Expert interview: NanoKnife with Mark Emberton

More than 130 men are diagnosed with prostate cancer every day in the UK. There has been a sharp increase in incidence since the 1990s and it is now the number one form of cancer affecting men in the UK. Diagnosis with any cancer can be frightening, but for many men, being told they have prostate cancer can also spark additional worries about their continence and sexual health.

Focal therapy demonstrating efficacy and reduced side effects

The good news is that as well as being one of the most common forms of cancer, prostate cancer is also one of the most treatable. Survival rates have trebled over the last 40 years and new and minimally invasive treatments, such as focal irreversible electroporation, more commonly known as NanoKnife, have not only demonstrated excellent efficacy but have also been shown to substantially reduce the risk of incontinence and loss of sexual function.

‘The risk of incontinence is not quite zero, but it is very, very rare – close to zero – with Nanoknife and 90 to 95% of men undergoing the procedure will maintain sexual function,’ says Mark Emberton OBE, Professor of Interventional Oncology at UCL and Consultant Urologist at the world-renowned King Edward VII’s Hospital in London.

This is because unlike more conventional forms of prostate cancer treatment, such as surgery and aggressive radiotherapy, NanoKnife only targets the cancerous cells, leaving the surrounding tissue and organ function unharmed.

Treatment takes place under general anaesthetic but despite the name, there are no knives or incisions involved. Instead, needles are inserted through the skin and guided to the precise location of the tumour using MRI scanning. The NanoKnife machine then delivers high voltage electrical pulses around the cancer, which effectively forces the cells to self-destruct.

Rapid recovery from treatment

Professor Emberton has pioneered the use of NanoKnife in the treatment of prostate cancer over the last decade and is currently the only consultant able to perform the therapy in the UK.

‘The procedure is carried out in exactly the same way as a prostate biopsy and is painless,’ he says. ‘The whole thing takes around 30 minutes so treatment can be carried out as a day case procedure – patients come in in the morning and go home in the afternoon.’

The treatment does cause some temporary swelling of the prostate which means patients will typically need a catheter for two or three days post-procedure. However, patients are fully recovered within a matter of days.

‘Compared to surgery and radiotherapy, the advantages are significant,’ says Professor Emberton. ‘There is maintenance of sexual function and avoidance of incontinence, but also rapid recovery. These guys are up and walking in a couple of hours whereas with surgery they would have to take weeks off, while radiotherapy is delivered over many weeks or months.’

Currently in the UK, NanoKnife for the treatment of prostate cancer is only offered at King Edward VII’s hospital. However, there is a growing body of international evidence to support its use in the treatment of localised prostate cancers. More than 2,000 patient outcomes have been reported internationally and in 85% of cases patients are free from disease progression at five years.

Minimal risk of side effects

According to Professor Emberton, around 20% of all men presenting with localised prostate cancer could benefit from the technique. And it is particularly useful in the treatment of those anterior tumours which would previously have been considered hard-to-treat with minimally invasive procedures.

However, like all cancer treatments, NanoKnife is no panacea and may not be suitable for all patients, he says. In some cases, the position of the tumour means other forms of focal therapy such as cryotherapy or HIFU are more appropriate.

And despite the strong safety record for NanoKnife, there is risk involved in all forms of cancer treatment. Professor Emberton has used the technique on over 300 patients over the last decade and has not experienced any adverse incidents. However, he says patients should always consider all of the risks involved in any procedure.

‘NanoKnife is very safe and there are no long-term risks, but as with all prostate cancer treatment, the surrounding structures could be damaged,’ he explains. ‘There is a very small risk of incontinence and damage to sexual function and there is a risk of damage to the rectum. That’s a risk in all prostate cancer procedures because of proximity, but usually NanoKnife is very well tolerated.’

In common with other forms of prostate cancer treatment, there is also a risk that the procedure could fail and has to be repeated. Or that it fails more than once, in which case more invasive treatment may be necessary.

Most promising treatment for localised prostate cancer

Despite demonstrating superior outcomes in the preservation of sexual function, Professor Emberton says men considering the treatment should also think carefully about whether they wish to preserve their fertility.

‘Although most men will be able to ejaculate, semen volume can be reduced because it is made in the prostate,’ says Professor Emberton. ‘I never make any guarantees about fertility and would always advise men who care about fertility to save sperm before they have their treatment.’

Men who have been treated using NanoKnife will also require ongoing surveillance with MRI scans and PSA testing. However, if there is recurrence of the cancer, the treatment can be repeated. And it is suitable for use across age groups.

‘I have used it in men in their nineties and in the older man it works very well because they are in and out in a day and don’t suffer the consequences of hormones and radiotherapy,’ says Professor Emberton.

It may not be suitable for everyone, but NanoKnife is considered to be one of the most promising treatments for localised prostate cancer and, in future, Professor Emberton, hopes its use will become much more widespread.

‘The technique is widely used by interventional radiologists for treating pancreas and other cancers, so it is just about widening the indications and applying it to prostate cancer,’ he says. ‘Large programmes for its use in prostate cancer are now underway in Australia, the US and Germany, so this is happening. And I would like to see it disseminate so that more men benefit as a result.’