How far are we from another test?

How far are we from developing another test for prostate cancer diagnosis?

Professor Cory Abate-Shen, University of Columbia, USA:

I would have to say that the answer is, we're not far away from developing more and more tests for diagnosis. But what we are probably in very serious need of is to understand how effective those tests are. And I think that's really the critical distinction. So really the proof is going to be in the pudding as to how important and how relevant these new tests are. I think this will play out within the next five years or so, because prostate cancer is a quite slow growing tumour, which means that the tests take longer to get the right kind of validation. The other thing that I think is critical is to really compare the tests back to back. But this can be hard to do because of intellectual property issues. So something that Prostate Cancer UK could do is to provide resources to allow these tests to be evaluated - sequentially or together - to compare them. Because I don't think that's something that's going to be funded by most government institutions, and certainly not by companies who have a vested interest in their test being the best.

Dr Hayley Whitaker, Cancer Research UK Cambridge Institute:

So when we're testing for prostate cancer, and looking for a diagnostic test, there are lots of different ways we can do it. We can try and look for a blood test or we can try and look for a urine test. And actually there's been huge advances in the last five years of finding potential new markers that we can detect in those different fluids to try and diagnose prostate cancer better. I think the key thing to remember is that although we say PSA isn't very good, it actually isn’t that bad. What we need to do next is to combine new markers with PSA to actually make it a better test. And with the huge advances we've made recently, we've got some really good markers going forward that are likely to make a huge difference. I think that probably within the next five to ten years we'll see something coming through that will be an improvement on the PSA test.

In terms of a urine marker, it's slightly more difficult, because we all know that when you have a wee, your urine can be different strengths. And so we have to sort of standardise our test according to concentration, which adds a little bit more complication. So although it's a very accessible fluid, there are a few complications in working with it. But actually I’m working as part of a large Movember funded consortium looking at lots of markers all at the same time, and I think that something very fruitful will come out. Possibly a little bit longer than an improved blood test, but maybe in the next ten years.

Read more about the PSA test.


Do doctors all break the news the same?

How do clinics around the world deal with telling men they have prostate cancer?

Professor Christopher Woodhouse, The Royal Marsden Hospital, London:

Giving bad news in medicine, and particularly giving news of cancer, is extraordinarily difficult. It's something that nowadays is actively taught in medical school, right at the beginning, reinforced at the end and included in the final examinations for qualification. In the specific case of prostate cancer, the huge majority of men come to a doctor with a slightly raised PSA, immediately raising the question in the patient's mind - have I got cancer? So in a sense, some of the preparation for a difficult conversation is made simply by finding that the PSA is raised. Then there's a process of investigation. If there’s no cancer then one is giving good news, and everyone feels very happy. If it's bad news, the techniques that we were taught in medical school, and reinforced in our careers, lock in, and I hope allow us to explain the issues in a kind and gentle way. There certainly isn't a standard protocol across the world, any more than there's a standard protocol for treatment.

Read more about prostate cancer diagnosis.

Is there a decision aid for PSA testing?

Is it feasible to develop a decision aid for PSA testing?

Dr Nora Pashayan, University College London:

There’s currently no national screening programme for prostate cancer using the PSA test.  But for individuals who have a concern - whether they have any urinary symptoms, or if they have a family member affected by prostate cancer - the advice is to go to their GP and discuss their concerns.  Even for those with a father, brother or close relative with prostate cancer - particularly if the cancer occurred at a younger age - we don't yet have a national guideline recommending screening, because of the uncertainties surrounding testing and treatment. But there are currently studies on the way, such as the IMPACT study and the Barcode 1 study, led by Professor Ros Eeles at the Institute of Cancer Research in London, which are looking into the effect of family history and the genetic risk associated with prostate cancer. These studies are looking at what would happen if we screened those high risk men? How many of them would be identified with prostate cancer? And would this save lives, which is obviously the main aim of any screening programme? And we’re expecting these results to come out in the next few years. Together with other evidence, these studies will give us a better idea about whether screening high-risk men will be beneficial.

How good is MRI?

How confidently can MRI detect a prostate tumour?

Professor Mark Emberton, University College London:

MRI has a number of roles. One is detection, and this is about the likelihood that an abnormality in the MRI is truly a prostate cancer. So in other words, if I see an abnormality on an MRI and the MRI is done well, there's an 80 per cent chance that that lesion is a cancer. And the reason that it's only 80 per cent certain is that there are other things that look like cancer that I want to rule out - the principle one is inflammation, and the second most common is something called atrophy, which is a type of chronic inflammation that can also mimic a cancer. Obviously if the biopsy confirms that the abnormality is cancer, then (a) you know it's definitely cancer, and (b) you know where it is. And if we apply a margin of five millimetres, we can be 95 per cent confident that if you treat that margin you will treat all the cancer within that area.

Most people don't have cancer, or don't have a clinically significant cancer, and they want to be reassured that they are in fact in that group of men who don't have disease. This is about ruling out disease, and MRI is remarkably good at this - it has negative predictive values of between 93 and 100 per cent. I don't think anybody believes it's 100 per cent, but the most recent study from Rotterdam showed that if the MRI was negative, no man had any pattern 4 prostate cancer within their prostate. So we can use that really valuable information to reassure a man that he doesn't have prostate cancer, and maybe he can avoid a biopsy.

We can also use that information within the prostate. So if the man has an abnormality high up on the left, but the rest is absolutely normal, I can say there's an 80 per cent chance you've got prostate cancer there, but there's a 95 to 97 per cent chance you've got no cancer elsewhere. And those are the kind of odds we see very rarely in medicine. I can use those odds to confirm that it's cancer, but also to limit the number of biopsy needles I have to deploy in the normal area, because it's very unlikely that there's disease there. And so we use those two attributes of MRI to declare our lesions, and also to declare the amount of prostate that we have to treat.

Taking part in the NanoKnife trial

And a follow on question: I’m taking part in the NanoKnife trial, so what does this mean for me?

Professor Mark Emberton, University College London:

NanoKnife, is just a form of energy; electricity that bursts holes in the cell membrane and forces the cells to commit suicide - something we call apoptosis. The beauty of NanoKnife is that you can place the needles around the area of treatment, so if I can define the area as well as I've said I can define it, I can then put four needles around the cancer, and those four needles will conduct electricity across at a square, but also across the diagonals, and treat the area within the box I've created. That gives us an exquisitely precise and accurate way of destroying the tissue we want to destroy and preserving everything else. And just in case we got it wrong, MRI will also be used for follow up, so the question will be re-asked over time in case we may have missed a tiny cancer that maybe in seven, eight or ten years would start to manifest.