5 – 3.0). The use of combination therapy for more than five years resulted in the highest risk: OR 3.0 (95 % CI 1.9 – 4.7). Earlier use of oestrogen products did not result in a higher risk. Neither oestradiol nor tibolone caused a statistically significant increase in risk. 232 cases of breast cancer (17 %) in women aged 45 – 64 could be attributed to the use of hormones.