A high-pressure water jet treatment could help prostate cancer patients avoid one of the main complications of existing therapies – erectile dysfunction.
A UK-led international clinical trial is recruiting 280 patients to see if the technique to remove cancerous cells, known as aquablation, could prevent incontinence as well as erectile dysfunction, which affects up to 80 per cent of those who undergo a radical prostatectomy (removal of the prostate). By eradicating only cancerous tissue, it is hoped the treatment will preserve the nerves that control erections and ejaculation.
Current treatments for prostate cancer, which affects around 60,000 men in the UK a year, include chemotherapy, radiotherapy and hormone therapy – where drugs are used to suppress the production of testosterone, as it can feed tumour growth.
But around 5,000 men a year with localised cancer (where it has not spread beyond the prostate) undergo a radical prostatectomy.
Although very successful at eradicating cancer, the surgery carries a high risk of damage to sensitive nerves and arteries that keep the penis in good working order.
Modern techniques – known as nerve-sparing surgery – can reduce the risks. However, some surgeons aren’t able to offer this.
Aquablation has been in use on the NHS for years in the treatment of benign prostatic hyperplasia (BPH), or an enlarged prostate.
A non-cancerous, age-related condition, BPH causes more frequent urination (as the swollen prostate presses on the bladder) or trouble passing urine (because it is pressing on the urethra, which carries urine out of the body).
A high-pressure water jet treatment could help prostate cancer patients avoid one of the main complications of existing therapies: erectile dysfunction
Current treatments for prostate cancer, which affects around 60,000 men in the UK a year, include chemotherapy, radiotherapy and hormone therapy
Treatment often involves drugs, but around 50,000 men a year with BPH end up having surgery to reduce the prostate. This, too, carries a risk of impotence and urinary incontinence.
Various therapies have been developed to reduce these side-effects in both BPH and cancer.
These include laser treatments, where a focused beam is directed on to the diseased tissue to destroy it; and radiofrequency ablation, where electric currents are used. However, the heat used in these treatments can also damage healthy tissue.
Aquablation instead relies on room-temperature salt water to blast it away.
Trials show it is very effective at easing BPH symptoms and, crucially, preserves erectile function in about 90 per cent of men.
Now it is being tested for men with early-stage prostate cancer (where the disease has not spread beyond the gland).
The Royal Marsden, Guy’s and St Thomas’ NHS Foundation Trust and the Royal Free London NHS Foundation Trust – all in London – and Norwich and Norfolk University Hospitals NHS Foundation Trust will take part in the trial, along with at least 20 other centres around the world.
Around three-quarters of the men will have aquablation, the rest will have a prostatectomy.
Those in the aquablation group will first undergo an ultrasound to map out the diseased areas.
Then, while the patient is under general anaesthetic, a tube with a miniature camera will be inserted via the urethra to give a close-up view of the prostate.
A thin probe will also be fed through the urethra, with water pumped through under pressure.
The probe is controlled by a robot – overseen by a surgeon – which can be programmed to automatically adjust the water jet’s pressure, depending on how much tissue needs to be removed.
Rather than providing a constant stream of water, the probe squirts it in ‘pulses’, each a fraction of a second long, to avoid flooding the area with fluid.
A pump sucks out the fluid, along with the fragments of cancerous tissue, and any bleeding from the prostate is stopped by cauterising the blood vessels with a heat probe. Six months after the procedure, the two groups’ erectile function and urinary incontinence will be compared.
The procedure is not completely problem-free. Some BPH patients, for example, complain of a burning sensation when urinating after the water jet treatment, or blood in their urine – resulting from damage to blood vessels during treatment. Studies show it can take a few months to fully recover.
Commenting on the trial, Neil Barber, a consultant urological surgeon at Frimley Health NHS Foundation Trust, says: ‘There have been a couple of very small trials in Hong Kong and the US which looked at the safety of the procedure in prostate cancer – these showed that there are very few complications. However, we don’t have data yet on how well it treats cancer.’
Mr Barber adds that the treatment won’t be quite as straightforward with cancer as it is with enlarged prostates.
‘When we use aquablation for BPH, we usually do it in about 50 minutes or so,’ he explains.
‘But with cancer, you need to treat a much larger area of the prostate, without damaging the parts packed with nerves that control erectile function or the bladder. It will be a technically challenging procedure that’s more likely to be a two-hour operation.’
Professor Roger Kirby, a leading prostate surgeon and former president of the Royal Society of Medicine – who was himself diagnosed with prostate cancer in 2013 – also welcomed the trial, but warned that the treatment might not be as effective as prostatectomy.
He says: ‘It’s an innovative trial. It would almost certainly reduce the side-effects associated with prostatectomy. But that might be at the expense of an increased risk of local or distant recurrence of cancer, as the capsule of the prostate [a thin layer of tissue surrounding the gland] will be left behind. Many prostate cancer cells occur close to the capsule.’