Surgery for prostate cancer
Radical surgery for prostate cancer (radical prostatectomy) is carried out with the aim of curing the patient by cutting out all tumour. Surgery for prostate cancer is major surgery. Radical prostatectomy is an operation that requires enormous skill, refined by practice. A patient who is undergoing radical prostatectomy should be operated upon by a surgeon who has considerable experience of this technique – In such hands, the rates of urinary incontinence and impotence should be small. There are two operations to be discussed: the open operation and the robotically assisted operation. Neither operation should be advised to patients who have disease outside the prostate on MRI scan or whose other prognostic criteria suggest that this may be the case (for example: high gleason score or advanced disease within the prostate). Any breach of the prostatic capsule on the high quality MR scan is a contraindication to surgery.
Operation has an advantage over radiation methods in patients with marked obstructive symptoms (difficulty in generating a reasonable urinary stream) in that in treats the obstructive element at the same time but in all other regards it is major surgery that has to be justified against equivalent cure rates by other technologies.
Whilst there was excitement over the capability to perform the operation via a smaller incision and using robotic technology, there is a current concern that the low rate of microscopically clear margins achieved by the robotic technologies compromises the cure rates and more patients will require back up therapies (such as radiotherapy to prostate bed after the operation) to make up for this higher rate of positrive resection margins. This is not a desirable state of affairs as first time complete excision is the basic requirement of all cancer surgery. This is a research field that is ongoing. One thing is clear is that going into the operation with the mentality that the disease is probably within the capsule (but that radiotherapy can mop up any disease that may appear outside he capsule afterwards) is a bad plan and compromises cure. Far better to correctly stage the disease beforehand and then give the right treatment – post-operative radiotherapy does not make up for an inappropriate operation plus the patient has the side effects of a major operation.
Patient selection for prostate cancer surgery is strict and only specific groups of patients are deemed operable. The reason for this is that the high 85% cure rates of surgery are much compromised if there is transcapsular spread on the MR or there are other high risk features – for these patients, a primary radiotherapy approach (often preceded by a period of anti-hormonal therapy) gives better outcomes as it treats a wider volume (bigger area of safety margin around the prostate gland) to a curative dose (as compared to the very confined resection ot he prostate gland – to its capsule only – in the operation.
Patients who are older than 70+ are not considered to be suitable for surgery. This is because the side-effects of the operation are considered to be too great in patients older than 70: wound healing may be delayed and mortality rates increase.
Patients who have PSA levels of over 15 are also generally considered to be unsuitable for surgery. This is because these patients have a greater likelihood of spread of the prostate cancer beyond the confines of the gland and/or into neighbouring lymph nodes.
Patients who have existing medical conditions, such as heart failure or chronic lung diseases, are also considered to be unsuitable for surgery.
Those men who are under 70 years of age, have low PSA levels, no pre-existing significant medical conditions are considered to be suitable for radical prostatectomy.
The Run Up to Surgery
Radical prostatectomy has advanced as a surgical technique over the last 20 years. These improvements have meant that the side-effects of surgery may be less. The name of the operation has been changed over this period and is now called a ‘radical nerve sparing prostatectomy’. The vital nerves that are saved are those nerves that control sexual function.
Prior to surgery, the patient with prostate cancer requires staging. By this is meant testing by scanning to find out whether the tumour has spread.
Admission to hospital is usually on the day before the operation. On the day of the operation a pre-med will be given prior to surgery to help the patient relax and dry up lung secretions so that anaesthetic complications are reduced. The patient is given a suppository and fitted with thigh length anti-thromboembolism support stockings. The suppository will cause emptying of the bowel which makes surgery easier, and reduces the risks of side-effects, such as infection. The stockings prevent clots forming in leg veins. The patient is usually given an injection under the skin of Heparin, which is a drug that prevents blood clots forming. An antibiotic may also be given.
The patient will be wheeled to an anteroom outside the operating theatre. He will be given an injection into a vein by an anaesthetist.
The surgical incision is usually abdominal but, rarely, it may be in the area of the perineum which extends from the scrotum back to the anus. The surgeon will initially remove the lymph nodes that drain lymphatic secretions from the prostate. These iliac lymph nodes are removed and examined using a technique known as frozen section. By this is meant that the pathologist is on standby waiting for the nodes to arrive from the operating theatre.
The pathologist looks at the lymph nodes whilst the surgeon waits to proceed with the next operative steps. If there is any lymph node involvement then the operation will not continue. This is because lymph node involvement suggests further distant spread of the cancer so that an operation on the primary tumour is clearly inappropriate. The operation proceeds if the pathologist finds no cancer cells in lymph nodes.
The surgeon will dissect down to the prostate. The urethra, which is the tube that conveys urine from the bladder through the penis, will be exposed and divided to reveal the rectum. The nerves that control erection lie between the prostate and the rectum. These are identified in the nerve-sparing procedure and not cut because cutting them will lead to complete loss of potency. At this point the prostate is exposed, together with the seminal vesicles. The seminal vesicles are a system of tubes and ducts that contain semen and contract during ejaculation.
The surgeon then dissects around the area around the neck of the bladder. This is a very important part of the procedure because in this area are sited the muscles that control urination. If they are damaged, it is possible that incontinence will result.
The surgeon, having dissected around the bladder neck, will next remove the prostate itself. The bladder neck is reconstructed. This is a very delicate and absolutely critical part of the procedure because, if it is done incorrectly, there may be subsequent scarring which leads to the formation of a stricture or narrowing, which will cause many post-operative difficulties. A catheter is then placed in the urethra and the urethra sewn around the catheter and on to the reconstructed bladder neck. This concludes the major part of the operation. The abdomen is then repaired and the patient sent to the anaesthetic recovery room.
On waking in the wards, he will find a drip in his arm, a catheter in his penis and wound drains emerging from his abdomen. These are plastic tubes which drain the ooze of blood and serum from the prostatectomy bed.
Two or three days after the operation the drains are shortened. It may be that the drains remain in place for a few more days if there is leakage from the abdomen. In uncomplicated circumstances the drains are taken out around the 5th post-operative day.
The urinary catheter may remain in place for 7 days or longer, commonly for 2 weeks. Antibiotics continue for between 3 and 5 days during the post-operative period. The heparin is discontinued at the beginning of the second post-operative week, when the patient is up and about and may be at the point of being discharged home.
Surgeons were initially very happy about the consequences of prostatectomy but recently, prompted by oncologists and patient support groups, they have begun to look in more depth at the side-effects of surgery.
Potency may be dramatically affected by this procedure and there is some evidence that up to 70% of men potent before radical prostatectomy are rendered impotent as a result of prostatectomy, even though the procedure is nerve-sparing.
There is a degree of recovery of potency and there is hope that, as time goes by, sexual function will improve. Where specialist centres report their results, the most highly skilled surgeons will describe loss of potency in between 25 and 45% of men. This can be helped by Sidenafil, more commonly known as Viagara, which is a tablet that will benefit between 40% and 80% of patients with prostate cancer who have been rendered impotent by surgery.
The other complication of prostatectomy is incontinence which affects the lives of up to 40% of men post-operatively. This problem tends to decrease with time and, at 6 months from surgery, 1% of patients will have complete incontinence and a further 20% minor problems. The problem usually consists of urinary dribbling when the man stands or coughs or laughs.
Strictures are reported in between 5 and 10% of patients. These are due to scarring around the surgical join between the bladder and urethra. This causes a slowness of urination. If it is severe, further surgery may be needed. This is minor and involves a small cut made by inserting a very small cutting instrument into the urethra.
The results of surgery for prostate cancer are good if we exclude those patients who were badly selected for operation. In general, approximately 85%+ of patients who have been properly selected as being suitable for suregery are cured. Occasionally the disease is not cured despite good pre-operative staging and the clue to lack of success is often given by a post-operative PSA that fails to fall to zero a month or so after the procedure, or later starts to rise.