A combination of three genetic alterations that dramatically reduce chances of surviving prostate cancer have been identified by researchers at the UK's Institute of Cancer Research (ICR). It is hoped that this finding could lead to the development of a genetic test to help doctors decide how aggressively to treat tumours.
The research team, led by Dr Alison Reid, published its work in this month's online edition of the British Journal of Cancer. The report describes how the group screened prostate tumour samples for alterations in three genes - PTEN (a known tumour suppressor gene), ERG and ETV1. They found that loss of the PTEN gene and lack of rearrangements in the ERG and ETV1 genes led to a higher risk of dying from cancer. Only 13.7 per cent of the patients with this combination of genetic alterations were alive after 11 years, compared with 85 per cent of those with the normal form of the genes.
In an ICR press release, Dr Reid suggested that 'men diagnosed with prostate cancer could be tested for all three genetic alterations, and this information could be used to help determine how aggressively they should be treated'.
Prostate cancer is the most common cancer in men world-wide. It affects more than 35,000 men in Britain each year and only two-thirds survive the disease. Patients typically fall into two groups - those with an aggressive form of the disease who need immediate treatment, and those with slow growing tumours who may not even require treatment. Professor Colin Cooper, head of the Everyman Male Cancer Campaign and a co-author on the study, emphasised that 'there is an urgent need to find biological markers like these that will help us distinguish between the two groups of patients'.
Helen Rippon, head of research at the Prostate Cancer Charity, cautioned that the new test to distinguish between high- and low-risk patients would not necessarily prolong the lives of carriers of the high-risk genetic alterations. She explained that 'the next stage will be to carry out a 'prospective' clinical trial using the new test to identify men with a poor prognosis and select them for aggressive treatment'.If clinical trials are successful the new test could also benefit the patients with a low risk of dying from the disease. Two studies published in the New England Journal of Medicine in March 2009 found that current tests used to screen for prostate cancer frequently lead to risky and unnecessary treatment in low-risk patients.