Carcinoma of the prostate
Carcinoma of the prostate is the commonest malignant tumour in men over the age of 65 years. About 10—15 per cent of younger men who develop prostate cancer have a positive family history of the disease, but the aetiology is unclear. Carcinoma of the prostate usually originates in the peripheral zone of the prostate so ‘prostatectomy’ for benign enlargement of the gland confers no protection from subsequent carcinoma.
Types of prostate cancer
•Microscopic latent cancer found on autopsy or at cystoprostatectomy
•Tumours found incidentally during TURP (ha and Tlb); or following screening by PSA measurement — T1c
•Early, localised prostate cancer (T2)
•Advanced local prostate cancer (T3 and T4)
•Metastatic disease which may arise from a clinically evident tumour (T2, T3 or T4) or which may arise from an apparently benign gland (T0, T1), i.e. occult prostate cancer
Histological appearances:The prostate is a glandular structure consisting of ducts and acini; therefore the histological pattern is one of an adenocarcinoma. The prostatic glands are surrounded by a layer of myoepithelial cells. A classification of the histological pattern based on the degree of glandular de differentiation and its relation to stroma has been devised by Gleason; this (and the volume of the cancer) appears to correlate well with the likelihood of spread and of prognosis.
Local spread,Locally advanced tumours tend to grow upwards to involve the seminal vesicles, the bladder neck, trigone and, later, the tumours tend to spread distally to involve the distal sphincter mechanism.
Spread by the bloodstream occurs particularly to bone, the pelvic bones and the lower lumbar vertebrae. The femoral head, rib cage and skull are other common sites.
Lymphatic spread may occure.
Staging using the tumour, node, metastasis (TNM) system
1.T1a, T1b and T1c:these are incidentally found tumours in a clinically benign gland after histological examination of a prostatectomy specimen. T1a is a well or moderately well-differentiated tumour involving less than 5 per cent of the resected specimen. T1b is a poorly differentiated tumour or a tumour involving >5 per cent of the resected specimen. T1c tumours are impalpable tumours found following PSA screening
2.T2a disease presents as a suspicious nodule on rectal examination of <2 cm
T2b disease is a nodule involving greater than 2 cm
T2c is tumour in both lobes but still clinically confined
3.T3 is a tumour involving the seminal vesicles or bladder neck
4.T4 is a tumour involving the rectum or pelvic side wall
Clinical features:/Only advanced cases give rise to symptoms, but even advanced cases may be asymptomatic. Symptoms of advanced disease include:
•BOO;•pelvic pain and haematuria;• bone pain, malaise, ‘arthritis’, anaemia or pancytopaenia;• renal failure;• locally advanced disease or even asymptomatic metastases may be found incidentally on investigation of other symptoms.
Early prostate cancer is asymptomatic and it may be found:
• incidentally following TURP for clinically benign disease (T1);
• as a nodule (T2) on rectal examination.
Rectal examination :Examination under anaesthesia together with cystoscopy and needle biopsy or TRUS may be used to assess the local stage. Irregular induration, characteristically stony hard in part or in the whole of the gland — with obliteration of the median sulcus — suggests carcinoma.
General blood tests there may be leucoerythroblastic anaemia secondary to extensive marrow invasion or anaemia may be secondary to renal failure. There may be thrombocytopenia and evidence of disseminated intravascular coagulopathy with increased fibrinogen degradation products (FDPs).
Liver function tests:The alkaline phosphatase may be raised from either hepatic involvement or secondaries in the bone..
Prostate-specific antigen:The finding of a PSA >10 nmol/ml is suggestive of cancer and >35 ng/mI is diagnostic of advanced prostate cancer. A decrease of PSA to the normal range following hormonal ablation is a good prognostic sign.
Acid phosphatase has been superseded by measurement of PSA.
Radiological examination:X-ray of the chest may reveal metastases either in the lung fields or the ribs. An abdominal X-ray may show the characteristic sclerotic metastases in lumbar vertebrae and pelvic bones .
Ultrasonography:TRUS remains the most accurate method of staging the local disease.
Bone scan:Once the diagnosis has been established, it would be normal to perform a bone scan as part of the staging procedure if the PSA is >20 nmol/ml.
Lymphangiography:This is no longer carried out. If accurate information is required then pelvic lymphadenectomy can be performed by means of laparoscopic surgery.
Bone marrow aspiration:Sometimes examination of the bone marrow will reveal the presence of metastatic carcinoma cells
Treatment of carcinoma of the prostate:(The median survival of men with metastatic disease is about 3 years)
Prostatic biopsy:If there is suspicion of prostate cancer, because of either local findings, a raised PSA or metastatic disease, then a transrectal biopsy using an automated gun with appropriate antibiotic cover is indicated•a TURP can be performed which will provide diagnostic material and symptomatic relief;
•transrectal biopsy can be carried out. If the diagnosis is positive and there is locally advanced disease, then hormone ablation can provide good symptomatic relief without the need for operation.
Early disease:Curative treatment can only be offered to patients with early disease (T1a, Tlb, T1c and T2). The treatment of patients with advanced disease (T3, T4 or any MO) is only palliative.
Radical prostatectomy: is only suitable for localised disease (T1 and T2) and should only be carried out in men with a life expectancy of >10 years. Exclusion of metastases would -require a negative bone scan, chest X-ray and a serum PSA <20 nmol/ml.
Pelvic lymph node dissection is carried out immediately prior to radical prostatectomy when radical treatment is being considered.
Radical radiotherapy for early prostate cancer to the prostatic bed and pelvic lymph nodes rather than radical surgery has tended to be the treatment of choice in the UK for locally confined prostate cancer.
Advanced disease:Patients with local or general symptoms should be offered androgen deprivation.
Orchidectomy is performed to carry out androgen ablation in the treatment of locally advanced (T3 or T4) disease or of metastatic disease.
General radiotherapy for symptomatic metastases is an excellent form of palliative treatment
Strontium is now being employed as a bone-seeking isotope which delivers effective radiotherapy to metastatic areas.
Medical forms of androgenablation have been available since the discovery of stilboestrol.
The other commonly available treatment to reduce testosterone levels to the castrate range is LHRH agonists. it is wise to give flutamide, bicalutamide (Casodex) or Cyproterone acetate . LHRH agonists may be given by monthly or 3 monthly depot injection.
Other treatments have become available recently which block the androgen receptor. Cyproterone acetate also has some progestogenic effect, whilst flutamide and bicalutamide are pure antiandrogen. In general, oral monotherapy has not been shown to be as good as LHRH agonists or orchidectomy.
Cytotoxic agents in the treatment of these elderly men have proved disappointing, but whether this is because the tumour is inherently insensitive or because these elderly men will not tolerate effective doses is uncertain.
Prostatitis
In both acute and chronic prostatitis the seminal vesicles and posterior urethra are usually also involved.
Acute prostatitis/ is common, but underdiagnosed. The usual organism responsible is Escherichia coli, but Staphylococcus aureus and albus, Streptococcal faecalis and Neisseria gonorrhoea may be responsible. The infection may be haematogenous from a distant focus or it may be secondary to acute urinary infection.
Clinical features
The patient feels ill, shivers, may have a rigor, has ‘aches’ all over, especially in the back, and may easily be diagnosed as having influenza. The temperature may be up to 390C. Pain on micturition is usual, but not invariable. The urine contains threads in the initial voided sample which should be cultured. Perineal heaviness, rectal irritation and pain on defecation can occur; a urethral discharge is rare. Frequency occurs when the infection involves the bladder. Rectal examination reveals a tender prostate, one lobe may be swollen more than the other and the seminal vesicles may be involved. A frankly fluctuant abscess is uncommon.
Treatment / Spread of infection to the epididymes and testes may occur. Prolonged treatment with an antibiotic which penetrates the prostate well is indicated (trimethoprim or ciprofloxacin).
Prostatic abscess /The temperature rising steeply with rigors. Antibiotics disguise these features. Severe, unremitting perineal and rectal pain with occasional tenesmus often cause the condition to be confused with an anorectal abscess. Nevertheless, if a rectal examination is performed, the prostate will be felt to be enlarged, hot, extremely tender and perhaps fluctuant. Retention of urine is likely to occur and in such men suprapubic catheterization is best.
Treatment. The abscess should be drained without delay.
1.The abscess can be drained by perurethral resection .
2.The perineal route is rarely indicated .
Chronic prostatitis:Many urologists find the syndromes of chronic prostatitis and ‘prostatodynia’ very difficult, for many men present with perigenital pain, testicular pain, prostatic pain exacerbated by sexual intercourse or pain which apparently renders sexual intercourse out of the question. Psychosexual dysfunction in such patients may be the underlying problem. The diagnosis of chronic prostatitis has to be based on:
•persistent threads in voided urine;
•prostatic massage showing pus cells with or without bacteria in the absence of urinary infection.
Aetiology:This is thought to be sequel of inadequately treated acute prostatitis. While pus is present in the prostatic secretion, often the responsible organism is difficult to find. Otherorganisms such as Chlamydia species may be responsible for chronic abacterial prostatitis.
Clinical features
The clinical features are extremely varied. Only men with symptoms of posterior urethritis, prostatic pain and perigenital pain accompanied by intermittent fever and pus cells or bacteria in the postprostatic massage specimen should be diagnosed as having chronic prostatitis.
Diagnosis
1. The three-glass urine test is valuable. If the first glass with the initial voided sample shows urine containing prostatic threads, prostatitis is present.
2.Rectal examination of the prostate may be normal or may show a soft, boggy and tender prostate.
3. Examination of the prostatic fluid obtained by prostatic massage should show pus cells and bacteria.
4. Urethroscopy may reveal inflammation of the prostatic urethra, and pus may be seen exuding from the prostatic ducts. The verumontanum is likely to be enlarged and oedematous.
Treatment
Antibiotic therapy should only be administered in accordance with bacteriological sensitivity tests. Trimethoprim penetrates well into the prostate. Where trichomonas or anaerobes are the responsible agent, a rapid response is obtained from administration of flagyl (metronidazole, 200 mg t.d.s. for 7 days to both partners). If Chlamydiais suspected, doxycycline is the antibiotic treatment of choice.
Prostatodynia
This diagnosis is made by the presence of perigenital pain in the absence of any objective evidence of prostatic inflammation.
Tuberculosis of the prostate and seminal vesicles: is rare and associated with renal tuberculosis. In 30 per cent of cases, there is a history of pulmonary tuberculosis within 5 years of the onset of genital tuberculosis.
Tuberculosis of one or both seminal vesicles may be found when examining a patient with chronic tuberculosis epididymitis, On rectal examination, the affected vesicle is found to be nodular.
‘When the prostate is involved, rectal examination reveals nodules in one or both lateral lobes.
Patients with tuberculous prostatitis usually present with the following:
•urethral discharge;•painful, sometimes bloodstained, ejaculation;•mild ache in the perineum;•infertility;•dysuria;•abscess formation.
Special forms of investigation
Radiography sometimes displays areas of calcification in the prostate and/or the seminal vesicles.
Bacteriological examination of the seminal fluid yields positive cultures for tubercle bacilli.
Treatment:The general treatment is that for tuberculosis. If a prostatic abscess forms it should be drained transurethrally.
Seminal vesicles
Acute seminal vesiculitis/ occurs in association with prostatitis. Prior to the antibiotic treatment of gonorrhoea, gonococcal vesiculitis was common.
Chronic seminal vesiculitis/ usually presents with haematospermia and pain on intercourse. TRUS demonstrates the features of distension, thickening and the presence of turbid fluid. The treatment is the same as for chronic prostatitis.
Tuberculous seminal vesiculitis/The clinical features and treatment have been discussed above.
Diverticulum of the seminal vesicle: occurs occasionally. In such cases, the kidney of that side is absent and the diverticulum represents an abortive ureteric bud. It is a cause of persistent infection.
Cyst of the seminal vesicle/ is uncommon and rarely requires treatment. It may be removed by dissection through an incision similar to that for perineal prostatectomy, if it is large or giving rise to symptoms.