'Why some prostrate cancer cases become aggressive decoded'

Researchers have discovered why some prostate cancers are more aggressive and ultimately cause death, while others don't, a finding that may lead to new treatment strategies for the malignant disease.

The study, published in the British Journal of Cancer, shows how the number of 'aggressive' cells in a tumour sample defines how quickly the disease will progress and spread.

It is based on a test developed by the researchers from the University of East Anglia (UEA) in the UK, that distinguishes between aggressive and less harmful forms of prostate cancer, helping to avoid sometimes-damaging unnecessary treatment.

According to the scientists, the findings also reveal three new subtypes of prostate cancer that could be used to organise patients for different treatments.

"Prostate cancer usually develops slowly and the majority of cancers will not require treatment in a man's lifetime. However, doctors struggle to predict which tumours will become aggressive, making it hard to decide on treatment for many men," said Colin Cooper, study co-author from UEA.

"This means that many thousands of men are treated unnecessarily, increasing the risk of damaging side effects, including impotence from surgery," Cooper said.

The test distinguishes aggressive prostate cancers from less threatening forms of the disease, by applying some complex maths known as Latent Process Decomposition, the scientists noted in a statement.

"By applying the Latent Process Decomposition process and analysing global prostate cancer datasets, we discovered an aggressive form of prostate cancer known as DESNT - which has the worst clinical outcomes for patients," explained Vincent Moulton, another co-author of the study from UEA.

In the study, the scientists studied gene expression levels in 1,785 tumour samples, and found that the amount of DESNT subtype cells in a sample is linked with the likelihood of disease progression.

The more DESNT cells, the quicker the patient is likely to progress, the scientists said.

"If you have a tumour that is majority DESNT you are more likely to get metastatic disease, in other words it is more likely to spread to other parts of your body. This is a much better indication of aggressive disease," noted Daniel Brewer, another study co-author.