Management of Castration-resistant Prostate Cancer
If you have been diagnosed with castration-resistant prostate cancer, your doctor will recommend a care pathway to manage your symptoms and allow you to live longer. It is important to remember that castration-resistant prostate cancer cannot be cured.
Castration-resistant prostate cancer can be managed with:
- Anti-androgen therapy
- Oestrogen therapy
- Adrenolytic agents
- New hormonal agents
- Radiation therapy
Because castration-resistant prostate cancer still responds to androgens, your doctor will recommend to continue hormonal treatment to keep the levels of testosterone low.
Additional treatment with anti-androgen therapy
When you have been treated with either surgical or chemical castration, your doctor may recommend additional treatment with anti-androgen therapy. The most common anti-androgen drug to manage castration-resistant prostate cancer is bicalutamide. Treatment with this drug aims to slow down the growth of the tumour. It will not relieve your symptoms. Side effects may include swelling of the breasts and liver problems.
Stopping anti-androgen treatment
If you have been treated with LHRH agonists or antagonists in combination with anti-androgen therapy, your doctor may recommend to stop taking the anti-androgen drugs. This approach may lower the level of PSA in your blood for a few months. The effect will be seen 4-6 weeks after you stop taking the drugs.
Drug therapy with the hormone oestrogen can slow down the growth of the tumour and lower the level of PSA in your blood, without affecting your bones. This treatment can cause cardiovascular disease, including blood clots and heart attacks. Because of these risks, oestrogen therapy is rarely recommended today.
After castration, the adrenal glands continue to produce small amounts of androgens. Adrenolytic agents stop the adrenal gland from producing the hormones. Side effects of these drugs are diarrhoea, itching and skin rashes, fatigue, erectile dysfunction, and liver damage. These drugs are not commonly used.
Hormonal therapy with abiraterone acetate
The body needs an enzyme called CYP17 (17α-hydroxylase) to produce testosterone. CYP17 is found in the testicles, adrenal glands, and prostate cancer cells. The new hormonal agent abiraterone acetate blocks CYP17 so that no testosterone is produced.
Treatment with abiraterone acetate aims to slow the growth of the tumour and metastases. It may allow you to live longer and with fewer symptoms.
The most common side effects of abiraterone acetate include fatigue, lower levels of potassium in the blood, high blood pressure, swelling or discomfort of the joints, and swelling caused by fluid retention.
While taking abiraterone acetate you may become tired and feel out of breath because of lower levels of red blood cells. Other changes to the blood may cause a fast, pounding, or irregular heartbeat, increased thirst and loss of appetite, nausea or vomiting, or fast weight gain.
Abiraterone acetate is taken twice a day as a tablet, and always used in combination with the steroid drug prednisone. Discuss with your doctor if abiraterone acetate is an option for you.
Hormonal therapy with enzalutamide
Prostate tumours need androgen receptors to grow. Enzalutamide is a new hormonal agent that blocks androgen receptors. It aims to lower the level of PSA in the blood and slow down the growth of the tumour. Unlike abiraterone acetate, you do not need to take additional steroids while taking enzalutamide.
The most common side effects of enzalutamide are a feeling of weakness, back pain, and fatigue.
Immunotherapy is a type of treatment that uses your own immune system to fight the tumour cells. In prostate cancer the drug Sipuleucel-T is used as immunotherapy. Because your own blood is used to prepare the drug, you need to get blood drawn before the procedure.
Immunotherapy is administered through an IV, in an outpatient setting at the hospital or clinic. You need to go to the hospital 3 times every 2 weeks to get treated. If effective, immunotherapy will allow you to live longer, and slow the growth of the tumours. It will not lower the level of PSA in your blood. Common side effects can include fever, fatigue, nausea, and headache.
Chemotherapy with docetaxel
Chemotherapy is a type of cancer treatment that uses chemicals to destroy cancer cells. Chemotherapy drugs can be injected into the bloodstream to attack cells throughout the body. They can also be applied directly to the tumour.
Your doctor may recommend the chemotherapy docetaxel to manage castration-resistant prostate cancer. The drug relieves pain caused by the tumour or metastases. If effective, it allows you live longer and with fewer symptoms and side effects.
Docetaxel is administered through an IV in an outpatient setting at a hospital or clinic. The treatment lasts 1 hour and it is usually repeated 10 times, once every 3 weeks. During the course you will take the steroid drug prednisone, which generally comes as a pill. You need to take prednisone twice a day for 5-10 cycles.
Docetaxel may cause side effects. Many of these are mild and can be managed at home. Side effects of docetaxel may include:
- Lower levels of white blood cells
- Hair loss
- Fluid retention
- Allergic reactions
- Nail changes
- Loss of appetite
Treatment after chemotherapy
After you have been treated with docetaxel, your doctor can recommend treatment with hormonal therapy or another chemotherapy drug. The main hormonal treatments are abiraterone acetate and enzalutamide. Cabazitaxel is the chemotherapy drug most commonly used in these cases. You could also receive a second course of docetaxel. Your doctor will discuss the different treatment options to find the best one for you.
If your treatment with docetaxel was ineffective, your doctor may recommend hormonal treatment with abiraterone acetate. If effective, this drug can relieve pain, lower the level of PSA in the blood, slow the growth of the tumour and the metastases, and allow you to live longer.
Side effects of the treatment include fatigue, lower levels of potassium in the blood, high blood pressure, swelling or discomfort of the joints, and fluid retention. Abiraterone acetate is always administered in combination with the steroid drug prednisone to manage the effects the drug can have on your blood pressure.
Your doctor may recommend hormonal treatment with enzalutamide. If effective, this drug can lower the level of PSA in the blood, slow the growth of the tumour and the metastases, and allow you to live longer.
Possible side effects of the treatment are a feeling of weakness, back pain, diarrhoea, and fatigue.
If docetaxel was not effective, your doctor may recommend treatment with the chemotherapy drug cabazitaxel. If effective, cabazitaxel will relieve pain, lower the level of PSA in your blood, slow the growth of the tumour and metastases, and allow you to live longer.
The side effects of cabazitaxel include a severe drop in white blood cells, and diarrhoea. Your doctor will recommend medication to manage these effects.
Discuss with your doctor which type of treatment after docetaxel is best for your individual situation.
Castration-resistant prostate cancer can be managed with radiation therapy. The radiation damages and kills cancer cells. The treatment will help to relieve pain and may allow you to live longer. Common side effects are a burning sensation when you urinate, urinary frequency, and anal irritation.
Treatment of bone metastases
Bones that are affected by tumours fracture more easily. If you are at risk of bone fractures, your doctor may recommend drugs to stabilize your bones. The most common drugs are bisphosphonates and denosumab. These drugs will help postpone the complications caused by bone metastases. Bone metastases can also be treated with radiation therapy.
Bisphosphonates are administered with an IV every 4 weeks. They increase your bone mass, and can postpone the complications caused by bone metastases. The most effective bisphosphonate in prostate cancer is zoledronic acid. This drug can cause kidney damage.
Denosumab is administered under the skin every 4 weeks. It also increases bone mass but generally causes fewer side effects than bisphosphonates. Denosumab may cause low calcium levels in the blood.
Because these drugs can damage your jaws, your doctor will advise you to see a dentist before you start treatment.
Radiation therapy for bone metastases
Bone metastases from prostate cancer can be managed with radiation therapy. The treatment will help to relieve pain and may allow you to live longer.