Understanding Hormone Therapy for Prostate Cancer: a Guide for GPs

Prostate cancer remains one of the most prevalent cancers among men worldwide. In its advanced stages, hormone therapy, also known as androgen deprivation therapy (ADT), becomes a cornerstone of treatment. As a general practitioner, understanding the fundamentals of hormone therapy for prostate cancer is crucial in providing comprehensive care to your patients.

What is Hormone Therapy for Prostate Cancer?
Hormone therapy aims to reduce the levels of testosterone, as testosterone can stimulate the growth of prostate cancer cells. This therapy is administered 1, 3 or 6 monthly injections that either stop the production of testosterone in the testicles or block its effects on prostate cancer cells.

Indications for Hormone Therapy
Hormone therapy is typically recommended for:

• Advanced Prostate Cancer: commonly used when cancer has spread beyond the prostate gland or has recurred after initial treatment.
• High-Risk Prostate Cancer: In some cases, hormone therapy may be recommended alongside other treatments like radiation therapy, especially for high-risk prostate cancer cases.
• Palliative Care: Hormone therapy is often employed to alleviate symptoms and improve the quality of life in advanced stages of the disease.

Types of Hormone Therapy
There are several approaches to hormone therapy:

• Gonadotropin-releasing hormone (GnRH) agonists and antagonists are commonly used to suppress testosterone production in the testicles, may be continuous, or used intermittently (on therapy for ~12 months, then ceased till PSA rises again).
• Anti-Androgens: block the action of androgens on prostate cancer cells. They are often used in combination with GnRH agonists / antagonists.
• Orchidectomy: Surgical removal of the testicles reduces testosterone levels immediately and permanently, rarely used now.

Monitoring and Management
General practitioners play a crucial role in monitoring patients undergoing hormone therapy:

• Regular Follow-ups: Schedule regular follow-up appointments to monitor treatment response and manage side effects.
• Side-effect Management: Potential side effects such as hot flashes, loss of libido, osteoporosis, and mood changes, including irritability, anxiety and depression. Weight gain, lethargy and loss of muscle mass are also common.
• Bone Health: Assess bone health regularly and consider interventions such as calcium and vitamin D supplementation or bone-modifying agents to prevent osteoporosis.
• Cardiovascular Health: Monitor cardiovascular risk factors closely, as hormone therapy may increase the risk of cardiovascular events.

Psychosocial Support
Recognise the psychological impact of hormone therapy on patients, including concerns about body image, sexual function, and masculinity. Offer counselling and support services to address these issues.

Exercise
ADT is a cornerstone of treatment for advanced prostate cancer. General practitioners play a vital role in educating patients, monitoring treatment response, managing side effects, and providing psychosocial support. By understanding the principles of hormone therapy, GPs can contribute significantly to the holistic care of patients with prostate cancer.