Genetic changes cause cancer

New research shows how genetic changes make cancer deadly London - Arabstoday British scientists have begun to unlock one of cancer’s most deadly secrets.In a breakthrough likened to going from watching TV in black and white to colour, they’ve discovered that a single cancer can be dramatically different within one person. Different parts of a single tumour can have different genes. And a tumour that has spread to the chest can be genetically very different to the original tumour in the kidney. The finding is important because cancer has traditionally been thought of as a disease in which a single cell starts dividing out of control, creating a tumour in which every cell is the same. Now it is clear that the disease is much more complex. The genetic changes could help explain why cancer causes so many deaths, despite huge advances in medicine, and why a drug that has helped initially suddenly stops working. Within just five years, patients could have their own bedside ‘mutation map’, charting the genetics of their disease and indicating the best drugs to treat them. Researchers funded by Cancer Research UK tested samples taken from kidney cancer patients being treated at London’s Royal Marsden Hospital. Several biopsies were taken from the main kidney tumour and their genes compared with each other and with samples from parts of the body to which the tumour had spread. No two samples from the same patient were genetically identical, with even two pieces that lay next to each other in the same tumour having significant differences. Overall, only around a third of genetic faults were found in every sample taken from a patient, the New England Journal of Medicine reports. Only a small number of patients were involved in the study but other recent research has suggested that brain, blood and breast cancers act in the same way. The study’s lead author, Professor Charles Swanton, of Cancer Research UK’s London Research Institute, said the study gives a much more detailed view of cancer. He said: ‘I liken this little bit to going from a black and white television with for pixels to a colour TV with thousands of pixels. ‘We are going to understand at much higher resolution the individual mutations in a solid tumour.’ The research is still at an early stage, but, in future, doctors might take several biopsies from a patient, instead of just one. Identifying the mutations that are common to all of a patient’s tumours and those that occur early in the process could be crucial to successful treatment. The genetic changes in the tumours accumulate over time, so early diagnosis will also be vital. Professor Peter Johnson, Cancer Research UK’s chief clinician, describe the research as ‘very exciting’. He added: ‘This is going to change the way that we analyse cancers. ‘The encouraging thing is that we can see the way forward despite this complexity. ‘Targeting the point at which the diversity sets in may very important for developing new treatments in the future.’