Postmenopausal hormone replacement therapy and cancer of the female genital tract and breast.

Taking into account data from recent case-control and cohort studies, this review addresses anew the controversial issue of a possible relationship between hormone replacement therapy and an increased risk of female cancer. The adequate addition of a progestogen reduces considerably the significantly increased risk of endometrial cancer seen in current and in past long-term estrogen replacement therapy (ERT) users. However, a small risk increase might still be present with combined estrogen-progestogen replacement therapy (EPRT), and with low-dose continuous combined treatment. Whether long-term hormone replacement therapy increases the risk of breast cancer remains controversial. All four recent case-control studies report a small, marginally significant risk increase of about 20-30%, while two recent cohort studies are very reassuring. Sequential addition of a progestogen does not seem to influence breast cancer risk. Unfortunately, no data are available on the both practically and theoretically interesting option of continuous combined hormone replacement therapy. It can be concluded from the present data that hormone replacement therapy can be safely prescribed for periods of less than five years to women with climacteric symptoms. Short-term hormone replacement therapy for climacteric complaints in women who have been treated for the above-mentioned cancers should not be considered to be absolutely contraindicated as the available but scanty new data do not indicate any detrimental effect in such women.