Dr Peter Prinsley

Thank you for chairing this debate, Dr Murrison. I declare an interest in that I am a surgeon and appointed chair of the all-party parliamentary group on prostate cancer. Prostate cancer bewilders people. They think, “Surely it must be like other cancers we know about? Find it early, treat it early and save lives.” Only lung cancer causes more death in men, but prostate cancer is not so simple. We know it to be a range of diseases that behave quite differently. At the one end is the dreadful spreading disease of cancer that kills men, sometimes quickly and sometimes very young, and at the other end are the indolent cancers that simply sit around causing little trouble, so that the patient lives with the cancer and dies of something unrelated. The great dilemma is how to distinguish which is which. If we identify cancers that are, in fact, not going to cause any trouble and we treat them, we will need to deal with the consequences of the treatments and side effects that so many men fear—incontinence and impotence—and we risk doing more harm than good. That, in simple terms, explains why the screening experts have determined that at present whole-population screening is not the way to go. People find that a little difficult to understand, and so do I, to be honest. As we have heard, at least two former prime Ministers have been advocating for screening, as have a number of famous sportsmen. The blood test used in screening is the PSA test. What is the problem? False positives—three quarters of men with PSA greater than 4 ng/ml will on biopsy be found not to have cancer—and false negatives, as men with cancer can have normal PSA. So it is not a yes or no test, and is perhaps not massively useful. The UK National Screening Committee says we should do targeted screening of men with the BRCA2 gene and a family history of prostate cancer, but it might be best to use MRI for those men. I would like to say that there is hope. Analysis of surgical samples of prostate cancer subjected to genetic study at the University of East Anglia, where I too lately completed an MD in medical genetics studies, will soon allow us to distinguish between bad prostate cancer and good prostate cancer. We can be proud of how British science is contributing. I urge our Government to use this Parliament to support that research and those amazing scientists in their bold endeavour.