The goal of hormonal therapy is to eliminate and/or inhibit the activity of any male hormones (primarily testosterone) that may fuel the growth of cancer from within the body. Hormonal therapies are classified as either androgen deprivation therapy (ADT) or secondary hormonal therapy.
Androgen Deprivation Therapy (ADT)
There are three types of ADT:
- Surgical castration (orchiectomy): This involves surgical removal of the testicles, which secrete testosterone, a hormone that can potentially stimulate prostate cancer growth. This is the simplest form of ADT.
- Medical castration (LHRH agonist and LHRH antagonist): This involves the use of medications that block your body from making testosterone, which may encourage growth of prostate cancer. These agents are given by injection on a scheduled basis.
- Antiandrogens: Medications used to augment the effects of surgical or medical castration. These agents are provided as oral tablets and block the activity of testosterone in the body.
The most common side effects associated with androgen deprivation therapy include hot flashes, decreased libido, erectile dysfunction, and increased bone fracture risk. Additional, less specific effects include fatigue, increased risk of diabetes and heart attacks/strokes, weight gain, cholesterol increase, decreased muscle mass, anemia, and memory loss.
Secondary Hormonal Therapy
Secondary hormonal therapy is a different type of hormonal therapy, used in patients who experience a cancer relapse despite being on primary ADT. These medications may be given orally, injected, or infused. Patients who receive secondary hormonal therapy generally continue their primary ADT as well. Examples of secondary hormonal therapy include estrogens (diethylstilbestrol), ketoconazole, and androgen receptor signaling inhibitors (abiraterone acetate and enzalutamide).
Use of diethylstilbestrol (DES) is associated with cardiovascular complications, including blood clots and heart attack. Ketoconazole is associated with fatigue, abdominal pain, hepatotoxicity, and nausea; abiraterone may cause shortness of breath, low potassium, and edema; enzalutamide may cause muscle pain, diarrhea, and edema.