What is endocrine therapy for prostate cancer?

Endocrine therapy (hormone therapy), also previously known as androgen deprivation therapy or androgen suppression therapy, is the treatment of prostate cancer by eliminating, blocking, or adding hormones.

Therapeutic drugs

Prostate cancer cells need androgens (such as testosterone) for “nutrition” to grow, and anti-androgen therapy can temporarily or permanently reduce and block the synthesis of androgens.

Endocrine therapy can be administered by injection or orally. The drugs block testosterone synthesis in the testes and protect prostate cells from other androgens that remain in the body. Endocrine therapy includes:

  • Anti-androgen drugs: Blocking androgen binding to receptors, including steroids and non-steroids.
  • Drugs that lower testosterone levels: including luteinizing hormone-releasing hormone (LHRH) analogs or agonists; androgen biosynthesis inhibitors (which block androgen synthesis by testicular, adrenal, and prostate cancer cells).
  • Use of combination hormone therapy that reduces testosterone synthesis in the testes as well as the adrenal glands.
  • Endocrine therapy also includes surgical removal of the testes (orchiectomy), which synthesize testosterone, thus preventing androgens from further stimulating the growth of prostate cancer.

    Timing of treatment

    If the tumor has spread beyond the prostate, endocrine therapy is used primarily, but endocrine therapy does not cure the cancer; it aims to slow its progression and improve quality of life while extending survival time.

    If the patient does not respond to the initial endocrine therapy, the doctor may try switching to other endocrine therapy drugs first and consider chemotherapy second.

    Population indicated

    Endocrine therapy is indicated for patients with varying degrees of progression of prostate cancer. It is often used for patients with prostate cancer who want better outcomes after surgery or radiation therapy or who do not want to undergo other treatment modalities, for patients with advanced prostate cancer, and for patients who are on neoadjuvant endocrine therapy before radical prostatectomy or radical radiation therapy.

    Pre-treatment consideration needs to be given to the patient’s quality of life, the cost of treatment, and the efficacy and safety of endocrine therapy in specific cases.