Hormone therapy for metastatic prostate cancer
Hormone therapy, also known as anti-hormone therapy, is a frequently used treatment for metastatic prostate cancer. This type of cancer has spread from the prostate to other regions of the body, such as the bones.
The testicles
The testicles are two small, oval-shaped organs located below the penis, enclosed in a skin pouch called the scrotum.
Image of the testicles (cruk)
Starting from puberty, the testicles begin producing sperm. Inside the testicle, small tubes come together to form the epididymis, a single tube that becomes wider as it exits the testicle. This wider tube is known as the spermatic cord.
The spermatic cord leads to a short passage called the ejaculatory duct, which opens into the urethra, the tube that carries urine and semen out of the body through the penis.
Testosterone:
The testicles produce the hormone testosterone, which is responsible for developing male characteristics such as:- A deeper voice
- Facial hair growth
- Increased muscle mass
- The ability to achieve an erection
- Male sexual drive (libido)
Where does testicular cancer start:
The testicles consist of various cell types, and the kind of cancer you have depends on the specific cell where it begins. Most testicular cancers arise from germ cells, which are responsible for producing sperm. Doctors classify germ cell cancers into two main types:- Seminoma
- Non-seminoma
6.1:What is Hormone therapy:
Hormones are natural substances in your body that regulate the growth and function of normal cells. Testosterone, a male hormone primarily produced by the testicles, is one such hormone.
Prostate cancer often relies on testosterone for its growth. Hormone therapy works by either blocking or reducing the levels of testosterone in the body.
While hormone therapy doesn’t cure prostate cancer, it can control or reduce the cancer, alleviate symptoms, and improve your well-being and quality of life for a period of time.
6.2:When you might have hormone therapy:
Most men with metastatic prostate cancer undergo hormone therapy. Typically, you may receive:
– a combination of various hormone therapy drugs, or
– hormone therapy paired with chemotherapy, such as docetaxel.
Hormone therapy combined with chemotherapy is often highly effective in controlling metastatic prostate cancer for several months. However, the cancer can sometimes resume growth. If this occurs, your doctor might refer to it as castration-resistant prostate cancer, indicating that hormone therapy is no longer effective. In such cases, your doctor may recommend:
– switching to a different type of hormone therapy
– beginning a new type of treatment
6.3:Types of Hormone therapy:
There are three types of hormone therapy:
– Injections
– Tablets
– Surgery
Injections:
The injections function by interrupting the signals from a gland in the brain that instruct the testicles to produce testosterone.
Luteinising hormone-releasing hormone agonists (LHRH agonists or LH blockers)
The pituitary gland in the brain produces luteinising hormone (LH), which regulates the amount of testosterone produced by the testicles. LH blockers inhibit the production of luteinising hormone, thereby stopping the testicles from making testosterone.
Initially, the injections might worsen your symptoms, a phenomenon known as tumor flare. To prevent this, your doctor might prescribe an anti-androgen tablet such as bicalutamide. You usually take bicalutamide for the first 4 to 6 weeks of your hormone therapy.
Types of LH blockers include:
– Leuprorelin (Prostap): Administered every 4 weeks or 12 weeks
– Goserelin acetate (Zoladex): Administered every 4 weeks or 12 weeks
– Buserelin (Suprefact): Given as an injection 3 times a day for 7 days, followed by a nasal spray 6 times a day
– Triptorelin (Decapeptyl): Administered once a month, every 3 months, or every 6 months
Gonadotrophin-releasing hormone antagonist or GnRH blocker
This is an alternative type of hormone injection that interrupts signals from the hypothalamus, a part of the brain that instructs the pituitary gland to produce luteinising hormone (LH). Since LH stimulates the testicles to produce testosterone, GnRH blockers prevent testosterone production by the testicles.
Currently, Degarelix (Firmagon) is the only available GnRH blocker. The treatment begins with two injections on the same day, followed by one injection every month. This treatment does not carry the risk of tumor flare.
Tablets :
Hormone therapy pills are typically anti-androgen medications or the drug abiraterone.
Anti Androgen Tablets :
These pills prevent testosterone produced by your testicles from reaching the cancer cells. Some examples of anti-androgens are:
– Bicalutamide (Casodex)
– Flutamide (Drogenil)
– Enzalutamide (Xtandi)
– Apalutamide (Erleada)
– Darolutamide (Nubeqa)
Abiraterone Tablets :
Abiraterone, known by its trade name Zytiga, is a form of hormone therapy that inhibits the enzyme cytochrome p17. This enzyme is crucial for the production of testosterone by the testicles and other body tissues. Without it, testosterone can’t be produced.
Abiraterone is generally prescribed to individuals who have already undergone other hormone therapies or received docetaxel. It is administered as a daily tablet.
Surgery to remove the testicles (Orchidectomy):
Surgical removal of the testicles is not a common method for reducing testosterone levels.
This procedure is typically considered only if there’s an urgent need to lower testosterone, such as when cancer has spread to the bones and is putting pressure on the spinal cord, requiring a rapid reduction in testosterone levels.
Doctors may also recommend this surgery if you prefer not to undergo regular injections or take tablets.
Before you start Hormone treatment:
Before starting treatment, you will need to have blood tests. Your doctor will also conduct a physical examination and inquire about your symptoms.
Keeping a symptom diary can be beneficial. For instance, note if your bone pain worsens at night but improves with painkillers.
How often you have Hormone therapy:
Hormone therapy is typically administered continuously, but in some cases, it may be given for several months followed by a break, known as intermittent therapy.
Treatment options may include:
– A single hormone therapy drug
– A combination of two hormone therapy drugs
– Hormone therapy combined with chemotherapy, such as docetaxel
Your doctor will discuss the recommended hormone therapy options and the duration of treatment with you.
Checking your Hormone therapy is working:
Regular blood tests are conducted to monitor the levels of prostate-specific antigen (PSA), a protein produced by both normal and cancerous prostate cells. All men have small amounts of PSA in their blood unless the prostate gland has been entirely removed.
During your treatment, you may undergo various scans, such as CT, MRI, and bone scans, similar to those you had at diagnosis.
As long as hormone therapy is effective, PSA levels should remain stable or decrease. However, if the prostate cancer starts to progress, PSA levels may rise. This condition is often referred to as hormone-resistant or castrate-resistant prostate cancer. If this occurs, your doctor might need to adjust your treatment plan and will discuss the options with you.
When Hormone therapy stops working:
After a few months or years, hormone therapy often becomes less effective, and the cancer may begin to grow again. At this point, your doctor might suggest discontinuing or altering the hormone treatment.
If you are taking anti-androgens and your PSA levels start to increase, your doctor may advise you to stop the medication. Occasionally, this can lead to a temporary reduction in cancer growth, known as the anti-androgen withdrawal response.
When hormone therapy ceases to be effective, there are various treatment options available, including chemotherapy and steroids.
Side effects:
Hormone therapy side effects occur due to reduced testosterone levels. Many men experience more severe side effects at the beginning of treatment, but these typically ease after a few weeks or months.
Certain side effects are common across all hormone therapies for prostate cancer, while others depend on the specific medication. You may not experience all of these side effects. Discuss any side effects with your doctor or nurse, as they can often recommend ways to alleviate them and improve your comfort.
The primary side effects include:
– Difficulty achieving an erection (impotence)
– Hot flashes and sweating
– Fatigue and weakness
– Breast tenderness
– Tumor flare
Long-term treatment side effects are:
– Weight gain
– Memory issues
– Mood swings and depression
– Bone thinning (osteoporosis)
– Increased risk of heart failure
Daignosis
If you have any symptoms, your first step is usually to visit your GP. They will discuss your symptoms with you and conduct an examination. Based on their findings,
Treatment options
A team of healthcare professionals (multidisciplinary team) will determine your treatment plan. Most people undergo surgery to remove the affected