Scientific breakthrough in determining early cancer risk
28th March 2013
dna sequenceA ground-breaking study could pave the way for the introduction of a quick and simple £5 saliva test to determine a patient’s risk of developing breast or prostate cancer, and it could be available within just five years. The saliva test would find those who are genetically susceptible to the cancers and lead to thousands of lives saved each year with high-risk patients being monitored and even undergo treatment early enough to stop a cancerous tumour from even beginning to develop. The research into early cancer prevention was conducted by scientists at the University of Cambridge and the Institute of Cancer Research (ICR) in London and funded by Cancer Research UK (CRUK) and the Wellcome Trust. Researchers studied the DNA extracted from approximately 200,000 people; of which half were suffering from cancer and half were healthy. The massive project spanned four years of thorough genetic analysis by 1,000 scientists and they described their findings as the 'single biggest leap forward' in relation to the genetic causes of prostate cancer. Each person is born with three billion pieces of code comprised of chemical letters: A, C, T and G; known as the ‘genome’ and is passed to us from our parents. A single nucleotide polymorphism is a single letter variation in DNA between people and we can have millions of these variations. Because cancer patients were compared with healthy individuals, scientists were able to see the genetic spelling mistakes that were prominent in the cancer group. They discovered more than 80 genetic markers which are linked to the risk of somebody developing cancers. There were 49 for breast cancer, 23 for prostate cancer and 11 for ovarian cancer. Unfortunately, scientists were unable to ascertain around 60% of the genetic risk factors for the cancer types they focused, however their findings can still help increase knowledge of the inherited causes of the condition. Interestingly, for the prostate cancer patients, 18 of the 23 variants were attributed to the most aggressive forms of the disease. The next step for scientists is to create simple blood or saliva tests that can accurately obtain the future risk breast and prostate cancers. These samples would probably have to be sent off for a lab analysis but the hope is to have results available immediately at the doctors’ surgery. New medicine for difficult-to-treat cancers could also be produced in addition to a new ovarian cancer test. It is thought that even bowel and lung cancers risks may be found with similar methods. Dr Harpal Kumar, chief executive of Cancer Research UK, said: “It can help us identify exactly what is driving different types of cancer, which could enable us to develop new therapeutic approaches.” He added: “By understanding why some people seem to be at greater risk of developing cancer we can look towards an era where we can take steps to reduce their chances of getting cancer or pick up the disease at its earliest stages. The principle is broad and the potential gains are huge.” Professor Ros Eeles, from the Institute of Cancer Research, also commented: “These results are the single biggest leap forward in finding the genetic causes of prostate cancer yet made. The work could have a big impact on the number of people dying from the disease, which is still far too high.”