What Causes Prostate Cancer?

One of the problems with this disease is that prostate cancer symptoms are difficult to spot early on and rarely show up. When they do appear they can include difficulty in passing urine, pain when passing urine, blood in semen or urine, pain in the lower back, and disturbed sleep because of the need to pass urine. New genetic tests for prostate cancer are being developed to try and spot symptoms much earlier on. In many countries routine tests that could detect early signs of the disease are not available.

 The exact causes of prostate cancer are unknown and have yet to be pinpointed. But fundamentally it's due to a change in the DNA of prostate cells. There's an increasing body of research that is pointing towards genetic causes, whether those are inherited mutations or acquired mutations during a man's lifetime.

It has been known for some time that a man who has a family history of prostate cancer is at an increased risk of contracting the disease. According to Cancer Research UK if a man has a relative diagnosed with the disease, his risk of getting it is double compared to the average man. If he has a brother with prostate cancer, the risk is just under 3 times the average risk.

Amongst the possible genetic causes of prostate cancer are:

• A set of 7 genes that have been linked to the growth of prostate tumours were discovered in 2008. They were uncovered by researchers from the UK's Institute of Cancer Research. Out of a study of 10,000 individuals, genetic variants were found in over half of all cases of men with prostate cancer. These 7 genes had not previously been linked with prostate cancer, although one of them - LMTK2 has been linked to others. The scientists were looking for variations in single "letters" of DNA associated with prostate cancer. According to the scientists 6 of the genetic variants are carried by between 8 per cent and 72 per cent of men and raise the risk of prostate cancer by 20 and 60 per cent.

• The UK study was part of a wider study into the possible genetic causes of prostate cancer. A further 5 gene variants associated with the disease were discovered by other teams.

• The tumour suppressor gene EphB2 has been shown to be inactive in prostate cancer.

• Some mutations on the so-called breast cancer genes - BRCA1 and BRCA2 - have been shown to be linked to increase risk of prostate cancer.

In addition there may be a number of factors that might contribute to DNA damage, such as higher levels of some hormones,

You may well be wondering what this all means - genetic variants and increased risk? First of all, the presence of a risk factor doesn't mean that you will develop the disease, it is not an absolute thing.

In trying to find the causes of prostate cancer scientists look at genes. This is because a cancer is basically cell division going out of control, and cellular processes are controlled by genes.

If scientists see the same genetic differences in prostate cancer patients - and these are not present in the average population - it gives them a pretty big clue that these variants may some how be to blame. They can then use this knowledge to develop tests that could spot these variants at any time of life. So for example, if you're a teenage boy and a test picks up that you have some of the variants, your lifestyle could be modified so that you hopefully won't develop the disease.

At the same time researchers will also study these variants to see if and how they cause the disease. By knowing the mechanics of the disease process, therapeutics can be developed to target the genetic causes and stop them before they do too much damage. And that could one day mean gene therapy for prostate cancer.

As always the road from initial discovery to therapeutics can be a long one, taking several years. But the more we understand, the better are our chances of making prostate cancer history.