Are the progestins responsible for breast cancer risk during hormone therapy in the postmenopause? Experimental vs. clinical data.

摘要: Evidence is increasing suggesting that adding progestins to estrogen replacement therapy may be more harmful then beneficial, however it debatable whether all act equally on breast epithelial cells. Experimental data with the comparison of various in same vitro model present a rather high evidence there differences between regarding cancer risk. Especially concern differentiate primary and secondary risk i.e. benign malignant The epidemiological studies especially Women's Health Initiative (WHI) trial, so far only prospective placebo-controlled interventional study, demonstrate an increased under combined estrogen/progestin therapy, but they have limitations up now cannot discriminate mostly due too small or not comparable patient numbers subgroups progestins. However, natural progesterone, possibly also transdermal usage synthetic progestins, avoid risk, this must proven further clinical trials.