Hormonal therapy — also called hormone therapy or androgen deprivation therapy — is a common treatment used to slow the growth of prostate cancer.

In this article, we’ll explain why it’s used, different types, possible side effects, and what to expect if hormone therapy stops working.

What’s Hormonal Therapy for Prostate Cancer?

Hormonal therapy for prostate cancer lowers or blocks androgens, a type of sex hormone. Testosterone and dihydrotestosterone (DHT) are the main androgens. Prostate cancer cells often rely on hormones to grow and spread. By reducing androgen levels in the body, hormonal therapy aims to slow the growth of prostate cancer.

Hormonal therapy is sometimes called “androgen deprivation therapy” or described using the term “castration.” While this word can sound alarming, in most cases it refers to lowering hormone levels with medications rather than surgery. Using hormone therapy helps people with prostate cancer slow its growth and shrink tumors.

What’s the Goal of Hormonal Therapy?

Hormonal therapy isn’t a cure for prostate cancer on its own. It can, however, play an important role in treatment.

The main goals of hormonal therapy are to:

• Slow tumor growth
• Shrink tumors
• Reduce symptoms caused by prostate cancer
• Lower the risk of cancer recurring (coming back) after other treatments
• Keep metastatic prostate cancer (cancer that has spread beyond the prostate) under control

For some people with advanced prostate cancer, hormonal therapy can help extend life. It may also improve quality of life by slowing cancer growth and managing symptoms.

When Is Hormonal Therapy Recommended?

Hormonal therapy is a common part of prostate cancer treatment. About 1 in 3 people with prostate cancer will receive hormonal therapy. However, not every person will need it. Doctors most often recommend it for people with:

• Prostate cancer that has spread beyond the prostate (metastatic or stage 4 prostate cancer)
• Prostate cancer that is considered high-risk (more likely to grow or come back)
• Cancer that has returned after previous treatment (recurrent prostate cancer)
• Cancer being treated with radiation therapy, to help improve outcomes

Hormone therapy is usually not recommended for earlier-stage or lower-risk prostate cancer. In these cases, surgery or active surveillance may be the only treatments needed.

Decisions about whether to use hormonal therapy depend on several factors, including:

• The stage of your cancer
• Your blood levels of prostate-specific antigen (PSA) after treatment
• Your overall health

Your care team can help explain your options and recommend the approach that is best for you.

When Does Hormonal Therapy Happen?

Hormonal therapy can be used at different points during prostate cancer treatment, depending on each person’s situation. It can be given:

• Before radiation therapy
• During radiation therapy
• After radiation therapy
• Instead of surgery
• After surgery, if cancer returns
• As the first treatment if the cancer is diagnosed at a later stage

The length of treatment with hormonal therapy can vary depending on your situation. Short-term hormonal therapy may last from two to four months. Long-term can continue for up to three years. For some people with metastatic prostate cancer, hormonal therapy may be continued indefinitely.

Using hormone therapy helps people with prostate cancer slow its growth and shrink tumors.

Some people with prostate cancer receive intermittent therapy. This means treatment is paused and restarted, based on the results of PSA blood tests. Other people may receive continuous therapy, which is given without breaks. Continuous therapy helps keep hormone levels consistently low, which can help slow cancer growth.

Based on your specific situation, your care team will recommend a treatment plan to fit your needs.

5 Types of Hormonal Therapy for Prostate Cancer

Hormonal therapy for prostate cancer comes in several forms. Each type of hormone therapy works to block androgens and slow the growth of prostate cancer.

1. LHRH Agonists

Luteinizing hormone-releasing hormone (LHRH) agonists are medications that lower testosterone over time. They tell the body to slow down the production of the hormone. Common examples include:

• Goserelin (Zoladex)
• Leuprolide (Lupron)
• Triptorelin (Trelstar)

These drugs are usually given as injections or implants each month or every three months, depending on the specific medicine. During the first few weeks of treatment, testosterone levels might increase temporarily. This is called a flare, and it may make cancer symptoms worse, especially in individuals with bone metastases. Over time, though, testosterone levels drop and help slow tumor growth.

2. LHRH Antagonists

LHRH antagonists work similarly to LHRH agonists. They lower testosterone production in the body. An example is degarelix (Firmagon). These medications are sometimes preferred by doctors because they don’t cause a testosterone flare like LHRH agonists. However, the side effects may be different or more severe compared to LHRH agonists.

3. Anti-Androgens

Anti-androgens block testosterone from reaching cancer cells, but they don’t lower overall hormone levels. An example is bicalutamide (Casodex). These medications can be used alone or may be combined with LHRH agonists or antagonists for a stronger effect. This combined treatment is known as a complete androgen blockade.

4. Androgen Synthesis Inhibitors

Androgen synthesis inhibitors stop the body from making testosterone. An example is abiraterone (Zytiga). Testosterone is made in many places in the body, like the adrenal glands and the prostate cancer tumor itself. Androgen synthesis inhibitors stop testosterone production in all of these places. They’re usually used for people with advanced or metastatic prostate cancer.

5. Orchiectomy

Orchiectomy is a surgical procedure that removes the testicles. It’s very effective, as the testicles are the main source of testosterone, but it’s rarely chosen today. Most people with prostate cancer prefer medication, as it offers a reversible way to reduce testosterone.

How Hormonal Therapy Works in the Body

Testosterone is a hormone that helps prostate cancer cells grow and survive. Hormonal therapy helps by lowering testosterone levels in the body or by blocking the hormone from reaching prostate cancer cells.

Hormone therapy is usually not recommended for earlier-stage or lower-risk prostate cancer.

When prostate cancer cells can’t get the hormones they need, the tumor may shrink or grow more slowly. Over time, however, some cancer cells can adapt and find ways to grow even when testosterone levels are very low. This is known as castration-resistant prostate cancer. For this reason, hormonal therapy isn’t a cure and may become less effective the longer it’s used.

The benefit of hormonal therapy is that it can be combined with other treatments to help control prostate cancer. Your care team will help determine how well hormonal therapy is working and discuss other treatment options if the therapy stops being effective.

Side Effects of Hormonal Therapy

Hormonal therapy lowers testosterone levels throughout the body, so it can cause a range of side effects.

Some of the most common physical side effects include:

• Hot flashes
• Fatigue (extreme tiredness that doesn’t improve with rest)
• Weight gain
• Lower muscle mass
• Lower sex drive
• Erectile dysfunction (difficulty getting or keeping an erection)

Hormonal therapy can also affect your bones, heart, and metabolism (how your body uses energy). These side effects can include:

• Osteoporosis (bone thinning)
• Heart disease or heart problems
• Changes in cholesterol levels
• Changes in blood glucose (sugar) levels

Some people experience emotional or cognitive (brain-related) side effects with hormonal therapy, such as:

• Mood changes
• Depression
• Anxiety
• Brain fog (feeling less clear-headed)
• Memory problems

Managing Side Effects

Many side effects of hormonal therapy can be managed with lifestyle changes. For example, regular exercise can help with fatigue, weight gain, muscle loss, and bone health. Balanced nutrition and good sleep habits can help with overall health and mood changes.

Medications and other supportive therapies may also be used to ease hot flashes, protect bones, or manage mood changes.

It’s important that you tell your cancer care team about your side effects as soon as you notice them. Your quality of life matters, and there are steps you can take to feel better.

What if Hormonal Therapy Stops Working?

Sometimes, prostate cancer adapts to low testosterone levels and continues to grow, even while you are receiving hormonal therapy. This is known as castration-resistant prostate cancer. Reaching this stage does not mean your treatment options are finished.

Many people with prostate cancer receive other effective treatments. These may include:

• Newer types of hormone therapy
• Chemotherapy
• Targeted therapy (drugs that attack specific cancer cells)
• Immunotherapy (treatments that help your immune system fight cancer)
• New medications or approaches through clinical trials

If hormonal therapy stops working, you still have options. Your oncology team can help you understand the next steps and recommend treatments based on your health, past treatments, and personal preferences.

Join the Conversation

On MyProstateCancerTeam, people share their experiences with prostate cancer, get advice, and find support from others who understand.

If you’ve been on hormonal therapy, what’s one thing you wish you’d known before starting? Share your experience in the comments below.