Prostate cancer is one of the most common cancers, affecting around 1 in every 10 men. It is a malignancy of the prostate gland, a walnut-sized structure that produces semen. The prostate is located near the bladder and rectum and surrounds the urethra, the tube that carries urine from the bladder.
Prostate cancer tends to grow slowly, with many decades passing between the first microscopic changes and the tumour becoming large enough to produce symptoms.
Symptoms of prostate cancer
In men with prostate cancer, symptoms tend to occur only when the tumour has grown large enough to exert pressure on the bladder and urethra. The prostate naturally enlarges in middle-age so many men will experience symptoms even if they do not have cancer.
Any of the following symptoms should be reported to a physician: Frequent urination, especially at night; inability to urinate; trouble starting or stopping urination; a weak or interrupted flow; pain or burning while urinating; blood in the urine or semen; painful ejaculation; or pain in the lower back, pelvis, or upper thighs.
Diagnosis
The long asymptomatic period makes prostate cancer suitable for screening, which involves testing men for a substance in the blood called prostate-specific antigen (PSA). Raised PSA levels indicate that something is wrong with the prostate gland, although not necessarily cancer. By catching problems at an earlier stage, screening allows treatment to be started sooner, when it is most likely to be effective. However, there is an ongoing debate regarding the benefit of routine screening for all men.
If a physician thinks someone is at risk of prostate cancer, because of symptoms or raised PSA levels, he or she will feel the prostate gland via the rectum to assess its size, shape, texture, and tenderness. However, a definite diagnosis of prostate cancer requires a biopsy, in which a small amount of tissue from the gland is removed and examined under a microscope. If this returns a positive result then further tests and scans are necessary to see whether or not the cancer has spread to other parts of the body.
Recognised treatments
There are many different ways of treating prostate cancer, including drugs, surgery, radiation therapy, or simple surveillance. Each of these approaches has benefits and risks that differ according to tumour characteristics (e.g., how big it is, how fast it is growing, whether it has spread) and the patient’s age, general health, and lifestyle.
If the tumour has not spread outside the prostate gland it is known as “localised” prostate cancer. If it has spread to tissues just outside the prostate it is called “locally advanced”. If it has spread to other parts of the body e.g. the bones it is known as “advanced” prostate cancer.
The best treatment option can therefore only be decided after thorough medical assessment and a full and frank discussion with the patient. For most patients there are several reasonable options so seeking a second opinion is often useful.
There are a number of treatment options depending on how early or late the cancer is diagnosed. These include: - Watchful waiting (also called wait-and-see, observation, or surveillance) is commonly used in older men without symptoms whose tumours are small and slow-growing. They are examined regularly and instructed to report any new symptoms to the doctor immediately.
- Surgery, in which all or part of the prostate gland is removed under general anaesthetic. The operation sometimes involves cutting the nerves needed for an erection; nowadays, better surgical techniques mean that many tumours can be removed without causing impotence.
- Radiation therapy, which uses high-energy X-rays to kill the tumour cells. Radiation may be beamed from a machine through the body to reach the prostate, or given internally via tiny radioactive seeds (brachytherapy) implanted directly into the prostate gland. Conformal radiation therapy uses sophisticated computer software to direct radiation beams into the prostate without affecting nearby normal tissue.
- Hormonal therapy, which aims to remove the source of male hormones (e.g., testosterone) that encourage tumour growth. This can be achieved through surgery to remove the testicles (castration or orchiectomy), which are the main source of testosterone. Alternatively, a variety of drugs can be used e.g. luteinizing hormone releasing hormone agonists (LHRHa’s) to cut off the supply of male hormones (medical castration) or antiandrogens to block the effects of male hormones in the body.
- Chemotherapy , which is the use of powerful medicines to kill the cancer cells in men whose tumours have stopped responding to hormonal therapy. More information on chemotherapy
Dependent on the type and stage of the prostate cancer, these treatment options may be combined or used in sequence e.g. - Neoadjuvant hormonal therapy involves starting drugs as soon as possible after diagnosis, to help shrink tumours before surgery or radiotherapy.
- Adjuvant hormonal therapy involves using drugs with or after surgery or radiotherapy to help ensure that any remaining cancer is destroyed.
Other treatments
A variety of other treatments for prostate cancer are either not widely used, are of uncertain benefit, or as yet unproven:.
Cryosurgery is one experimental approach, in which liquid nitrogen is injected directly into the prostate gland to freeze and kill the cancer cells.
Photodynamic (light) therapy, gene therapy, cancer vaccines, drugs to stop the tumour growing blood vessels, and high-frequency ultrasound are also being investigated.
Side Effects
None of the above treatments are free from possible side effects. The type and nature of these will vary and are dependent on the treatment used. The possibility of side effects should be discussed with your doctor.
The importance of maintaining a positive outlook
If you or a loved one has been diagnosed with prostate cancer there are many reasons to be hopeful. Scientific research in the past decade has yielded many effective treatments for prostate cancer, meaning that most men will survive for many years following their diagnosis and will enjoy a good quality of life.
In most cases, prostate cancer is very slow growing, and many, if not most, patients will live with the cancer until they eventually die of some other natural, unrelated cause. The majority of patients with localised prostate cancer (cancer which has not spread to other parts of the body) can live for a long time after diagnosis: 85% of all prostate cancers are diagnosed before the cancer has spread to other parts of the body and the 5-year survival rate for patients who are diagnosed in these early stages of the disease is 100%.
New therapies are being developed all the time, many of which have shown promise in preliminary testing and will hopefully improve the lives of men with prostate cancer yet further.
Further information:
The Prostate Cancer Charity
http://www.prostate-cancer.org.uk
Cancer Research UK
http://www.cancerresearchuk.org
CancerBACUP
http://www.cancerbacup.org.uk
American Foundation for Urologic Disease
http://www.afud.org
American Cancer Society
http://www.cancer.org
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