taken from Small Gland, Big Problem 4th Edition
by Professor Roger Kirby, Health Press 2011
Almost inevitably, cancers that initially respond to the hormonal treatments eventually begin to grow again (the diagram on the next page explains why this happens). This stage of prostate cancer is often referred to as hormone-relapsed prostate cancer. The PSA value starts to rise again.
If you reach this stage, your doctor may recommend one of the following treatment options:
- modifying existing hormonal therapy by adding or withdrawing anti-androgen
- cytotoxic chemotherapy (drugs that destroy the cancer cells)
- hormone therapy (this is different from that discussed earlier)
- another form of treatment that aims to prevent stimulation of further growth of the cancer.
Cytotoxic chemotherapy is an option, but the drugs used can have side effects, such as sickness and hair loss. Improvements to therapy mean these are less frequent these days. Increasingly effective chemotherapy drugs are now available, so if your doctor discusses this with you, ask what side effects you might expect and whether it is possible to counter them effectively. Oncologists rather than urologists are experts in this area.
So what is the point of these drugs? It is possible that chemotherapy might give you an extra few months or even years, and if the side effects are minimal or can be overcome, you might feel that this option is worthwhile, particularly as they have also been shown to improve symptoms and quality of life. Medications given intravenously in 3-weekly cycles, such as Taxotere (docetaxel), have been shown to improve survival rates. Taxotere given every 3 weeks may result in a sharp reduction in PSA values as well as an improvement in quality of life. Side effects include nausea, vomiting, hair loss and a reduction in the white cell count in the blood, known as leucopenia – your urologist and oncologist will be able to discuss the latest treatments with you and organize treatment in an oncology centre. A second-line chemotherapy agent, cabazitaxel, has just been approved for use in the USA and Europe and can be used when Taxotere begins to lose its effectiveness.
Oestrogens, female hormones, may offer some benefit at this stage of your disease. They appear to be able to reduce stimulation of cancer growth and they may also damage the cancer cells directly. The reason that oestrogens are not used in earlier disease is that they can have some potentially serious side effects, such as nausea, blood clots and other cardiovascular complications, such as heart attacks or even strokes. Many doctors advise that you take a low dose of aspirin (75 mg) if you take oestrogen-based drugs, in order to to help overcome the potential cardiovascular side effects. Oestrogens should not be used if you have previously had problems with deep vein thrombosis, pulmonary embolism or heart failure.
There are a number of so-called ‘growth factors’ in the body that stimulate the progression of prostate cancer. Blocking the action of these growth factors should potentially block their stimulatory effects on the cancer. However, the drugs that are being developed with this aim are very new and are still under investigation. Angiogenesis inhibitors such as Avastin (bevacizumab) have already been mentioned (see page 33); immunotherapy with Provenge (sipuleucel-T) holds considerable promise (see pages 71 and 72), although it is very expensive and not available in the UK at the time of writing. Again though, if you do eventually reach this stage, knowledge of the effects of these drugs may then be such that your doctor is able to prescribe them for you.
Abiraterone. A new drug, abiraterone, has been developed at the Royal Marsden Hospital, London. It is a hormone therapy that blocks an enzyme involved in the production of testosterone. At the time of writing the regulatory authorities have not approved it for use in patients, but early results are encouraging. It can be given orally but it does have side effects and has to be combined with a steroid such as prednisolone. Current studies have involved a small number of men with very advanced disease. The role of abiraterone in the treatment of earlier stage prostate cancer is not clear, but more studies are planned.
Palliative care aims to provide you with support to make you feel free from pain, comfortable and composed in the final stages of the illness. Over recent years, considerable progress has been made in this area, and medical opinion now holds that no patient need feel the pain or discomfort that was characteristic of the last stages of cancer in bygone years. If your cancer progresses to this stage, you will usually be assigned a palliative care team – specialist doctors and nurses who have considerable expertise and experience in this area, and who will support you and your family. You will have opportunities to talk to members of the team about your care, and you should discuss any medical, social or financial worries that you have. Macmillan and Marie Curie nurses can be very helpful and will visit you at home.
Patients with very advanced prostate cancer tend to experience bone pain, and you may be given strong and effective painkillers to help overcome this. In addition, you might have radiotherapy (either as a short course or a one-off). Another effective method of alleviating bone pain is with injections of a radioactive substance known as strontium. If you are offered radiotherapy, make sure that you know whether it is likely to result in other side effects, such as nausea and tiredness, so that you can weigh up the advantages and disadvantages in the light of all the facts and your own circumstances. In this situation, the first consideration of the medical team should be to preserve your dignity and help your family and friends to support you, ideally in your own home. The palliative care teams are geared up to do just this.