The use of hormone replacement therapy in patients after breast cancer

Four prospective randomized studies and at least 15 observational studies investigating hormone replacement therapy (HRT) after breast cancer are available. Only the Hormonal replacement therapy After Breast cancer: Is iT Safe (HABITS) study shows an increased risk of relapse. This is probably associated with the relatively high number of patients with HRT treatment after estrogen receptor-positive cancers as well as to the preferred use of estrogen/progestin combined preparations. As is generally known, the progestin component especially seems to be mainly responsible for the probability of increased diagnosis frequency of breast cancer. However, the patient samples in all studies investigating HRT after breast cancer are small. Therefore, HRT should only be used if alternatives, such as specific not contraindicated phyto-preparations or serotonin reuptake inhibitors, are not working. This is primarily due to forensic reasons. According to medical criteria, the data for the alternatives seem to be even more sparse, since many important questions remain unanswered, such as side effects and risks, or also regarding interactions with adjuvant hormone therapy.