Androgen deprivation therapy, also known as hormone therapy, involves reducing the flow of male hormones (androgens), especially testosterone, in the body. Since these hormones promote growth of the prostate and of prostate cancer, depriving the body of androgens usually slows the progression of the cancer.
Like chemotherapy, hormone therapy is normally used to combat prostate cancer when it has recurred following surgery or radiation or for patients who come to medical attention after the disease has spread. For some patients with higher-risk, localized prostate cancer, a six month or two year course of hormone therapy is used in conjunction with radiation therapy. About one-third of men diagnosed with prostate cancer receive hormone therapy.
Often, after some time, prostate tumors find ways to survive and grow without the same input of male hormones. However, hormone therapy does tend to slow the cancer’s spread and reduce or delay the onset of many symptoms of advanced cancer. It can also be combined with other therapies for a more comprehensive treatment. Hormone therapy has many possible side effects, ranging from sexual dysfunction to muscular weakness and bone density loss.
In the past, the standard way of conducting androgen deprivation therapy was to remove the testes, the organs inside the scrotum that produce most male hormones. Known as orchiectomy, the procedure is effective and simple, involving only one surgery. It is a viable option, but it is permanent, and tends to be infrequently chosen in the United States. Most men prefer alternative hormone therapy techniques, the effects of which are often more reversible. LHRH agonists, for example, interfere with the signals the body uses to initiate testosterone production. They will cause testosterone levels to massively increase for a very short period of time and then drop to almost nothing and remain there. Normally delivered by an injection, LHRH agonists may be taken at intervals from monthly to yearly (most often given at intervals of three to six months) depending on the specific drug and the dose. You may also receive anti-androgen therapy, alone or in combination with LHRH agonists. Anti-androgens prevent male hormones from binding with cancerous cells. Depending on your situation, you may undergo periodic hormone therapy sessions, then taper off and pick up again if your cancer comes back or starts to progress, or you may remain on hormone therapy indefinitely.
Androgen Deprivation Therapy and Radiation Therapy
Androgen deprivation therapy is given in conjunction with radiation therapy for men with high risk prostate cancer. For men with one or more high risk prognostic features (PSA > 20 ng/mL, Gleason score 8-10, or T3/4 disease) combining long-term androgen deprivation therapy typically lasting two years, with a full course intensity modulated radiation therapy is considered a standard of care treatment. Results from many large clinical trials completed over the last 30 years demonstrate improved cure rates when the two treatments are combined. For some men with intermediate risk prostate cancer, a shorter course of hormones (4-8 months) can be combined with radiation therapy