The prostate is a walnut-sized gland that is situated just beneath the bladder in men. This gland produces the fluid that carries sperm in semen.
Facts and figures of prostate cancer
Prostate cancer is the most common male cancer in the UK, accounting for 25% of all new male cancers.
Age-related, the incidence rises sharply from 50 years of age with the highest incidence in those 75-79 years and higher incidence in men of Afro-Caribbean descent.
Risk factors include a first or second-degree relative diagnosed with prostate cancer, a mother having breast cancer, BRCA2 gene mutation, a diet high in calcium, prostatitis and having had a vasectomy. 95% of prostate cancers are adenocarcinomas and many will cause no problems.
Post mortems on male patients dying of unrelated causes have shown that 75% of these patients have some evidence of prostate cancer. An enlarged prostate, a condition is known as benign prostatic hypertrophy (BPH) is common in older men but will not necessarily become malignant; however, some symptoms will be similar.
Symptoms and signs of prostate cancer
- In early stage disease, there may be no symptoms.
- Sometimes detected following blood tests if prostate specific antigen (PSA) test requested, although this is not conclusive of prostate cancer as the PSA can be raised due to other factors such as urinary infections.
- Urinary frequency, particularly at night.
- The urgency to pass urine.
- Difficulty and /or pain on passing urine.
- Blood in the urine or semen (rare).
Prostate cancer diagnosis
A GP can do a physical examination to check for an enlarged prostate or recommend a prostate specific antigen test (PSA).
Investigations may include:
- Blood tests (will include prostate specific antigen – PSA).
- Rectal examination.
- Ultrasound scan.
- Needle biopsy.
- CT scan.
- MRI scan.
- Bone scan (not routine).
Metastases occur when cancer cells break off and spread through the lymphatic channels or blood vessels to settle in other parts of the body. With prostate cancer, it typically spreads to the bones.
Prostate cancer treatment
Depends on several factors:
- Symptoms and impact on quality of life.
- Cancer cell type (Gleeson score).
- Stage of cancer.
- Age and general health.
Monitoring (watchful waiting and active surveillance)
Most prostate cancers develop very slowly and in some cases do not cause any problems, therefore it may be inappropriate to actively treat these patients, consequently avoid long term side effects which can impact on the patient’s quality of life.
Watchful waiting may be undertaken for locally advanced or metastatic cases that are symptomless and involves keeping treatments in reserve to control the disease if required at a later date. These patients may have blood tests and examinations and possibly a bone scan but would not usually have prostate biopsies.
Active surveillance involves regular PSA blood tests, rectal examinations and prostate biopsies at 12 monthly intervals and would be used for localised tumours.
If the tumour starts to develop on active surveillance or is thought to be intermediate/high risk localised disease,surgical removal of the prostate (prostatectomy) may be advised.
Localised disease is defined by the tumour being contained within the capsule covering the prostate gland. If possible surgeons will try to avoid damage to the nerve bundles around the prostate to preserve potency.
External radiotherapy may be advised for patients with high-risk localised or locally advanced disease.
Locally advanced disease is defined as the tumour having broken through the capsule but has not spread to other parts of the body. In cases of localised disease, there is around a 66% cure rate with radiotherapy. It can be used as an alternative for patients not fit for surgery or who have declined surgery.
Post-operative radiotherapy might be recommended if there is thought to be a risk of recurrence at surgery.
Radiotherapy can have long-term side-effects due to the proximity of the prostate in relation to bowel, bladder and nerves. However, the use of Intensity modulated radiotherapy (IMRT) has proved to increase the effectiveness of treatment by enabling the disease to be targeted very accurately hence reducing dose to healthy tissue and reducing side effects.
Image guided radiotherapy (IGRT) also enables the radiotherapy to be precisely delivered to the intended area which reduces potential radiation dose to healthy tissues by allowing the radiography team to monitor organ position and ideally adapt the patient position on a daily basis to ensure precision.
Internal radiotherapy (brachytherapy) can be used in some cases of localised disease thought to be of low/intermediate risk. This may be the implantation of small radioactive seeds into the prostate, which slowly release a low dose of radiation over a few months or high dose brachytherapy (HDR) where a radioactive wire is inserted into thin tubes that have been put into the prostate.
The HDR procedure takes about 2 hours and is likely to be followed by a course of external radiotherapy. Radiotherapy is often used if the disease has spread to other parts of the body, particularly bone secondaries for pain control.
The purpose of hormone therapy is to either stop the production of testosterone (this occurs in the testicles) or block the effects of it as prostate cancer depends on this to be able to develop.
It may be prescribed for early prostate cancer to reduce the risk of recurrence after surgery or radiotherapy or in advanced cases to either shrink the tumour or slow the progression of it and relieve symptoms, sometimes hormones only are a suitable treatment.
In cases of locally advanced prostate cancer, particularly before radiotherapy (neo-adjuvant therapy), hormones may be given to reduce the size of the prostate and increase the effectiveness of treatment (this is usually for a minimum of 3 months).
In very few cases now, patients will have the testicles removed (orchidectomy) which results in no further production of testosterone.
Chemotherapy is mainly used to treat the disease that has spread to other parts of the body and is not responding to hormone therapy.