Hormone replacement therapy (HRT) for transgender people replaces the hormones naturally occurring in their bodies with those of the other sex. However, not all cases of hormone replacement therapy are used by transgender people. Some reasons for this include men who wish to have a hair-free body, as a result of less of the testosterone, androgen`s in their body.
Hormone therapy is the use of hormones in medical treatment. Treatment with hormone antagonists may also referred to as hormonal therapy.
Its purpose is to cause the development of the secondary sex characteristics of the desired gender. Some intersex people also receive HRT, either starting in childhood to confirm the gender they were assigned, or later, if this assignment has proven to be incorrect.
Hormonal therapy is one of the major modalities of medical treatment for cancer, others being cytotoxic chemotherapy and targeted therapy (biotherapeutics). Because steroid hormones are powerful drivers of gene expression in certain cancer cells, changing the levels or activity of certain hormones can cause certain cancers to cease growing, or even undergo cell death. Surgical removal of endocrine organs, such as orchiectomy and oophorectomy can also be employed as a form of hormonal therapy.
Hormonal therapy with natural hormones or bioidentical hormone replacement is used for several types of cancers derived from hormonally responsive tissues, including the breast, prostate, endometrium, and adrenal cortex. Hormonal therapy may also be used in the treatment of paraneoplastic syndromes or to ameliorate certain cancer. Perhaps the most familiar example of hormonal therapy in oncology is the use of the selective estrogen-response modulator tamoxifen for the treatment of breast cancer, although another class of hormonal agents, aromatase inhibitors, now have an expanding role in that disease.